My intro and my 1000cc Gecko

[gecko1000]

Well hello guys.

first off, what a killer site for guys like us building exocars! here's my history:

every now and then, i jump on ebay and brose the "other" category just to see what there is. i saw an ad for a TINY micro car called the electraking. a little mr magoo car. i then saw a top gear segment on the peel p50 (smallest production car) and kept dreaming about how awesome it would be to drive around in a car that small, and the reactions i would get. i started laying out some plans on paper, and my microcar quickly developed in to an exocar type design.

what it has turned in to has been dubbed the "Gecko." my car is still VERY small, coming in with a wheelbase of only 5' 9" long, and an overall length of 8' 4.5". the top of the rollbar sits a mere 3' 4" above teh ground, and the car itself sits only 4" above the ground. It has a tube chassis (obviously) and seats two.

power will come from a 1000cc yamaha r1 engine--chain drive to the rear wheels. i am reaching for a target 0-60 of 3.6-3.8s.

the difference between most of you and myself, is that i am building mine entirely from hand drawn plans. no CAD or other design programs to aid me. i have quite a bit of experience with technical drawings, so this shouldnt be a problem. also, the car will have a body that covers most of the vehicle. so not quite as exo-carish, but still falls in the same category.

the car is set to get underway in the next month or so. i'll keep you guys updated.

http://i73.photobucket.com/albums/i216/stroik08/CIMG1412.jpg

http://i73.photobucket.com/albums/i216/stroik08/CIMG1408.jpg

[Gage]

More power to you! I'm looking forward to hearing updates and seeing your progress. Self builders are an elite group of people in my book.

[Gage]

How about a front/rear view?

[gecko1000]

sure i'll get the top/front/rear shots as soon as i get my camera charged.

i will say that the car will take quite some time, as i work mon-fri and go to an automotive tech school all week too. only time to work on it will be weekends, so it might be slow. but its not an overly complicated vehicle. im aiming for mid summer finish date.

[Karlo]

Keep us posted!!!

[cheapracer]

Too much power! Yes there is such a thing, from your dimensions/specs I would heartily suggest either an easy to buy and cheaper 600cc or a V Twin 1000, much more controlable

http://au.youtube.com/watch?v=iSmxaORvBQI

[Gage]

Too much power! Yes there is such a thing, from your dimensions/specs I would heartily suggest either an easy to buy and cheaper 600cc or a V Twin 1000, much more controlable

http://au.youtube.com/watch?v=iSmxaORvBQI

That is the most fun video I have seen since the Top Gear Atom video. I love it! LOL!!! I want one!!! hahaha

[gecko1000]

as far as power, i think it will be just about right. my old man has a yamaha apex snowmobile with an r1 engine in it, and im used to that power. and i know this car wont be as fast as that snowmobile. plus, i've got 10.5" wide rear wheels to keep the tires locked to the pavement.

i also wanted to mention a couple things about my design process. i first draw a body, and get general specs (wheelbase, width, engine placement, etc) and then I draw a frame that would capacitate that body and set up, and then the body may be tweaked as i see fit. so discrepencies between the different views are understood, and will ultimately be addressed.

more to come

here's a front shot:
http://i73.photobucket.com/albums/i216/stroik08/CIMG1414.jpg

[cheapracer]

Ok JD, I don't agree, I've seen these projects before but if you continue then make a big, big effort to get everything as low as you possibly can (your Dad's sled's CG is very low) and when it comes to doing your suspension I'll help you so we can get you some nice low and dynamically stable roll centers etc. By the way, as with overpowering there is also such thing as overtiring too - not even a 300 hp Atom uses 10.5 inch tyres :-)

[cheapracer]

That is the most fun video I have seen since the Top Gear Atom video. I love it! LOL!!! I want one!!! hahaha

Thats a totally irresponsable reply.

Don't you just love that we never grow up, he he!!

[gecko1000]

please forgive my confusion, and feel free to explain for me.

when i was doing my initial research, trying to decide how to power it, i took in to consideration vehicles that were similar. for instance, a campagna t-rex uses a 1400 `busa motor. and i've seen smart cars with gsxr's in them. so i figured and r1 engine would actually be fairly tame.

also, this car does have an extrememly low cg. the bottom of the chassis sits only four inches off of the ground, and the highest point of hte the car is about 3.5'. almost all of the weight is below the centerline of the wheels, and the car has just as wide of a stance as the wheelbase. in comparison, the snowmobile sits quite a bit higher, with the rider sitting about 3.5' above the snow. i would defend the fact that my snowmobile has a higher cg over my car anyday.

anywho, feel free to post arguements. i'm all for hearing your support!

[cheapracer]

R1 power will never be tame in a 69" WB car that we presume will be faily light.

However some things as a package will help such as keeping all the weight as low as possible and inbetween the WB. You need to aim for longish A-arms to keep a number of parameters stable. I would ceratinly want a baffled fuel tank too to limit slosh.

3 inches or 75mm chassis average clearance would probably be sufficient clearance for most daily situations on a 69" WB, I have no problems with 4" on a 90" WB daily driver.

Snowmobile CG's are flexible according to the rider, cars are not.

[gecko1000]

thank you for the suggestions. i will tweak my desings a little bit to incorporate your ideals.

[cheapracer]

I still think you will have serious problems packaging your legs and fuel tank within 69" - the Smart is 74" but the driver sits high which hugely helps with a short car, but you want low seating I presume. If you extend your design to 75" you will have more chance and you will still be suprised just how small it will still look especially with stubby front and rear. I have a friend who has a packaging design software package, I'll try and find the website.

[cheapracer]

Here it is...

http://www.sportscardesigner.com/

and does this one looks suprisingly familiar to you....?

http://www.sportscardesigner.com/s1.htm

From this picture it has a 72 - 73" WB.

[Gage]

That is the first Cart sized car I have ever really wanted to drive.. the one in that link Cheapracer posted. I like it!

The whole Idea is sweet.. super small, high horse power to weight ratio, but still large streetable wheels, instead of the baby wheels on Carts.

They are mini-Atoms. /exocars

[cheapracer]

Gecko, what was your thoughts on how to do the exo skeleton, I kind of like your drawings and a mix with that car in the link actually has good potential. With your design it looks as though a folded sheet structure might be practicle - was that your thinking?.

[gecko1000]

alright in order:

as far as room, yea, its way cramped. i measured it all out, and the leg room is about 5 inches farther than my foot with my legs fully extended (laid it out on the floor). thats sitting on the floor, legs flat on the floor (no bent knees).

so it will be tight, but im def. not building this thing for comfort. oh and im 6' even.

that designer is sweet, and that car does look like mine! only smaller wheels. and shorter rear end.

my car's frame: here's a couple shots of the frame (i kinda wanted to keep it under wraps, but oh well), which is what ive been working on the past couple days. if things dont make sense, thats probably because they do to me, and if you are confused on something, let me know.

also, i've decided instead of using the r1 engine out of the street bike, im going to use the r1 engine out of the yamaha rx-1 snowmobile, and keep the centrifugal clutch. (like yellow-somethings car). that way i will have reverse as well as instant rev instead of having to let the clutch out first. (and i realize the pulleys on the drawings are extremely off--its just for my reference)

anywho: pics speak:

side shot:
http://i73.photobucket.com/albums/i216/stroik08/CIMG1416.jpg

rear view:
http://i73.photobucket.com/albums/i216/stroik08/CIMG1422.jpg

top view frame only:
http://i73.photobucket.com/albums/i216/stroik08/CIMG1417.jpg

top view frame and components (steering column will be relocated):
http://i73.photobucket.com/albums/i216/stroik08/CIMG1421.jpg

front suspension:
http://i73.photobucket.com/albums/i216/stroik08/CIMG1415.jpg


again, these drawings are still in the works. im tweaking things and what not, so things that seem out of place or out of dimensions or alignment, probably are.

[gecko1000]

oh and the body at this point will probably be sheet metal. bent in to the sharp edges on the concept drawing

[cheapracer]

The CVT engine is an exellent idea and your going to die first corner with your suspension :-)

[cheapracer]

Oh and i sold your plans for $30 to a Chinese company, expect production next month ;-)

[gecko1000]

$30?! i would have charged at least $45. why is my suspension so terrible? its nearly identical to the suspension on the superlite roadster?

[gecko1000]

i've also just gone through the vstorm builds and the front suspension on that is the same as what i have, so what is so lethal about mine?

[cheapracer]

Umm, oh no it's not. Have a good look yourself and see what happens even over a simple bump in compression - the top arms will arc outwards and the lower arms will arc inwards giving you severe positive camber (the top of the wheel will go outward).

Lets be as simple as we can here - most A-arm setups are parallel with a 80% shorter top arm that in compression gives negative camber (the top of the wheel goes inwards). This compensates for a car's natural bodyroll when cornering to keep the wheel straight up and down.

Do you see that, during a corner that car leans the top of it's chassis outwards so the suspension leans the top of the wheel inwards to counteract each other.

http://au.youtube.com/watch?v=K6UFc59pfEg&feature=related
http://video.google.com/videoplay?docid=5675477640642918727&hl=en
http://au.youtube.com/watch?v=ZYXcBz2jqHg&feature=related
http://au.youtube.com/watch?v=n78aA52JiS4&feature=related

[gecko1000]

indeed. that was a much more productive post than "youre going to die the first corner."

glad we're both learning. points taken, will adjust

[gecko1000]

also, is the 20% shorter an exact number? if the lower is 10", does the top HAVE to be 8"? that would be optimal? (example dimensions)

[cheapracer]

also, is the 20% shorter an exact number? if the lower is 10", does the top HAVE to be 8"? that would be optimal? (example dimensions)

Not at all - we have a quandry here, your wanting simple answers to a very complicated sum. I suggest you look at a couple of websites FSAE race cars (worldwide university challenge series held yearly) and Locost (Lotus 7 replica's). Which country are you in by the way?

Couple of rules for you first time out at design stage - keep the arms parallel with each other and to the ground, as long as you can and as far apart as you can (and that solely depends on your uprights). With your 8/10 question, the further apart the arms are the shorter the top arm will be. With your current drawings with your short uprights you might use closer to 9/10 for example. These numbers are for cars with packaging issues, if you feel you can get the lower arms to the middle of the car by all means do so then we will consider the lower arm fairly static and use a computed length top arm to do the camber control.

Getting confused? And I'm really keeping it newbie simple.

So first decide what uprights you are going to use and this also depends on where you want to place the steering rack if you want to go for some production uprights - many cars builders want the rack up front ahead of the axle line but not many production uprights have the steering there so you end up with reverse ackerman steering and thats bad.

I am still learning thats true but I have been doing this for more than 30 years and I must be doing something right because I haven't gone hungry yet :D.

[gecko1000]

gotcha. i'll line em up, parallel, and post up the dimesions (length of each a-arm, distance from each other) and get your help to decide the percentage of change. im not too car off, just a little tweaking to help camber. i understand.

[gecko1000]

oh and im in texas, usa. and, yes, i want this thing street legal

[Gage]

This is great fun to listen too.

[gecko1000]

ha you got your popcorn bucket?

im not trying to be controversial. in fact, i greatly appreciate theed feedback i am getting from cheapracer (although it may be sharp and borderline attacking). its just that one of my pet peeves on any of the forums i belong to, is when someone posts something like "thats gay." or "youre going to die first corner." i dont get cross about people disagreeing with my car, or my exocar on this forum, but i just prefer that someone leave a constructive comment, which cheap has done eventually each time he makes a statement, and i respect that.

but so far hes the only giving me feedback. anyone else? notice any problems? i want to get this right first time around.

[cheapracer]

You have to take the good with the bad.

[Goin South]

Gecko,

You REALLY need to do some homework before you build something that can go 100+ mph. Get some books and study chassis, suspension and handling. 2 good authors are Herb Adams and Carroll Smith. Find them at Amazon.com or a local bookstore. When you’re ready to get down and dirty, get “Race Car Vehicle Dynamics” by William F. Milliken and Douglas L. Milliken. Serious engineering book.

Saying that your suspension is “nearly identical to the suspension on the superlite roadster” is like saying that a formula one tire is nearly identical to a monster truck tire. Both are round, both are made of rubber. Nearly identical. You REALLY, REALLY need to get some understanding of suspension and steering geometry and their effect on handling. Small errors in geometry can have large negative impacts at speed. Stress the word “impact”.

Not a thing wrong with hand drawn plans. Just because someone knows where to click the mouse on a CAD program doesn’t mean that they know how to design parts.

Asking design specifics on a forum like this is like asking surgery specifics on a health forum. You get what you pay for. You’re asking some good questions. You need to have a firm understanding of why things are done as they are, especially when it’s your ass in the seat.

[gecko1000]

thanks for the input.

in my mind, "doing research" is getting on forums like this. you guys are my reasearch.

i would also like to repeat myself by saying that these are crude, preliminary drawings meant to give an overall idea of what the final product will look like. i have just begun to make plans that i can cut from, and those havent been posted yet. i am starting with the main structure, and will perfect the suspension in the mean time.

also, when i stated that the suspension was nearly identical to the superlite's, i was referring the type of suspension used--a dual a-arm set up with a spindle. since cheap was very vague when he all he stated was "youre going to die with that suspension," i thought he was talking about the type of suspension, not just that i needed to make a few adjustments to mine. i know the dimensions and everything are way different, but they are, at heart, the same type of suspension, no?

[cheapracer]

Well I have a little time to spare for the Gecko project, I always was a softy to help people with their personal projects.

Goin South, nothing wrong with what you say but does he have a couple of years or so to study up first? Probably not. Does he want to? Ask him.

There is nothing wrong with following some basic sound principles that are out there for free from many highly experienced people, thousands of club race cars (track day cars these days) have been built by people who don't know a thing but follow others advice or copy from known cars. How many Locost's have been built according to the book without anyone knowing or questioning why? You don't really have to know but it's certainly nice to have someone who does check it for you as your doing it.

To quote Colin Chapman "get the track as wide as you can and the weight as low as you can and the rest hardly matters".

[cheapracer]

thanks for the input.

, at heart, the same type of suspension, no?

Read Goin South's comment re; tyres.

[B-T]

I applaud your attempts at design. It is fun to read, and educational in some respects. I would be fairly wary of the super small size you are designing. It is similar to putting an actual go kart on the road. I drive a small car for fun on the weekends (my Ginetta), and I have to be very defensive as many people simply do not see me "down there". You might try taking a racing kart out on the street in your neighborhood and see if you feel comfortable driving something that small on the street. I would also check with the Texas DMV and see what specific home built car requirements they might have. If they require headlights to be at 26" minimum ,and require a front and rear bumper at a minimum of 18" those dimensions could cause problems with your small car design.
Best of luck, it seems like a cool project!
BT

[gecko1000]

thank you for the kind (and appropriate) words BT. i completely understand your warning about size. and youre right, i will always have to be on the defense. ive thought about things like amber LED flashers that are constantly on, or something of the sort to draw attention to the car. but while its very small, it is quite wide, and has normal size wheels. so hopefully, that will help some.

also, as far as DMV requirements, the car will be built to suite. if they require a certain headlight height, i'll put them up there. if something else is needed, i'll add it. i've looked up the list of requirements for homebuilt vehicles, and it shouldnt be too difficult by the looks of it.

[gecko1000]

ok guys. as of right now, im finishing up final dimensions on the frame itself (less engine mounts, susp mounts, etc) and would like to work on the drivetrain plans while i start construction on that.

my question is now this: what could i use for a limited slip differential on the back of the car? i need something that i can still hook up to CV axles. I was thinking about sourcing the suspension and diff. from an older mazda miata. that way it would already be a proven design, and less fabrication for me. any ideas?

[cheapracer]

First can we know are you staying with front wheel drive or rear? Yes i can see in the pics at the moment you have rear but I would encourage you to consider front wheel drive for your needs which I guess are of a non sportive type?

Oops, sorry this post was for another thread - bet it looks strange here! :-)

Nothing to see here, please move on.....

[Ken_Kim]

Those Miata parts are a great choice especially with your CVT.

[cheapracer]

I would recommend that you don't use a LSD.

But as an aside, why don't you write to Z Cars, explain what your doing and ask them about an LSD for street use - they would have more experience than most on the subject of short WB cars with bike power for street use..

http://www.zcars.org.uk/

Miata front uprights are quite popular for kit cars too.

[gecko1000]

cheap, whats your reasoning behind NOT using an LSD? everyone i've talked to has said i would greatly regret not using one. this car is WIDER than a miata, and i dont want to be dragging tires. now, at the same time, not using an LSD would be much easier to build.

[Ken_Kim]

Going without LSD would be half ass. Do it right or not at all.

[gecko1000]

agreed. i found a complete miata rear end for $350. so i think im gonna do that.

[cheapracer]

Going without LSD would be half ass. Do it right or not at all.

Bold statement with no foundation.

A 60" WB car weighing 450kg's(?) with probably a 40/60 weight bias that will transfer to something like 20/80 under full belt and will simply try to push the front straight off the road during acceleration under cornering with a LSD. On the other hand when the LSD engages right at the same time as you hit a slippery spot (or a wet day), your going to rotate so fast on a 60" WB you won't know whats going on.

Many lightweight real race cars (not road based race cars) don't use a LSD at all and many use just a light setting - I'm sure many think they all have LSD's, they don't.

A small, short WB, lightweight car with good RC to CG coupling and wide track doesn't need a LSD and with one "you might die at the first corner" :)

If you really do need a LSD you will know soon enough after some time in the car but why waste your money and time now when it's most likely not required.

[gecko1000]

after looking some things up, atoms use lsd's, caterhams use lsds, and miatas and s2000's use lsd's. i think you get the feeling that im going to give this thing full throttle around every corner. i had an ASE certified master mechanic look at my plans and as soon as he saw my original rear axle set up (no LSD) he said right away "you cant do that," and went on to explain how it would tear the cv axles apart as it drug the outer wheel across a corner. and i dont understand your logic behind the "pushing hte front off the road" as i dont think that has anything to do with a LSD, because under load, an LSD locks up power to both wheels, just like an LSD. and with a solid axle, i would still be pushing hte front off the road anyways with your theory.

[Ken_Kim]

The first time you spin tires is the last time you’ll be happy with your car. That’s why you buy LSD. Listen to your mechanic, don’t go cheap.

[cheapracer]

I didn't realise you were optioning a LSD against a solid axle, i thought you were choosing against an open diff.

To be clear in order of my preferance;

open
LSD
Solid

Solid can be certainly made to work and quite easily but entails some different thinking outside the square and can be a bit tricky, even dangerous to drive in some situations.

[cheapracer]

The first time you spin tires is the last time you’ll be happy with your car. That’s why you buy LSD. Listen to your mechanic, don’t go cheap.

Please tell me your guess-timated difference of load spread and why on the rear tyres during cornering of a Mazda Miata and the Gecko. Simple terms is no problem.



Gecko besides A grade certification, I am also a Bachelor of Mechanical Engineering and whats more I have a Blockbusters Gold Card - so what, none of that taught me what I know from 30 years of building race and rally cars and my Mate didn't pass high school, is a little illiterate but he builds championship winners and has been for 40 years.

[cheapracer]

after looking some things up, atoms use lsd's, caterhams use lsds, and miatas and s2000's use lsd's. i think you get the feeling that im going to give this thing full throttle around every corner. i had an ASE certified master mechanic look at my plans and as soon as he saw my original rear axle set up (no LSD) he said right away "you cant do that," and went on to explain how it would tear the cv axles apart as it drug the outer wheel across a corner. and i dont understand your logic behind the "pushing hte front off the road" as i dont think that has anything to do with a LSD, because under load, an LSD locks up power to both wheels, just like an LSD. and with a solid axle, i would still be pushing hte front off the road anyways with your theory.



Atom's most likely use a Torsen style and I doubt the 120hp model does, but I don't know. Torsen's come under the grouping of LSD's but they aren't in the true sense, in simple speak it's a device that allows the outside wheel to go faster than the inside wheel in a turn. If you can get your hands on/afford a Torsen (read Quaife) or a Viscous LSD, all the more power to you - stay away from Lockers, Cam/Pawls (both too dangerous for your application) and Salisbury are too much trouble, especially if used.

Cats, Miata's and S2000's are a front engined car's with forward sloping roll line, high CG and largish CG coupling distance from the RC and anti roll bars for comfort - all this means in a corner they will have a large weight transfer to the outside wheel and therefore can quite easily spin their inside rear wheel. They need a LSD because of this. You'll note that mid engine mass production cars such as Toyota MR2's dont use LSD's (some countries have an option for the later ones, more specific to traction in snow etc.).

Your beast should have low CG, short CG coupling distance to RC, very wide relative track, flat, low and fairly stable roll line, probably won't need anti roll bars and therefore only a small weight transfer to the outside wheel during cornering and would only suffer severe wheelspin in hairpin type cornering with an open diff.

Anyway, some things to consider.

[Ken_Kim]

Cheap-you’re using old Geo Metro 3 cylinder-maybe 40 hp going downhill. That can’t spin the tires on ice. Gecko has a Yamaha 4 cylinder with 160 hp. Notice any difference?

[gecko1000]

Your beast should have low CG, short CG coupling distance to RC, very wide relative track, flat, low and fairly stable roll line, probably won't need anti roll bars and therefore only a small weight transfer to the outside wheel during cornering and would only suffer severe wheelspin in hairpin type cornering with an open diff.

Anyway, some things to consider.

i do have all those things?

also, im not doubting your experience, but all I have seen is a picture of (in my opinion) a silly little chinese car thats a grown up fiat 500, and no pics of an exocar (that is supposedly being built under strict secrecy).

so im just a little weary of where your facts are coming from. and when you said no differential (which has now been cleared up) i said to myself "no way, this guy really has no idea." but we got that cleared up. also, post some pics of YOUR supposed exocar for us. i'd love to see how youre doing all of your construction

[cheapracer]

Cheap-you’re using old Geo Metro 3 cylinder-maybe 40 hp going downhill. That can’t spin the tires on ice. Gecko has a Yamaha 4 cylinder with 160 hp. Notice any difference?


I don't know what the hell you are talking about.

I don't take drugs but I really don't mind if others do, but please refrain from using them before posting.

[gecko1000]

cheap, ive come to a conclusion.

youre kind of a douche.

the way you respond, the way you post, etc--makes you kind of a douche. while i was trying to respond without blowing up to your comments, i no longer wish to hear your input. you DEFINATELY think you are car god and know everything there ever was and no other way is right.

i think i've got my gecko pretty much figured out as of this evening, so feel free to enjoy WATCHING my project come along without your help from now on

:)

good talk.

[cheapracer]

i do have all those things?

also, im not doubting your experience, but all I have seen is a picture of (in my opinion) a silly little chinese car thats a grown up fiat 500, and no pics of an exocar (that is supposedly being built under strict secrecy).

so im just a little weary of where your facts are coming from. and when you said no differential (which has now been cleared up) i said to myself "no way, this guy really has no idea." but we got that cleared up. also, post some pics of YOUR supposed exocar for us. i'd love to see how youre doing all of your construction

My post's about my Exo Car are on public record here, you'll be able to buy one by June. At no point have i mentioned secrecy and I've even given a post publically here of some of my frame dimensions. Thats a real steel frame by the way.

This is what I get for making an effort in helping you? I have to prove who I am? And you call one of my real "can touch and drive" cars in development silly compared to your bits of paper with your just awesome suspension design (thats just like a Superlite :thumb2: ).

This is my fault I should have stopped earlier when I noticed your condesending nature.

[gecko1000]

no problem. take care :)

[gecko1000]

anyways. now that our resident car god is out of the way. anyone else want to put some input on this? i will be using the rear end out of a first gen miata, which (as some of you may know) includes dual a-arm suspension, a limited slip differential, and cv axles. the r1 engine will be sourced out of an RX-1 snowmobile, and turned 90 degrees with the CVT transmission driving a short driveshaft to the rear differential. front suspension will also be sourced from something, not quite sure what yet. maybe the miata too. im about to start work on the frame as soon as i can find a garage or something. pics of BUILD to come soon!! woot!

[cheapracer]

now that our resident car god is out of the way.

Excuse me?

[Gage]

Why do people take anything seriously on the internet?

:old:

[cheapracer]

Lets go for a drive in the Gecko shall we, just some simple cornering getting a few degrees of roll up and then some braking tests

:omg: :hitfan:

[Goin South]

Cool suspension software. Details please: What is it called? Who makes it? Where to buy it? What else does it do? etc, etc.

[Ken_Kim]

Dude get that miata front end too- made for the same car so you can just bolt it on and go!!! does that r1 in the snowmobile turn 10 grand?

[gecko1000]

actually i found an EVEN better source! prowler. they have great aluminum alloy a-arms for the front, PLUS they have the brackets for the fenders. as for the rx-1 spinning 10 grand? are you asking HP or price? cuz the answer is yes to both. they run up to about 12k rpm, and run about the same price for a new decked out sled.

[cheapracer]

Cool suspension software. Details please: What is it called? Who makes it? Where to buy it? What else does it do? etc, etc.


Hey Mate.

This simple software is from Performance Trends.

It opens your beer, gets your woman turned on and turns the lights off when you leave home.

It's not too indepth such as Adams, but certainly is user friendly for the home user and probably very easy to use for most.
http://www.performancetrends.com/SuspAnzr.htm

I do suggest if it's your first go at this stuff then try this one first which is a simple roll center finder - the demo has a lockout for many of the inputs but if you open the files in RCfiles folder they are actually .txt and you can open them with notepad and manually input your measurements. http://www.performancetrends.com/download.htm#rcc

I am happy to answer any questions as you go along and if i don't know one of my Mates will - we are all involved in the industry.

Hope it helps.

[gecko1000]

update: the frame plans (less engine mounts, suspension mounts, and seat brackets) are finalized (with sub-frames and build instructions) and have been sent to the metal fab shop for cutting. once they are cut, welding will begin, and the frame should be together in a few weeks. requests have been sent to a couple of motorcycle shops to keep an eye out for an engine. i know ive changed my mind a couple times (what else is new in custom modification?) but ive finalized on using a bike engine, bike transmission, shaft driven to a limited slip differential.

i'll keep you guys posted.

[Karlo]

Thanks

JD Jensen

[gecko1000]

hmm....do i smell.....CBR 1000? i think i do....

found a powerplant :D

[Gage]

Sweet, Go man.

[gecko1000]

yea im stoked. after months on paper, ive finally got the metal ordered, a place to build, and im picking up the motor on saturday! ah that tingly feeling....

[Gage]

This reminds me a little of your car Gecko.

http://revver.com/video/648214/racing-car-chassis-with-aprilia-rsv-engine/

[gecko1000]

ohh good find gage. that rear end is very similar to what im planning on doing. i know ive changed my mind ten times now, but now that ive found chain driven LSD kits, it makes my task a lot easier. (he has one on his car). And his susp. set up looks like i want mine to look.

[gecko1000]

hey for those still interested, i have created a blog for the Gecko.

check it out at http://thegeckodiaries.blogspot.com

[Gage]

Thanks for the link. I'm following along. I would love to build a sub 900 lb. exo-skeleton only Hayabusa powered two seater with off set seating as seen in the Caparo T1.

Do you have any suggestions for a cad/software program that could make measured curving chassis components?

[gecko1000]

yea a busa 1300 would have been nice, but i got a smokin deal on the CBR1000. and with a turbo kit, you can bring it up to 240hp.

as far as CAD, i dont really have any advice. sorry. the only CAD i've done was a CAD drafting class in HS.

[gecko1000]

i feel years wiser after reading some books and doing some research. NOW the car is DEFINITELY on the right track. i most likely wont be posting progress on here as there is relatively little following, but for those interested follow my blog at http://thegeckodiaries.blogspot.com

[mkim1]

Good for you, Gecko! Thumbs Up!!!

[cordycord]

Good job--I really like that you didn't let the differential problem slow you down. Very nice workaround.

As for CAD, it's like a foreign language--if you're not immersed in it daily, you won't "speak" it as well as a native and may tend to forget it over time. SolidWorks is the the most user-friendly & powerful system out there, but (of course) not cheap.

[txjeepn]

Having solidworks is one thing. I have had it and used it for work for the last 4 years. A person can design all sorts of great things. Another thing is having all the tools to make what is on the screen.

[gecko1000]

thanks for the direction. i'll look in to solidworks

[gecko1000]

hey guys check out my blog for my latest update:

http://thegeckodiaries.blogspot.com

[gecko1000]

hey for those still interested, here is a montage of pics from my build:

questions and friendly criticism welcome

[gecko1000]

more:

[cheapracer]

Now the reason I am actually bothering is because I happen to love the unique and kitcar industry and I really don't want people like you making it harder for the people who actually know what they are doing to get their cars on the road.

So in order to help the unique and kitcar industry as a whole, take some advice - never butt weld tubes if you can help it and never, ever do it in suspension control arms for not the least reason that its actually illegal in most countries. Why you didn't do true A'arms I don't know as in my drawing but if you must retain the arms as they are then do the world a favor and gusset them as in red including leaving an air gap in the corners. I suggest you use 2" x 0.95" flat. But don't, make new and true A'arms as in black below.

You can run your heim joints horizontal if your worried about the angles because, and very sensibly, your suspension pushrods are coming direct off the uprights therefore the heim joints are not exposed to vertical loads.

[cheapracer]

dude. why you seem to know what you are talking about, you are the biggest douche when trying to get a point across. you dont know what type of metal i used or what thickness it was or if there are smaller diameter reinforcement tubes underneath of it so dont start throwing facts around like you know everything about my car.

Firstly "Dude" for one besides others, I am a Ba of Mechanical Engineering and I dont give a toss if you are running solid, you have commited an engineering fopa for no reason other than a determination to follow just one, bad as it turns out, idea. Bite the bullet, scrap those arms and do it again - oh, I'll even add please. While your at it box in those poorly designed pivot mounts too. I bet you wont but I hope you do.

I don't care if you don't like my truth, I don't care if you don't like me, this is a serious business your doing and I'm not a "sick, awesome, radical, sweeeet" ect. person that you probably enjoy hearing the words so much from other clueless people in other forums I guess.

Once again I will tell you I don't want you damaging either this industry or worse, someone else if for some incredible stroke of luck you actually get it passed the licensing engineer on the day.

PS and by the way, I have no idea why you used Miata uprights and then with your admitted lack of knowlege didn't either use the Miata arms or at least use the same length arms and geometry as Mazda who are reasonably smart on the subject.

Sincerly yours,
Mr Douche Bag.

[Lynn]

Firstly "Dude" for one besides others, I am a Ba of Mechanical Engineering and I dont give a toss if you are running solid, you have commited an engineering fopa for no reason other than a determination to follow just one, bad as it turns out, idea. Bite the bullet, scrap those arms and do it again - oh, I'll even add please. While your at it box in those poorly designed pivot mounts too. I bet you wont but I hope you do.

I don't care if you don't like my truth, I don't care if you don't like me, this is a serious business your doing and I'm not a "sick, awesome, radical, sweeeet" ect. person that you probably enjoy hearing the words so much from other clueless people in other forums I guess.

Once again I will tell you I don't want you damaging either this industry or worse, someone else if for some incredible stroke of luck you actually get it passed the licensing engineer on the day.

PS and by the way, I have no idea why you used Miata uprights and then with your admitted lack of knowlege didn't either use the Miata arms or at least use the same length arms and geometry as Mazda who are reasonably smart on the subject.

Sincerly yours,
Mr Douche Bag.

Now its getting ugly. I can see or hear your frustration with the kid that just does not want to listen. I remember being that way many years ago. the good thing is he is trying to do something positive even if it is not completely right, that's how we learn sometimes, the bad thing is he is making a lot of mistakes. even if he is going to do it his way, he would be a wiser person if he would stop and take sometime to see that you are just trying to help him get it right the first time. he might even do a little research on the subject of suspensions systems. maybe read a book on the subject.
as for his present design, if he does not make some changes, he will find out what you are saying is good advice. the machine will probably never be driven over 40 mph, with that engine and suspension setup it will be scary, A 70" wheel base is not going to work at hiway speeds. and with the suspension working with the wrong camber change on bump, it will be almost un-driveable in a corner. most young designer do not understand how a very little change in geometry can make such a big difference in handling and his is way off track. I do applaud the fact that he is trying to do something with real steel and real parts and not just creating another vaporware car like most of the youth are doing these days. As for your design, it looks great and wish you all the luck in your venture.

[OneFastRide]

Hey, give the guy a break. I've actually been following this thread, and it was a good read until Mr. Douche Bag (aka I wanta be a car builder) started butting in with his unwanted opinions. The end result is he is building a car for himself and only himself. Mr. Douche bag on the other hand is trying to build a car to sell. They say a picture is worth a thousand words. Take a close look at Mr. Douche bag's build site. Does this guy actually think he is going to sell this crap????????? There's a BIG difference between inexpensive and CHEAP, and if that doesn't scare you, can you imagine buying a kit from this guy with that attitude????????????? I think "Build it and they will RUN" is more appropriate....

[golftdibrad]

Now the reason I am actually bothering is because I happen to love the unique and kitcar industry and I really don't want people like you making it harder for the people who actually know what they are doing to get their cars on the road.

.....

You can run your heim joints horizontal if your worried about the angles because, and very sensibly, your suspension pushrods are coming direct off the uprights therefore the heim joints are not exposed to vertical loads.

Firstly "Dude" for one besides others, I am a Ba of Mechanical Engineering and I dont give a toss if you are running solid, you have commited an engineering fopa for no reason other than a determination to follow just one, bad as it turns out, idea. Bite the bullet, scrap those arms and do it again - oh, I'll even add please.



While the delivery leaves something to be desired..... He is right. Those arms are a big no - no. Re-do them or your car may double as you coffin; its that serious.

Other than that to pics look good and you'll have yourself a hot little car when its done. Keep it up!
-Brad

[gecko1000]

i dont see where you guys are getting any information to support that i have not done any research or read any books. i have carried out months and months of research and design to get to the wishbones i have now. thats why i went away from my original (and faulty) design. why not use miata wishbones? a) because they look ugly b) mine are better. after using several suspension geometry calculators, my wishbones allow only .8 degrees of camber change at full bump, and i can even dial that in. try finding that kind of vertical on a miata.

also, the wheelbase has been extended to 86, and the car shares the same width as a miata.

who can give me links or information telling me buttwelding wishbones is a bad idea? you HAVE to buttweld them at some place. you can get a single pipe bent to a curve, then youd still have to buttweld the component that holds the ball joint. if you know how to weld, the weld bead will be stronger than the steel surrounding it.

so before you start throwing around "oh this is a horrible idea youre goin to effing kill yourself" show some links. ive seen TONS of examples of hillclimb and other bike powered cars that use buttwelded a-arms. ive spoken (in person, in front of hte car) with people who have built race cars from scratch and they say the suspension looks fine, if not a little over-strengthened. so why, after so many experts have seen the car in person, are some of you trying to say i dont know what im doing based on pictures youve seen on teh internet? i think YOU dont know what youre talking about cheapracer. and i wouldnt trust your chinese built nonsense for a nanosecond. youre on my blocklist so i dont have to listen to your useless ramblings. and these forums are extremely dead as it is, so i most likely wont be coming back much. those of you that are interested, you know where my blog is.

[Gage]

It might be beneficial to simply read comments and criticism, absorb anything useful, and let the rest slide through the useful/not useful filter. Spending emotion and engaging in name calling are wastes of energy, especially here.

I have only admiration for your determination, ingenuity, and project Gecko1000.
I keep up with your project, but I don't have the technical back ground to offer any constructive criticism or tips. Others may. However, all people have strengths and weaknesses. Bear in mind that someone with a great deal of knowledge and wisdom may have a great weakness when it comes to diplomacy and tact. Very few imperfect human beings are balanced across their personality stat chart.

[golftdibrad]

i dont see where you guys are getting any information to support that i have not done any research or read any books. i have carried out months and months of research and design to get to the wishbones i have now. thats why i went away from my original (and faulty) design. why not use miata wishbones? a) because they look ugly b) mine are better. after using several suspension geometry calculators, my wishbones allow only .8 degrees of camber change at full bump, and i can even dial that in. try finding that kind of vertical on a miata.

I wasn't commenting on your suspension geometry. It looks like you have a good place to start with the pickup points, and that is half the battle. A-arms are easier to redesign than chassis pickup points. I also like the vertical orientation of the heims. A lot of people put them the other way and it escapes me as to why.

also, the wheelbase has been extended to 86, and the car shares the same width as a miata.

good. FYI, a length to wheelbase ratio close to the golden ratio shows up in a staggering amount of good sports cars and race cars.... this is no accident.

who can give me links or information telling me buttwelding wishbones is a bad idea? you HAVE to buttweld them at some place. you can get a single pipe bent to a curve, then youd still have to buttweld the component that holds the ball joint. if you know how to weld, the weld bead will be stronger than the steel surrounding it.

Well.... if you have not read engineer to win by Carrol Smith.... do it now. Get his whole series and read the nuts, bolts, and fasteners next.

There should be no buttwelds. I think what we have is a misunderstanding of nomenclature... this was the most difficult thing to do when I was in school getting my ME degree. The connection to the rod end (threaded section where the hiem goes) absolutely must be sleeved. Near the ends where the tubes are cut at an angle are not a buttweld and is fine; I however would include a gusset of either solid 3/16 plate or better yet box it with 1/16th plate.

You are correct that the weld bead is stronger, however by definition it is stiffer and therefore a stress concentration. The strength of the weld is not the issue its is its fatigue life. A stress riser in the middle of the tube IS going to crack after a certian number of cycles. As suspension components are subjected to many, many vibrations it is JUST BAD PRACTICE. It may last a week. It may last ten years. You don't want to know how long it was going to last entering the braking zone of your favorite track at the end of the main straight, or on your favorite curvy road.

Finding info on such a specific trade thing is hard on the net. Get a few used texts of ebay. Materials science, ME design, and manufacturing process are three to have. Go back a couple of editions and they are less than $10 each. Don't try and read the whole thing; just use as a reference.



so before you start throwing around "oh this is a horrible idea youre goin to effing kill yourself" show some links. ive seen TONS of examples of hillclimb and other bike powered cars that use buttwelded a-arms. ive spoken (in person, in front of hte car) with people who have built race cars from scratch and they say the suspension looks fine, if not a little over-strengthened. so why, after so many experts have seen the car in person, are some of you trying to say i dont know what im doing based on pictures youve seen on teh internet? *snip*

I'd look for more pictures. I have never, and I mean never, seen a tube buttwelded in the center of the tube like that. I am simply concerned for a fellow enthusiast's safety.

Go to a tube bender and get the parts bent out of one tube, saddle cut the cross support and weld it in.

Good luck,
-Brad

[cheapracer]

my wishbones allow only .8 degrees of camber change at full bump, and i can even dial that in. try finding that kind of vertical on a miata.

.

As with yours and the Miata and a million other cars, when you go around a corner the car will lean - thats why you have camber gain, to compensate. The wheel is vertical because the car leans and the tyre leans the opposite way at the same time. (in a good sytem that is).

Your car will only have positive camber gain in the balance, yours will have serious positive camber and you are in real danger of tripping the car over

Read your books again.

[cheapracer]

I . I also like the vertical orientation of the heims. A lot of people put them the other way and it escapes me as to why.



-Brad

To avoid using bends in the tube if the arms aren't loaded.

His are not loaded, the load is direct to the upright so there isn't an issue running horizontal hiems therefore he can run true A'arms not U'arms.

I have seen stupid loads put into hiem joints both vertical and horizontal.

[cheapracer]

Now you see in this simple picture the Miata is leaning over but the wheels are vertical because the shorter top Aarms are arcing inwards sooner and dragging the top of the tyre inwards.

Simple as that.

PS; Wow dude thats sick! :coolnana: (I'm in Xtreme training at the moment)

[JonW]

The reason Heims should be oriented horizontally on control arms is the fact that the axial strength of the joint is only 10 to 15 percent (depending on joint construction type) of its radial (published) strength. Do not ignore this difference in strength.

The limitation on horizontal mounting is the misalignment angle that the Heim will be subjected to which is a function of arm length. On my Atom, the rear arms are much shorter than the fronts so my rear Heims are vertically mounted. I believe (I'm too lazy to actually calculate the values) that the front braking forces will load the front arms more than the rear braking or engine torque will load the rear arms.

[golftdibrad]

Agreed. The forces are not 100% axial though. I had a discussion with a fellow engineer that sells the things and apparently once the force is no longer purely axial the heim quickly returns to a value near the published one. Now, taking that at face value I have never seen a vertically mounted one pop out in a suspension. Furthermore, one of the projects i had to do for fsae involve destructively testing one axially. It took ALOT of force and tools to break that thing... i had no doubts after that experience. :thumb2:

On a well developed car though they should be horizontal.

The reason Heims should be oriented horizontally on control arms is the fact that the axial strength of the joint is only 10 to 15 percent (depending on joint construction type) of its radial (published) strength. Do not ignore this difference in strength.

The limitation on horizontal mounting is the misalignment angle that the Heim will be subjected to which is a function of arm length. On my Atom, the rear arms are much shorter than the fronts so my rear Heims are vertically mounted. I believe (I'm too lazy to actually calculate the values) that the front braking forces will load the front arms more than the rear braking or engine torque will load the rear arms.

[cheapracer]

Now, taking that at face value I have never seen a vertically mounted one pop out in a suspension. l.

They do but I dont know if it was just from wear and tear for the ones I have seen - I believe a few have popped off for some Atom owners too but I am not aware of the circumstances, probably age.

You cant use them on the roads in Oz for this very reason.

[Crazyhippy]

In the SCORE 1400 (unlimited pre-runner) truck i built, the Heims for the front suspension were vertical (couldnt get the angle needed if they were mounted any oher way:D).

The truck has caused WAY, WAY more abuse to those joints than any exo car ever will, and we haven't broken a joint yet...:thumb2:

[Crazyhippy]

Another pic, w/ the front end on it:king:

[golftdibrad]

In the SCORE 1400 (unlimited pre-runner) truck i built, the Heims for the front suspension were vertical (couldnt get the angle needed if they were mounted any oher way:D).

The truck has caused WAY, WAY more abuse to those joints than any exo car ever will, and we haven't broken a joint yet...:thumb2:
When i did my FSAE suspension the judges got on my case for the verticle heims.... I believe my exact quote was 'If they make it through the baja 1000 like that then they'll certainly survive some college kid driving around a parking lot for a few hours'

[cheapracer]

In the SCORE 1400 (unlimited pre-runner) truck i built, the Heims for the front suspension were vertical (couldnt get the angle needed if they were mounted any oher way:D).

The truck has caused WAY, WAY more abuse to those joints than any exo car ever will, and we haven't broken a joint yet...:thumb2:

And they are used on millions of tractors every day to connect implements that pound away but not 3/8" or 1/2" either as I'm sure you use the size thats relative to your loads.

[Crazyhippy]

So you up size slightly, and pay the 1/2lb weight penalty... No biggy.

I guess they are slightly more expensive, 10 bucks each vs 7. Gives you a whopping 12 dollars more over the 4 required per end.

The other thing you should do is keep an eye on things. Nothing major, just give the arms a tug when you wash the car sort of thing. It's SUPER easy to inspect on a car w/ exposed suspension.