[4000GT]

Well I am at a cross roads... and really looking for advice from people with experience here.

I have gone TRD N2 and will be running 10" wide wheels. Its a track only car, and I want to go S13 for the wider track to give me more wheel and coilover options, and the capability to hold more power in the diff end as I have a 7A block with turbo ambitions down the track.

I have read some experiences where people didnt like the S13 front suspension, but wonder if these were track cars, and also assume that they didnt change the rear end.

So before I make the move and do the chopping, keen for some input!

[Bean]

My best tip albeit not easy is to track down someone who did it and try if it suits you.

I can't comment myself as I never driven that setup myself. I did own an S13 and have a AE now. One thing to consider is the approach people took to solve some of the issues when doing the swap. For instance did they just made the parts fit up front or done the calculations and maintained the proper geometry. Same goes for the rear axle and it's install height and suspension travel capabilities.

I'd need to refresh my own memory to help you out better but I think you get the idea.

[4000GT]

Bean Bandit Wrote:My best tip albeit not easy is to track down someone who did it and try if it suits you.

I can't comment myself as I never driven that setup myself. I did own an S13 and have a AE now. One thing to consider is the approach people took to solve some of the issues when doing the swap. For instance did they just made the parts fit up front or done the calculations and maintained the proper geometry. Same goes for the rear axle and it's install height and suspension travel capabilities.

I'd need to refresh my own memory to help you out better but I think you get the idea.

Yeah no one in NZ has done it that I am aware of. I think you are right that the poor handling ones are likely hack jobs. I have seen very few front and rear conversions, mostly just front.

[Bean]

4000GT Wrote:

Bean Bandit Wrote:My best tip albeit not easy is to track down someone who did it and try if it suits you.

I can't comment myself as I never driven that setup myself. I did own an S13 and have a AE now. One thing to consider is the approach people took to solve some of the issues when doing the swap. For instance did they just made the parts fit up front or done the calculations and maintained the proper geometry. Same goes for the rear axle and it's install height and suspension travel capabilities.

I'd need to refresh my own memory to help you out better but I think you get the idea.

Yeah no one in NZ has done it that I am aware of. I think you are right that the poor handling ones are likely hack jobs. I have seen very few front and rear conversions, mostly just front.

You might want to contact mcnsport in Ireland as they done it more than once and I'm pretty sure they'll give you some pointers... there's also a thread on driftworks maybe also here with pictures of a conversion (green subframe, blue chassis)

EDIT: here's the link http://www.aeu86.org/viewtopic/mcnsport-...nsport+s14

Peter's pictures don't work for me but might for you http://www.aeu86.org/viewtopic/another-s...nsport+s14

[4000GT]

I have been in touch with Darren at MCN just today on another matter, and they said the AE86 front is fine, just use a longer arm over the S13 front. But thats a convenience thing I suspect.

[Bean]

4000GT Wrote:I have been in touch with Darren at MCN just today on another matter, and they said the AE86 front is fine, just use a longer arm over the S13 front. But thats a convenience thing I suspect.

the S13 LCA is already some 50mm longer than the AE86 one? anyway as said do your measurements and math and everything should work out if well executed. Anyone with a slight racing suspension setup background should be able to cover the brain part of the conversion the rest is some precise cutting and welding every decent metalworker can do.

[4000GT]

Welding and cutting isnt the issue, as you say its the math and geometry. i dont have experience in setting up race suspension geometry. Ill check autospeed perhaps.

[Bean]

4000GT Wrote:Welding and cutting isnt the issue, as you say its the math and geometry. i dont have experience in setting up race suspension geometry. Ill check autospeed perhaps.

In that case I'd advise you to read the following books as they give you a very good starting point on how to approach the brain aspect of the swap.
If you have the whole rear axle you can remove the swaybar (to make your life a bit easier, it's already pretty heavy to move) and do your own testing and observations of how it behaves in different situations.

http://www.amazon.com/How-Make-Your-Car-...0912656468
http://www.amazon.com/Race-Car-Vehicle-D...0768011272

the first one is in my opinion a very good entry to vehicle dynamics - the fact it's a bit dated on some aspects doesn't outweigh the principle of physics that are well and comprehensively explained for such a short read (and let's be honest our cars are just as dated).

the second one is a bit more in-depth and much brainier math/physics heavy.

both can be found on the net as downloads if you don't want to spend the cash right away or at all.

In my opinion doing proper research, including reading AND understanding the basics is just as crucial as discussing the whole matter with like-minded and experienced people.

Last but not least have a chat with some S13 drivers and see what issues and improvements they had/made with their setup.

[NoHachi]

I think Axle kinematics are a bit beyond the scope of normal enthusiasts. Its difficult enough to get any existing setup to work based on those books. Figuring out how everything will react when you graft it onto a different chassis is close to designing a car from scratch unless you keep every (and I mean every) pickup point in exact relation to the others and the steering setup. This will not happen on the S-body swap.

The thing I'm having a hard time with is imagining why you would use S13-S15 stuff? McPherson front setup that chews through tires, outdated multilink rear that needs all kinds of improvements to "work" and be adjustable (and like most AE86 stuff, the S13 mods are very poorly executed, read Beans books to know more). Also nearly all the available shock options are shit for road racing.

There are just so many better starting points that have better geometry and are totally adjustable out of the box. Stuff like the Elise, MX5, the later S2k's with the rear toesteer fix, RX8. Etc etc. You could even try and adapt some Locost wishbones to a custom built subframe.

If I were to do this I would be looking at dropping an AE86 chassis over one of these: http://www.pixelthis.co.nz/envy/images/u...x5_ppf.jpg

[Bean]

You are aware that the MX5 rear setup is vastly different with level mounting points that vastly interfere with the AE chassis (same applies to the S2k and Elise). The RX8 and 7 designs are better but you'll run into another problem, their subframes are so wide you'll be mounting the front to the sills at best.
So altering the subframe or making your own is necessary, as you said this would stretch the capabilities of almost every fabricator.

Chewing through tires? racing in general tend to be hard on the tires. Outdated it may be but so is the AE setup and the use of steel, welding, carbs and a internal combustion engine.

The S-Body swap has been done before and occasionally including keeping all the pickup points in place and relation except for wheelbase (BTW MX5 is 100+mm shorter than the AE).

Last but not least - cost, S-Body parts are cheap, especially S13, whereas the others are much harder to source and dearer on the purse.