Solo content: should STX Twin be setup like S2k, RX-8, MX-5?
 

Now that my car's suspension is on & ready to be set up, I'm wondering if we shouldn't try & emulate another car's setup that may be similar to our car, dynamically?

I've heard that the S2k may be a close match to our cars.

Since I've been in AWD mode since ~'05, I'm outta the loop for RWD.

Anyone have similar thoughts on copying what works?

The s2k does run a similar setup but there are so many variables it might be best to just get someone that is really good with suspension to take it for a spin and start getting advice from them.

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If you need second opinions on setups, I'll be glad to test pilot your beast :)

Don't baseline a S2K, Miata, or RX-8, all use double a-arm style front suspensions. Geometry wise, we are at a disadvantage here on camber curve and keeping an optimal contact patch.

Completely different suspension designs....don't bother use those cars as a starting point.

EDIT: see above.

- Andrew

Interesting subject. In terms of suspension, drivetrain, and chassis, what cars are similar to the twins?

BMWs :( kinda...

Yeah, in uncharted territory on this car with this car, so I guess it'll be a work in progress trying to figure out what works on these cars as far as camber/toe/caster/rake etc. Thought I'd post this up as I'm sure many are trying to get a handle on things as we go into the season.

So when someone figures it out--pls share all of your 'proprietary' info w/ us--we sure you won't mind. lol

And Henry, strangely a lot of people share your sentiment & enthusiasm abt driving the car. lol

Probably wouldn't be able to fit double wishbone with a boxer engine. This beg the question, would people prefer double wish and an inline 4 over boxer and strut?

If there's any setup you should replicate, I'd say @robispec and @CSG Mike.

I thought BMWs had struts? :iono:

BMWs and 911s both have struts in the front, albeit not a traditional design. There is probably room to design a front wishbone suspension but it would have required a lot of work. Most of what's on the BRZ is adapted from the Impreza and likely required a lot less R&D than designing something from scratch.

As for the car setup, I've heard from one national champ autocrosser who feels the car is close enough to his S2000 he'll use the settings off of it as a starting point.

We're set up for track duty, not cone dodging, so I wouldn't necessarily recommend following our setups. Additionally, it may kick you out of your desired class....


I've AutoX'd exactly once, and drove a few STR cars that were offered to me. These are my observations based on the STR cars i drove; my CR falls into STR as well. They kindly turned a blind eye to my pulled fenders, as they were of no performance benefit with the stern warning that if I were at a national championship, I'd be DQ'd for it.

- AutoX cars value ultra fast response and weight transfer
- That response and transfer typically comes at the cost of understeering during steady state cornering
- Because of that understeer, they believe in the slow-in fast-out approach, with a hard rotation after the slow-in

I noticed that a STR s2000 was slaloming nearly 7-8 mph faster than I was in my CR with stock suspension, but I could easily hold an advantage through sweepers using throttle steering. Unfortunately, due to the nature of AutoX courses, sacrificing a few sweepers for the tons of quick transitions makes the properly set up STR cars faster.

I was also chastised for my driving style (loose rear, but not sliding)... but still took 2nd fastest novice of the day; I lost to a guy who was ending his first season and was a novice by technicality. He was in a fully prepped car. Grr.

My bad. For some reason, I was thinking about a track setup when reading this thread. :brokenheart:

Thanks for thinking of me though :happyanim:

I do want to sharpen my AutoX skills... just never had the proper car or time to do so.

They do. Tony Zwain at Edge Motorworks said that the suspension resembles E36 BMWs. Looking at Edge's BRZ, I agree. Since I built the current STX National Champion car, I'll tell you how mine is set up. First, my car weights ~2850, a good Twins build will be 300 lbs lighter, and the cg will be lower, so take that for what it's worth.

600# front springs, Ground Control swaybar, 4 degrees negative camber. Front motion ratio of Edge's BRZ does look very similar to my car. Both swaybars go to a tab on the strut, so swaybar motion ratio is also similar to the E36.

700# rear springs, Ground Control swaybar, 2.5 degrees negative camber. Rear motion ratios of both the spring and swaybar on the BRZ looks like it's a lot better than the BMW (at ~0.54 spring and ~0.25 swaybar).

With info that a very successful E36 STU car is at 650/800# and knowledge that my car slides the front tie wraps up really close to the upper spring plate, I'm trying 700/800 this weekend.

I hope this is of some help.

Charlie Davis

I dunno... if there was only some autocrosser around with a good track record and some knowledge of the car. Hmmm

!Is that a cryptic way of saying we should contact you, Sam? lol

I've asked for some info before, but it seemed like it was proprietary... :iono:

Shoot, I'd really appreciate some setup info from you!

Well, I bought a car to learn about it. I think I've proven pretty well I'm at least ok in getting cars setup to the point they can win things.

I am quite open with people who I can trust to not take my information and run off with it. I work hard to figure out what I figure out, and it's a kick in the nuts to have folks milk that from me, then go buy parts other places. Nobody likes working their ass off and then someone else getting your paycheck, right?

This isn't a side job for me, this is how I make my living. :) I can't be doing setups on shocks that Joe got paid to build but can't support. Well I can, I've thought about consultation type work... but I hate the idea of charging someone for information I'd be happy to give folks who buy their stuff here. Sadly, and maybe it's the price of the car that has something to do with it, I've already had a number of experiences being on the phone for, say an hour... or more, only to be tossed aside for someone who made them a "better deal". Well, if I didn't spend the time on the phone I do and could just move volume without any support I could probably sell for less too, even though my prices aren't really at all out of line on most everything.