I won't say it went to poop, but understeer reared its ugly head. I like the planted feeling in high-speed sweepers and esses, but acute turn-in is nearly non-existent. Having already addressed the skittishness of the car via front anti-sway bar and alignment(s), I believe the GTC-200 is one of the bigger contributing factors to my understeer. It could be entry speeds, but I have been aware of that. It seems as if nothing short of stopping helps.

I'm going to break down and add the SPC camber kit. Front splitter w/ undertray is something I'll be working on during the off-season.

 

JP I must say your contributions in this thread are very insight and useful. Thanks!!!

 

JP, like his cat norman (not to be confused w/ "normal") are uhm special

 

Norml.

 

not to be confused w/ your cat !norml

 

Yeah, wow, we must be setup differently. I would say I have understeer, but only at speed and only slightly (as I said, it still rotates at low speeds, with the balance shifting as I speed up). What else are you running?

My setup:

2001 MY

Suspension:
-Stock Springs over Koni Yellows (Front almost full stiff, rear somewhere in the middle)
-Saner front sway (at the middle setting)
-Bridgestone RE-01R F:205/55-16 R:225/50-16 on Regamster Evos

Aero:
-GTC-300 Wing
-Mugen style top

Weight Dist Notes:
-No spare or tools
-J's 70RS (full titanium)
-Plus a hitch

It's basically an A-Stock autocross setup plus wing and top.

Also, what sort of speeds are you reaching on the tracks you are at? What kind of angle is the wing at?

 

First off, a disclaimer: I am not an Aeronautical Engineer! Some of you guys are far smarter than me when it comes to aerodynamics. With that said...

The 3D wings are still effective below the roof lines. The APR wing data is a CFD model, so it will tell us something, and they are doing their due dilligence. They don't have the budget to do wind tunnel testing on every application.

However, we've used this wing and did some of the testing on the final production peice, and it WORKS. Buttonwillow is a great track to test aero on with the high speed corners. The car will stay planted through Riverside.

Per APR's recommendation, run the wing between 0-10 deg AOA. Right now we have ours set to ~5 deg.

We are running the 1/2 height wing bases. APR also has full height wing bases. Another bonus is that the OEM rain channel will still function. So if you remove the wing for DD use, water will not run into your trunk if it rains.

Also if you are running a big ass wing on the middle of the trunk, you can deform your trunk lid. With the mounting bases being near the edges of the trunk, you don't have to reinforce the trunk.

Here's what the S2000 Specific wing looks like.


Compared to the universal.

 

They sell an S2000 specific 200 now?

also, NASA time trial rules add points if the wing

"if height greater than 13" above the deck, chord length greater than 8" width greater than the vehical, gurney tab greater than .5" or extends more that 1.5" past the body of the vehical when viewed above"

in case anyone cares.

 

Thanks, mikegarrison, for the book recommendation(on aerodynamics). Only a couple of chapters in, and I'm already looking at things differently.

 

That was McBeath's Competition Car Aerodynamics, right? (Just in case anybody else wonders which book....)