I know the S2000 isn’t ideal for C Street, but I’m fairly new to autocross, and this is where I plan to get seat time.

After reading several threads, it seems the top 3 priorities are: 1) Tires, 2) Alignment, & 3) Sway Bar.

What is the consensus in 2023 on running square or staggered on stock AP1 wheels?

I’m under the impression that it’s safe to run 225/50R16‘s in the front without rubbing.

 

Around my local group C street AP1s usually run non stagger. You can run 225 safely without rubbing in the front. I think the TR tire and wheel combo test threw a wrench in a lot of peoples understanding of setup however I'd say that the stock AP1 would be an exception to this since the 16 inch tire is so pinched anyways. Between 205 and 225 both are really pinched so you might as well run 225 IMO. You should at least get some sort of stiffer front sway bar if you go nonstagger. It doesn't have to be the Karcepts bar. Even the Eibach bar can provide some benefit to settle the rear down. You should max out the front camber. At stock height I think it tops out just shy of -2* with some variance given manufacturing tolerance stacking. I would match the rear camber to what your front is as a starting point and then adjust it as you see fit. Run 0 front toe. Rear toe preference seems to be very personal for some. I've had some recommend low toe and some recommend high toe. I'd just leave it as is for now to reduce the number of variables you are changing at a time. I personally run some where in the middle.

BTW, I'm KCR as well, might have run into you before. Black AP1 usually running in XA.

 

We've run 225/50/16 square on our AP1. It's "ever so slightly" faster than staggered, but requires more attention to steering, and you'll have to run upper 30's in the front tires if you want them to last. My recommendation would be to stick with the 205/225 stagger.

 

An alignment is definitely on my list, but I’ll probably run 1 event with just new tires to see how they compare to my current ExtremeContact Sports.

I bookmarked this page for alignment specs: https://www.s2ki.com/forums/texas-ce...ttings-770115/

I’ll probably go with the Karcepts bar eventually, but they suggest different sizes for square vs. staggered setups:

• 1.14": staggered tire and wheel setups
• 1.25": square tire and wheel setups

 

It wouldn't be a bad idea to stay staggered and just get a super 200 tire to feel out how the car is as is. Make one change at a time. I will add that CS#134 is running 225 nonstagger with the Eibach bar and he's quite fast. If you get the Karcepts bar I'd get the narrower center core. For some reason I remember reading they suggest the smaller bar for stagger and narrow tire CS setups. I have their big bar with 255 and it can definitely overpower my tire setup at times and cause understeer so with less tire I'd be cautious.

 

Yeah, I’m leaning toward staggered right now. It’ll be easier to see how the 200 tires compare to my existing 340’s.

Here’s my current OEM alignment (image attached):

 

On the old crop of street tires (OG RE71s), I ran my 2003 AP1 first with 205/225 and then 225 square. Stock with 225s, it's definitely tail happy. It's controllable but tail happy. I didn't realize how oversteer oriented it was until I got the Karcepts front bar after running the 225 square in stock configuration. I think you're fine either way and you'll learn a lot with either. Front sway bar is definitely preferable and Karcepts is the best option available. You can always get a new center section if need be. I think Yokohama A052s come in 245s also and you could do 245/225. 16's are nice to learn on because they're cheap.

Another option, if you want to do it, is to buy AP2 wheels. It's not technically CS legal but locally, nobody should care. They may but they're really a weenie if they care that much, especially if they're in an ND Miata. They at least won't care until they get beat. On AP2 wheels, I ran 245/255. Idk if the current crop of street tires is best @ 245 pinched on the fronts or not. I do think the new Bridgestone RE71RS seems to be the best tire for street class cars. Seems ST cars are still going for the Yokohamas. I even think the RE71RS has made street cars more competitive in PAX this year relative to last. Maybe that's bias to where I'm running but I've run all over east coast to mid-west this year. CS and DS particularly have been killing it and they're talented drivers. Still though, the ST drivers are good too. The stones seem to be working in street and I can't decide if the Yoks are in ST because they're better with camber or because people are reluctant to change. I'm stuck w/ Falkens because I'm running SSC this year so I've got no opinions on the stones.

For alignment, max the front for sure. You should get 1.7ish degrees out of it. That's what both my cars (AP1 and AP2) got in CS trim. 0 toe front, max caster. Rears, I think I ran 2.25 degrees camber or something? I preferred high rear toe in the AP1 (.6 degrees total) and would definitely recommend that if you're not doing the front sway yet. There are plenty of arguments on here about it but in autocross, I've never heard of someone in a fast s2000 running low rear toe.

 

I'm local to him, the usual C street gang is another AP1 and a Porsche Boxster. There is the occasional NC and ND however they do not show up as consistently. I don't think either will care too much if you get AP2 wheels as they're good sports however CS#134 is very fast and would be a good benchmark for you if you stay on AP1 wheels.

And to poke a dead horse, back in the day when the S2000 was still in BS and the M2 had just showed up on the block my buddy ran his AP1 with 225 square, Karcepts 1.25X0.188 bar and 0 toe and would dominate the class. That said it was not an easy car to co drive so it takes a certain driver. I think if you ask Karcepts they will recommend around 0.4-0.5* total rear toe. The old STR threads will show you that there's a wide range of preference. I run around 0.2-0.3* total rear toe. I would just leave your toe setting where it is right now and adjust based on preference after you've gotten a good feel of your new setup. I've had friends tell my my car has too much trailing oversteer and others say it's fine. You will get your own feel with the car after enough seat time. Our region holds a decent number of school and test and tune events at the beginning of the year that you should try to take advantage of.

 

Changing topics a little bit while I look at tires.

TireRack shows the RT660 tread width (7.9”) a full inch wider than the RE-71RS (6.9”) in a 225/50R16. That seems like a lot, yeah?

 

RT660s are known to run wide and the manufacturers may measure them differently. I don't think either will rub and I'd still bet the RE71RS will be faster.