SCCA Solo C Street Discussion

[em99sport]

Originally Posted by Jawnathin

Did need to shift into 3rd on your FRS? Hard to tell but it looks like it was kept in 2nd the whole time.

My co-driver and I were driving his RX8 at the Tour and we got up to 63-64mph on both courses at the end of the big straights according to the GPS. I figured the 86 would have needed a shift to not ride the rev limiter. Its looking like we may have made up some time on the straights but got murdered in the transitions where the RX8 is a bit softer and not as quick.

I kept it in second for all six runs, but gearing was definitely an issue. After the first course walk on Friday, I was worried that the RX8s would eat our lunch in the straight stuff (of which there was plenty). The short second gear encouraged me to cut distance at all costs, especially exiting the sweeper on Sunday, in order to stay off the limiter for as long as possible.

[em99sport]

Originally Posted by ryan t

how do you like the traklites compared to the rpf1? i thought about ordering a set but tire rack list a different weight for each color and thought that was odd.

They look alright, but I only have a set because RPF1s were back ordered when I bought my car. The Motegis are ~17.5# IIRC, so a good bit heavier than the Enkeis. Also, they do require hub rings, which TR provides.

[Briankbot]

Originally Posted by SeanRTR

...are you the one with the Giant rear sway bar that I smashed beers with shortly after we ran at nats?

http://sololive.scca.com/CS.html

That was me and I wouldn't call it "Giant"...

[TMF]

Haven't been in this thread for a while...somehow missed the last email notification of updates.

Anyway, my FRS is out of storage and ready to play! I'm getting it re-aligned today with the new Koni spacers/inserts, and I will post up my results.

Has anyone experimented with toe-in in the rear? I'm tempted to try a hair of toe-in for less oversteer on corner exit and to put down the power better. FYI, I'm on Koni's, TRD springs and bars.

[Biggins]

Originally Posted by TMF

Haven't been in this thread for a while...somehow missed the last email notification of updates.

Anyway, my FRS is out of storage and ready to play! I'm getting it re-aligned today with the new Koni spacers/inserts, and I will post up my results.

Has anyone experimented with toe-in in the rear? I'm tempted to try a hair of toe-in for less oversteer on corner exit and to put down the power better. FYI, I'm on Koni's, TRD springs and bars.

I run a little toe-in rear (1/8) and a little toe-out front (1/8). I like the crisp turn in from the toe-out, but I'm going to go closer to zero or 1/16 toe-in rear this year.

[TMF]

^^thanks for the info.

Here are my alignment results before and after installing the Koni strut hole spacer to bring the Koni's back into compliance.

Before spacer (ignore that it says Impreza outback):



After spacer:



So I only lost about 0.5 degrees of negative camber, which isn't too bad. I'm not sure why the rear negative camber increased...although this time I did have my spare tire removed and the resonated muffler delete installed.

[Locust]

What is everyone's thoughts on running a TRD rear bar, TRD springs, and an aftermarket front bar? I've heard some people say it's better to not run the TRD rear bar with a stiffer front if you're on the TRD springs and I've heard others say run it. A lot of conflicting viewpoints out there...

Right now I don't have the TRD rear on but I have a 22mm Whiteline on the front (set to stiffest) and it's oversteering a bit. Was going to set that 1 softer and add the TRD rear but just wanted to know what everyone's experiences with it were before I do.

[SeanRTR]

Originally Posted by Locust

Right now I don't have the TRD rear on but I have a 22mm Whiteline on the front (set to stiffest) and it's oversteering a bit. Was going to set that 1 softer and add the TRD rear but just wanted to know what everyone's experiences with it were before I do.

I'm pretty sure most cars are running a larger than TRD front, with TRD rear....




However, what you're describing is going to create even more over steer if you going from:
22mm whiteline on stiff and oem rear
to:
22mm whiteline on soft, and TRD rear.....


That's going to create more oversteer.


I have a 22mm Perrin front that I run on soft with TRD rear....balance is pretty perfect. Something seems off with your setup/feedback.

[renfield90]

Originally Posted by SeanRTR

I'm pretty sure most cars are running a larger than TRD front, with TRD rear....




However, what you're describing is going to create even more over steer if you going from:
22mm whiteline on stiff and oem rear
to:
22mm whiteline on soft, and TRD rear.....


That's going to create more oversteer.


I have a 22mm Perrin front that I run on soft with TRD rear....balance is pretty perfect. Something seems off with your setup/feedback.

What Sean said. While I've never run the Whiteline, I have a hard time imagining you're oversteering with a 22mm bar on the stiff setting and an OEM rear.

Where does the car oversteer? Entry, exit, mid corner, in slaloms, everywhere?

[Locust]

Originally Posted by renfield90

What Sean said. While I've never run the Whiteline, I have a hard time imagining you're oversteering with a 22mm bar on the stiff setting and an OEM rear.

Where does the car oversteer? Entry, exit, mid corner, in slaloms, everywhere?

exit / mid corner. Our course didn't have any slaloms this weekend.

[TMF]

Originally Posted by Locust

exit / mid corner. Our course didn't have any slaloms this weekend.

Sean and renfield are correct - decreasing front bar and increasing rear bar will typically induce even more oversteer. Might want to start with the basics and check your tire pressures and strut settings. Decrease rear tire pressure and decrease rear rebound.

This chart is helpful for shock tuning (it's annoying that left and right turns are split up, but you get the idea):



Other option (before changing bars) is to add some rear toe-in. I'm considering adding some rear toe-in, as I also get some corner exit oversteer. I think part of the reason I'm getting corner exit oversteer is because I'm jumping on the throttle too much, too early. It would be nice to be able to just put the power down though.

[JimR]

We do drive a car with non-linear torque delivery and a Torsen that biases to the loaded tire. Adding more rear bar will exaggerate the effect, and mid/exit on throttle is where it's going to be more step-outy.

Before you turn knobs or wrenches, put someone else in the car and see if there is a technique change you can make to drive around it. Many years of continuous sucking at autocross have shown me that many oversteer problems are driver induced.

I came from a floppy Torsen ES Miata, and those are a real crapwagon on exit if you try to ham-fist them. They like slow hands, big arcs, and making the Torsen help turn the car after it's settled into a happy place. With all the TRD stuff and inherent low CG, a FR-S will change direction nicely. Sometimes a more delicate touch is what you need.

[LenA]

Question on front bar for BRZ. Do folks use a stiffer bar to counter the soft springs and use front camber and rebound settings to dial out the understeer the bar added? Or is there other reason for using stiffer bar up front.

Most searches I've done don't talk about rationale for stiffer front bar

Thanks

Len

[drewbot]

Originally Posted by LenA

Question on front bar for BRZ. Do folks use a stiffer bar to counter the soft springs and use front camber and rebound settings to dial out the understeer the bar added? Or is there other reason for using stiffer bar up front.

Most searches I've done don't talk about rationale for stiffer front bar

Thanks

Len

In CS, front camber is very limited. Stiffer front bar is great for the slalom

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