Race Tracking Your Supra - Information exchange

[visbits]

Alignment, alignment, alignment, alignment. Of course, this takes into account all your bushings and such are in good condition as well.

We've already been discussing this with @Rensuhlo in another setting but I figured I would make this post for informative and discussion reasons here.

Here are some samples of tire wear from my personal supra that is tracked 95% of it's working time and is driven to/from the track. The other 5% is street driving for fun or data logging purposes.

Alignment and relevant modifications:

Front
-3.9 camber
0 toe
Turner caster spherical bushings in OEM caster arms
Verkline LCA
SPL tie rod ends
SPL endlinks
Vorshit camber plates
MCS 2WNR 650lb springs

Rear
-2.5 camber
3mm total toe in
SPL toe arms
SPL traction arms
MCS 2WNR 600lb springs (true coilover)

Are you running 18x11 square setup on your car?

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[razorlab]

Are you running 18x11 square setup on your car?

All my track wheel sets are square.

 

[Todday1]

Thanks for sharing set up. I am interested in what everyone thinks is best on toe. I have been running about 1/8th total toe out in front and then 1/8th total toe in, in rear. I have tried 0 in front but slight toe out seems to help on turn in and minimize understeer in the off camber tight turns. Others had suggested to keep the toe out in front but go to zero in rear. All this is very fine tuning but I am curious what others think works the best.

 

[Rob_SER]

anybody gets rear-end instability under hard braking braking?

Do most of you run less agressive brake pads in the rear than the front?

 

[tomfree]

anybody gets rear-end instability under hard braking braking?

Do most of you run less agressive brake pads in the rear than the front?

Yes, I do get the rear end bouncing around a little under hard braking *

The * part - There's a whole lot of "It depends" going on here. The surface has a bunch to do with it - if it's a little bumpy, I can have the wheel straight in the braking zone and still have a little movement. If the surface is smooth, the back end is light (yay physics), but not moving around.

I run track brake compounds on front and rear. Was running CSG for both, but now Pagid RSL29 front and CSG 11 rear. Probably not an ideal mix of compounds.

 

[Evolution]

Looks like I will soon to be joining the holy hood group!

 

[razorlab]

Others had suggested to keep the toe out in front but go to zero in rear.

That is a good recipe for the car to swap ends when sneezing.

anybody gets rear-end instability under hard braking braking?

Do most of you run less agressive brake pads in the rear than the front?

Yes. Almost all of that went away when I added aero. The brake pressure is dynamic so adding different pad friction in the rear won't make a huge difference because the system will compensate. Unless...

Changing brake coding also helps with this. The factory coding has some "interesting" strategies.

 

[Rob_SER]

What's going on with that super secret brake coding update?

 

[Nugs]

What's going on with that super secret brake coding update?

Also keen to know this.

 

[Rocksandblues]

if it wasn't secret, everyone would have it.
very very few need it.

It radically alters the braking program which has its own very serious implications and risks.

 

[FLtrackdays]

Thanks for sharing set up. I am interested in what everyone thinks is best on toe. I have been running about 1/8th total toe out in front and then 1/8th total toe in, in rear. I have tried 0 in front but slight toe out seems to help on turn in and minimize understeer in the off camber tight turns. Others had suggested to keep the toe out in front but go to zero in rear. All this is very fine tuning but I am curious what others think works the best.

I’m with a similar setup. Just a pinch toe out up front (or neutral) and slight toe in on the rear. Any deviation from that and the car doesn’t feel/do as well for me. Especially at Sebring.

anybody gets rear-end instability under hard braking braking?

Do most of you run less agressive brake pads in the rear than the front?

Hawk DTC30s have plenty of rear bite for me. You don’t want too much bite in the back.

There is a huge weight transfer from rear to front, increasing front end load, giving less rear tire grip. W/out a wang, I have even less rear downforce, traction and braking capability. Thus less aggressive rear pads helps maintain proper brake balance and stability. I found out even more so in my S2K that would loose ABS from time to time. Less weight on the rear tires, with Hawk DTC70s all around would cause the rear wheels to lock up way more easily. That’s an extreme. Regardless, too much rear pad can lead to less control.

 

[racebuild]

if it wasn't secret, everyone would have it.
very very few need it.

It radically alters the braking program which has its own very serious implications and risks.

I wouldn’t say the changes are radical. It gets rid of the braking system “nannys”, in turn you get more consistent pedal pressure at the track. However there are associated risk with the coding if you’re driving on the street… i.e. Emergency braking is no longer active.

 

[razorlab]

However there are associated risk with the coding if you’re driving on the street… i.e. Emergency braking is no longer active.

Bruh, back in the day, we did emergency braking like a man, uphill both ways, in the snow.

 

[Nugs]

I wouldn’t say the changes are radical. It gets rid of the braking system “nannys”, in turn you get more consistent pedal pressure at the track. However there are associated risk with the coding if you’re driving on the street… i.e. Emergency braking is no longer active.

Keen!
Mine definitely has some inconsistency that I've struggled to explain with hardware.

 

[racebuild]

Bruh, back in the day, we did emergency braking like a man, uphill both ways, in the snow.

Agreed. Back in the day we didn’t have to deal with retarded pronouns either.. but here we are.

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