Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB

Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB (https://www.ft86club.com/forums/index.php)
-   Tracking / Autocross / HPDE / Drifting (https://www.ft86club.com/forums/forumdisplay.php?f=39)
-   -   making the car turn!! (https://www.ft86club.com/forums/showthread.php?t=91303)

puma 07-08-2015 03:57 PM

making the car turn!!
 
asking the experts here, what would you do to the setup if the driver complains that the car pushes too much in the slow corner like in the hairpins.


Our car is fast in the fast curves but we cant keep up with the other two fast cars in the serie in the slow corner.


My driver is coming from a FWD so he is used to get a car that rotates really well which doesnt seem to work with this one.


It seems like the nose is too heavy for the rear, all the weight that was removed was in the back and we added a supercharger in the front which makes thing worst.


we tried a lot of different alignment, tire pressure and shock adjustment but haven't been able to nail it yet so i taught i would ask here what you guys do. One opponent with a Genesis is much faster than us in the slow corner si it is not a fwd rwd thing.


By the way, we run on extremely cheap 300 threadwear tires, don' ask, that is how the serie is made.


thanks

King Tut 07-08-2015 04:17 PM

My suggestion would be soften the front sway bar or stiffen the rear sway bar. It will probably affect your mid and high speed cornering as well, so you will need to adjust your aero again.

juliog 07-08-2015 04:20 PM

Videos?

Jawnathin 07-08-2015 04:24 PM

Are you running a square or staggered tire setup?

Is the understeer on corner entry or corner exit?

7thgear 07-08-2015 04:30 PM

Quote:

Originally Posted by puma (Post 2314132)
we tried a lot of different alignment, tire pressure and shock adjustment but haven't been able to nail it yet so i taught i would ask here what you guys do.


maybe you should post the chronological order of things you did so that you wouldn't get a bunch of people telling you to try something you already tried.

puma 07-08-2015 04:46 PM

right i agree, well we went from 500# springs to 400# because the last track we raced at is extremely bad and the tires have no grip what so ever. We are thinking about going stiffer in the rear but it seems counterintuive compared to what other people do on the forum.

swaybars are stock but we tried with and without a rear one and didn't help much. we tried every tire pressure from 30 to 40. We also tried to add toe out both in front and in the rear and didn't help much, i beleive in the end we were like 2mm toe out in front and 2mm toe in in the rear on each side.

We tried 2,5 deg camber up front and than 3,5 deg, a little better but still not as we want.

This is what i am thinking for now, we don't have an aftermarket LSD, i don't know if that would change something or make things worst

puma 07-08-2015 04:47 PM

Quote:

Originally Posted by King Tut (Post 2314167)
My suggestion would be soften the front sway bar or stiffen the rear sway bar. It will probably affect your mid and high speed cornering as well, so you will need to adjust your aero again.

yeah we didn't try to unhook the front swaybar, it rides well in fast corners so was afraid to mess it up but it might be something we could try. Otherwise we would need to get some adjustable ones and play with those.

puma 07-08-2015 04:49 PM

Quote:

Originally Posted by Jawnathin (Post 2314180)
Are you running a square or staggered tire setup?

Is the understeer on corner entry or corner exit?

we are running square 245/40/17, with such low grip tires we try to use as much patch as we can, our only other option is 225/45/17.

I would say understeer is in the middle of the corner or maybe more towards exit. It only happens in hairpin or very sharp type of curves and the last track had a lot of those.

CSG Mike 07-08-2015 04:50 PM

Can't help without videos or data, and specifics on your setup...

King Tut 07-08-2015 04:53 PM

Quote:

Originally Posted by puma (Post 2314220)
yeah we didn't try to unhook the front swaybar, it rides well in fast corners so was afraid to mess it up but it might be something we could try. Otherwise we would need to get some adjustable ones and play with those.

You definitely need adjustable ones. They are the easiest way to tune a car quickly at the track. Unhooking the rear bar should have only made it worse. In the series I run in the rear sway bar is basically the only adjustable piece we are allowed other than alignment adjustments.

wparsons 07-08-2015 05:01 PM

You've mentioned front spring rates and camber, what about the rear?

What gear is the driver in, and what speed?

Racecomp Engineering 07-08-2015 05:06 PM

More caster. (#1 thought)
Stiffer rear compression damping.
Softer front rebound.
Raise the rear of the car slightly.

I would use a rear adjustable swaybar for sure.

A better rear LSD would help as well especially if your problems are from mid-corner to exit. But are a little bit of money.

Do 1 change at a time (especially if the car is good the rest of the time like you said).

Understeer in very tight slow corners with those low-grip tires isn't too surprising but is easily fixable with a little tuning.

- Andy

Racecomp Engineering 07-08-2015 05:10 PM

BTW if the driver is coming from a fast FWD racecar that I assume is extremely loose on entry (as those platforms should be), then there may be some driver adjustment as he adapts to a different RWD platform. It sounds like your results are still very good so I wouldn't get too drastic with changes.

- Andy

solort 07-08-2015 06:14 PM

Give the car some toe out in the front and especially toe out in back and it will turn in AND rotate better. Maybe too well....


All times are GMT -4. The time now is 09:21 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, vBulletin Solutions Inc.
User Alert System provided by Advanced User Tagging v3.3.0 (Lite) - vBulletin Mods & Addons Copyright © 2025 DragonByte Technologies Ltd.


Garage vBulletin Plugins by Drive Thru Online, Inc.