Race Tracking Your Supra - Information exchange

[Rob_SER]

You sure about the alignment? Had it check recently.
And I don’t know that particular track but you can try going softer on your dampening. Some peeps have their cars set way too stiff as they get faster. You could be loosing some contact patch if set too stiff. Bleeding your tire pressures down as the day goes on is equally as important.

Yes or if the track is a little bumpy, if you hit a small bump mid corner with a car too stiff, it can be quite confidence sapping.

Sponsored

 

[jbirdsupra]

Got the Supra out on track for the second time at Laguna Seca. Current mods are Verus camber plates (-3.1, 0 toe & -2.0, .1 toe in), stainless steel brake lines, Hawk DTC60/30 pads, SRF fluid, and RE71RSs in stock sizes on the stock rims. Car feels fantastic on the track despite the stock suspension -- the dampening feels great but the spring rates do feel a bit floaty. I haven't tried any other track pad, but the DTC60/30s performed very well throughout the day and maintained a high level of bite and modulation. Coming from an E92 M3, this car's front end is wayyyy more nimble, but I need to relearn what a tail happy car is. High speed trail braking, and low speed track out almost always kicked the ass out. I ran throughout the day with one click of traction and feel like thats the best way to go. I can't see any need for going fully off quite yet -- I never felt like the car was pulling power or being overly intrusive at any point. Included the Catalyst vid of the PB below (don't mind me screaming when I get it ? ). Looking forward to more track time and continuing to build out this awesome car.

 

[Rob_SER]

I feel like even with one click off, the car is pulling power out of corners sometimes even if the TC light does not turn on.

But for now I'm not confident enough to drive it full off

 

[Illest1Five]

tldr; I'm a novice driver struggling with very abrupt/unpredictable oversteer

Hey guys, I wanted some of you more experienced folks' input here. Earlier in the week, I was at Chuckwalla trying to get a feel for the car after some upgrades/changes I've done over the past few months.

I had a pretty difficult time keeping the Supra composed during medium/high speed corners. The car seems to oversteer way too quickly/abruptly -- I like oversteer, but it feels like the car is on a razors edge once I feel it slip even slightly. I decreased the dampening/rebound a little bit in the rear coilovers to hopefully promote slightly more understeer to balance it out a bit, but it still felt way too unpredictable and twitchy when it'd start to oversteer. I've considered removing my Cusco sway bars and perhaps changing spring rates on my coilovers, but before doing anything too drastic and wasting time, I'd like your input.

Edit: I will absolutely not dismiss the notion or idea that I just don't know how to drive the car with the changes made, driver mod and all that. I have one more track day this year at Buttonwillow and I'm leaning towards keeping the car as is just to get more time with the car and it's setup and make micro adjustments early next year when I'm able to go to the track again.

Perhaps reduce rear dampening/rebound and drop rear 1-3 PSI incrementally to see if it helps reduce rear twitchiness. Some extra .2-.5 rear camber can help with mid-corner grip. I can only imagine how twitchy the rear is w/ 196 N/mm rear + sways. I run Ohlins w/ 140 N/mm rear + 23mm rear bar and I find it pretty snappy.

Similar to you, I've recently switched to coilovers+sway bars+track tires. I'm learning to be more smooth with steering inputs + throttle modulation as the car is much more sensitive to inputs.

I'll be going to Chuck this weekend for the first time. How would you characterize your exp at Chuck vs Buttonwillow/Big Willow/Streets of Willow?

 

[AHP]

Major shudder issues at VIR with the PMU Club Racers. I bedded them on the street and they felt fine. Midway through the first session and they are rattling the car apart. Worse on the 2nd session. Any suggestions before I swap the stock pads and toss these in the dumpster?

 

[Bug2th]

Major shudder issues at VIR with the PMU Club Racers. I bedded them on the street and they felt fine. Midway through the first session and they are rattling the car apart. Worse on the 2nd session. Any suggestions before I swap the stock pads and toss these in the dumpster?

had the same issue. Thought I bedded them too. Took wheels off and looked at rotors and saw regularly spaced black spots in the middle - I just got some fine sandpaper and mildly sanded that area - not even trying to remove the spots as such but next track day didn’t have the shudder. Not sure if this did it or just driving a bit between the track days may have worn the pads in a bit.

 

[AHP]

had the same issue. Thought I bedded them too. Took wheels off and looked at rotors and saw regularly spaced black spots in the middle - I just got some fine sandpaper and mildly sanded that area - not even trying to remove the spots as such but next track day didn’t have the shudder. Not sure if this did it or just driving a bit between the track days may have worn the pads in a bit.

Thanks. There's no heat checking, spots or even smear on the rotor and they are perfectly fine when cold. Once they get some heat they start shuddering and just get worse and worse.. worst pad I've ever run on any car to date. ?

 

[Evolution]

Thanks. There's no heat checking, spots or even smear on the rotor and they are perfectly fine when cold. Once they get some heat they start shuddering and just get worse and worse.. worst pad I've ever run on any car to date. ?

if you didn’t clean the old pad material off the rotors before you bed the pads in, that’s your problem. For whatever reason the pmu don’t play well with other pad material.

 

[AHP]

if you didn’t clean the old pad material off the rotors before you bed the pads in, that’s your problem. For whatever reason the pmu don’t play well with other pad material.

I bedded them hard on the street same as I have for every other track pad I've ever run. Different brands, compounds, etc.. and never a single issue until now. So that alone makes them a shitty option, IMO. I'm not sanding or resurfacing rotors just to run a cheap pad.

 

[Rensuhlo]

@Traxion

 

[Rocksandblues]

I was at VIR last week on Grand course
lol I showed up w Virgin rotors and pads. do NOT try to bed brakes the first session! Should have gone to home track to bed in and I knew it

Had to over drive for second session to get them cut in.

 

[razorlab]

worst pad I've ever run on any car to date. ?

PMU don't do well with other compounds on the rotor so you need to REALLY bed them in. Like if you think they are bed in, bed them in some more.

It's not the pad, the problem is you.

 

[Traxion]

if you didn’t clean the old pad material off the rotors before you bed the pads in, that’s your problem. For whatever reason the pmu don’t play well with other pad material.

I bedded them hard on the street same as I have for every other track pad I've ever run. Different brands, compounds, etc.. and never a single issue until now. So that alone makes them a shitty option, IMO. I'm not sanding or resurfacing rotors just to run a cheap pad.

It's a pad problem with stock software. The car does not like a more aggressive pad. I put on brand new rotors and brand new Pmu Club Racers and had this issue, I believe it's mentioned a few pages ago. The options are currently:

1. deal with it (it is fine overall and braking power is still basically 100%)
2. revert to oem pads
3. wait for someone to fix it

 

[razorlab]

It's a pad problem with stock software. The car does not like a more aggressive pad. I put on brand new rotors and brand new Pmu Club Racers and had this issue, I believe it's mentioned a few pages ago. The options are currently:

1. deal with it (it is fine overall and braking power is still basically 100%)
2. revert to oem pads
3. wait for someone to fix it

I've run:

PMU Club Racers (three sets)
CSG C21
Hawk DTC60

Zero issues like this. 60+ track days.

Programming change helps with other things, but the shudder has nothing to do with it.

 

[Rocksandblues]

I've run:

PMU Club Racers (three sets)
CSG C21
Hawk DTC60

Zero issues like this. 60+ track days.

Programming change helps with other things, but the shudder has nothing to do with it.

What he said x100

Bed in hard. Should be violent process

Sponsored