Starting tire pressure?

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freeform911

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Soooo...just finished my first track day with the supra...what a blast...car is very capable in stock for..
The stock Michelins held up better then I thought they would...
Ran the car for 4-5hrs on track...
Seems 38psi hot was the sweet spot for me...
Still alot of rollover....alot of wear on the outside edges but I'll chalk that up to camber settings....


Like to thank everyone again for the advice...

Steve
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gcmak

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Thanks for sharing your experience. SPL LCAs might be in the cards for me to get that negative camber dialed in...
 

TimM.

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When I ran the OEM Super Sports, and later the Sport Cup 2’s on the stock suspension, I stayed in the 40-42psi range with good success at lowering times and mitigating some outer front treadeear. Rear camber was adequate keep excessive wear in check but the fronts need more camber and I have the SPLparts LCA’s on order too ( in addition to other spl control links).

There seems to be this train-of-thought that lower tire pressures equal improved traction and performance at the track. There is truth to that at the drag strip but not-so-much on a road course (within limits of course)...

TireRack competition tire pressure guide
https://m.tirerack.com/tires/tiretech/techpage.jsp?techid=58

and from “care and feeding of Hoosier R7/A7”... be sure to read the “+Higher pressures...” part highlighted first
155CB056-6968-4C59-9B54-FAE908023DE8.jpeg

The Hoosiers will need much more camber, of course, but the Sport Cup 2’s have survived 4.5hrs of Sears Point and Laguna Seca looking like this at 40-42psi. Sears Point lap times were 1:56-ish, and Laguna was 1:45-ish.
AFE6E083-B121-4486-9160-19ABF526DF7C.jpeg
 
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freeform911

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Thanks for the info TimM....
I think my next time out in April I'll try for around the 40 psi mark...

My tires look similar to your pics maybe a little more wear on the outer edge(on the driverside)..

Definitely needs more front camber but I have no plans on adding any aftermarket parts to add more....
Been down that road a few times and told myself not with this car..haha..

Thanks again
Steve
 

TimM.

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[Thanks for the info TimM....
I think my next time out in April I'll try for around the 40 psi mark...

My tires look similar to your pics maybe a little more wear on the outer edge]

Oh, I should probably add that I didn’t have the Sport Cup 2’s pictured above on OEM wheels. My wider dedicated track wheels certainly helped some to mitigate outer edge wear... not a lot but, some.

I am also trying to keep modifications to the absolute minimum, lol! But since I plan a track day for pretty much every month, I figured additional camber adjustment would save me tire wear and subsequently some cost from tire wear.

4017ADCE-F127-45F5-8CF5-02A664B78487.jpeg
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freeform911

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Oh..I get it..when I has heavy in track days I would mod my car in any way required for better lap times...

I had an 86 911 that started as a mild track rat...then grew to more hard core...I never ran full slicks(to rich for my blood).. the closest I came was running toyo rr a 60 treadwear...

I completely understood r compound cold/hot psi...
But summer tires have me a bit confused...lol..

Btw car looks good on track..
What springs you running?
 

TimM.

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Oh..I get it..when I has heavy in track days I would mod my car in any way required for better lap times...

I had an 86 911 that started as a mild track rat...then grew to more hard core...I never ran full slicks(to rich for my blood).. the closest I came was running toyo rr a 60 treadwear...

I completely understood r compound cold/hot psi...
But summer tires have me a bit confused...lol..

Btw car looks good on track..
What springs you running?
Stock springs and dampers. Only thing I've done is changed fluids, wheels/tires, and brake pads. I ordered several SPL control links mainly so I could adjust camber and I'll be installing them this weekend. I have no intention of changing anything else at this point. Maybe I go with a splitter and wing.
 

gcmak

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Stock springs and dampers. Only thing I've done is changed fluids, wheels/tires, and brake pads. I ordered several SPL control links mainly so I could adjust camber and I'll be installing them this weekend. I have no intention of changing anything else at this point. Maybe I go with a splitter and wing.
hey Tim - you're running the two tracks that are local to me that I have gone to as well. Would you mind sharing the fluids and pads you've swapped to (if you like them?). I'm also thinking after my first day at Laguna I'll be wanting the SPL LCAs for the front camber (not sure if other supporting suspension add-ons will be needed?).

thanks in advance, really learning a lot from this thread as a whole.
 

TimM.

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hey Tim - you're running the two tracks that are local to me that I have gone to as well. Would you mind sharing the fluids and pads you've swapped to (if you like them?). I'm also thinking after my first day at Laguna I'll be wanting the SPL LCAs for the front camber (not sure if other supporting suspension add-ons will be needed?).

thanks in advance, really learning a lot from this thread as a whole.
Regarding the SPL control links, I called SPL directly and asked them what I needed for front and rear camber adjustment... For the front, the front Lower Control Arms for camber adjustment, the sway bar end links for clearance issues created by the LCA’s, and the adjustable caster rod bushings were recommended mostly due to “deflection” caused by soft stock bushings and to maximize desirable additional caster. For the rear, on 2021 Supras rear camber is just ok for 200tw rubber, but for 100tw and lower additional negative camber is needed so the rear upper control links are needed for camber, and the rear toe link with lock-outs is highly advisable because of an OEM adjustment slipping issue, and also to reduce OEM bushing deflection. I’ll be installing these parts this weekend and going to Laguns Seca with TrackMasters Racing March 28th.
C808F5CF-D1A4-4DBF-B317-B7B8816E685D.jpeg

My brake pads have been very good. No fading, powerful stopping the entire session, and they seem to be wearing great so far.
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I use Castrol Edge 0w-20 because it meets the SN and C5 recommendations in addition to other top industry ratings. It’s cheap so while my car is up on jack-stands before and after every track day, I drain and fill with fresh oil... but I wait for filter changes after approximately 3,000 miles.
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Brake fluid is Motul RBF600 and I’m considering going to RBF660 even though RBF600 seems to be adequate. Brake pedal gets a smidge spongy on my hardest efforts.
98F0E501-B403-461A-8D7A-BB15668D6D29.jpeg

for the rear differential, I recommend only premium stuff. For me Royal Purple is locally available. I’ll be changing this roughly every 5,000 miles. The track is BRUTAL on diff oil especially with sticky tires.
FBE1ABAA-D95A-43D4-A2B3-3667889A8A16.jpeg

and last, I haven’t checked the condition of my transmission oil yet but, I plan to do drain-and-fill on a regular interval with Valvoline MaxLife. It is a replacement for ZF8 LifeGuard and passes the Shell 1374 standard ZF8HP transmissions call for specifically.
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I think I covered everything. Come to Laguna Seca March 28th! TrackMasters is a great club. Speed SF is another great club I love running with and lots of Supra’s!
 

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I think I covered everything. Come to Laguna Seca March 28th! TrackMasters is a great club. Speed SF is another great club I love running with and lots of Supra’s!
awesome track! just watch out for those red sausages or i think it's yellow now..:dunno:
 

gcmak

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Regarding the SPL control links, I called SPL directly and asked them what I needed for front and rear camber adjustment... For the front, the front Lower Control Arms for camber adjustment, the sway bar end links for clearance issues created by the LCA’s, and the adjustable caster rod bushings were recommended mostly due to “deflection” caused by soft stock bushings and to maximize desirable additional caster.

I think I covered everything. Come to Laguna Seca March 28th! TrackMasters is a great club. Speed SF is another great club I love running with and lots of Supra’s!
Amazing, thanks so much Tim! This is very comprehensive. Kind of funny (but understandable) that the FLCAs will cause clearance issues requiring new endlinks haha.

Unfortunately end of the month is too soon, I won't have completed my break-in miles before then. I'm waitlisted for April Laguna - so we'll see! People sign up really early this year haha. Maybe I'll try to follow up to see how your day went at the end of the month!
 
 




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