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Old 01-12-2018, 11:09 PM   #1
Tim202
 
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RE-71R Auto-X Pressures

Getting my RE-71R's put on tomorrow (305 square) and was wondering what pressures people running 305's for both street and auto-x are? Trying to get a baseline starting point.
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Old 01-13-2018, 02:47 PM   #2
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Sweeet.

Use some chalk or white shoe polish to see how much you are rolling over. I start a wee bit high, like 38 psi HOT(mebbe 36 psi before first run). A lot of tires have arrow markers on the sidewall that will tell you if you are flexing too much. I will knock it down 1-2 psi per run until either the car starts to feel greasy or I see fresh scuffs creeping onto the top of the sidewall from the shoulder. Then I back go up 1-2 psi from that point and look at tire temps to evaluate alignment.

I ran 40 psi up front last season on the normal shmormal goodyear eagles to keep the tire churning around hairpins. The rears were maybe 36.

RE-71s are stiffer, you will probably end up running much lower pressures, especially if you have a good dose of negative camber.

YMMV, just my own experience, I'm sure there are better ways to optimise pressures.

Good luck this upcoming season! May I ask your wheel specs? I'm planning a 305 square setup too...
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Old 01-13-2018, 04:14 PM   #3
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Quote:
Originally Posted by Tim202 View Post
Getting my RE-71R's put on tomorrow (305 square) and was wondering what pressures people running 305's for both street and auto-x are? Trying to get a baseline starting point.
I start off at 28 cold and then bleed off to 35 after the first run. Depending on how many runs you have it should level off to where you don’t have to bleed anymore air off. I do this for both track and autox.
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Old 01-13-2018, 07:01 PM   #4
ICTsccaCamaro
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Fast FS drivers have been running extremely low tire pressure with RE71's. On my 5th gen 1LE I was running hot auto cross pressures of 30PSI front and 26PSI rear with 305 RE71's this was copy catting the set up of a national level driver that was nice enough to let me know his shock settings, alignment and tire pressures. The tires at low pressure have an extreme amount of grip but you are sacrificing extremely accelerated side wall and edge tire wear with the low pressures but when every 10th or 100th of a second counts at a national level event you don't care about treadwear.
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Old 01-13-2018, 08:10 PM   #5
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How's is the 1LE handling with a square 305 setup? Reduces understeer or what?

Are you running the same wheel size front and rear so you can rotate them?
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Old 01-13-2018, 11:04 PM   #6
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30 psi.
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Old 01-14-2018, 03:05 AM   #7
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I have the same set up for street and autox, street I run 32 psi and for autox I run 27 psi.
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Old 01-14-2018, 07:58 AM   #8
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Quote:
Originally Posted by ICTsccaCamaro View Post
Fast FS drivers have been running extremely low tire pressure with RE71's. On my 5th gen 1LE I was running hot auto cross pressures of 30PSI front and 26PSI rear with 305 RE71's this was copy catting the set up of a national level driver that was nice enough to let me know his shock settings, alignment and tire pressures.
I'm surprised that more people aren't staggering tire pressures at least a little - including for their street driving. Especially with a car as cornering-focused as anything with '1LE' in its name.


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Old 01-14-2018, 10:41 AM   #9
Tim202
 
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Quote:
Originally Posted by HyperspaceTurd View Post
May I ask your wheel specs? I'm planning a 305 square setup too...
I have the factory ZL1 1LE wheels (19x11 front & 19X12 rear)

Quote:
Originally Posted by carguy55 View Post
How's is the 1LE handling with a square 305 setup? Reduces understeer or what?

Are you running the same wheel size front and rear so you can rotate them?
Running same wheel size because (and this may prove to be dumb, I have yet to compete in first event this year) I don't want to lose any grip in the front, and Bridgestone doesn't make the 71R any wider than 305 so I'm stuck with that for the rear too.
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Old 01-14-2018, 10:51 AM   #10
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Thanks everyone for the inputs. After I got them put on yesterday, the installer had them set at 37-38 PSI and I reduced them to 32 after I got home. I did a little spirited driving on the streets (I know, not the brightest thing to do) but after a couple hard turns I noticed the scuffing was just starting to reach the little arrow markers on the front. Now that I think of it I wasn't smart enough to check the rears, but can do that next time I head out somewhere.

A few other notes. These tires are LOUD compared to the factory Eagle F1 Supercar 3Rs. Not that I mind, I don't, but just noticed it.

These tire have way more starting/cold grip than the 3R's. Before, when entering most onramps, 1/2 throttle would spin up the rears, but not with the 71R's.

Looking forward to a good auto-x season this year.
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Old 01-14-2018, 11:52 AM   #11
ICTsccaCamaro
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I plan on killing my 3R's and then swapping onto 305 RE71's before solo nationals this year.
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Old 01-14-2018, 11:54 AM   #12
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33 front, 28-30 rear depending on balance on 275 square RE71R in F-Street trim.

I've been running about the same on 315/30-18 Rival-S. I'll have 305 square RE71 on the car for at least part of this season, I expect it to be within 2 lbs.
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Old 01-14-2018, 03:00 PM   #13
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Quote:
Originally Posted by ICTsccaCamaro View Post
I plan on killing my 3R's and then swapping onto 305 RE71's before solo nationals this year.
I'm saving what's left of my 3R's for when I get to an actual track.
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