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Discussion Starter #1
Has anybody already played with tire pressures different from stock and what were the results?
 

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I am leaning towards 33/35 street as ANYTHING above 36 is TOO much. At track last week rear got REAL greasey at anything above 38 hot so even on the street 36 cold will yield 39-40 hot on the street. I ran ~30/31 front and ~32 rear cold at LRP to get ~36/38 hot. As it was day 1 that was a ballpark and next time out I will be using a pyrometer.
Car feels quite good on cool mornings where pressures are around 32/34 so I think the ideal range is ~31-33 front and 33-35 rear cold. Just IMHO.
 

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I run my Evora at 35/38 cold, and I find it gives a nice neutral to slight oversteer bias.

Tire wear if anything seems reduced by running slightly higher pressures: I got 12,000 miles out of the original Pirelli rear tires and I'm not at all gentle.

If you do a lot of high-speed driving, you should definitely at least increase the pressures to the high-speed recommendations in the owner's manual. But my experience is that those higher pressures work equally well for around town.
 

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I have to disagree. I was at an SCDA event last week and the speaker was the head developer (engineer) for the new Dyson Prototype. He was scary smart and knew about ALL our cars in detail! We discussed the Evora as it was 1st day on track. When I said ~40 psi hot in pits , he said TOO high. At 40 PSI hot, car was a handful!! Even at 38PSI hot rear end was quite loose. While this is a track v street thing, 40PSI is a constant. What I found in 1 day at track was very similar to what Pobst felt when Motor Trend tested the Evora. Too much pressure makes for an ill handling car.
Tire wear aside, handling IMHO is compromised. No one with a clue ever ran their Elige with greater than stock pressures. Similar car and handling dynamics here. I have engineers guiding me as well as street and track experience to back it up. Also a very infamous Skip Barber instructor with tons of experience in Evoras confirmed my findings last Thursday.
Hethel. start at 38 cold someday and take your usual drive then check hot pressures. I think you'll be shocked! Maybe even over max PSI!
 

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Tire pressure isn't something to play around with. Don't endanger others with your experiments if decide you're going to mess with it anyway..

Tyre Pressures: Tyre Safety - Continental Car Tyres - YouTube
Is this sarcasm?

If not then a guy experimenting with pressures in a reasonable range and under controlled conditions is likely to be safer than a guy just blindly going by the placard.

In fact the video implies one should check wear and consider load to make adjustments from the placard pressure. It doesn't mention temp, because it's aimed at Joe average street driver, and he isn't going to be that meticulous.

The over gist of the video is to check and maintain your tires often instead of never paying any attention to them. And the guy experimenting and adjusting on track is pursuing that goal to far greater lengths than Joe Average is.

With enough experience, I know the limits of grip for my car cruising around town, on a variety of road surface qualities, and depending on time of day and sunshine level. Don't you think that's safer than Joe Average who confirms placard pressure a couple times per year?
 

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Thanks XTN. Squid is at best Joe Average. I'm making comments on direct experience. Maybe Squid also doesn't know that indicated tire pressures on the placard are designed for max loads. How often do we travel with 4 passengers and a boot that is maxed out!
 

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Is this sarcasm?

If not then a guy experimenting with pressures in a reasonable range and under controlled conditions is likely to be safer than a guy just blindly going by the placard.

In fact the video implies one should check wear and consider load to make adjustments from the placard pressure. It doesn't mention temp, because it's aimed at Joe average street driver, and he isn't going to be that meticulous.

The over gist of the video is to check and maintain your tires often instead of never paying any attention to them. And the guy experimenting and adjusting on track is pursuing that goal to far greater lengths than Joe Average is.

With enough experience, I know the limits of grip for my car cruising around town, on a variety of road surface qualities, and depending on time of day and sunshine level. Don't you think that's safer than Joe Average who confirms placard pressure a couple times per year?
No, this is an honest response to the post.

Perhaps more context should have been provided, otherwise I'm assuming he wants to mess with the tire pressures 'for the hell of it', which I don't think is a wise idea.

If he's doing it for racing purposes, ask the guys in the track forums they'll know a lot more about racing than Evora owners.

Knowing what our sports cars are capable of, most owners will a hard corner more often it it than their econobox. Do it the wrong tire pressure can lead to unexpected, and possibly dangerous results (for others).

Am I wrong?


how about I just say, F*ck yeah try 20PSI bro, it'll let you rip into those corners like schuey!!! :)
 

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Squidward you do have valid points. A guy should have a good idea what constitutes a reasonable pressure range to explore within, and a basic understanding of how the handling might be expected to change with pressure changes.

However it is just as likely for an inexperienced driver to ground loop his vehicle at placard pressure as at a few psi either side of it. There will be some limit of adhesion depending on pressure, temperature, rubber compound, road surface, suspension settings, etc., and the inexperienced driver who finds that limit unexpectedly - regardless of his tire pressures - is going for a ride he didn't intend on.

Whether or not you know when to expect that limit and how to keep the car going where you want it to go beyond that limit is not dependant on tire pressures.

So I would re-word your claim by saying that inexperienced drivers charging hard into corners - regardless of tire pressures - are dangerous. These cars are prone to swapping ends quickly when a newbie accidentally exceeds the limit. Did it myself several times when I started out tracking, and that was a controlled environment in which I was carefully trying to find that limit and learn what it feels like.

I'm a lot more nervous around an inexperienced driver with placard pressures yelling ye-haw and throwing the car around an intersection than I am with a guy trying to carefully tune his car for optimal performance performing an educated, thought-out regimen of progressive, repeatable experiments on tire pressure.

And for the record, I've experimented with 20 psi cold, and the car sticks basically as well as it does at higher pressures, at least when compared cold to cold. It just feels less precise. Of course that is only one data point and it's only claimed with regard to my car, my tires, and every other variable that might be said to be a factor.
 

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We've gone thru this stuff for years with our Eliges. Mark Starr etc gave us a great fundamental guide that helped us all get far more out of our cars more readily than we'd have done on our own in a short time. Bottom line, an Elige/Evora with too much tire pressure is NO fun. Randy Pobst found out also.
Again notice its rear pressures that come into play on our hot US roadways
 

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Tire wear aside, handling IMHO is compromised. No one with a clue ever ran their Elige with greater than stock pressures. Similar car and handling dynamics here. I have engineers guiding me as well as street and track experience to back it up. Also a very infamous Skip Barber instructor with tons of experience in Evoras confirmed my findings last Thursday.
Hethel. start at 38 cold someday and take your usual drive then check hot pressures. I think you'll be shocked! Maybe even over max PSI!
Hilariously wrong.

I'll skip the point-by-point and just refer you to page 171 of the owner's manual, where Lotus recommends 40.5psi front and 43.5psi rear (cold, of course) for "high loads and/or speed".
 

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I run 40 rear 38 front. Live in Brisbane so 35 in summer and 20 in winter. Still on the same tyres as new and done 22,000 Kms ride is fine
 

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So I would re-word your claim by saying that inexperienced drivers charging hard into corners - regardless of tire pressures - are dangerous. These cars are prone to swapping ends quickly when a newbie accidentally exceeds the limit. Did it myself several times when I started out tracking, and that was a controlled environment in which I was carefully trying to find that limit and learn what it feels like.
I definitely agree with your comments, xtn. But I'd like to point out that I'm not talking about that guy that goes gung ho balls out without knowing the limits of his car--yeah that's the guy we want to avoid anyway.

I'm talking about the fact that most of us, be it novices with incredibly capable cars, get to know our car's handling better over time. I've driven faster around bends over time without even realizing confidence I've gained in the car's handling. It's just a natural progression for any driver, actually, not just sports car owners. I drove my wifes Jeep like a grandpa today because it was totally foreign to me (lots of body sway and play on the wheel) , but she drives it twice as fast as I do around corners.

What I was cautioning is that if a guy like me were to drastically change my tire pressure from 36 to 20 and then go out and "test" the car's limits assuming the handling will have improved some, and continue to push it, I may find myself in a ditch or worse hurt somebody else. As you stated, unless you're in a controlled environment to do this, you can learn relatively quickly what they are since you will spin out safely once you go over it. I think on that note we are aligned...
 

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Discussion Starter #14 (Edited)
Tire pressure isn't something to play around with. Don't endanger others with your experiments if decide you're going to mess with it anyway..

Tyre Pressures: Tyre Safety - Continental Car Tyres - YouTube
Without having watched the video, I wouldn't believe in anyone's knowledge of driving dynamics who is driving an Audi :p
Besides, nobody is talking about 20psi ... and I would never try to get to the limit if/where exceeding it would endager other people's life.

My experiences with different tire pressure are in accord with brgelise's.

West-of-Hethel: I have driven those high pressures on the track and handling became just awful when tires got hot. My subjective impression was that the contact area got too small and too hot. I let the tires cool down and, following a hint of my instructor, reduced to 30psi (cold, front&rear!) then, and it was just fine for the track.
 

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I spent the first 2500 or so miles at 35/38 (highway, not track). Handling was fine, but wear was not. There is clearly excessive wear in the centers of the tires, consistent with over-inflation. Given the price tag on the P-Zero Corsa's, I'd prefer to avoid over-inflation for this reason alone.
 

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Squidward,

Yes we are aligned except in one detail. I believe if a guy with your experience goes out and pushes the limits until he finds them, it doesn't matter if he is running placard pressures or 20psi. If he's doing it around traffic he might hurt somebody either way.

Playing around with tire pressures is not the dangerous bit.

I strongly suggest you attend at least a couple of HPDE events with good instructors if you plan to continue along your "progression" of being more aggressive. What happens when you find the limit on accident? I humbly - being an HPDE instructor myself - suggest that your tires pressures will not effect the outcome very much.
 

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I spent the first 2500 or so miles at 35/38 (highway, not track). Handling was fine, but wear was not. There is clearly excessive wear in the centers of the tires, consistent with over-inflation. Given the price tag on the P-Zero Corsa's, I'd prefer to avoid over-inflation for this reason alone.
35/38 is not overinflation. And I got 12k miles on the Pirellis in back running them at that level. (Front tires still going strong at 15k, hoping to get 25k or 30k out of them.) But as always, YMMV. :D

Dmpriso, as I said I was talking about around town and on the highway. I make no claims for what track pressures ought to be. But anyway if you already know, why are you asking? ;)
 

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Discussion Starter #18
Because I'm interested in other people's experiences - including yours. :)
 

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Hilariously wrong.

I'll skip the point-by-point and just refer you to page 171 of the owner's manual, where Lotus recommends 40.5psi front and 43.5psi rear (cold, of course) for "high loads and/or speed".
Funny feelings mutual:shrug:

You seem to have a mileage centric viewpoint whilst I have a driver centric viewpoint. Considering the history with Lotus and tire placards I find those high speed / high load numbers comical. I also consider high speed and high load different. Load regardless of driving style generates a lot of heat. You probably generate a lot less heat at 150mph in a straight line than on a road course with an average speed of 75 or so where significant cornering forces are involved.
Might help you understand if you experienced the car at the track v. being like squid and looking at the tire placard like its the bible. (You know-- The Greatest Story Ever Told) Tire mileage is about the last concern I have. On this car when they're ~3 years old they come off as they are degraded. Anyone with OE Yokos on their Eliges still is driving a BIG compromise regardless of pressure.
 

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35/38 is not overinflation. And I got 12k miles on the Pirellis in back running them at that level. (Front tires still going strong at 15k, hoping to get 25k or 30k out of them.) But as always, YMMV. :D
-eek-

Wow, my fronts wear faster than the rears, have not done 10k miles and they won't last more than another 2-3k
 
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