Tire pressure street/track

[Trond]

Hi !

I know the NSX's standard cold tire pressure is 33psi front and 40 rear.

What is normally used on the street and track with 17/18'' or 18/19'' wheels ??

Thanks

Trond.



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92 Honda NSX, Style Auto body kit (fully repainted incl. roof), Bilstein/Comptech suspension, RH AL 8x18/10x19'' rims with 225/40 & 275/30 Yokohama AVS Sport, RM Racing air inlet/exhaust/gearknob, Comptech cat. pipes, Cantrell CF engine cover, Taitec CF mirrors, AP Racing 330mm brake kit (f&r), SoS sway bars, Taitec hub, SoS CF brake air ducts, Momo steering wheel, DC Sports headers.

 

[MvM]

I have 17" wheels with 215/40ZR17 in front and 18" wheels with 265/35ZR18 rear.
Have just replaced all my tires and am running 2.3 bar in front and 2.8 bar in the rear. Have not yet seriously tried any other pressures yet but am certainly planning to try a bit lower pressures (like 2.1 front /2.6 rear).

 

[Gerard van Santen]

Originally posted by Trond:
Hi !

I know the NSX's standard cold tire pressure is 33psi front and 40 rear.

What is normally used on the street and track with 17/18'' or 18/19'' wheels ??

Thanks

Trond.

That depends if you use slick tires for track or street tires. For the the track you normally use a pressure of 32 PSI (HOT) that means 23 PSI(Cold) Front tires and 34 PSI (HOT) and 25 PSI (Cold) for the rear tires.

I you use street tires for track use, you need
39 PSI (Cold) for front and 43 PSI (Cold) for the rear tires. Street tires need more pressure because of the softer sidewalls.

Under rainconditions you go at least 2 PSI lower, to make the tires to come under racing temperatures earlier. Although some people say you must ad more PSI to make more use of the grooves of the tires (I mean under rainconditions).

You have to practice yourself, because pressure does also affects under or oversteer.

Have luck,
Gerard

 

[j14nsx]

Gerard,

Your pressures you mention for the street tires seem very high. I have been recommended to use lower pressures. I only have the 15/16 A022s, is this why?

 

[Gerard van Santen]

Originally posted by j14nsx:
Gerard,

Your pressures you mention for the street tires seem very high. I have been recommended to use lower pressures. I only have the 15/16 A022s, is this why?

The reason why you need this high pressure, is because of the weaker sidewalls in comparising to slick tires. If you go lower on pressure with street tires the temperature will go up because of air moving in the tire (street tires have a weaker construction than slick race tires, because of comfort and so on). This can cause overheating the tire with all the consequentes of this (disrupting the tire).

The lower the tire (I mean the sidewalls) the less you have to go up with your pressure. As you are using OEM wheels and tires with high sidewalls, I should think of going up with your pressure and not going down.

Gerard

[This message has been edited by Gerard van Santen (edited 10 September 2002).]

 

[MvM]

Gerard,
I was thinking about lowering my tire pressure a bit for more grip on the road (not for track) but if I understand you correctly it would be better not to do this.

 

[Gerard van Santen]

Originally posted by MvM:
Gerard,
I was thinking about lowering my tire pressure a bit for more grip on the road (not for track) but if I understand you correctly it would be better not to do this.

Maarten,

You doesn't get more grip lowering your pressure. It only effects your under- oversteer characteristics and if you go to low on pressure you'll risk a flat tire (but we all know you know all about that).

I suggest to keep the OEM pressure for road use and go a little up (0.3 to 0.5 bar) when using street tires for track use under dry conditions and lower a bit when you drive on track under wet conditions to make the air temperature in the tire go up.

Gerard

 

[MvM]

Gerard,

but we all know you know all about that...
;-) O yes, I do know about that now. Don't worry.

Thanks for the expo. With default pressures allround the cars feels lighter in the front now than before but I'm getting used to it.
I keep those pressures as there are right now.

 

[Trond]

I changed back to default pressures myself some days ago. The car is definitely "lighter" in the front.

Seems some of the US guys prefer lower pressures on the track. I will start with 35/40 on Saturdays track event, as I felt default was too low last time I really pushed the car.

I will have to use my street Yoko AVS Sport on the track - at least one more time

Trond.

 

[Trond]

My experiences as an almost newbie tracker:

Did this weekends track event with default pressures 33/40 Psi (cold). Set my Comptech sway bars to middle front and soft rear, and got the most neutral handling car I've ever driven. Did about 40-45 laps I guess.
However I still felt my pressure was too low, because of the sidewall giving in under pressure.
I am recommended to use both higher and lower pressures than default, so I guess I'll have to test both, to see what suits my driving style.

The Comptech sway bars made an incredible difference in body roll from my last event with OEM ones. I still have to buy the metal collars to secure the bars from moving, if that can make my car even more stable.

(With my rear sway at middle position I felt I got to much oversteer when pushing the car on the street.)

AP Racing brakes from SoS also made an incredible difference over OEM. Highly recommended, and felt like a perfect front/rear combination.

Only problem - not enough power

(and 2. gear too long for a couple of the turns)

Anyone interested in Basch SC, and a joint installation session somewhere in Europe ??

Trond.