mx5cartalk.com

Hey,

So everyone is saying on the forum play with your tyre pressures and alignment, to get the most fun out of the car.

What do people say we should be running at?

What tyre pressure's do you run, and in what environment?

I'm running 195x50x15 on 15x8s

I was running 34psi cold and gone up to 40psi this week, to see how it goes

195/50 Yoko s Drives on 15x7's 32psi all round,good for spirited road driving.Anything more is too harsh with my suspension set up and on roads with bumps(unlike a smooth track) higher pressures result in too much bounce and less grip.

Peter

205/50/16 Bridgestone Adrenalines. 30 PSI cold, I have never bothered playing with the pressures on track; the tyres get greasy before pressures come in to play and they only creep up to around 35 PSI anyway. Anything less than 30PSI and they are all baggy and wooly feeling.

I dont think anyone will advise running 40 PSI but it depends on your tyres, if they have a very soft sidewall then you would need a higher pressure to try and keep them propped up.

195 stretched over an 8" rim

You don't need a high pressure to control tyre wall flex 'cause you won't have any.

I'd run them around 29psi and as pcmx5 says get less bounce and more grip.

For the NA series 1, your tires are part of the suspension, to get a little forgiveness to the ride, 26 psi is the factory recomendation for standard rim and tire size.
This is part of the set up, because the front and rear suspension dont have enough travel and bottom out on the overhard factory bump stops, which are not just there to protect the shock absorber but are part of the suspension design and you are actually ment to ride on the bump stops under certain cornering and road conditions.
The NA series 2 tried to give more travel to the suspension by increasing the height of the top hats.
If you put low profile tires on 17 inch rims and run them at 32 psi, you are going to get a sore backside.
Unless you are tunning up the car for a fast lap at the track, you want to try and find a nice lower pressure, that feels ok.

28psi on 195/50r15 Adrenalins for day-to-day running. I might put them up to 32 for long trips and trade grip and comfort for better fuel consumption.

Charlie Brown wrote:195 stretched over an 8" rim

+1!

don't see under-tyring much - usually over-tyring.

damn i droped them down to 30psi for a mountain run for the weekend, and all I can say is that it is a massive differance with a good alignment and tyres pressures and new tyres... can't wait to take this car down to GOR, and to Yarra valley for some good runs

I generally run higher pressures (33 - 36psi cold) on the street with my 205/50/15 Toyo T1Rs on a 15x7 rim as it gives a more responsive feel to the sloppy sidewalls.

However I have found on the track that this does not generate the most grip and they perform better at ~32 - 34psi hot, which is probably around 28psi cold. Next time on the track I may even go a bit lower and see how they go.

So it really depends on what you're after. Do you want outright grip, better feel/responsiveness, better fuel economy, wet weather performance, etc. It's always a compromise and what works for one tyre brand, tyre size or wheel size combination won't necessarily be the best for another.

If it's just for the street I'd probably go for better feel, which may or may not be a higher pressure, depending on the construction of the tyre.

If it's for the track I'd talk to people running the same or similar tyres who are quick, and test test test! If it's faster on the stopwatch, heat and wear issues aside, that's really all that matters.

40psi does seem very high though, particularly with that tyre size/wheel size combination, as others have pointed out.

Lately I'm running 28 psi cold on 195/50/15's, doesn't feel sloppy & the car doesn't skip around too much. When I had them at 32 psi & higher the car was too skittish & unstable on the crap roads in metro SA, felt like it had no grip.

I have stock standard 14" on my NA6 and find the difference between 26psi cold and 28psi cold remarkable. I run them at 28psi. Of course, my worn bushes would contribute to the sloppier feeling at 26psi. The difference is about 7% in pressure so although 2psi doesn't sound like much...

205/50 R888 on 15X7 rims, I run them at 24psi cold on the track and 28psi cold on the street. They get up to around 28-30 psi hot on the track.

Reviving an old thread to see what people are running these days.

I started with 36 PSI and felt like it should have more grip. I run 32 PSI cold - 205s 595 RSR on 15x7 RPF01s and it provides me great grip.

I'm thinking of going down to 29 psi cold.

Any one else with 205 595 rsr on 15x7s have other favourite pressures for track and street?

yeah 205/50/15 595 RSR on 15x7, i use 28 psi cold. This seems to create wear over the whole tread face when at the dirt track, higher was showing evidence o the edges of the tread face not really doing anything.

Tried 36 once, seemed to make the car very happy to swap ends with no warning.

Got both an NA and an NB8A - both run Kumho KU36 tyres

NB both on track and road runs 36psi cold - 15 x 7.5 6UL's
NA runs 34psi cold and only used for road, not tracked

For the record the NB has done over 20,000kms on this set and of that over 600 laps have been done at both Queensland Raceway and Lakeside, all tyres still on their original corners, never rotated. I could get another 2 meets out of them but will change for 2014 and pass them down to a friend who has a dedicated track car in a Corolla GTi