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Triumph TR6 - Tire pressures?

Hi!

I suppose this would have been discussed at some point, I just could not find any good posts even in the archives?

What kind of tire pressures are you guys using?

I'm running 205/70-15 on standard wheels. Someone ones told me to use a little more pressure in these tires as they are newer & bigger than stock, so I am currentlu running 23 and 27 as opposed to the 20/24 recommended in the manual for the factory tires. Sometimes the car feels a little unstable in high speed cornering, and I was thinking that maybe I shloud just use 20/24. I suppoise it is a trial and error process to find the most suitable pressures, but I'm still curious about what others are running!

I'm also a bit uncertain about the tire pressure "theory". Less pressure = more grip&more wear, more pressure=less grip&wear? (within reasonable limits of course!)

SR
SignalRed

With the 205/70-15 tires, I have been running in the 24/25 front and 28/29 rear ranges. This gives me good stability, yet enough pressure to resist tire corner roll in somewhat more spirited driving conditions. I wouldn't think that going up 3 psi at all corners should give you a problem. How is your alignment set up? What kind of shape are your suspension components in? What kind of tires and what is the speed rating? And finally, what are you comparing it against? Remember that to a large extent, these are still old crocks running the very best of late fifties, early sixties technology (other than the tires) so comparing to a rather late model car can leave the wrong impression.

When I used to autocross the TR6, depending on conditions I have run as high as 36 psi at all corners with 205/50-15 tires.
Stevep

This has been touched upon previously but it bears repeating.

TR6 stock wheels have centers that won't stand hard use especially with larger than stock tires fitted.

I have personally seen cracked centers on stock TR6 wheels that were fitted with large tires.

Just something to think about.

hth,

Jim
Jim Deatsch

Tire pressure should vary with the weather conditions, driving style and type of tire.

It surprised me when at my first pre-race 'orientation', it was suggested to increase the pressure 3-5psi in wet conditions. It was explained that water on the road will deform the centre of the tire making it concave with a resultant loss of contact with the road (aquaplaning). The more pressure, the less the deformation.

Day to day, I have 30 up front (where the weight is) and 28 rear (set cold @ about 15-20C).

R
Roger H

But Roger, what is that in MPa for the fully metricated folks?
SteveP

Hi SteveP - I thought it was sacrilege to talk in metric about our LBC's ;-) - old habits die hard, but for those young'uns among us, 1psi=6.895kPa.

(Here's a handy link for stuff like that http://www.convert-me.com/en/ )

Cheers (in pints!)

R

Roger H

Steve,
took your advise and put the tire presures up from
20F/24R to 26F/30R. Better cornering,better mileage.
Thanks,
Chris
Christopher Trace

Hi everyone! Hope I can contribute to the discussion.
The air pressure in the tire holds up the weight of the car so if the tire is wider but the same profile it will hold more air and need less pressure. As you have lower profile tires of greater width it is a bit difficult to know the total volume of air in the tire, but you may be able to look it up or find a formula to calculate it on the internet.

The differential between front and back tires is due in part to the manufacturer making sure a safe amount of understeer (front end pushing wide) is built into the cars handling. Also the pressures specified by the manufacturer will be biased somewhat towards a softer ride at the expense of grip, so for better grip and steering response increase pressures a moderate amount and reduce the difference front to back. Chris is also right that this may give a reduction in roling resistance so better gas mileage.

Simon.
Simon Rasmussen

This thread was discussed between 10/08/2004 and 17/08/2004

Triumph TR6 index

This thread is from the archive. The Live Triumph TR6 BBS is active now.