Tyre pressure for Uniroyal Rainsport 3's

Tyre pressure for Uniroyal Rainsport 3's

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Discussion

black_potato

Original Poster:

282 posts

239 months

Friday 2nd February 2018
quotequote all
I'd be curious to know what pressures people have tried and their experience of these tyres.

When originally fitted they came at something like 35PSI and not having checked them at the time they felt pretty good in what was in effect a blind test pressure wise.

Since then I was advised to drop the pressure to 24PSI all around by "somebody in the know" and now the car feels pretty squirmy and less positive, especially under acceleration which I can only assume is down to sidewall flex. So my current thinking is to ~30 PSI front and rear and see how that works out.

What have others experienced are and what have you found the best pressures are with these ?

black_potato

Original Poster:

282 posts

239 months

Friday 2nd February 2018
quotequote all
Thanks for that. Its interesting to know everybody else is wrong. rolleyesrolleyes

black_potato

Original Poster:

282 posts

239 months

Monday 5th February 2018
quotequote all
Interesting you had the same experience. I think that's where I will likely end up. I pushed them up to 26 PSI all around and it felt better, still need to play a bit more with the pressures, damper settings and rear ARB...

Whilst I was jesting a little in my last post its key to appreciate that different tyres require different pressures to operate well, it often isn't just a case of reading the handbook as that was based on the tyres we originally sold the car with (what ever they were). I'm not surprised the ADO8R work at that pressure though, they will have very stiff sidewalls. The RS3's though are pretty soft in the side wall so may well want a bit more.

Anyway, You can all laugh at me when I leave the road backwards into a hedge !

black_potato

Original Poster:

282 posts

239 months

Wednesday 7th February 2018
quotequote all
And...

Compound
Geometry
Suspension rate
Spring rate
Bush material and age
ARB stiffness
Intended use
Driving style
Weather


I'm sure there are a few others that are escaping me

black_potato

Original Poster:

282 posts

239 months

Wednesday 7th February 2018
quotequote all
No I'm not "a great expert" but I have have Tracked/Sprinted/Raced cars for several years so I have some practical understanding that suggests it is more complex than the 3 dimensions you suggest. I was (and still am) interested to see what pressures people were running, if they had played around with them and what the results are as my experience is questioning what I'm being told.

Relax soapboxdrink

black_potato

Original Poster:

282 posts

239 months

Wednesday 7th February 2018
quotequote all
The track stuff is in the past, at least for now and if i do get the hankering its more likely id take he lotus.

I have no plan to take the Griff on track although having a play at the limit at an airfield activity day would be fun.

The plan at the moment is just to get the planted feel on the road and good manners over bumps and in the wet for my summer road trip. At the moment i want to get a few bits refreshed that have a little play and then try and balance the damping and tyre pressure. I also think the Nitrons could do with a service but i have yet to play with them in a bid to confirm that. Its actually quite hard without much knowledge or reference for the car which after all considers it chassis a ls a big spring !

black_potato

Original Poster:

282 posts

239 months

Wednesday 7th February 2018
quotequote all
Thanks, that all makes sense.

I had the basic alignment checked when I had the tyres fitted and the front was out quite a bit so I had it corrected, the rear was close to spec.

I think the ride height and front splitter ( assume this is the spoiler here https://www.racetechdirect.co.uk/car-parts/body-tr... are both a good call.

A full alignment and corner weight will happen but I want to get it all nice and tight first as if you have play in things it just isnt worth the money.


black_potato

Original Poster:

282 posts

239 months

Friday 9th February 2018
quotequote all
griffdude said:
A lot of guys use Rainsports in various speed championships, the consensus is to increase the pressure as you say, by 4-6 psi dry, 6-8 wet. Oh & most have ditched the rear ARB.
Useful info.. thanks thumbup