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Rob Clarke

TR4 Tyre Pressures

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On a standard roadgoing TR4 with live axle I always favour a higher front wheel tyre pressure.

Says Mik

 

Stuarts mentioned 195s

 

I run 205,s on 7 inchers

and frunts ive fun oot are best at 40

this stops outer edges wearing away wid cornerings forces

even wid 2 deg neg camber

rears are 30-32 wid 2 deg neg

 

granted its a GT, but just to show, diff tyres, diff rims and some ones own prefference

shows tyre pressures are very subjective

as thee,s bear no relation ship to standard set ups

 

M

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The logic seemed to be that some at least of our North American friends were undiscerning when it came to handling, and that the 'bigger is better' cosmetic view prevailed, along with the greater ride comfort offered by the larger dimension rubber . . . . .

 

Cheers,

 

Alec

 

I think i'm right in saying that TR's were often exported on a larger tyre. I would suggest that this was an easy way of giving slightly longer legs and lower revs at cruising speeds, and they were prepared to sacrafice the handling to give a larger diameter tyre. what they didn't do is go low profile.

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Ok, lots of views about tire pressures and anti roll bars, thank you all. The only mod I was intending to make to the suspension on my TR4 (still in a million bits) was to fit a front anti roll bar and leave everything else as standard. Reasons being; a) I am tight, B) I have read in books that the first and probably best mod is to fit the front arb, c) I am not an experienced TR driver, so wanted to find out what the car is like in its raw form before I started on the modifying / upgrading road, d) they fitted a front arb to the TR6 (& TR5?), and e) the factory found it was a good mod in their 62 & 63 rally cars and offered it as an upgrade.

 

Having said all that - is in now current wisdom to bin the front arb and leave the suspebnsion alone?

 

Cheers,

Rob

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Drive it first Rob before ordering or making a decision. The TR 5 and 6 you may have noticed have independent rear suspension which make them handle differently from a live axle TR4.

 

It's easy to do when the cars on the road and as somebody who's raced a TR4 I'd never fit just a front anti roll bar without a rear one to keep the car balanced otherwise the normal TR4 drive stance of under steer will be transformed to UNDERSTEER.

 

Mick Richards

Edited by Motorsport Mickey

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Cheers Mick,

I will try it first, as nature intended, no arb. Will see how it handles and mod from there to suit my driving.

Thanks,

Rob

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What i know about tyre pressure is that testing is the answer to getting the pressure right for you. and the good news is; it's free

 

less pressure gives comfort and (sort of) grip, ie less wheel spin.

 

Higher pressure improves directional stability more progressive predictable handling.

 

but it is a balance, so if you have too much understeer, either increase your front tyre pressure or let your rears down a bit!

 

tyre dealers tend to encourage you to run higher pressures because there is less chance of a tyre failure, and often car manufacturers go for lower pressures to make the car have a more comfortable ride.

 

if you would like some more sweeping generalizations please let me know.

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This generalisation maybe?

 

"As a standard road car you are never going to get it to handle very well on a 195/65 tyre."

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My Michelin Pilot Exalto 195/65s don't touch the pavement across the tread at 25/27 psi front/rear. A good 1/2" of tread is aloft on either side.

 

I'm going with 185/70 XWXs to replace them.

 

Cheers,

Tom

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Yokohama C drive 2 195/65 28 front 26 rear. Even wear right across.

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195/65R15 is a cheap way of getting a tyre with approximately the correct diameter. Howerver it won't handle very well, unless you dramatically modify your car and compromise on comfort and progressive handling.

 

and you should not fit inner tubes into a 65% tyre.

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Tom - I'm sure there will be many who look forward to a hands-on review of the XWXs :)

 

Best I've experienced in 40+ years with my TR250(s). Grip, steering response/ lightness, and even the looks. They do sing like their XAS kin, but not too loudly. Traction A, Temperature A and V speed rated. 51 psi max pressure. Same diameter as originals fitted to P.I. cars ( 3.45:1 diff ratio ).

post-1059-0-64133000-1493137647_thumb.jpg

 

So it's French [ branded ] tyres for my TRs. 165-15 XAS for 3.45:1 diffs and 4-1/2" - 5-1/2" wheels, 185-15 XVS for cars with 3.7:1 diffs and XWX for 5-1/2" or 6" wheels -_-

 

Cheers,

Tom

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I'm very pleased with the new T-Trac 2s on my 4A. Currently have them at 22 front, 24 rear, but haven't done much mileage due to an allergic reaction to something, that's left me looking like Michael Gambon in the Singing Detective, crossed with the Monster From the Black Lagoon.

 

Pete

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I'm sure everyone has their own preference. I find the 24psi front and 28psi rear to work really well for me. My car has toyo tires right now. Good ride and handling.

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I'm sure everyone has their own preference. I find the 24psi front and 28psi rear to work really well for me. My car has toyo tires right now. Good ride and handling.

Quite right bonreji (with no name, why so shy) I found that my Honda CRV was exactly correct with those tyre pressures also just the same as your......? which you are happy to use on the roads around.....? Jeez this is hard work.

 

I've found if you put a little more information in on your profile many of the questions other posters would ask is filled in for you every post with no further effort required.

 

Mick Richards

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My experience of Toyo 330 tyres is that they were very good when new but at 4 years they had become prone to break adhesion a bit too suddenly for my liking.

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Quite right bonreji (with no name, why so shy) I found that my Honda CRV was exactly correct with those tyre pressures also just the same as your......? which you are happy to use on the roads around.....? Jeez this is hard work.

 

I've found if you put a little more information in on your profile many of the questions other posters would ask is filled in for you every post with no further effort required.

 

Mick Richards

 

Thanks for reminding me. I will update my profile.

Edited by bonrej32

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Hi can i suggest that characteristics like snap overseer are enhanced by oversize tyres. keeping the tyres fitted that triumph knew were right will make the car more predictable.

 

When it comes to what brand to fit i would suggest this might be of interest to you https://docs.google.com/viewerng/viewer?url=http://www.longstonetyres.co.uk/image/longstone/english-website/porsche/porsche-classic-article.pdf

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