Running in Tyres

[VINTY]

I have just had a pair of Toyo T1-R tyres fitted to the rear of my Chimaera and have covered about 100 miles. At anything over 80mph the rear end feels very floaty and unstable and the car just doesn't seem as grippy as it was. could it just be that the tyres need running in? Have checked tyre pressure 24psi so it isn't that Anybody any ideas?

[tvrbob]

24psi is a Bridgestone pressure. Tyre pressure is used in conjunction with side wall rigidity to supply the required amount of tyre deformation. I'm not sure whether Toyo's are harder softer or the same. If they are harder then you'll need to reduce the tyre pressure to regain the correct deformation.

Regarding running in, Toyo's are well known for retaining mould release lubricant for many 100's of miles so you could be sensing loss of stability at speed as the air starts to get under the car and lateral forces increase.

I don't have experience of Toyo's but have decided that they are not going on my car. I believe they do come good eventually. You'll just have to be patient and go very carefully in the wet and damp for a while.


>> Edited by tvrbob on Friday 6th August 20:49

[bsdnazz]

I believe the Toyo's have softer sidewalls than the Bridgestone SO2/SO3s. This could cause them to have less lateral stability than the Bridgestones. It's this softness that means the Toyo's don't break away as suddenly as the Bridgestones when cornering with gusto.

[chris547]

Can anyone suggest the correct pressures for Toyos on a Chim?

If they are softer than the original SO2's does the handbook pressures of f 22 r24 still apply?

I have mine set to f 20 and r 22 to make sure they grip.

Bearing in mind the car only weighs a Tonne 20/22 seems quite high to me.

I will email Toyo and ask them.

[Steve_T]

Ballpark figures:

SO2s : 22 F / 24 R (Handbook figures)
SO3s : 20 F / 22 R (Stiffer sidewall)
Toyos: 24 F / 26 R (Softer sidewall)

Steve.

[chris547]

I enclose Toyos reply

Chris.

The pressures I would recommend for your Chimera are

Front: 1.7 bar (24 psi)
Rear: 1.7 bar (24 psi)

These pressures have been specifically worked out for TVR.

I would say all tyres need to be bedded in irrespective of make. I would
suggest you do 200 to 500 miles normal driving before you explore their full
potential.

Regards

Alan.



-----Original Message-----
From: Barclay, Chris [mailto:[e-mail]]
Sent: Tuesday, August 31, 2004 1:57 AM
To: 'Alan Meaker'
Subject: RE: TVR Tyres


Alan,

Getting my TOYO Proxy tyres this week and wondered what tyre pressure you
recommend for a 1 Tonne car. Is there a range I can experiment with safely?
Book says 22f, 24r but that was for Bridgestone's SO2.

[tvrbob]

I don't like that. 24psi all round is just plain stupid. The construction of the tyres, the compound used, the experience of road users and the experience of trackers all say 1 to 2 psi lower than SO2pp's.

[shredder]

I thought exactly the same when I had Toyos fitted to the rear of my Chimaera. I was beginning to wonder if I had made the wrong choice. They were quite hairy to start with. Exactly as you describe. Changing lanes at 80+ on the motorway was frightening at anything more than a snails pace!! But.... Stick with them, eventually the effect wore off and now.... there is so much grip in the rear. I can sling it into roundabouts far quicker than I could with my old S02's

I personally think they are very good tyres, slight screechy when you give it some, but I guess that’s just the softer compound.