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924s wheel related handling trouble

mr brightside

mr brightside

New member
hello, i've changed the 6J/15ET 52.3 teledial wheels on my 924s for the wider 7J/15ET 52.3 ones but kept the same 195/65/15 tyres to keep costs down, now the handling has deteriorated to a pretty dangerous stage with the back end of the car feeling like it's breaking away on cornering with relatively little persuasion and the nose trying to embed itself in the inside of the corner. can anyone firstly confirm that tyre size is to blame, as i've been through the other possible causes, and secondly suggest the correct tyre size for this wheel. thankyou in advance for reliable advice.
 
I've had that odd behaviour. The car seemed happy on standard teledials (15x6 195/65) but when I fitted the same tyre on a different rim, it felt horrible. (pressures were correct)

Recommend putting 205/55 on the rear. That's cured that for me, and the car feels rock solid.
 
Hi

I moved from the standard Teledial wheel to a set of cup 3's , from 195/55/15 to 215/45/17 and the difference it made was like driving two completly differnt cars. Its a far safer and better drive with the cup3 than the teledials, so i would guess messing with the tire size on differnet rims would make a difference.
 
My guess is that the extra width of the new rim is causinig the tread surface to become concave, due to the wall at the tread shoulder needing to flex further, so you may need to try out some different tyre pressures to get the tread lying flat. If they are new tyre's I would give them time to scrub in, they are not going to give up their best grip for the first hundred miles. I never launch my 924 turbo hard into a corner when the tyres are first fitted, and actually having driven an unblown 924 on 205/60 x 15s and this turbo on 195/? x 15s I can't feel a lot of difference. Probably the biggest difference is in the mind.
 
thanks for the replies. pleased to see i'm not the only one to have had this trouble, i thought i'd have a battle on to convince anyone it wasn't in my head.
 
Standard for 924 with 6Jx14" rims is 185/70, and with 6Jx15" rims is 205/60
Standard for 924T with 6Jx15" rims is 185/70, and with 6Jx16" rims is 205/55
according to my '79 owners manual.

I acquired the car with 6Jx14" with 205/60 tyres on and changed to 6Jx15" rims with the same size tyres and there was a big improvement in handling.

IMHO you need to go for a minimum of 205 on 7" wide rims otherwise you are not making the most of the extra width.
If you look at a standard car with a 185 tyre on a 6" rim, the sides of the tyre are about inline with the sides of the wheel rim (assuming proper inflation).
You've just increased the wheel rim width by 25mm but the tyre by only 10mm . . . .

Also have a look at this link http://www.alloywheels.com/tyrecalc.asp

 
+1 on the 205's, its been explained already but those tyres are to narrow for the rim, they'll be going into all sorts of funny shapes when you corner, not much you can do but go and buy 4 part worns or new.
But you can be sure the car will feel 1000 times better after you do
 
i've worn in a set of 205/55's on the rear and after 300 mls the problem is still persisting to a cirtain degree. i'm going to move the 205's to the front and fit 215's to the rear but if that doesn't cure it i'm throwing in the towel and selling the 7j wheels to move back to 6j's. any potential buyers?
 
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