C4 Wheels

[timatt]

OK: I know the subject of wheel sizes has been beaten to death, but I have a specific question that I cannot find an answer for by searching this and the Rennlist forums.

I have an '89 C4 that I want to fit with 17 inch Cup 1 wheels. I have already purchased 7JX17 ET 55 fronts. I have been looking for 8JX17 ET 52 rears, but these are very difficult to find. The 9JX17 ET 55 wheels are apparently an approved fit and are much easier to find. MY QUESTION: Will going to a 9 inch wide wheel on the rear while staying with the 7 inch wide wheel on the front make the C4 understeer tendencies worse????

[Bill Verburg]

Originally Posted by timatt

OK: I know the subject of wheel sizes has been beaten to death, but I have a specific question that I cannot find an answer for by searching this and the Rennlist forums.

I have an '89 C4 that I want to fit with 17 inch Cup 1 wheels. I have already purchased 7JX17 ET 55 fronts. I have been looking for 8JX17 ET 52 rears, but these are very difficult to find. The 9JX17 ET 55 wheels are apparently an approved fit and are much easier to find. MY QUESTION: Will going to a 9 inch wide wheel on the rear while staying with the 7 inch wide wheel on the front make the C4 understeer tendencies worse????

Compared to what?

[timatt]

Actually I think I just answered my own question by looking at tire sizes. My current setup is 7JX17 ET 55 front with 205/50 tire; 8JX17ET52 rear with 255/40 tire. It appears that I can use the same tire sizes on the 9JX17 ET55 rears.

'73.5 911T
'89 C4
'10 Panamera Turbo

[Bill Verburg]

Originally Posted by timatt

Actually I think I just answered my own question by looking at tire sizes. My current setup is 7JX17 ET 55 front with 205/50 tire; 8JX17ET52 rear with 255/40 tire. It appears that I can use the same tire sizes on the 9JX17 ET55 rears.

'73.5 911T
'89 C4
'10 Panamera Turbo

You will get a tiny increase in understeer because of the wider rear wheel. Not enough to be concerned about.

If you actually want a noticeable reduction in u/s use a 235/40 front w/ 255/40 rear

[timatt]

Bill: Thanks for chiming in, I was hoping you would.

I assume that the 7J wheel would be to narrow for the 235/40 tire and I would have to go with an 8J rim with. That's the problem that I'm having in the first place; finding 8J Cup I wheels for a reasonable price.

At any rate, what I have seems to be working reasonably well for my purposes so I'll probably stick with the existing tire sizes.

T

[Bill Verburg]

Originally Posted by timatt

Bill: Thanks for chiming in, I was hoping you would.

I assume that the 7J wheel would be to narrow for the 235/40 tire and I would have to go with an 8J rim with. That's the problem that I'm having in the first place; finding 8J Cup I wheels for a reasonable price.

At any rate, what I have seems to be working reasonably well for my purposes so I'll probably stick with the existing tire sizes.

T

True,

good plan