The Dodge Challenger Message Board

does anyone have 17 ich torque thrust 2's??? if you do what rim width and tire size do you have on the front/back?? oh and what backspacing? thanks

Hey. Check out Fat tony's 70 challenger in members cars. heres a pic. He has 17's T Thrusts. I forget his combo, but I believe he has 235's on it. backspacing??? It's incredibly difficult to not love his car.

good luck with your decision and purchase.

7 x 17 TT2's wrapped in Pirelli P Zero's 235 x 50 x 17 all round . I think the std backspacing is 4''. Fit REAL nice with no mods to body.

ok thanks, just worried about my front tires rubbing or hitting against something

how wide are those 235's on a 7 inch rim? and what does offset mean? and how does it affect the rim?

The 235s will be.....err 235mm wide.

That's just over 9-inches. The wheel width effects the overall tire width at the sidewall but the tread width on the gound does not alter.

By offset he means back space. That is the distance in the back of the wheel from the mounting face to the rim. More back space moves the wheel under the car. Less moves the wheel out. You have to look for this if you want to avoid hitting the leaf spring on the inside (too much backspace) or rubbing the wheel arch (too little backspace).

dave-r wrote:The 235s will be.....err 235mm wide.

Are you sure?

Another thing to consider is to use one step smaller (less wide) fronttyres. (Then I assume that you use the same rim-width all around). That will probably add some cornering stability. Since most cars are heavier in the front (and due to that understeer) 215 or 225 tyres for instance(on 7 inch rims) will be better to withstand the forces during cornering (compared to 235 tyres). I am sure that there already is something written about this on this message board....

In the end, it is always a matter of taste and preferances....

Christer wrote:

dave-r wrote:The 235s will be.....err 235mm wide.

Are you sure?

Of course it is not completely straight forward. Although the tyre tread width will be the same, the overall width of the tyre at the sidewall depends on wheel width. A wider wheel pushes the sidewall out and a narrow wheel pulls it in.

You should really aim for a wheel that is around the same width or up to 1.5-inches more narrow than the tyre tread size. So a 235 tyre really needs a wheel around 7.5 to 9 inches wide. 8 inches wide would be ideal.

dave-r wrote:The 235s will be.....err 235mm wide.

Quite obvious, or? A funny thing is that I have a set of VERY OLD tyres that makes me wonder if it really is true. Here is the story: I have four tyres. All of them are mounted on 7" rims, two of the tyres are Firestone S660 215/60-14 and two are Firestone S/S Radials, 235/60-14. According to all rules, the 235 is a wider tyre than the 215 but that is not perfectly correct in this case.

Comparison:
215: Footprint width: 190 Maximum width: 220.
235: Footprint width: 190 Maximum width: 250.
(The footprint widths are hard to measure exactly.)

The only reasonable explanation I can come up with is that the manufacturer use different ways of measuring. Since both of these tyres are manufactured by Firestone, I find these differences a bit odd. Why would they have any intrest in measure them in different ways?

Maybe not much to discuss, I don´t know?

The 215 has a much rounder profile and I doubt the full width would be making full contact with the ground when at the correct pressure. Although to the eye it might look like the full width is on the ground how much of it has the full weight of the car on it and how will that change when the car is moving at speed?

The 235 is more square in profile. Much more of that tread will have weight bearing on the ground.

So I think the width size really reflects how much load bearing surface of the tyre is actually in contact with the ground at any given time when the car is moving.

One way to prove this. Do a burnout with each type and measure the width of the rubber marks on the ground. I would bet they would come close to the given sizes when at the same pressure.

Christer wrote:The only reasonable explanation I can come up with is that the manufacturer use different ways of measuring. Since both of these tyres are manufactured by Firestone, I find these differences a bit odd. Why would they have any intrest in measure them in different ways?

Maybe not much to discuss, I don´t know?

A funny coincidence is that Richard Ehrenberg at Mopar Action seems to have a similar experiance himself. This is what he writes in the latest Mopar Action (April 2006):

Up, front, massive "real" Goodyear Eagle F1s (left) replaced the OEM Ford-spec ones we had bought on ebay (right). They were the same size designation - 275/55-17 - but have one inch wider thread.

Btw: Thanks for your comments on this, Dave.