What's the maximum width wheel I can fit under the front of my '79? It seems that even the later models were using the 225 width.



After searching, I found this great treatise on wheels. Many facts and answers.
http://www.landsharkoz.com/forms/928wheels.pdf

 

275 with the right off set 9-9.5" rim, and 255 on a normal, no special offset as long as its close. one size up front and rear can work fine too, on stock rims.

MK

 

My 1980 very brown with 7.5x17 x 235 front rim lowered a bit low while spinning on the skid pad ( not intentional ) the tire caught the inside lip of the fender opening rolling backwards at near full lock . That was a C-2 replica . The Gt and 1990 > all came with rolled fender lips ( pinched flat ) for extra tire clearance .

 

That's interesting Jim as when I did my upper control arm bushes, I carefully measured all the various clearances. I found that on full lock, a wheel wider than 235 would rub on the skirt and rail and as such determined that any tire that was too wide as to prevent me utilizing full lock was too big. So my two kronor are 225 to 235

 

My 1980 has 245/45-R16's on 8 inch wide BBS wheels... not exactly sure of the backspacing, so that probably doesn't help a whole lot. (I think they are 60mm offset) Never had any problems with rubbing anywhere.
Andrew

 

Hmm. Mine's white. Could make a big difference.
235's on a 7.5. That's what I wanted to hear. Pretty subtle difference, but it's a bit more meat.

You know, the reason I bring this up is that my experience with cornering is that the front usually slides before the rear. But then that's simplifying a rather complex subject. Which would make one wonder what the object is of having wider rears and 225's or even 235's up front.........

 

With 11" wheels, you can fit a 305 and have limited turning

for a street car, a 9.5 with 275 is about the max.

Marc
DEVEK

 

Mark, how do you apply the 1.15:1 maximum width rule.
I'm trying to keep this puppy stock enough to not limit turning, but it sure would look beastly in that width.
According to that rule, the widest tire that is to be fit on a 7" rim is a 205mm. And they come stock with a 225. So I'm confused.

 

Front slides first? Thaat's different I think. Reminds me of those Daytona Turbo, Mitsu Eclipse days...

305, now that's a tire. - Ruf

 

Rufus, I just realized, I'm not done with my final alignment. And my limited brain capacity has me remembering how the car handled before I realigned it to it's present state. It sounds like I'm incorrect or you wouldn't be questioning. Good. Actually, GREAT.

 

if you enter the corner too hot, or are braking to hard then yes the front will break first

 

Oh yeah, I remember doing that a couple times (hard breaking between entry and apex) and yup it did start to "dance", but I learned my lesson and that particular curve doesn't get me anymroe. - Ruf

 

I did a bit of research and found that the GT-3 only uses 235's on the front. That's all I needed to convince me that there's not much need for me to go much more than 225. Weird, I didn't expect that. I guess as good a driver as I think I am, I've got a lot to learn.
Rufus, uh oh, I see those Cup wheels on your car. That's what's got me doing this research. A bit of money to improve on the already nice look of phone dials.

 

I have beenb through this with my 82 928S

After a disasterous event which left me missing one front wheel and hub whilst travelling down the road, I decided to upgrade the entire front.

We used the 928S4 Front Suspension, the S4 track rod ends, and custom disks from Devek, the 993 Calipers, after which I fitted the 18" turbo twist rims with 235/40 ZR 18 tyres, we had to have the front arches modified slightly, this was not apparent until the car encountered some hard bumps at speed which split one arch but the car handles better and has a nice feel to it on smooth roads,

It now reminds me of the carts I used to race and personally that is the feel I like

 

Greg auto makers try to have a car understeer . So when you cook it into a corner and push /slide the front end first off the road you know you screwed up ! If the car oversteers and spins off the road odds are you will blame the CAR for spinning being dangerous and not that you were going too fast . The GT3 911 is a rear engine tail heavy car so .....they run small front tires to .....try to make it understeer !!!! With the 928 the wider rear tires will allow you to accelerate and turn at the same time . You have a limited amount of traction which you can use to stop turn or brake . If you are cornering near the limit of traction and get on the gas the rear wheels get loose and you have power over steer as the rear end trys to pass the front end . Hit the brakes in a hard corner and the front end jumps sideways because the front brakes get most of the braking.