Tire Width

tim944 · 07-21-2003, 01:53 PM

Any advantage to changing to a wider wheel/tire on the rear? I have seen several different combinations depending on the model year. I am currently running the stock 7 X 15's on my 86 NA.

TCMdocs944 · 07-21-2003, 03:47 PM

Well, I know that wider on the back looks baaaddddddd...

Practically it is supposed to prevent oversteer.

More rubber on the ground, the less side slip.

More rubber the heavier the tire.

I've planned some Dunlop 8000 - 245 / 15's for the rear.
I beleive they make the widest tire rated for that size rim.

UconnTim97 · UconnTim97's Garage

I have 16x7's on the front and 16x8's on the back. I definitely like the look of the wider tires. It handles great, but that is the way I bought the car, So I have no reference to how it would handle with smaller tires.

TNT25169 · 07-21-2003, 08:24 PM

I have 225/50/16 on the front and 245/45/16 on the rear with yokahama AVS es 100s. They don't oversteer at all when I'm racing if I lower the front tire pressure and keep the rears higher. The car handles amazingly and everyone comments on how they like my rear tires when they first see my car. Just my thoughts.

gearhead290 · 07-21-2003, 08:34 PM

IMO-wider tires in the back is a waste on the n/a. I have a hard time believing there would be a big advantage to it, not to mention it would help create UNDERSTEER. The n/a car already suffers from a real mild understeer so I wouldn't even consider it.

just my .02

very~worn~944 · very~worn~944's Garage

I have 17 x 9.5's on all corners....yikes....at one point i was running 235's up front...and 275's in the rear. I know i have said this before...but i just love the look SO much...Especially when you park with the wheel turned...you can see acres of tire in the front...and see 275 yokahoma Advan street slicks on the back. Looks wicked. I LOVe all the tire. The thing handles like no other. From what i have noticed...any car setup will both understeer and oversteer...It is all about balancing the car in the turn...the perfect amount of gas to keep it planted, not plowing or spinning. i can even get my car to throttle oversteer around a turn, with the superglue on the back. Keep the car weighted and balanced and 195's will handle. 225's all around my n/a worked fine...just had a little lift-throttle oversteer since i was not used to suck a balanced car. In a long smooth SAFE turn practice keeping the car weighted by staying in the gas...but not flooring it...just enough to keep your speed...not to accel or decel...and slowly bring your speed up. You will notice how much more you can get than you would expect...just make sure you be SMOOTH..and do not have to slow down...cause once you get to the very edge...your tires can't take any breaking or decel force cause it is ALL being used in turning. At this equilibrium you will start to notice...EVER SO SLIGHTLY let off the gas...and the car will turn in and you feel the back kinda pick itself up....and if you EVER SO SLIGHTLY give it gas..you will feel the rear start to push the front...and it will dip a bit. At this point you can use the throttle to steer your car. If you crash...don't blame me...cause i used the word "SLIGHTLY" with emphasis. I find those turns on a track that look the most like freeway onramps and offramps to be the best to test these limits.

Just do me a favor and make sure the crosswalks aren't being occupied at the other end. Godspeed.

Z-man · Z-man's Garage

Quote:

Originally posted by gearhead290
IMO-wider tires in the back is a waste on the n/a. I have a hard time believing there would be a big advantage to it, not to mention it would help create UNDERSTEER. The n/a car already suffers from a real mild understeer so I wouldn't even consider it.

just my .02

That's why you need to get a wider tire for the front too!

With 16x7 front and 16x8 rear, the max you can go is: 225/50-16 front, 245/45-16 rear. You get more grip all around, and some understeer is eliminated with that setup.

For track use, I recommend using 16x8's all around, shod with 245/45-16 tires. That setup really helps eliminate most of the understeer: my car only understeers on the really tight, really slow corners now!

Side note: I don't recommned the Dunlop SP8000's: I had them for a season and while I thought they were great, they really aren't.

Just my $0.42,
-Z-man.

tim944 · 07-22-2003, 10:12 AM

Why did our friends in Germany put 15" wheels on this car? They seem to have gotten everything else right, why skimp on an inch of wheel diameter?

Z-man · Z-man's Garage

tim944:
Back when our cars were new, 15 inch wheels were the norm: even most 911's had 15's! 16 Inch rims were the upgrade.

Nowadays, with "dubs + 4" (24 inch rims) being the norm on lots of SUV's, people consider 15's to be too small.

IMHO, 15's and 16's are just fine on our cars. Granted, a 17 or 18 inch wheel looks better and fills in the fender wells of our cars better, but it doesn't really help that much in terms of performance: you get a stiffer side wall, but greater unsprung weight with bigger diameter wheels.

Just my $0.42,
-Zoltan.

ronin · 07-22-2003, 10:44 AM

remember, back then (almost 20 years ago) when these cars came out, 15s & 16s (for the turbo) were considered large. It hasn't been until the last five or more years that "twennies" and such have become all the rage. Even then, people weren't quite that willing to compromise too much ride quality for handling, nor were they necessarily aware of the increased handling benefits as they are now. The 16s were available as an option though.

tim944 · 07-22-2003, 10:48 AM

Thanks Z-man,

That makes sense. I may try and pick up a set of 16X7 & 16X8 phone dials I saw last week. For $350, I'll refinish them and put some meaner rubber on. Then, maybe I'll put some snows on my 15X7's.

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ronin · 10:55 AM

that's weird, z-man, your post wasn't there when I posted mine but the clock says that you got there 4 mins before me. Makes mine look a bit redundant. Anyway, (pointing to Z-man's post) WHAT HE SAID!