I have an 85.5 944 na and have upgraded to the 16" early off set Phone Dial rims and running 215 front and 225 rear tires now, I want to install Potenza's Re-11 225/50R16 front and 245/45R16 rear will this larger rear size have any ill effect? slower acceleration??
thanks

 

James, that depends on the overall diameter (circumference, really). Without knowing the aspect ratio of the 215s and 225s you're currently running, one can't say....

 

Heres a good calculator where you can enter stock and desired sizes and it tells you the speed correction required. http://www.1010tires.com/tiresizecalculator.asp

 

Your speedometer
might be slightly affected, but your acceleration will be negligible. When I went from 215's to 255 race slicks, the car didn't seem any slower.

 

Those are the sizes most people run on their 16's if they've still got them on. I have them on my Fuchs.

I had an 85.5 years ago and I put 16" Phones and 225/55-16 front and 255/50-16 on the rear. Lots of people told me that they were too big, but it seemed fine to me.

 

The phone dials are pretty heavy wheels. I assume you had the 15's before. You have to compare the weights of the wheels and tire combo to what you had before. A heavier combination is more rotational mass to get moving. That will slow your acceleration. Also a bigger diameter tire will have the effect of running taller gears, which will slow your acceleration also.

You might not be able to notice the difference too much on the street, but on the track, you don't want to run those big tires/wheels on an NA.

 

I have 225/50r16 tires on the rear wheels of my car, and I believe they are the correct diameter (coming from 15x6" stock wheels). I have 205/55r16 tires on my front wheels for what its worth, but I have less room under the narrow 924S fenders

 

the effects will be negligible.
















































.

 

and still drive a good deal slower than it looks.

 

as crackership says, thats a stock size so rotational diameter shouldnt change if you're also running stock tyre sizes on your 15"s. i run those sizes too. you may or may not feel the weight difference http://www.944racing.de/wheelweights.php

 

I used the Tire Rack tire calculator to get the proper size tire (diameter) for the 17" Cayman wheels I put on my '87 944 N/A. I wanted to make sure the speedo was accurate plus the tires that were on the 17" rims were just a hair too wide, causing a fender lip rub under hard accel during turns. I was able to get tires that were 1/8" narrower that solved my problem. Also had to use a 1/4" spacer on the front hub because of a rounded corner on the hub and the wheel wouldn't seat properly.

 

That is to big. when you go wider, you go smaller in profile. i went from 225/50 R16 to 245/45 R16 to get the same/similar diameter.

fronts are 205/55 R16 and you put them to 225/50 R16