Forrest Gump 9

Hello all

I'm slowly stransform my 964. A local guy have a set of cup wheels that he's selling. Before I pull the trigger just want to check if they will fit on the 964. Here are the specs

235 x 55 R 17 - Rear (52mm off set) and 225 x 45 R 17 Front (45mm off set) 5 x 130 mm bolt pattern

My car is a 1989 C4. Thanks

cobalt

What are the wheel widths? These are not factory offsets unless the rears are 8's? The front are definitely not factory. A 235 in the rear with a 225 up front will cause the car to be tail happy. Usually a 205/255 setup on 7 & 8's

Forrest Gump 9

The tires are no big deal, I'm changing them out. Just want to make sure the wheels will fit.

cobalt

You still did not mention what the widths are. Offsets mean nothing if you don't know what widths they are.

Forrest Gump 9

Fronts are 7.5
Rears are 8.0

cobalt

They will work but not ideal. The usual upgrade over the stock 7" ET55 is to put the 8 ET55 up front which will push the wheel out by 13mm. The 7.5 you are discussing will push the wheel out 16mm. How much of an impact will the extra 3mm make is dependent on tire size and suspension setup.

I am not sure why you want to go with an aftermarket 7.5 upfront and an 8 in the rear. If anything most people are looking for 7 & 9's running a 225/255 setup. I am not sure what a 205 stretched on 7.5 and a 255 on an 8 in the rear will do for handling.

I would make sure the wheels are straight and true. Most used wheels are not. if they are all aftermarket they aren't worth much and are usually far heavier than the stock wheels. I hope they are cheap because they will be a hard sell in the future if you don't like them.

If you are looking for a perfect set of factory 7 & 8 or 7 & 9's I will be having a set of each with period correct NLA crested center caps for sale soon but they are not inexpensive but less than new.

jgj

Talking about tail happy. My 90 C2 Targa came from the PO with 7.5J (ET 26 or 76 can't read it properly) and 9J (ET47). I'm running 205s and 255s with that. I ran it off the road backwards (no injuries or 3rd parties). My driving’s pretty average at best, but could my rim/tyre combination have contributed?

Earlydays

.....I would guess that you might have been going faster in a corner than you wanted and got off the gas too quickly and induced trailing throttle oversteer....a Porsche 911 trait. Each successive generation of the 911 has had less and less of this trait, but it is still there.

cobalt

Most likely it is as Earlydays states however a 964 can be setup in many ways. Suspension condition and settings play a key roll in how the car will react. I have driven 964's on skidpads setup in such a way that I could not get the car to spin period. It was the strangest thing you could push it hard going round and round on a wet surface and lift but the car would not spin.

Another concern is tire choice, condition, age and temps that can all play a factor in changing handling characteristics.

Be careful it takes time to learn these cars if you are a novice at driving them. I can't tell you how many friends over the years with considerable driving experience couldn't get a 911 to move without stalling them and at one point early on found a way to get the tail to slip out on them. If you think these can be a little crazy try an old long nose.

My .02 worth. Take it to an autocross event and have some fun with it. You don't have to win or even place just go out and learn to drive it at its limits in a controlled safe setting. We offer Car Control and AX schools for our PCA region members to do just this. I love it when I instruct a new older 911 owner and they are amazed at what these cars are capable of doing.

jgj

Thanks cobalt. I've booked a day on a test track with an instructor for this very reason. The OP’s post and some of the answers just got me wondering whether my rim/tyre combination was not helping. 255 seems widely used on 9Js, but 205s on a 7.5J is not a combo I see regularly on these posts. And you're both right, I went into that corner too fast and lifted off. Rookie error some of us learn the hard way I suppose...

cobalt

We all do it once. My turn was in a 71E going sideways on an offramp with cement all around me. I caught it just in time but learned a lot in an instant that day.

Good Luck.