944 Rear suspension differences information

[Michael Ghia]

I've just done some measuring of the 3 different suspension and brake setups which come on the 944.
I found out the following.
Note...We already know that the difference between the mounting face on a 4-stud Beetle drum to an early 944 (pre '85) disk is 24mm... i.e. if you were to put a wheel with exactly the same offset and width as a Beetle wheel.. it would stick out 24mm further.

(All measurements were eyeballed up from springplate surface to wheel mounting surface (i.e disk)... so may be out by 1-2mm)

From the early 944 rear suspension to the first (narrow track) ally arms. There is a difference of 23mm.

From the early (narrow track) ally arms to the late (wide track) ally arms there is a difference of 30mm.

So from am early setup to the late ally arm setup... there is a difference of 53mm!

Add this to the 24mm from Beetle drums to Porsche disks and you end up with 3 inches per side! That's a lot of width!

Hope this helps with your projects.

Mike Ghia

[Pillow]

Good information Michael. Thanks for posting it!

To add to the fun if I remember right Boxster wheels are 60mm offset which might help a little to bring it all back in. There are some 65mm as well, but I think from a 928? Also some crazy 90mm off the rears of like a 993, but they are too wide anyway like 8 or 9"s.

Ahh the joys of modification :)

[Supa Ninja]

Micheal,
Thanks for the post on different 944 control arms. You wouldn't know what the part numbers for the alloy control arms. I picked up a couple and I'm wandering if they are early or late.

Nick

[Michael Ghia]

Boxster rims come in offsets from 40mm-55mm depending on width and diameter.
Anything from the front of a 928 has a 65mm offset and 993 rear (16's) wheels had a 70mm offset on the rear wheels (9's) which is the most offset I've ever seen on a Porsche O.E wheel.

The easiest way to work out which arms are which... the early ally arms have the same rear disk as the Steel arm'd brakes where as the late ally arms have a rear disk which has an extra shoulder on it out towards the wheel.
Email me and I'll send you pictures of all three setups.

MG

[Wally]

Michel,
I have 993 wheels and the rears are indeed 70mm off set but are not 9 '' but 8 '' x 16. Fronts are 7 '' x 16 and have an offset of 55 mm. I use the late (994 turbo) arms and with an spacer of 1 inch and inner and outer widened Kerscher wings, the wheels aline exactly with their tire walls with the wing sides.
Hope this adds to your info (and for others doing this mod)
Walter

[Michael Ghia]

Walter,
Sounds cool... can we see a pic?
How close do the 8's run to the springplate/trailing arm? Could we have some more spec on the car?
Thanks
Mike Ghia

[Tim]

Hello Wally,
What size (how many cm widened) Kerscher rear wings you are using? I am planning to use late 944 ally arms and 9" wheels at the rear but I have no idea what size of widened wings I should order.
Thanks
Tim

[chigger]

I am running the steel arm with the early disk brakes. The stock 23mm offset plus the 23mm offset of the brakes equal 46mm. The Phone dials I will be running are 52mm offset. More than enough. When I can get the pan back on the body, spring probably I will be able to check the tire clearance. Just mocking it up before I took everything apart, I may be able to run the 8 x16 rims on the rear under stock fenders. That is my hope anyway.

[Wally]

I have the 7 cm (inside widend and outside widend -> extension) wider version rear and 4 cm outside widend front ones. This required front and rear 1 inch original porsche spacers front and rear, which in turn required longer original porsche wheel bolts (expensive!), which come from a 944 rear (needed two sets obviously).
Nice thing about the wheel spacers up front is that the tire's don't hit the original 1303 spring anymore (Idon't have adjustable aftermarket ones) and I have the original wheel turning circle (which is very small = good on a 1303 with rack&pinion steering).

Tip: the rear springs from an old (1978 or so) passat (european name) are just right (same diameter) for the front 1302/03 . They lower the front by appr. 4 cm's and are noticebly stiffer!

Lately I have installed (a new development of Gerd Weiser) a steering damper, since 1303's with rack&pinion don't have this. It is great!

Pics: well, I dont have a digital camera, but will have my next film put on CD. Will look for an old .jpeg pic at home later.
Walter

[Tim]

Thanks Wally, that's the extension I have in mind. I like the style of the flared (outside widened) fenders too. Are you using stock brake in the front? Do you think if using 944 brake setup and 7.5" wheels in the front, it doesn't need any spacer? Also, will the rear accomodate 9" or 9.5" wheels without the spacer? By the way, are you using the late ally arms setup? - the one which widens the track by 3" per side as mentioned by Michael Ghia.
Hope you don't mind my series of questions.
Tim

[Wally]

Tim,
No of course I don't mind: that's what we're her for, to help each other with our shared passion/hobby.
I use 944 turbo Cup (there has been Cup races with 944 turbo in 86/87 I believe) brakes, who even sligthly bigger than normal 944 turbo brakes, front and rear complete with spindels, 3 " wider arms, torsion bars (23,5 mm, same as T3 variant) alu torsion housing covers and ABS sensors. Believe me, unfortunately, there are differences in the Cup version and don't ask me how I know.
7,5 inch wide rims with stock springs and no spacers will almost certainly NOT fit.
Acually, the reason for the fared fenders was because with the 3'' wider track at the rear, none of the porsche wheels would fit under the stock fenders. Originally I wanted to use 6 + 7 x 16" Fuchs rims, which I like(d) a lot. These would't fit the Brembo brakes!!!! not even with spacers! 6x16"Fuchs would have cleared the Mc Pherson springs. So I needed different rims. In 16", I could only find 993 rims that would fit, but they were 1" wider than I thought necessary. Therefore extentions were also needed in the front.
Now I hear that Boxster Brembo's are slimmer and even 15"Fuchs would fit a 1200/1300 front with adapted spindels and boxster Brembos. But I like my 993 rims now even more than Fuchs, so I have peace with it now.
In my example it becomes also clear that the German Look is more 'form follows function' for ME.

At the rear I have ample space between the rear tire and the torsion trailing arm. Also more then enough space for a Ahnendorp silencer system, which has a demper just between the valve cover and the rear tire. Good thing too.

I tried to attach a picture, but my picture file seems to be too big (?!)

I'am sorry Tim, this is probably more info then you bargained for LOL,
Walter

[Wally]

Tim,
I see now, I even forgot one of your questions:
Fitment of 9,5 "rims at the rear with the later, wider, alloy arms without spacers will be a close call. Cup-like wheels would almost have all of the extra wheel width towards the inside (extremely large ET numbers) and you migth just than start hitting the torsion arm next to the torsion house cover...
BTW I don't like spacers either, but only than the wheel would be in line with the fender end. Less wider fenders would not cover the tire, so I had to more or less...
Walter

[Michael Ghia]

Wally,
It sounds like you're running the M030 option brakes on the car. The front calipers are the same as on the 928S4 and are a lot bigger than the normal 951 4-pot calipers.
Do they bolt on radially?
Mike Ghia

[Tim]

Wally, thanks a lot for the valuable info. It saves me all the guess works. It would be great if we could see the pics of your car one day.
Tim

[Wally]

Originally posted by Michael Ghia
Wally,
It sounds like you're running the M030 option brakes on the car. The front calipers are the same as on the 928S4 and are a lot bigger than the normal 951 4-pot calipers.

Yeh, tell me about it. Looks nice, but downside is a very, very heavy disk at each corner (new about 33 mm thick!). I even thougth to replace them with carbon disks, just for the weigth saving (they weigh only 25% of the steel parts. But then I heard the costs of those: about $ 4000,-- for the set of 4 with new brake pads: Outch !!)

Do they bolt on radially?
Mike Ghia

If you mean by that 'not in the normal way', then: Yes.
BTW Brake balance is way off also, but I still have the original master cylinder, soon to be replaced by a Kerscher m/c (found out piston diameter is 23,64 mm front and rear) with a separate brake 'bias thing' which can regulate pressure to lessen the front a bit. Other possibility is an Audi part (model 100 or 200: in Europe) so I'am told, but they are either right or not i.e. not adjustable, but cheap to get second hand.

Later,
Walter