V2Rocket

Can't recall reading anything about fitting 17"+ wheels to early model cars. KNow that on late cars Porsche suggests fitting 968 caster blocks. But earlies have a U-clip and large rubber bushing rather than the round bushing bolted to the control arm like late 944/968.

Any upgraded components needed to fit 17+ wheels on an early 944?
Before Roger jumps into this one, I am aware of the impact of larger wheel/tire weight...

924srr27l

No, get them fitted, weigh them before and after and see what happens.....




R

H.F.B.

You're surely referring to the Technical Bulletin 9303, which is here attached. See Installation Information cipher C.
I changed my steel control arms to the early offset Aluminium control arm. So as well, I changed to the late rubber bushing, sway bar mount and the 968 style caster block.
The improvement due to this change is huge.
The A-arm is indeed stiffer, the new bushings, sway bar mount and the 968 style caster block improved the hysteresis behavior of the steering to a great extent.

I wouldn't bother for 17" tires, if I still had steel control arms and these old rubber bushings. Don't forget, the steel control arms date back from the Volkswagen Rabbit I in 1974. I doubt that the steel control arms were designed for this sort of big/wide tires you'd like to fit.

V2Rocket

I wouldn't put anything wider than perhaps 225 on the car, front or rear. Not enough power to need it and the car is only for the street...all rubber bushings on the front are new from 2006, all the rear is new in 2014.

The only reason I ask is the complete and total lack of availability of performance tires for 15" wheels in a 215/60 or similar size, short of the horrifically expensive Pirelli P6000 ($1000/set of 4). I am not quite ready to drop to a tiny donut tire of 225/50 because my car needs to sit at stock ride height to maneuver over the roads/driveways where I live.

Am considering upping wheel size to get a better tire, mostly to make the brakes more effective versus the All-Season tires I have been running since buying the car.

924srr27l

The answer is 16" wheels then Not 17"


R

H.F.B.

225 on the front with manual rack, is a daily workout program.

Porsche says the change of the caster blocks is necessary due to a change in caster spec on vehicles equipped with Porsche 17" wheels --> 3° 15'-45'. But if aftermarked 17" wheels, then what...?

924srr27l

Yes good point !


205/55/16 on 7x16 Rims all round are a great Street set up.
Although I have gone to 380mm Steering wheel for less steering effort and more leverage on the Manual rack and it works really well.





I have driven a 944 on 17's and manual rack and that was not nice at all.




R

V2Rocket

Used to it...haven't had PS since 2006. Ran 225 fronts for probably 3 years? Otherwise 215s.

Keeping the tires at the right pressure makes a big difference in effort...

924srr27l

I'm sure you probably are used to it, but the car's performance would be improved if also changed the steering wheel to larger and the tyre size narrower.


It also allows you to run Lower Tyre pressures for a bigger Footprint, and you can run a Stiffer suspension to control body roll and let the Tyre do all the work.


R

MAGK944

There is also some added information <here> that relates to this post.

V2Rocket

Can't do larger wheel - I have the factory 4-spoke wheel and don't have much additional clearance to my legs/knees under the wheel (I am 6'6" and sort of fold into place in the 944)

And I will not be making my suspension any stiffer than it already is, 200# front springs/26mm solid torsion bars are more than stiff enough for the quality of road we have here.

924srr27l

Oh I see, I did also have the Luxury of fitting the Kevlar seat to the floor gaining some Thigh room, although the 380mm Wheel is deep dished and this also assists in moving away from the centre boss and creating more leg clearance.


6 ft 6! Blimey that sounds tough, I'm 7.5" Shorter!


I'm on 190Lb fronts and 27mm rear T bars and I use 26 psi front / rear
but this is better on a 2300Lb car.
R

SloMo228

I have 225 fronts mounted on 17" wheels, with a manual rack and a smaller than stock steering wheel (350mm IIRC). It's a bit of a chore at low speed but I like it overall.​​​​

924srr27l

Yeah I did try 17's once they were not good in the twisty stuff!

I tried an 11" Wheel once on a Single Seater Racer down from 12" and it was a huge difference adversely, turned in far too fast, was too nervous and fidgity and was taken off asap! R

NCLA951

If you want to go 16x7 phone dials I've got 2 I'll sell you! In LA. Then you only need two more!