craig001

I recently put a set of 993 17 inch wheels with Sumitomo HTZR's, 225.45's and 255.40's on my S2. Now I am thinking of going back to my 16 inch wheels. The car is a lot harder steering and the drivers rear scrapes on right hand turns. I think it's telling to to adjust ride height and maybe get some new shocks. But any ideas on alignment spec changes with these? Or maybe some different pressures would help? I really don't know. Thanks in advance.

Adrian

Dear Craig,
I would be checking the offset of the rear wheels first. Make sure you got 55mm and not the 70mm ones. The number is stamped by the air valve.
With the size of tyres you are using I am not surprised about the steering. My 944 was a pig with 215s on the front. You have wider tyres on the front of your 944 as I do on my 911. However not next summer.
These wheels and tyres were designed to run max 36/36. Start with this and maybe reduce to 32/34. Just play around a bit, however it is still a lot of rubber to be lugging around,
Ciao,
Adrian
911C4

craig001

Adrian,

You were right on about the tire pressures. I dropped the fronts to 32 and the backs down to 34 and it made a world of difference. Still unsure if I will keep these 17's on though. Probably should get the 205.50's Porsche recommends.

Riff

Craig-

I run the same size tires on my S2, but without the scraping. You might want to get an alignment and have the ride height checked at the same time. If your car is used mainly for street, then the factory specs will be just fine. No need to dial in extra camber to clear the rears. You also might want to check the rear shocks.

As for the steering, I think it is weighted nicely with the 225's up front. Previously I had the 205's up there, but for some reason those would tramline way more than the 225's. Might have been due to the brand (was B-stone RE71, now Toyo T1S)I dunno.

Cheers

Adrian

Dear Riff,
Maybe with power steering but my 944 has no power steering and the 215s all round was a lug. 205/225 works much better as does lowering the tyre pressures a bit. RE71s are well known for tramlining. Another major factor in tramlining is profile. Lower the profile, the worse it gets.
Ciao,
Adrian
911C4

PS: I am a lightweight fanatic so I prefer not to have power steering is avoidable. Was with 944, not with C4.

spidey

Did you follow the factory recommendations regarding 17" wheels...if not I can email them to you or search the archives for " 17 inch on 944S " post. The factory says that you should upgrade some suspension parts to 968 parts and insert a 17mm spacer. You should have no problem with those size tires assuming 7 and 9 inch width wheels.

craig001

I found the TSB from 9/23/1993 on Porsche's approved 17" wheels and tires. It's bulletin number 9303. I found it on-line, but can't remember where. And of course right at the end of the service procedure it states "Not for cabriolet vehicles." Oh well, I got these rims from another 90 S2 cab owner. Porsche wants us to get new caster eccentrics (951.341.431.02 x 2); rear mounts (951.341.023.00 x 2); and nuts (900.910.115.02 x 4/Torque to 100NM). The new caster specs are 3'-15"-45. The place I found these didn't have the pics posted. But that's basically a quick synopsis of the TSB. Anyone interested in a S2 cab w/93.3k miles?