18 inbch wheels on 964?
03-04-2011 | 12:32 AM
#16
Pro
Joined: Mar 2009
Posts: 623
Likes: 0
From: Singapore
Yes, but if you use lighter 18" forged rims, there's less mass, and therefore less force. The 17" Cup 1s weigh a ton.
03-04-2011 | 01:59 AM
#17
Rennlist Member
Joined: Aug 2006
Posts: 4,324
Likes: 147
From: 6th gear!
Part of the issue, however, is that the shorter sidewalls transmit more impact to the suspension components. A car's tire sidewall flex is an integral part of the suspension "tuning".
03-04-2011 | 11:14 AM
#18
Instructor
Joined: Jul 2002
Posts: 166
Likes: 4
From: Northern VA
"..........only reason I changed wheels was those dreadful "style" 90 Phone dial wheels............."
Heyyyyyy... (see the avatar) You can see I have no experience with this, but you might want to at least look at:
http://www.pcarworkshop.com/images/d...0593geolab.pdf
This PCNA Technical Bulletin says "Retrofitting 18" wheels on Porsche vehicles which do not have 18" wheels as original equipment is NOT ALLOWED." While this was a technical issue back in 1993, everyone with 18" wheels here yells BS every time it's brought up. You might want to consider following the guidelines for upgrading to 17" wheels by fitting the improved caster mounts.
Now, everyone can restate, "Don't worry, it'll be fine...........
Heyyyyyy... (see the avatar) You can see I have no experience with this, but you might want to at least look at:
http://www.pcarworkshop.com/images/d...0593geolab.pdf
This PCNA Technical Bulletin says "Retrofitting 18" wheels on Porsche vehicles which do not have 18" wheels as original equipment is NOT ALLOWED." While this was a technical issue back in 1993, everyone with 18" wheels here yells BS every time it's brought up. You might want to consider following the guidelines for upgrading to 17" wheels by fitting the improved caster mounts.
Now, everyone can restate, "Don't worry, it'll be fine...........BTW Tech Bulletins are seldom BS! Looks like what it says is that Porsche wants their customers to be aware of a possible situation so they can make an informed decision. IIRC there’s another one about running 18s on early 993s. I think that one recommends reinforcing certain areas of the chassis.
