Twilightblue28A

Would anyone know whether or not 18" twist wheels were available as a Porsche factory option on 1995 Cabriolet Carrera's or Cabriolet Carrera C4's??
Thank you in advance for your response.

71-3.0-911

I don't believe 18s were an option on any 95s. If yours is equipped, check for the steering rack brace. I believe this was mandatory for cabs and targas.

the wanderer

I can not answer but will say I have date stamped 95 Hollow spokes for ze turbo

PNW993

I just put twists on my 95 cab, @71-3.0-911 is right, you need the steering rack brace. Here is the information you need to do it: http://p-car.com/technical/wheel.htm

orangecurry

If you are still looking for this information.... a great deal depends on when your 1995 car was supplied. What was it's MY?

But I have also owned a 1995 manufactured-date hollowspoke, but a rear narrow bodied version i.e. 993.362.140.01, so they were certainly available.

Bill Verburg

Based on TSB 9501, from Jan 19, 1995
no


That is the Summer Tire/Wheel Summary

It lists 3 different wheel./tire options for Carrera /Carrera4
cast aluminum 7 7 9 x16 5 spoke a very handsome wheel reminiscent of the Speedlines used on RS, these are often referred to as Cup Design 93 and usually used w/ snow tires

cast aluminum 7 & 9 x17 5 spoke often referred to as Cup2

cast aluminum 5 spoke 7 & 9 x17 , there have 965 part #s and are carryovers from 964 and are often referred to as Cup 1

the wanderer

Makes perfect sense cuz in 95 cars were having snap handling issues. TSB Brace. Re-design rear control arm geometry to alleviate the rear end snap surprise cornering issue :>)

71-3.0-911

This is the first time I've heard this. Any literature? The only change for 18" wheels that I am aware of is the steering rack brace. I have not heard of any of the suspension geometry changes between model years.

Bill Verburg

Take a look Suspension change TSB

it's a bit over blown to say they had snap issues but the handling of the very first 993s was sub par

the correction components are listed in the above link

that said the 993 can snap spin, BTDT, but it's more an alignment issue and/or driver error, In particle KT setting can drastically speed up or slow down the reaction of the rear, that combined w/ lifting at the wrong time can cause the car to snap spin.

71-3.0-911

Looking at the list, it seems contained to shocks, springs, and sways. That doesn't seem to imply any geometry changes unless the geometry changes are assumed with a different ride height enabled by the spring and shock changes? When someone mentions geometry changes, I think different arms, links, uprights... not necessarily ride height induced. Am I missing something here?

Bill Verburg

I don't believe that there was any geometry change, I have had old and new pieces side by side, there are slight casting differences but that's it

settings and bush spec are my best guess as to what changed

the wanderer

https://rennlist.com/forums/racing-a...ml#post3952070
input by J Reiser

Bill Verburg

I've had the original and new pieces side by side and w/ RS and RSR equivalents, There are casting differences but no difference in length, width, height, or geometry The old bushes were so far gone it was impossible to compare them to new, the discussion referenced was from early days when factual info was much harder to get, J.R. is a very knowledgeable source but he was also running a business where knowledge is power, in that situation it is common to be less than fully open about things. I'm pretty sure he had the TSB I posted and was giving advice based on that.

rear geometry is changed by rotating the eccentrics on the inner ends of the arms. This is called alignment. Changing to turnbuckle arms which could easily change rear geometry, doesn't because when the car is aligned the arms are adjusted back to original length.

several things i have learned over the years

1) The mono-ball joint on the leading leg of the a-arm goes bad(failure mode is increasing looseness) before the rubber bushes on the trailing leg, as it gets increasingly loose the handling gets increasingly bad

2) These cars are very sensitive to tire pressures, and alignment, KT is particularly sensitive as it directly affects the rear steer characteristics, drive your car backwards to see how powerful rear steer is. The toe arms also have a powerful influence in this and the stock toe bushes tend to go before the others, this enhances any hinkyness induced by faulty KT, changing to full mono-ball cures this.

3) These cars are also very sensitive to bushing condition and stiffness, Using the stiffer RS over even new stock greatly improves 7/10 and above performance, going even further w/ full RSR mono-***** does the same above 8/10, all this still relies heavily on proper alignment

4) When going really low, i.e. well below RS throws geometry way off, to correct this front RS wheel carriers and steering arms are needed and rear subframe bushes need to be eliminated and replaced w/ thinner solid versions that relocate the suspension back up into the chassis

5) The eccentrics used for changing the lengths of the arms are less than reliable in track use, I suspect that they slip over time when used on bad roads too, when they slip the handling gets very bad, this can happen in a very short period of time, one lap you are fine the next in the weeds because the alignment changed

6) very, very few '95s will still have their original parts.