kos11-12

Hi ,

I am gathering parts to upgrade my C4 1992 to big blacks the car will be 50/50road /track use , I would like to upgrade to 993 RS / TT alloy wheel carriers , according to the 964 PET the front whell bearings are the same across the models so I presum the 993 RS/TT wheel carrier will fit with no problems using the same bearings ? I suppose I need the 993 RS TT disc offset , do I need the shields behind the discs ? By reading some threads I understand that the lower bolt of the wheel carrier need to be drilled from 12 mm to 14mm to accept the 964 shock absorbers , I am planing to fit ERP tie rods , do they fit with no mods ?
thanks for your comments

Konstantin

Bill Verburg

993n/a and 993tt use the same wheel carrier(upright)
993RS/GT2 use a different version of that wheel carrier, designed to accommodate a lower ride height.

To use the 993RS/GT2 upright in a 964 it's best to use 993 struts, the 964 lower bolt is smaller than the 993 and the mating boss on the 993 upright is a tad wider than the 964 uses. Some have overcome these issues but it's still best to use 993 struts.

Yes, the wheel bearings are the same, but you will need new bearings w/ the new uprights you will also need at least the outer tie rod end that gos w/ the 993RS uprights.

Either 993 or 993RS/tt calipers are a bolt on(no adaptors) and you use the matching rotors, either 993 or 993RS/tt for the calipers.

kos11-12

thanks a lot for your reply Bill ,
the only difference on the 964 upright ( whell carrier ) to 993 rs/ tt or GT2 at the shock monting points is it only the diametre of the lower bolt ? why would you think it's still best to use the 993 shocks ( struts) ? I just fited recently KW V3 , I will definetly get new bearings , no disc shields then . the tie rods is the complit ERP kit from Smart racing is that it , and maybe new ruber boots.

Konstantin C4

Bill Verburg

The 993 strut mounting slot is a few mm wider than the 964 to accomodate the wider al. 993 uprights, the 964 uses steel uprights that aren't as thick in the mount area. As I said, some have managed to stuff them in there, whether by, trimming the aluminum or trying to spread the slot I don't know. Drilling the lower mount a few mm larger isn't much of an issue.

kurquhart

Does the ERP kit come with inner tie rod, too, or only outer? The ERP outer won't mate to a 964 inner, so you will need a 993 compatible inner, if it doesn't come that way from ERP. For example, I have an ERP outer and a GT2 inner on my car.

We found that the lower ball joint had to be changed to 993, too, but I haven't seen anyone else mention this part, so we might have made a mistake.

Are you changing uprights to run a lower ride height? If so, you may also want to consider Tarett drop links (at least one side). This is not required, but the length is adjustable so you can dial out the resulting preload.

kos11-12

Hi thanks for the pictures guys,

ok I definitly need the GT2 inners , yes the car is lower but the C4 doesn't give me the option to use the adjustable drop links do you think it will be a problem ,could have some made at a later stage ,did you reduce the thickness of the upright to fit the shocks ( struts) ?

thanks a lot guys

Konstantin

kurquhart

993 inners will be fine for a (part) street car and can be purchased individually. The GT2 tie rods only come as a complete set, but the outers are easy to sell.

Changing the drop links is an optimization, should not be a problem w/o them.

The only change we made to the 964 strut was to drill out the lower bolt hole to 14mm; they fit the upright just fine. I can't explain why our fitting experience is different from others that have required 993 struts.

DAVISRILEY

The part of the ball joint that connects to the spindle is the same for 993 and 964, but where the ball joint mounts to the control arm is different, ie the stud that is pressed into the control arm is thicker for 993's versus 964. I know you can go back and forth, as I have 1 993, and 1 964 on my car at the moment, as I had a stud problem last fall, and a fellow rennlister helped me out with a control arm from a 993. I will be switching to a 993 on the other side this year, when I do a similar conversion to Konstantin.

kos11-12

hi ,
I think I need to wait to see the uprights ( wheel carriers ) to see how we can fit the KW V3 shocks ,
davisriley you mean the inners are same as 964s ?
also you mean the ball joint that is bolt to control arm and go to the upright is different ( bigger on 993 )
I tried to attache the PDF diagrams but I can't the system is telling me it is to big , haa !

Konstantin

DAVISRILEY

Inner? What I meant is the end of the ball joint that connects to the knuckle seems to be the same between the 964 and the 993, so you should be able to bolt the knuckle to the ball joint that is on your car. I know I was able to.

NineMeister

We have a great relationship with KW (probably because we sell more KW stock than all the other Porsche specialists put together), so once you get your Evo uprights and see the problem of fitting them to the 964 strut, should you decide it's too much hassle or risk to make it all work if you send me your struts I could get them rebuilt into 993 KW V3 bodies. Not sure how long this would take as it will be a one-off (maybe 2 weeks?) but if you are stuck and need to use your car in the meantime I could lend you a pair of 993RS struts to fit and use until they were returned.

kos11-12

thank you Colin , that is really kind from you , by the sound of it there is no safe way arround this ,

Konstantin C4

Rioja del 73

Hello,

Where in Europe could I find these RS upgrade for my 964? To order and send to Spain, I mean.

Thank you

964TT

These are genuine Porsche parts. Should be no trouble getting them through Porsche Spain.