Bill Verburg

Not off the top of my head.

This is truly puzzling as on a 993 you can just swap the stock for RS uprights and outer tierods w/ no other changes.

several guys have done the 993RS uprights and GT2(monoball) inner + RS outer and RS upright on a 964

The 993 and 993RS parts are the same installed length, which should be compatible w/ 964 length.

DAVISRILEY

Tell me about it. I am dragging my feet on having the tie-rods cut back, as I would rather find out that I missed something, or did something wrong. But i can't think of anything. You can't put the knuckles on the wrong sides, the control arms were not off. the steering rack was not removed or replaced, and as far as I can see, the struts are in correctly. I have koni's, so they are an insert. But everything lines up, such as the brake line cut out and all of the abs sensor connections. So I am back at aquare one. I don't want to go back to the 964 knuckles, as I would have to get new adaptors, as I have gone to 993 turbo rotors.

DAVISRILEY

Finally got the whole thing together. Ended up shortening the inner tie-rods a little bit. Everything else ended up fitting pretty well. Got the alingment done, and have put about 50 miles on it so far. My initial feeling is while it is nice to get away from caliper adaptors, I don't know if I would do it again. I don't notice much of a difference, but I still need to play with the ride height and alingment a bit more, so hopefully I can "liven" up the steering feel just a little, as it feels kind of dead at the oment, and initial turn in is a little lackluster. Thanks for the help!

kurquhart

Good to hear that you finally got it all worked out.

Looking back on my similar conversion, I am also not sure that I would do it all over again. I am still fighting a push and my turn in is also not crisp (e.g. when compared to a similarly prepared 993). Then again, I thrive on the problem solving aspect of this hobby, so I always need something to fiddle with.

DAVISRILEY

I hear you. Mine is constantly a "work in progress". I think some of the "deadness" in turn in is due to the front of the car being too low. I thought I got it at the same height, but it sure looks a lot lower. Hopefully when I bring it up a bit, it will feel better. I am going to play with toe and camber, and see if I can get it better.

Geoffrey

Kurt, your push could be related to the Front / Rear track difference in a 964 compared to a 993 and / or an aero imbalance front to rear with the large rear wing. You'll want to determine if it is speed related which will help differentiate between mechanical and aero. FWIW, I have oversteer issues on my 964, not understeer. I have 993 components up front except for the 993 subframe side members.

kurquhart

It is definitely a high speed problem; at low speeds the car is neutral to slightly loose (easy to drive around).

I can change the balance by removing rear downforce and/or widening front track, but there are limits to how far I can go with these adjustments. I have tried a couple different front splitters, but no real change in balance.

My current theory is swaybar imbalance: I disconnected the swaybars (keeping aero constant) and the car was loose even at high speed, so I don't want to change the spring balance any more towards the rear. I then changed my front bar from 964RS (24mm) back to stock 90 C2 (20mm), and the push was reduced, but not eliminated. Do you know of an adjustable rear bar for a 90 C2 that is stiffer than 964RS?

How would you rate your turn in feel? Maybe my perception of deadness is simply the push...

DWS964

Dave,
Glad to hear you are back on the road again.

Steve Weiner-Rennsport Systems

Hi Kris,

I haven't bought one in awhile but TRG used to make a 22mm rear bar for 964's.

Its a good choice for race cars.

kurquhart

Thanks! I'll look into that.

DAVISRILEY

No kidding It took a whole lot more time than I thought. But, car feels good, all of my clutch release issues are gone, new wheels look good, and after cleaning the afm last night, car seems to have the throttle response it should. Life is good

Geoffrey

As Steve mentiones TRG makes a 22mm and I think H&R makes one as well. I have the TRG 22mm on my car and have never moved it off of its loosest position because my car has oversteer. I'm in the process of building a cockpit adjustable rear bar that should allow me some additional flexibility in adjustment.

My car's turn-in is fine, it suffers from corner exit oversteer which I've tried to dial out with damper adjustment, but a test with a standard RS bar shows that my current rear bar is too stiff. My car also suffers from high speed transition which was improved by going to stiffer springs, but is still not where it needs to be. My car is too high because of clearance issues from running 680 rear tires as well as a lack of front / rear downforce which is hurt by my ride height and no real wing.

kurquhart

Thanks for the information, Geoffrey.

Sorry, DAVISRILEY, I did not intend to highjack your thread.

DAVISRILEY

No worries, I am intersted in following it too. I actually have the h&r 22mm sway on my car with the stock front, and I like it. I have it full soft, and have not tried any more. I may next time it is at the track, just to see. Now if I can find a set of gt-2 tie rods......

Bill Verburg

I'm confused as to which knuckles you are using

I know that Geoffrey has on his race car the 993RS version which are also used on the GT2 and are compatible w/ the solid race tie rods.

But I was under the impression that you were using the long arm stock 993 versions that need at least the stock outer tierod ends