Glen

Here are links to the ERP stuff I use on my 993, I thought you guys would like to see it. Cary has some very cool stuff, used it on my 914-6 racecar and now on the 993, with the correct settings you can completely adjust bump steer to zero with these goodies on a lowered car. No affiliation, yada yada, just very good experiences...


<a href="http://boards.rennlist.com/upload/IM000407.jpg" target="_blank">http://boards.rennlist.com/upload/IM000407.jpg</a>
<a href="http://boards.rennlist.com/upload/ERP2.jpg" target="_blank">http://boards.rennlist.com/upload/ERP2.jpg</a>
<a href="http://boards.rennlist.com/upload/RUFSOLIDSTILT.jpg" target="_blank">http://boards.rennlist.com/upload/RUFSOLIDSTILT.jpg</a>


The last link shows the Solid Engine Cradle Mounts with Tilt Kit installed.

Glen

BTW the Solid Cradle Mounts and Tilt Kit were RUF components although ERP also makes them I found out.

JohnM

OK, I'll bite . What does a "tilt kit" do?

Glen

John, when you look under a factory RSR you will see it also has a tilt kit. It basically gets the suspension geometry where it needs to be on a lowered car. As you can see the Heim jointed links add an infinite amount of adjustment for the multilink rear while the monoballs really wake up the responsiveness of the rear susp. Note that the tilt is an option of the solid cradle mounts, you can still use the solid cradle mounts without the tilt if you want.

Greg Fishman

Cool set up Glen. I hope I don't have to go up against you at too many races next year .

Cary's parts look like a great alternative to the silly prices Porsche Motorsports wants for a their links.

Cary

Glen, Thanks for the positive post, I’m glad to see you’re happy with the parts.

Let me throw in what I know about this stuff. The Tilt kit was actually originally done by Porsche Motorsport for the later 993 GT2 Evo car. As it goes, I don’t like my parts copied so, I make it a point to NOT copy other’s yet, it seems in this case we sorta made an exception. The reason was this; at that particular time those mounts were only available to racers if they were willing to buy the complete rear suspension carriage supports members. The cost was not justified so, I agreed to make similar parts that accomplished the same goal for various teams so they could update their cars to remain competitive within the rules. Incidentally, Motorsports is now offering these parts individually for reasonable prices so, we are no longer building them. As a side note, I was unaware that Ruf also made these parts.

Now, as far as the exact function, it’s not 100% clear to me on the reasoning behind using these mounts. During the time they came out I think just about every team I dealt with had a different theory on them. However, what I can tell you is the obvious, using this part will DECREASE the amount of anti-squat in the rear as well as the caster. Caster in the rear of these cars effects the bump steer, which is also independently adjustable with the kinematics link within a certain range. At the time, if you had an early version GT2 car without the tilt kit, the Porsche Motorsport manual told you to just max the kinematics link eccentric. I find that the factory typically likes a more bump steer in the rear than I do so, I'm always changing that stuff around. You really have to drive the car yourself with your own driving style to see what works for you.

Later, we made completely adjustable links (like Glen has also added) that allows a wider range all the way up to and include ZERO bump (for a couple inches) with or without the tilt mounts. This way if you decide to remove the front spacer from carriage mount to raise the roll center (RC) (which I think is a good thing), you can still have the bump curve you want. BUT, (there’s always a big but(t)) remember while achieving the higher RC this way you will now increase the anti squat again. In case you might have huge spring rates this added anti-squat can sometimes cause a lose in side bite. God isn’t this stuff fun! And there’s more…but, I’m going to bed for today.