Don Hanson's Upgrades
I have made a lot of progress with the suspension and handling of my 90GT and though there may be some interest in what I have done and with what results. With a lot of help and advice I have my car handling the way I like it, considering it is still a highway driven car. Below, I will outline what I did. Delete now if you aren't interested or are going to tell me I didn't do something right. It all works for me. I am sure some would and have done things very differently, this is just what I have done -YMMV
I started with a good 5sp LSD with 17" supercups and BFG KDs, which worked pretty well. Good start. Then I went to Marc Thomas at Devek for some suspension work, externally adj. Konis and Hypercoil coilovers, I think he calls it "Level 1" for hard street, DE, and occasional track. This is what I am using now. Mark did the installation and the alignment, and set-up the shocks and their heavy sway bar for open road racing. Big big improvement! I have only just started tweaking the settings he used, and just a very little at a time, mainly for curiosity, not because anything needs changing...
I won't give any costs here as I don't feel like digging
back through the files.
I have been using 285 40 r and 255 45 f, on 17 x ? wide HRE wheels. I am guessing R-10.5" F-9" that were made to Deveks specs as to offset. I am running with the Weisach axle pinned. The one drawback of having such a lot of rubber is the car is a handful on rutted pavement. I guess it is not the "average" footprint of rubber, so it doesn't fit the ruts you encounter.
I added Louis' sway bar steroid treatment for the rear, but found at the most aggressive position, the rear of the car was loose. Lots of oversteer on hard cornering, even with no throttle, brake input. I moved the mounting hole back(shortened the lever arm) which I think Louis has made as an option on his later kits. This works fine, bringing the car back to neutral handling at the limit, yet reducing rear body roll.
Remember, suspension and handling are a combination of many components, adjustments, driver style, track and road conditions, etc. Every combo has a different result, and all adjustments to one thing affect everything else, so what is working for my car may leave you in the gravel trap.
I then upgraded to the Big Red brakes with a new bias valve, as my rotors were getting thin, and at the same time, mounted some DOT but sticky Yokohama A O 32 tires, just in time for Devek day at Thunderhill.
Another quantum leap. 1st big one--The Konis/Coilovers--2nd, big sticky track rubber and huge brakes. Now my car will do anything I am good enough to ask of it. I can run with the faster guys now, without slipping off the track. I can try different lines in corners, different brake points, etc. and not have to worry about the car getting away.
Yesterday, at Portland International at a race school, my car was one of the faster lappers out there, despite it's driver. M3's, 930s, Barabus Merc., one of those little hot rod round Mercedes $, they all found the shark chasing them down and gobbling them up!
I mounted the Yokos on the same rims above, and have a bigger set coming from Knessis, ordered by Marc to Deveks offsets. I am running 315 35 17s on the rear and 255 40s on the front, running about 35f and 32r for pressure. I had to add an 1/8" spacer on the rear as the tire was dragging on the trailing arm inside, and I ran a piece of plastic conduit around between the old tires and the wheel opening to flair the body ever so slightly. No clearance problems now.
So that is about it. No major engine work, yet (Hi, Marc) a cat bypass and RMB. Works great for me.
I had lotsa interest yesterday at the track. People wanting to know what kind of Porsche is THAT? "it sounds SO good" "How do you get that to go so fast?" "What have you done to the motor?" etc. The aircooled crowd is getting to know this car, they even talk to me. The 944 Turbos are moving over for me, too. Not your ordinary "dentists wife's grocery getter" anymore. Cool.
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