View Full Version : 90mm set-up question

Mike Keely
2012.11.17, 10:08 PM
These 90mm cars are new to me. I am finding the inside wheel is diffing up in the turns. What would be your first thought on the set-up to fix this issue?

Car is narrow now with the Reflex front end and the Atomic rear pod with only the top damper disc in the rear. Thanks guys.

2012.12.03, 02:58 PM
Softest t plate you can find with stiffer front springs.

2012.12.03, 11:09 PM
I'm assuming you're talking about 90mm narrow chassis? With those I would run a very stiff top spring to force the rear end down when you get on the power, this compounded with the soft T-plate will do an OK job of getting the inside rear down, and once it's down it's typically good to go. PN G10 #3 should be soft enough to avoid picking up the inside rear wheel, but I think some Lexan T-plates may be even softer.

The issue afterwards is that narrow MR03's sometimes traction roll on-power (!) on RCP, and my response to that is to run medium springs (PN Red or Green, for example) and jack the roll center up sky-high using an aluminum tower bar and 0.4-0.6mm worth of shims. That should curb most traction rolling, if there's any left during turn-in, then the superglue-on-sidewall will suffice. :)

2012.12.04, 12:19 AM
One local here has a really good 90mm vw bug. He uses a custom tds in the rear, but the rear suspension is super soft (equivalent to a dds with a pn 4 or 5 g10 tplate). Also, the front springs are very hard and I don't think they ever compress. I have driven his car multiple times and his car pushes but doesn't traction roll. For front springs, you could try the stiffest Reflex front spring. From what I remember, that spring was pretty stiff (long kingpin).

2012.12.04, 10:34 AM
Interesting topic.

I'm working on a Vitz setup. Right now it runs already very well stock out of the box. But turning in the inside rear wheel also comes up.

Mike Keely
2013.01.08, 06:07 PM
I have a pretty hot motor in the car now. I ended up with the green medium PN low down spring along with the Reflex front end bar raised very high so the front arms are angled downward to stop the camber gain in the turn. Using the 19mm front rims and 40 kyosho fronts. In the rear I liked the medium DDS springs and using nothing on the damper pucks. PN #6 radials in the rear.