ITR Expo is practically less than 2 weeks away and I'm still trying to put the car together.

Just got back from the Grand Am race (well not the race - just Thursday and Friday testing) at Road America. Wow - Road Racer heaven - what a facility. PIR is pretty humble by comparison. Saw Kings shop too - pretty good full service race shop.

Since my Bilsteins haven't come back yet and I need to do some adaptation to the upper spring cups for the Mugen N1's that I won't have the pieces for till Monday, I got out my bump steer gauges and evaluated the effect of rear camber adjustment on the toe setting: toe is unaffected over a range of 6.5 turns on the King arm which at 16 TPI roughly comes to about 2 degrees of camber change. Useful knowledge.

Then I looked at the front end with my new RTR clone bump steer kit. With only a crude setup on the tie rod length - eyeballed, I measured out the toe change over 1.5 inches of bump and 1.5 inches or droop. I was getting big toe change about zero, and the pattern had reversed from the stock arms: instead of toe in in bump and toe out in droop, I now have toe out in bump and toe in in droop. Without an accurate alignment I can't be sure that a small error in tie rod length isn't overwhelming the effect of the tie rod end height correction (which superficially now appears to have been excessive - but the big jump at near zero suggest somethings fishy). I don't have much time before the Expo so I don't see myself getting to the bottom of this this week - so I'm going to pull the kit off and run the stockers for the Expo, and then later sort out what's going on. Either there's more going on on the rack position on the RTR cars, or they are purposely breaking some taboo's, or it's just misalignment/rod end length. I'll briing the kit to BW for visual entertainment.

I've found it is possible to install the stock ITR rear shocks despite the restricted droop travel allowed by the Mugen bushings (the primary culprit here is the big trailing arm bushing). What this means is that I will drive the car to the Expo on cushy rates in the rear. I plan on running the 450 lb sprung Bilstein fronts for the trip - should be quite satisfactory, especially with a couple hundred lbs of stuff in the car. The stock ITR fronts turn out to be too long to mount with the Z-Speed arms in the full negative position because the ball joint reaches a limit of travel with just about a quarter inch to go to get the yoke under the shock. The King arms greater cup angle would only make this worse - oh well.

About Road America. 1) Beautiful track, beautiful countryside. 2) Bob Endicott is a pretty cool champion type person - he'll tell you about his problems and screw ups as readily as he'll tell you about his victorys. 3) Scott Zellner's operation is a cut or two above the rest, and while you always know he's not telling you everything, he'll tell you alot more than almost anybody else. He'll let you look at anything on the car, but if you see something interesting and ask questions he will tend to dissemble a bit. A big part of racing at this level is the psych war and I think Scott is good at it and probably enjoys it. 4) Lex Carson does an awfully good job of getting Moton on race cars, and he's relentless in selling the virtues of his expensive big-shafted shocks - you know I just may need another set of shocks

One of the HART Civics was running 1600 lb rear springs, 1100-1300 front springs and no front bar. The Spirit of Miami ITR's were running unknown rates on JRZ/Moton like spinoff shocks with NO REAR BAR and cable droop limiters - the crew chief didn't want to talk to me about his secrets - they ran nose high rake and appeared softer than average in front. The Planet Earth GSR's were running Motons with "stiff" rates, but ran Mugen N1's in one practice session - perhaps just to prove that the money they spent on the Motons was worthwhile - their crew chief was pretty tight lipped too. There was a grotesque GSR colored in Pink/Grey/Black that was driven by at least one very nice guy who had no real secrets but wasn't going as fast as the other guys - his car was a bit softer than the others. Virtually none of the H-A cars lifted the inside rear unless provoked by curbing (very surprising to me in the case of the Miami cars). The Hyundais by comparison were lifting long but not too high. Lex said that this had alot to do with damper progress over the last year or two and getting more grip at the front.

As stiff as these cars were, many of them were consistently running on the inside rumple strips on turn 8 the left hander at the bottom of the hill before the carousel. Even the stiffest of these cars showed surprising amounts of wheel travel and no sign of chassis upsetting - I was somewhat surprised and comforted by this observation.

Scott

 

Sounds interesting.
I'm starting to look at things for a third iteration of my suspension.
See you at Buttonwillow. ed

 

again, a wealth of information.

i should get started on rotor blank off plates this weekend. nelson ledges made it quite apparent that the need for brake cooling exists.

D