Too Aggressive COM for Rougher Track?

Jan 14, 2015
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First, let me say thanks again for all the information on this board - much appreciated and helped us win our pack for the 2nd straight year (my younger son this time).

Despite my older son's car being by far the fastest there - .03 faster consistently on the first 3 runs than my younger son, who ended up winning the pack easily - on his last run his car jumped the track and skidded down toward the finish in a painfully slow time which took away his easy win. There were probably about 75 runs total and there was 1 other car that did the same in that same lane. It was a 42' best track, but it's a little older and there are definitely some rough spots/seams. I think it came off the track on the first seam after transition, but not sure. I was in shock at the time (still am, quite frankly).

My question - we ran a 5/8-3/4" COM, in hindsight was that a little aggressive given the non-perfect track condition? Or was it just dumb luck that he jumped it? Weight on DFW was .5 oz.

Setup: non-canted rear wheels, 5 1/2" WB, rear fenders, .5 oz DFW, 4 1/2" in 4' steer

Thanks guys! Now that he's missing districts this year he wants to send in a car for NPWDRL, so hopefully we can get that done for March.
 
I don't doubt there were some less than perfect seams, in fact I had my file out prerace trying my best to smooth them. Ironic that I'm the one who got screwed by one. So much for karma.

I guess I'm wondering how much a com around 7/8 could have prevented it without losing too much speed?
 
BulldogRacing said:
it sounds to me like all your data shows a conservative car, it was probably a bad seam that stuck out on the vertical?

Bulldog - I just watched your video on sanding the track. You better believe after this incident I'm going to be spending hours doing the same to this damn track before next year's race. Thanks for that video!

JP
 
DerbyJP said:
BulldogRacing said:
it sounds to me like all your data shows a conservative car, it was probably a bad seam that stuck out on the vertical?

Bulldog - I just watched your video on sanding the track. You better believe after this incident I'm going to be spending hours doing the same to this damn track before next year's race. Thanks for that video!

JP

Nice!