1/4 mile test data on a new 396

I posted a shorter version of this elsewhere, but after reading the announcement topic, I am sure that it would have been ok to post it here originally.

The first 1/4 mile pass with my new 396 LT1 went very badly. The basic mods are these:

396 LT1, GTP stage 2 heads, JE pistons ~12:1, mechanical roller 256/262 .629"/.629"

It put down 450-455 on a rear wheel dyno earlier the same day, and it ran a little rich.

I recorded a Datamaster log of the run, and I think it shows three things: The clutched slipped (which I felt), there was detonation (the computer pulled out up to 15 degrees of timing) and the computer seriously malfunctioned (among other things, it registered a jump from 49 to 196 mph, simultaneous with throwing the first codes, 41 and 42).

I know very little about tuning, and I'd be grateful if someone with more knowledge could analyze the data. (I also have the .LT1 file of the pcm program.) If so, please reply here or email me at cklein@austin.rr.com.

Actually other than LT1 Tech this should be posted in the Computer Diag/Tuning forum. I'll move it there now for you.

And i'll update the announcement too...

ill take a look at the cam file and the data log if you email them to me.

what did you manage to rip off in the 1/4?

I just sent the data log. Thanks very much.

I ran 13.33 which is decent given that I decelerated when I got about two thirds down the track -- once the first warning light lit. I also had my worst launch ever -- first time with 4.10s. My best time with the same setup (but with 3.45s) was 12.44 -- which is way below its potential. I need more practice.