416ci (LS3) 12.4:1 CR, race gas to pump gas?

[pir4te]

LOL, thats cam specs at 50..... You need to use specs from when the valves actually open.

Mentioned that, but range is probably between 60 and 70 ABDC I reckon. I think LS3 DCR over 9.3 (without building some mechanical octane) gonna need more than 93. Entirely possible OP is way over.

[n8dogg]

Mentioned that, but range is probably between 60 and 70 ABDC I reckon. I think LS3 DCR over 9.3 (without building some mechanical octane) gonna need more than 93. Entirely possible OP is way over.

I must be missing something on the engine spec sheet from the builders. I'll take another look, any terminology I should be looking for?

[pir4te]

I must be missing something on the engine spec sheet from the builders. I'll take another look, any terminology I should be looking for?

Advertised IVC or IVC @ 0.006"

[joecar]

The cam spec sheet typically has the specs for 0.006" and for 0.050"... post a pic of it if you can.

[n8dogg]

The cam spec sheet typically has the specs for 0.006" and for 0.050"... post a pic of it if you can.

[pir4te]

Interesting cam! Not the info needed to confirm my guess, sorry can't help.

[n8dogg]

Interesting cam! Not the info needed to confirm my guess, sorry can't help.

I'll ask the previous owner if he has those specs.


Here is the tune file for those who are interested in looking at it and want to give their $.02. I expected a touch more spark, my stock block H/C/I C5 Z06 see's 28 degrees timing with 93 octane and no knock. Maybe the tune is conservative being a race car.

2005 Race Corvette.ctz

[joecar]

Yes, that's some builder's buildsheet, it's not the cam grinder's card.

[joecar]

Looking briefly at that tune:
- stoich is set to 14.08 so he's running something like E10-15.
- PE is not sufficiently rich at EQR 1.14 (EQR 1.175 would be safer).
- it is scaled for VE/MAF/IFR since IFR maxes out at 7.999 g/s).
- HO and LO spark tables have too much timing at high load (consider that LS heads are fast burn design).
- HO/LO separation is not sufficient,
- this tune looks like an E40.


If you do this:
- increase PE EQR to be sufficiently rich,
- reduce HO to 24 degrees at high load,
- set LO suitably wrt to HO,
- run E10+ (set Stoich AFR tp match your fuel)
then I think you'll be able to run safely (power will be down from 800HP since timing will be reduced).

Can you get any logs (showing LTFT's, KR, SPARKADV, MAF, MAP, LAMBDA/EQR, ECT, DYNAIR/DYNCYLAIR/APCYL and the other usual pids)...?