Aplah-N on an na LT1 stroker

[Birdzilla]

I've got a FAST computer controling my na 383 LT1. I recently slid an fairly aggressive solid roller in it and spent several days pulling my hair out trying to get throttle response, driveability and WOT tuned in speed density mode. I changed strategies and switched over to Alpha-N and the car seemed to really like it.
I've got a couple of questions that would really help me out in finding this thing's potential.

1. What AE tables (if any) are used in Alpha-N? I'm thinking just A/E FUEL VS. TPS RATE OF CHANGE. Is this true?


2. It seems to idle best about 1150rpm's with 30-32 degrees of timing, 38 total in by 3500. I've seen several other .gct files for na small blocks like this. Is this normal???? Everything I've ever read says 16-18 initial, 36-39 total. What gives?


3. I've got fairly respectable throttle response now, but I believe it should snap harder. What screen should I be looking at here? If its a 2D curve, can you give me an idea as to how it should plot out?

Thanks in advance. Here'e the combo:

383ci, 12:1
58mm tb, 1000cfm
ported LT4 intake
AFR 210's rr(285cfm @.700)
42# injectors
solid roller (312/325,.279/.286@.050,.679/.645, 108cl)
1.75 primaries on super comps

 

[DRAGRACR]

Are you still running the factory opti?? If so, any issues?? I have also been pulling my hair out with my setup. Basically the same setup with a little milder cam 250/259 @50 and a 1300 monoblade. I am making more power with my factorg computer than I am with the fast...........

 

[Birdzilla]

With the opti I was breaking up by 6800rpms. Disassembly showed some carbon build up on the 8 cap posts and a wobbly rotor tang. I'm now running an LTCC conversion (LS1 coils), with a modified opti that only has the eye and the slotted metal wheel in it for hi/low res...no cap or rotor, and I sealed the front cover or the opti due to the lack of the cap. Very clean. The cam has a 4/7 firing order swap, so that is also similar to an LS1. Its a Comp Cams grind.
The car is entirely controlled by the FAST, not piggy-backed. Its got a plug-n-play harness from White Racing, so that install is clean as well.

My vacuum at idle is low...haven't stuck a gauge on it but my brakes are pittiful cruising around the neighborhood just off idle. I spent hours, alot of them, trying to get it sorted out in speed density mode with slight success. Down right embarrassing driving around a roll cage car that sounds like a loud, abused '75 dodge station wagon off a stop light. I switched to Alpha-N and the combo just responded! ET Streets now bark under light load off idle. I'll be back tuning on it tonight. I'd be happy to share knowledge. I'm kinda feeling my way through this.

 

[RickWI]

That is a REALLY big cam for that displacement and compression to run on the street. may never get it perfect across the board.

AE Vs TPS is the only accel enrichment used in Alph N.

I have my timing at idle around that same area, 28 degrees. When I step into it I have the timing retard a bit under loaded conditions below 3000. By 3000 I have all my timing in, I only need 32 with my heads. It is also important to have those VE cells dialed in. It sounds like it may be more of a cell tuning issue. Your total timing of 36-39 sounds high based on my dyno work with AFR heads. You should make best power around 33-35 at most.

 

[Birdzilla]

Yea, I agree...it is a big cam. I'm more concerned with low ET's off a trans brake than streetability, which was what I expressed to Comp, Crower, ect. when I gave my specs and sought recomendations. Even with my amateur tune, it really turns on in the upper rpm's.

Thanks for the timing advice. I'm going to try pulling some out just as you recommended.