Tuning a LSX intake?

[Redline Motorsports]

We just installed an LSX90 w/TB on an 388 all bore motor that had an LS6 and stock TB. I was able to get the idle pretty decent by playing with the idle air flow and a few of the other parameters. I figure since it wanted to idle at 4K that too much air was entering around the large 90mm blade vs. the stock.

Tomorrow I am going to get the rest of the tuning cleaned up as it seems like it is running richer since the intake/tb change. Is this typically normal?? Besides A/F adjustments, is there any logic that the larger intake on this motor could favor more timing?

Finally I did notice that the idle seems to hang very slightly before returning to a solid idle. What table should I look at?

Thanks guys!

Howard

[Bruce Melton]

Mine which is probably mild compared to yours was not too hard to tame but the 36#SVOs were barely big enough with FAST90/LS2.

[dfe1]

Mine which is probably mild compared to yours was not too hard to tame but the 36#SVOs were barely big enough with FAST90/LS2.
You're saying that you've got heads and cam on a stock short block and the 36# injectors are marginal? Seems like 36# should be plenty large enough for your combination. Am I missing something? What fuel pressure are you running?

[Bruce Melton]

Mine which is probably mild compared to yours was not too hard to tame but the 36#SVOs were barely big enough with FAST90/LS2.
You're saying that you've got heads and cam on a stock short block and the 36# injectors are marginal? Seems like 36# should be plenty large enough for your combination. Am I missing something? What fuel pressure are you running?

Yes, as you say with stock pump/pressure. The SVO 30s were way outrun and the 36s are at 85%.

[Redline Motorsports]

How is it that you are running out of 30lber with a head cam stock displacement motor?

[Bruce Melton]

When I was running my 224/581 cam, headers, TEA stage ll 5.3 heads and FAST 90/LS2 with stock bottom end I was at upper end of 36#s . Now back to LS6/Shaner I am 78% with good A/F ratio at max.
The FAST just seemed huge in sucking fuel compared to the LS6. Granted I am self tuned but I had a pro at my FAST dyno and he looked at my V7 log and A/F and he thought it looked proper. I did not get expected power from FAST so came back to LS6. Was 400 with LS6 and 406 with FAST, torque about same. Have since replaced MAF and engine seems to run cleaner and crisper.
Any thoughts?
Thanks,
Bruce
meltn@new.rr.com