88-383

I've got a 355 10.1,TF CNC heads,219@.050 Edelbrock port matched TBI manifold. I bought a mail order chip to jump start the tune and I noticed it came with BPW set to 150 for use with 75# injs.

Does that sound right? What should it be? Fuel pressure is 15psi and it seems to flood the hell out of it at idle. Should I turn this constant down to like 100 or so?

Thanks

Kelvin

BMmonteSS

No that sounds like it's in the ball park. Most of the time cams make a car run rich at idle and lean up top. Sounds like your chip hasn't had any VE changes made to it at all. Probably a wast of your money.

You're going to need a bit more fuel pressure for that combo. I would try to get at least 20 psi before you dive too far into tuning. Set your BPW correctly based on the formulas available here on this site, then concentrate on your VE tables. This is a pretty healthy motor, you may want to consider getting Rbob's EBL setup, it's a code hardware solution that pretty much makes our TBI ecm's better than any other GM computer ever made, and possibly as good as some aftermarket setups. PM rbob for info and pricing.

88-383

I've allready upgraded the fuel pump, but do you think I'll really need that much FP on the 75#? As for the VE tables, to reduce fuel at idle, do I just lower the ve numbers in the cells surrounding idle? EBL may have to happen!

Thanks

Kelvin

honken

With 75# and 15 psi supports max 317 hp (BPW constant set to 103.8).
With 75# and 20 psi supports max 366 hp (BPW constant set to 89.87).
If you have 150 in BPW with 75# its like 7 psi and you have 15 psi.
This is with a 355 engine.

liquidh8

Yes, you could lower the Values in the VE table right around the IDLE cells to lean it out. But you should make sure you have the fuel pressure to feed the engine with those 75's. I have the EBL and love it, I don't know how I was tuning with out it.