A/F ratio at boost?

[91rss]

Just courious to know if anyone has an idea what number to look for when setting up a turbo car,I have one car on haltech, and one that I will be doing soon.and need to figure injector sizing etc as I go.I need to figure out if a 2-1 Fmu can be found for a LT1 chev fuel rail,so I can keep the idle pressure at 40 ish and get just under 70 at max boost of 15 psi or so(ecm cut out at 70 psi and 15 psi boost) any help would be appreciated...

[rage2]

It depends on a lot of factors, but generally speaking, you want to be 11.5:1 to 12.5:1 a/f ratio, with timing no less than 18 degrees and no more than 22 degrees at full boost approaching octane knock limits.

That's a REAL general rule of thumb, you'll have to take it to a dyno and A/F sniffer, knock sensor, and tuning tools to find out for your particular setup.

[Phuqu]

Richer is better than lean. If your going to err do it on the rich side.

[buh_buh]

having a mixture too rich could hurt the car too. If you run the car too rich you can foul your plugs or wash out the rings on your pistons.

[91rss]

Has anyone ever seen a 2-1 FMU. I have a LT1 style fuel rail,and either will try to get larger injectors than the 35 lb I have or work on fuel pressure also..
Thanks,

[rage2]

FMU's are for ghetto tuning. Good luck getting a perfect A/F ratio. You'll get a good proper A/F at WOT for maybe 300rpm's. The rest of the rev range, you'll be running rich (or lean if u dunno what you're doing).

FMU ==