MyE28.com

hey guys,

Ive been running about 12-13 psi of intercooled boost but with a weak spring(5psi) with a manual boost controller, so I lose about 2 psi after about 5000rpm.

Well, last night i finally installed my 255lph pump, and as I hoped, my mixture got richer. So I took some fuel out, and im still in the LOW 11:1's under boost.

At about 5400rpm(where i shift) and my Map drops to about 170kpa, Im hitting about 88-90 duty cycle.

Do you think If i took a little more fuel out(to lean it up to about 12:1), Id have enough Duty Cycle to handle about 184kpa(and peaks sumtimes at 190kpa) with my 1 bar Wastegate spring?

Im hoping i can keep the mixture in the low 12's, Duty cycle under 95%, and run 184kpa to redline.

Thanks,

Um,
I don't know about all that stuff, but my experience with 30lb inj in these engines is that there max is ~325whp w/stock fuel pressure. I know that cause thats what I have in the car right now. So whatever boost your running, at 325whp, there about maxed out. If you using a FMU, then you can get to ~350-375whp.

In a M30b34, 325whp is ~14-16psi. Is that ~184kpa? I don't have any charts right now. I would use psi here as more people are familar with that unit of measure.

russc wrote:Um,
I don't know about all that stuff, but my experience with 30lb inj in these engines is that there max is ~325whp w/stock fuel pressure. I know that cause thats what I have in the car right now. So whatever boost your running, at 325whp, there about maxed out. If you using a FMU, then you can get to ~350-375whp.

In a M30b34, 325whp is ~14-16psi. Is that ~184kpa? I don't have any charts right now. I would use psi here as more people are familar with that unit of measure.

16psi is ~110kpa -

PSI x 6.90 = KPA

KPA x .145 = PSI

http://www.unit-conversion.info/pressure.html

at my elevation, Atmospheric pressure is about 92-94kpa. so the total pressure is 94+ boost pressure. (should have mentioned my atmospheric pressure earlier)

So when i said, 170kpa, i meant 170-94 = 76kpa of boost.

Well, i went ahead and put the spring in, and tested it out by going easy on it.

And holy crap, the car is WAY WAY faster with onli 1/2 throttle.

Im out of fuel though, at 4800rpm, at 192kpa(bout 100kpa boost, bout 14.5 psi), im at 98% percent duty cycle.

My 30lb fuel injectors DO flow more with the new pump(must have increased the fuel pressure) but not nearly enough.

Whats kewl is I can hear my fuel pump over my exhaust from inside my car now, which is neat.

Im going to find a way to increase fuel pressure until I can Get my new injectors(maybe cheap Adjustable fuel pressure regulator?)

Is a cheap adjustable fuel pressure regulator the way to go before I can get fatter injectors in there?

Yes,
a FMU(RRFPR) are ~$250. You can get them from TCD. They can boost up fuel pressure to ~90psi.

RussC

90e34535i wrote:
Is a cheap adjustable fuel pressure regulator the way to go before I can get fatter injectors in there?

Larger injectors is the better way to go. I have 37 and 42s in stock. I should be able to give you a smoking deal on either. Shoot me an email.

Todd