need more fuel

[TCluff]

is 15psi at the fuel filter "before" enough pressure at wide open throttle, tst at 9x9 edge ez at 4 and 65 psi of boost? there is little smoke except from the clutch, egts around 1450 in the #5 ex port, not sure how much the fuel filter restricts flow?

 

[Matt400]

Are you saying you have 15 and want to know if its enough? or you are planing for 15 on an upgrade?

In either case I think is would be better to measure "after" the filter since your end result is to not starve the injection pump. Measuring before is just a guess what the injection pump is getting especially with a dirty filter.

 

[JStieger]

FWIW, my dirty fuel filter with only 12k miles on it was worth a 1-2 psi gain at the CP3 inlet after I changed the filter out last week. I'm currently running about 12-13 psi at the CP3 inlet at cruise and down to 7 psi at WOT with my mods. So I would say that 15 psi pre-filter should be OK.

 

[TCluff]

it is 15 psi before filter, "new one" i was just suprised how much 65 psi of boost would clean up the tst twins program, i think i need to add propane to pick the lag up off of that 16cm exhaust housing since these trucks fuel by boost

 

[Matt400]

i was just suprised how much 65 psi of boost would clean up the tst twins program

I would think 15 pre is plenty unless you let your filter gets super dirty. What fuel mods do you have to get 15 psi?

65 psi boost, wow. . did you "O" ring your head & change the intercooler?

 

[DLeno]

I'm wondering why we need high pressures, when the stock truck supplies 8 at curb idle. seems to me a regulated supply targeting 8-10 at the CP3 WOT would be ideal. I can't see a benefit to higher pressures.



a fuel delivery system that is not regulated well will have to raise pressure at idle in order to achieve 8-10 psi WOT. if that means 15 psi at idle, then so be it. My point is that I think the target should be 8-10 psi at the CP3 WOT, and then as much pressure regulation as you can find to limit pressure at idle. why go higher than 8-10? (maybe there is some work showing that higher pressures are a benefit?).

 

[TCluff]

you don't need to o-ring the head or even stud it if you read the truck under load, change the intercooler hoses so they dont blow, another key to keep the head gasket intact is to lower the drive pressure of the turbo by going to a bigger ex housing, but you gain more lag time, i am running a 16cm housing on the top and a 26 ex housing on the bottom turbo, also try to keep your egts below 1300 in the head port, this should keep head warpage to a minimal, the tst twins program is awesome and very smooth, but still not enough for me, now i am not saying not to o-ring, i will stud and o-ring before going to nitrous and propane, but i do believe you can run 550 h. p. on the stock bolts and gasket i have not dynoed yet with this set up, but similar trucks are making 530 rwhp with twins and a tst twins program, i do see temps over 1500 but that is in the #5 ex port with no failures and have held 65psi for about a quarter mile!!!!!