Rail pressure question

[bigbird]

I have a friend that has an 06 LBZ with a fully built motor including heads, 50% over injectors, dual fuelers, GT4202. my question is on a wot run the rail pressure will drop to around 21-22,000 and commanded is 26,000. is this acceptable, i think not? the truck will start to stutter. He has twin kennedy lift pumps and the tuning has been done by ppe for this setup. are the lift pumps he has enough to keep up? the truck did run a 12.0 on 37in. tires, but it is falling off huge.

Kelly

 

[bigbird]

anyone?

 

[beach_33]

he may be at the limit of the stock cp3

 

[NWTDIESEL]

50% injectors are way to huge IMO. I have a friend with 40% overs and twin cp3s and he is having a real hard time tuning it via EFI live. 21k-22k is not acceptable. he is loosing alot of power. Whos your friend? Got some pics? Would love to see it.

 

[slowlmm]

I have a friend that has an 06 LBZ with a fully built motor including heads, 50% over injectors, dual fuelers, GT4202. my question is on a wot run the rail pressure will drop to around 21-22,000 and commanded is 26,000. is this acceptable, i think not? the truck will start to stutter. He has twin kennedy lift pumps and the tuning has been done by ppe for this setup. are the lift pumps he has enough to keep up? the truck did run a 12.0 on 37in. tires, but it is falling off huge.

Kelly

gt42 = alot of fuel needed time to step up to dual cp3s and mabey a modded fuel reg. or a single modded cp3 at least

 

[JoshH]

It already has dual CP3s. I don't see a reason why they wouldn't be able to keep up unless you are running a ridiculously huge pulse width with the 50% injectors, or there's a problem with the CP3 setup.

 

[slowlmm]

It already has dual CP3s. I don't see a reason why they wouldn't be able to keep up unless you are running a ridiculously huge pulse width with the 50% injectors, or there's a problem with the CP3 setup.

oops missed tht one mabey check lift pump psi under wot

 

[bigbird]

50% injectors are way to huge IMO. I have a friend with 40% overs and twin cp3s and he is having a real hard time tuning it via EFI live. 21k-22k is not acceptable. he is loosing alot of power. Whos your friend? Got some pics? Would love to see it.

Truck will be in diesel power in the next few months. they did the shoot after the blackout in edmonton on sunday. nice truck, silver with charcoal flames, 6in. lift 37 in. proxies on 24's, and it ran a 12.0 1/4.

 

[slowlmm]

Truck will be in diesel power in the next few months. they did the shoot after the blackout in edmonton on sunday. nice truck, siver with charcoal flames, 6in. lift 37 in. proxies on 24's, and it ran a 12.0 1/4.

thts quick for tht big lift and tires

 

[beach_33]

no kidding.

 

[sweetdiesel]

How much fuel was in the tank?
does he have a lift pump pressure gauge?
Does it smoke the whole way down the track?

 

[bigbird]

How much fuel was in the tank?
does he have a lift pump pressure gauge?
Does it smoke the whole way down the track?

-over half a tank.
-no lift pump pressure guage, we will probably put one on shortly.
-light haze going down the track.

 

[othrgrl]

I am able to hold 21K psi on a single stock LBZ CP3 and 45% injectors with an AirDog Lift pump, ported fittings and a race valve. I am running low PW and timing and laying down a haze down the track. What does he have done to the Fuel Pressure Relief Valve, and are his fittings ported? How about his filters and as mentioned lift pump pressure, if they are having to suck fuel through a weak lift pump or dirty filters at WOT I could see it dropping but otherwise duel fuelers should handle 50% injectors.