So close to my goal....

Ridin'GMC

I like red
May 20, 2010
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Went to dyno day today at Bartling Enterprises. I think I was the outcast because everyone who dyno'd had Cummins, didn't see not one Duramax on the dyno except for mine :D

It put down 497 hp and 926 lb-ft of torque. My goal was to break the 500 hp mark. It had some tuning issue that needed to be corrected and a fueling issue. My lift pump pressure was set a bit too high at idle, a bit over 12 psi ( I will have to turn it down to 10 psi) but when it hits WOT, it drops to 8 psi. I am using a Holley Black 160 gph pump for a lift pump, looks like I may have to add another lift pump in to deliver the fuel at WOT or get a bigger pump.

This power is done on all stock engine (stock intake, stock turbo, resonator removed, still has the PCV intact), stock transmission besides a transgo Jr, and still has a cat on.

I guess I will have to delete the cat, get a full exhaust system with direct pipe, fix the fueling issue (planning to add in dual fuel filter setup and maybe another cooler after the lift pump or filters to cool the fuel), and get my own EFI setup to achieve the power I want to get.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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nicely done! thought about runnin down there with everyone but i had to me ta guy to see if he would buy some stuff off my ranger. I got th esame goal as you but as soon as the ranger is gone, the stock turbo is gettin a big brother :D
 

Ridin'GMC

I like red
May 20, 2010
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is that a DD tune? if it is that makes for a fun truck

Yes it is a DD tune. Been that way for almost a year now. Trans is still solid and does not limp unless it goes in 6th. It gets 19 mpg on 35's. Trying to break the 20 mpg mark too.
 

x MadMAX DIESEL

<<<< No Horsepower
Dec 30, 2008
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Shoulda takin the air filter out... I was in the same boat as you 498.7 I think that could have put me over 500 (my goal too). I bet that trans is done though, mine only limped for slippage 3 times in the last month before the build and was apperantly one of the worst looking trans theyve ever seen in a street truck. Limping or not limping its still gonna come back and bite you in the ass. As far as the needing another lift pump idea, I wish I could tell you your right but sadly I don't think its the case. If your not getting the RP you want its cause your popping hte FPRV, dirty filter, or weak cp3. You only need evidence of 1 psi lift pump pressure at WOT to let you know that your cp3 is getting fuel. What kind of rail pressure are you able to hold that makes you think that you need some more pressure BTW? Ohh and congrats on the HP
 

Ridin'GMC

I like red
May 20, 2010
614
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Shoulda takin the air filter out... I was in the same boat as you 498.7 I think that could have put me over 500 (my goal too). I bet that trans is done though, mine only limped for slippage 3 times in the last month before the build and was apperantly one of the worst looking trans theyve ever seen in a street truck. Limping or not limping its still gonna come back and bite you in the ass. As far as the needing another lift pump idea, I wish I could tell you your right but sadly I don't think its the case. If your not getting the RP you want its cause your popping hte FPRV, dirty filter, or weak cp3. You only need evidence of 1 psi lift pump pressure at WOT to let you know that your cp3 is getting fuel. What kind of rail pressure are you able to hold that makes you think that you need some more pressure BTW? Ohh and congrats on the HP

I have 35" tires so it takes away more HP. If I had stock tires, it would made over 500 no doubt. I know the fact that my trans will bite me in the ass someday but I drive like a grandpa 95% of the time which prolongs the tranny's life. I did change my fuel filter, air filter is practically brand new (6k miles on it and checked it before dyno) and has a new spin tranny filter. Trans fluid has been changed 10k miles ago and still is perfectly clean. It has a shimmed FPRV so that is not the case. The lift pump is not delivering enough volume, so adding another lift pump will increase the volume of fuel delivery which should solve the problem. Volume is the key, not PSI which is measured in restriction. CP3 seems to be perfect.

While it was dyno'd, the pressure was over 13 psi at idle which needs to be turned down but when it hits WOT it drops to 8 psi, so hence more volume is needed. I built my lift pump setup by using a Holley Black 160 gph and there may be some restriction in the fuel system somewhere. Might have to upgrade the fuel delivery line to 5/8" and the return line to 1/2" to get cooler fuel, the fuel gets pretty hot on the return line (about 130* due to restrictions). Cooler fuel will gain more power. Ask Mike L, just learned that from one of the fuel cooler thread.
 

S Phinney

Active member
Aug 15, 2008
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130 on fuel temp isn't bad really. If you eliminate all restrictions it will still get that warm if you stay in it. The biggest heat factor comes from increased rail pressures and the return get hots. You will get pressure drops on the supply pump also. I can suck my ADII down to 5 psi and it holds rail pressure so if you are holding rail pressure you don't have an issue.
 

MMLMM

Tunergeek
Mar 2, 2008
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www.dyncal.com
you just need zero to positive pressure at max power from lift pump. even 3 psi isnt going to help anymore that 1 psi so to speak. No sense in having too much pressure from lift pump messing with things.
 

Ridin'GMC

I like red
May 20, 2010
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Thanks guys. I have never taken her to the track, hopefully someday I will whenever I get the front end beefed up. Brian needs to take me there someday and have me race against somebody for fun :)

S Phinney- Last I know the lift pump fixed the rail pressure problem it had from a tuning issue. I think it is still holding rail pressure. I would like to install a gauge to monitor the rail pressure but not sure if any is available unless you know one. Killerbee did my tuning. I wont get his tuning anymore so I will start saving up for my own EFI because I would love to learn how to tune mine and read the parameters. I'm a quick learner :p
 

Ridin'GMC

I like red
May 20, 2010
614
5
18
MA
you just need zero to positive pressure at max power from lift pump. even 3 psi isnt going to help anymore that 1 psi so to speak. No sense in having too much pressure from lift pump messing with things.

I'm a bit confused. Do you mean I need to zero in the reading at max power first before adding in more positive pressure? So are you saying that I don't need to upgrade my lift pump?
 

x MadMAX DIESEL

<<<< No Horsepower
Dec 30, 2008
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Killerbee did my tuning.

Hmm I would have thought he would have got you thinking that you dont need a lift pump in the first place. Mike is saying the same as me, as long as you dont have a fuel vaccum right at the cp3 inlet then you HAVE FUEL. 17 psi is no better than 1 psi.
 
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