Need more fuel..read why.What pump do you guys recommend....
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Joined: Feb 2004
Posts: 662
From: Toledo
Re: Need more fuel..read why.What pump do you guys recommend....
I really appreciate everyones posts..great deal of help. Like I said I remember on the dyno the car would go to 55psi on the fuel guage at full boost then drop to like 44 I believe. That would indicate that the pump is not keeping up correct?
Thank you for clerifying the LS1 LT1 differences for me. Does anyone else agree that the 38 lb injectors won't support up to 380rwhp. I JUST purchased the racetronix kit today thinking its the culprit due to fuel pressure issues but like you said Chris I don't want to just go throwing parts in the car. I truely felt that the 255 walbro pump I have isn't keeping up.
Is my theory correct that if the pressure was indeed dropping as I see it the injectors would go to full duty cycle triing to keep up with demand?
Thanks
Adam
Thank you for clerifying the LS1 LT1 differences for me. Does anyone else agree that the 38 lb injectors won't support up to 380rwhp. I JUST purchased the racetronix kit today thinking its the culprit due to fuel pressure issues but like you said Chris I don't want to just go throwing parts in the car. I truely felt that the 255 walbro pump I have isn't keeping up.
Is my theory correct that if the pressure was indeed dropping as I see it the injectors would go to full duty cycle triing to keep up with demand?
Thanks
Adam
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From: Toledo
Re: Need more fuel..read why.What pump do you guys recommend....
Originally Posted by NC-LT1
If your running lean on 38 lb injectors at only 322rwhp.. something else is wrong!!!!!
i have made 410 rwhp on stock pump, stock 28lb lt4 injectors, and fuel was still around 12.8 : 1 on a wide band at 6700 RPM and although the injectors were very close to 85% duty cycle, it is far above what your seeing at 4400 RPM. you should still have plenty of injector left where she is going lean. is there an inline pump on here as well? this sounds like a bad inline i once had that would shut the motor down at about 5k rpm.. it was fried and I was unaware until the first time i took it out and romped on it and it fell on its face at 5k.
you should not be anywhere near 99% at that power and RPM. If it were me, before I started throwing parts at it, I would identify exactly what is going on there.
Anyone else agree?
Chris
i have made 410 rwhp on stock pump, stock 28lb lt4 injectors, and fuel was still around 12.8 : 1 on a wide band at 6700 RPM and although the injectors were very close to 85% duty cycle, it is far above what your seeing at 4400 RPM. you should still have plenty of injector left where she is going lean. is there an inline pump on here as well? this sounds like a bad inline i once had that would shut the motor down at about 5k rpm.. it was fried and I was unaware until the first time i took it out and romped on it and it fell on its face at 5k.
you should not be anywhere near 99% at that power and RPM. If it were me, before I started throwing parts at it, I would identify exactly what is going on there.
Anyone else agree?
Chris
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Joined: Apr 1999
Posts: 1,178
From: Cleveland, WI
Re: Need more fuel..read why.What pump do you guys recommend....
With my stock fuel system (lines, pump, FPR and injectors) with only an inline pump I made 372 RWHP and 486 RWTQ with my old turbo kit. I was seeing about 50 psi on the fuel press under WOT. No way your 38's are maxed under 322hp.
Being supercharged the Racetronix kit is going to be NEEDED, so I don't think you wasted your money.
One question to you though is why you even went out and bought 38# injectors. Why not step up higher. Larger injectors will idle and drive fine unless they are in the 160#/hr range (impedance converter needed) No such thing as to big an injector. I would have bought 50's or Lucas 42's for your app.
Being supercharged the Racetronix kit is going to be NEEDED, so I don't think you wasted your money.
One question to you though is why you even went out and bought 38# injectors. Why not step up higher. Larger injectors will idle and drive fine unless they are in the 160#/hr range (impedance converter needed) No such thing as to big an injector. I would have bought 50's or Lucas 42's for your app.
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Joined: Feb 2004
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From: Toledo
Re: Need more fuel..read why.What pump do you guys recommend....
Originally Posted by SMOKNZ
With my stock fuel system (lines, pump, FPR and injectors) with only an inline pump I made 372 RWHP and 486 RWTQ with my old turbo kit. I was seeing about 50 psi on the fuel press under WOT. No way your 38's are maxed under 322hp.
Being supercharged the Racetronix kit is going to be NEEDED, so I don't think you wasted your money.
One question to you though is why you even went out and bought 38# injectors. Why not step up higher. Larger injectors will idle and drive fine unless they are in the 160#/hr range (impedance converter needed) No such thing as to big an injector. I would have bought 50's or Lucas 42's for your app.
Being supercharged the Racetronix kit is going to be NEEDED, so I don't think you wasted your money.
One question to you though is why you even went out and bought 38# injectors. Why not step up higher. Larger injectors will idle and drive fine unless they are in the 160#/hr range (impedance converter needed) No such thing as to big an injector. I would have bought 50's or Lucas 42's for your app.
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Joined: Aug 2001
Posts: 252
From: wilmington, NC USA
Re: Need more fuel..read why.What pump do you guys recommend....
without a doubt I did not want to imply that the racetronix kit was a bad thing.. In fact, I run 4 of them on our vettes, and one twin intank setup.. you will definately need it down the road, but you are not going to be getting any closer to the issue at hand by just putting new parts on it. Are you absolutely sure you are tuning it correctly?
take a leak!
Chris
take a leak!
Chris
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Joined: Jul 2004
Posts: 1,174
From: MI
Re: Need more fuel..read why.What pump do you guys recommend....
I run an ati @ 15psi and MSD 72# injectors with an acceleronics box. My single 255 lph pump with K_Bell did not supply adequate fuel. Then I added a second pump (255lph walbro). Two electrical circuits with a Y pluming connector to a single 1/2 line to the engine. One big problem was the stock supply line. Fabbed my own plate and pump mount. Also used -6 an bulkheads with 3/8 socketless tube. No fuel problems now. I run 45 psi @ the rail.
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Joined: Feb 2004
Posts: 662
From: Toledo
Re: Need more fuel..read why.What pump do you guys recommend....
Originally Posted by NC-LT1
without a doubt I did not want to imply that the racetronix kit was a bad thing.. In fact, I run 4 of them on our vettes, and one twin intank setup.. you will definately need it down the road, but you are not going to be getting any closer to the issue at hand by just putting new parts on it. Are you absolutely sure you are tuning it correctly?
take a leak!
Chris
take a leak!
Chris
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Joined: Feb 2004
Posts: 662
From: Toledo
Re: Need more fuel..read why.What pump do you guys recommend....
Originally Posted by Racetronix
Did you check the fuel pressure under WOT yet?
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Joined: Nov 2001
Posts: 1,751
From: Surrey, BC, Can
Re: Need more fuel..read why.What pump do you guys recommend....
I had an 15# D1 on 50's injectors and a Walbro 340 high output in-tank and would run out of fuel in exactly the way you indicated. Fuel pressure would go to mid 50's and then drop quickly at about 4000 rpms.
I how have a Racetronic dual intank - I think I has one of the first, though I'm not sure - and don't have any problems now. I run on stock fuel lines.
to Jack for a great product.
I how have a Racetronic dual intank - I think I has one of the first, though I'm not sure - and don't have any problems now. I run on stock fuel lines.
to Jack for a great product.
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Joined: Feb 2004
Posts: 662
From: Toledo
Re: Need more fuel..read why.What pump do you guys recommend....
Originally Posted by 97TA-WS6-Con
I had an 15# D1 on 50's injectors and a Walbro 340 high output in-tank and would run out of fuel in exactly the way you indicated. Fuel pressure would go to mid 50's and then drop quickly at about 4000 rpms.
I how have a Racetronic dual intank - I think I has one of the first, though I'm not sure - and don't have any problems now. I run on stock fuel lines.
to Jack for a great product.
I how have a Racetronic dual intank - I think I has one of the first, though I'm not sure - and don't have any problems now. I run on stock fuel lines.
to Jack for a great product.Adam
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