LT4 HPFP on LT1 - Plumbing

DorkMissile · 01-08-2020, 09:45 PM

So a year ago I upgraded to a LT4 HPFP and the 12677004 "45" pipe that goes between the pump and the distribution block that feeds the rails, but was there a LT4 specific tube that goes from the HPFP to the quick connector on the driver's valve cover? I guess it would be the HPFP inlet?

Dysan911 · 01-09-2020, 06:59 AM

You might be talking about this line right?

Choda · 01-09-2020, 07:33 AM

was there a difference in the piping when you did the swap?

MP3BOOSTED · 01-09-2020, 08:03 AM

Quote:

Originally Posted by DorkMissile

So a year ago I upgraded to a LT4 HPFP and the 12677004 "45" pipe that goes between the pump and the distribution block that feeds the rails, but was there a LT4 specific tube that goes from the HPFP to the quick connector on the driver's valve cover? I guess it would be the HPFP inlet?

https://paceperformance.com/i-201648...pump-pipe.html

do we need that? If so i will order ASAP as my build is practically done

danhr · 01-09-2020, 09:48 AM

Quote:

Originally Posted by DorkMissile

So a year ago I upgraded to a LT4 HPFP and the 12677004 "45" pipe that goes between the pump and the distribution block that feeds the rails, but was there a LT4 specific tube that goes from the HPFP to the quick connector on the driver's valve cover? I guess it would be the HPFP inlet?

Are you sure you didnt misunderstand and didnt hear the tube from the pump to the rails?

EDFHOBBIES · 01-09-2020, 01:17 PM

Lt4 I thought was straighter and maybe a tad larger to help with starvation.

DorkMissile · 01-09-2020, 03:52 PM

Dysan - yes, that is the plumbing I am referring to. Mine is like yours pictured, it has the short piece of flexible line (my car is a LT1). What I see is Jannetty has a LT4 inlet pipe on their site, it doesn't have the flex line (I would assume this is where the restriction might be?)

DorkMissile · 01-09-2020, 03:55 PM

FYI - this is the updated mid pipe, the newer, high flow one has the double 45 degree bends, where as the original had one 45 deg, and one 90

TJay74 · 01-09-2020, 05:20 PM

You will want the Lt4 low pressure fuel line, the flexible one in the LT1 version has a restriction orifice in it, the LT4 doesnt have that orifice.

DorkMissile · 01-09-2020, 07:34 PM

Quote:

Originally Posted by TJay74

You will want the Lt4 low pressure fuel line, the flexible one in the LT1 version has a restriction orifice in it, the LT4 doesnt have that orifice.

Does anyone have a GM part number?

EDFHOBBIES · 01-10-2020, 08:13 AM

If your going to this much trouble Lingenfelter makes a hi flow line with a better ck valve. I picked up 10 psi on low side not changing a thing but the line. By now it should be for sale I had to go off some engineers directions. When you go to UWE or kaytech belt driven setup all the restrictions are non existent there's a bottle neck there that no one really speaks about.

DorkMissile · 01-10-2020, 05:39 PM

My biggest reason for asking is that I am going to place a large order to finish my engine build for my GM parts, want to add this to it.

L78toLT1 · 01-11-2020, 08:38 AM

I'm still running my stock LT1 tube and my low/high side pressures are holding up fine. Be that as it may, I would have swapped in the LT4 part if I had known at the time that there was a difference.

Eldi Z · 01-11-2020, 11:04 AM

Quote:

Originally Posted by EDFHOBBIES

By now it should be for sale I had to go off some engineers directions. When you go to UWE or kaytech belt driven setup all the restrictions are non existent there's a bottle neck there that no one really speaks about.

What does it mean?
What is a "Belt Driven Setup" in terms of fueling?
Who are UWE?

01-08-2020, 09:45 PM	#1
DorkMissile Drives: 18 1SS 1LE HyperBlue Join Date: Aug 2018 Location: Twin Cities, MN Posts: 612	LT4 HPFP on LT1 - Plumbing So a year ago I upgraded to a LT4 HPFP and the 12677004 "45" pipe that goes between the pump and the distribution block that feeds the rails, but was there a LT4 specific tube that goes from the HPFP to the quick connector on the driver's valve cover? I guess it would be the HPFP inlet? __________________ 2018 1SS 1LE / HBM - ECS Novi 1500 S/C Tuned by Carl @ CJ Tunes

01-09-2020, 06:59 AM	#2
Dysan911 Drives: 2017 50th Anniversary 2SS Join Date: Sep 2016 Location: Jacksonville, FL Posts: 930	You might be talking about this line right? Attached Images

01-09-2020, 07:33 AM	#3
Choda Drives: Turbo 6.2 Join Date: Feb 2019 Location: Buffalo Posts: 702	was there a difference in the piping when you did the swap? __________________ 2016 Turbo Camaro SS - 800hp/900tq 9.7@146 2018 LTZ Z71 Redline Silverado - 381hp/420tq 13.8@100

01-09-2020, 01:17 PM	#6
EDFHOBBIES Dyno Show Queen LOL Drives: 16 SS & 17 ZL1 Both Yellow Join Date: Jan 2014 Location: Houston Posts: 4,345 View My Garage	Lt4 I thought was straighter and maybe a tad larger to help with starvation. __________________ Kong Ported 2650, Crawford Racing Port Injection, Weapon X 112mm Adapter, NW112mm TB, Livernois Ported LT4 Heads, Lingenfelter GT32 stealth cam, Haltech Elite, and Carbon by Trufiber

01-09-2020, 03:52 PM	#7
DorkMissile Drives: 18 1SS 1LE HyperBlue Join Date: Aug 2018 Location: Twin Cities, MN Posts: 612	Dysan - yes, that is the plumbing I am referring to. Mine is like yours pictured, it has the short piece of flexible line (my car is a LT1). What I see is Jannetty has a LT4 inlet pipe on their site, it doesn't have the flex line (I would assume this is where the restriction might be?) __________________ 2018 1SS 1LE / HBM - ECS Novi 1500 S/C Tuned by Carl @ CJ Tunes

01-09-2020, 03:55 PM	#8
DorkMissile Drives: 18 1SS 1LE HyperBlue Join Date: Aug 2018 Location: Twin Cities, MN Posts: 612	FYI - this is the updated mid pipe, the newer, high flow one has the double 45 degree bends, where as the original had one 45 deg, and one 90 __________________ 2018 1SS 1LE / HBM - ECS Novi 1500 S/C Tuned by Carl @ CJ Tunes

01-09-2020, 05:20 PM	#9
TJay74 Drives: 17 Camaro SS 1LE & 16 Sierra AT CC Join Date: Nov 2016 Location: Norman, OK Posts: 2,424	You will want the Lt4 low pressure fuel line, the flexible one in the LT1 version has a restriction orifice in it, the LT4 doesnt have that orifice. __________________ 2019 Corvette Z06 2LZ A8 - Halltech CAI, AWE non-catted X-pipe, Mamo V2 ported TB 592rwhp, bone stock 566rwhp 2017 Camaro SS 1LE - Procharger D1SC w/ Tial 2" BOV & Race intercooler / ARH full length catless headers / Alky meth injection system - 650rwhp on conservative tune SOLD

01-10-2020, 08:13 AM	#11
EDFHOBBIES Dyno Show Queen LOL Drives: 16 SS & 17 ZL1 Both Yellow Join Date: Jan 2014 Location: Houston Posts: 4,345 View My Garage	If your going to this much trouble Lingenfelter makes a hi flow line with a better ck valve. I picked up 10 psi on low side not changing a thing but the line. By now it should be for sale I had to go off some engineers directions. When you go to UWE or kaytech belt driven setup all the restrictions are non existent there's a bottle neck there that no one really speaks about. __________________ Kong Ported 2650, Crawford Racing Port Injection, Weapon X 112mm Adapter, NW112mm TB, Livernois Ported LT4 Heads, Lingenfelter GT32 stealth cam, Haltech Elite, and Carbon by Trufiber

01-10-2020, 05:39 PM	#12
DorkMissile Drives: 18 1SS 1LE HyperBlue Join Date: Aug 2018 Location: Twin Cities, MN Posts: 612	My biggest reason for asking is that I am going to place a large order to finish my engine build for my GM parts, want to add this to it. __________________ 2018 1SS 1LE / HBM - ECS Novi 1500 S/C Tuned by Carl @ CJ Tunes

01-11-2020, 08:38 AM	#13
L78toLT1 Drives: Hyper Blue 2016 2SS 6M Join Date: Sep 2017 Location: North Ga Posts: 1,787	I'm still running my stock LT1 tube and my low/high side pressures are holding up fine. Be that as it may, I would have swapped in the LT4 part if I had known at the time that there was a difference. __________________ Baby Blue 2016 Hyper Blue 2SS/6m/MRC/NPP/Silver Rally stripes/ZL1 wheels & brakes/GForce DS and axles/ZLE Cradle Bushings/FE4 ARB front & rear/SEMA Grill/Rotofab dry/95mm TB/Magnuson 2300/Full LT4 fuel system/JMS boost-a-pump/E85 Sensor/Ported CID heads from LME/Cammotion PD cam/Thompson Motorsports forged shortblock/catted Kooks 1 7/8 headers /JRE remote tuned

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