[Hilltopper]

I just recently had a full build done on my 2018 SS 1LE which made nice power (846/803 on E85). I am very happy with the power this combo is making, but the more I think of it, the more I really don't care for the added complexity of the Meth Injection setup on the car. I fully understand the advantages of Meth Injection setup on this type of build, but hate the fact the tune is dependent on the Meth and, god forbid, if there was every a Meth Injection failure, it could lead to a major/expensive mess. I have been thinking about upgrading the high side fuel system from the LT4 Injectors/HPFP to the LPE KDI Injectors/LPE Big Bore HPFP or the FIC 30% Injectors/LPE Big Bore HPFP. I currently already have LT4 Low Side Fuel Pump and DSX Aux. Fuel Pump. My question is if the LPE KDI injectors have any advantage over the FIC Injectors other than the fact they are not rebuilt LT4 injectors like the FIC Injectors are. At this point, with the money I have already spent on this build, the difference in price of the injectors is not my primary concern (although it is a factor, if all else being equal). I am kicking myself for not going this route from the get go, but what's done is done. I know I am going to take a big hit on the 93 Octane side of the tune, which does not bother me in the least. I am, however, trying to make the best power I can on the E85 side of things. Driveability is of importance on this car, as I will drive it frequently when the weather warms up. Any input on the advantages and disadvantages of both (if any) would be greatly appreciated, if anyone has any real world experience with one or the other, or both of these injector sets. Right now I am leaning toward the KDI Injectors, but have not purchased anything at this time.

[KingLT1]

LPE injectors are +52% over LT4 hence why they cost the most.

Specifications:
Rated flow of 27 gram/second at 10 MPa

- 122% more flow than the production L83 fuel injectors
- 67% more flow than production LT1/L86 injectors
- 52% more flow than production LT4 injectors
- E85 compatible

[Hilltopper]

Originally Posted by KingLT1

LPE injectors are +52% over LT4 hence why they cost the most.

Specifications:
Rated flow of 27 gram/second at 10 MPa

- 122% more flow than the production L83 fuel injectors
- 67% more flow than production LT1/L86 injectors
- 52% more flow than production LT4 injectors
- E85 compatible

My understanding is the LPE injectors are rated at 52% more flow than the LT4 injectors, but LPE is basing those flow numbers using 100lb of low side pressure as opposed to 70lb the FIC are rated at 30%. So in an apples to apples comparison, at 70lbs of low side pressure, I don't think I would be getting a true 52% more flow from the LPE Injectors over the production LT4 Injectors. I don't want to do any additional low side fuel mods/upgrades, so I am assuming, based on what I have been told, the difference in flow between the two different injectors is not as large of in increase in flow, if both are using 70lbs of low side pressure.

[KingLT1]

I don't understand how 70 or 100psi on the low side would effect the injector flow when the low side feeds the DI pump and the DI pump feeds the injectors. I would think the DI pump pressure would have more of an effect on the Injector flow. As long as the DI pump gets enough fuel from the low side to maintain it's pressure, then it shouldn't really matter what the low side pressure is in theory but I could be wrong.


That being said, I am not saying to buy the LPE injectors. Several have used the FIC 30's on big HP builds. I was just pointing out that the LPE's flow more.

[Hilltopper]

Originally Posted by KingLT1

I don't understand how 70 or 100psi on the low side would effect the injector flow when the low side feeds the DI pump and the DI pump feeds the injectors. I would think the DI pump pressure would have more of an effect on the Injector flow. As long as the DI pump gets enough fuel from the low side to maintain it's pressure, then it shouldn't really matter what the low side pressure is in theory but I could be wrong.


That being said, I am not saying to buy the LPE injectors. Several have used the FIC 30's on big HP builds. I was just pointing out that the LPE's flow more.

That's a good question that I don't have the answer for, either. One thing I believe is true; the LPE injectors are capable of more flow than the FIC 30% Injectors. Whether that additional flow capability will add any additional benefit with my specific combination for the additional $1,000 is what I am trying to establish.

[Juiced1]

I believe the LPE injectors do a bit better with lower pressure numbers on the high side. The LPE high side pump isn't designed to put out as much pressure as the LT4 (it flows more fuel at a lower pressure). 70-100psi on the low side won't directly affect the injectors but it will help the high side keep pressure up in the range it needs to be for the injectors. The FIC's flow 30% more across the board. So if you can keep your high side up around 3000psi you can cover significant power.

[Hilltopper]

Originally Posted by Juiced1

I believe the LPE injectors do a bit better with lower pressure numbers on the high side. The LPE high side pump isn't designed to put out as much pressure as the LT4 (it flows more fuel at a lower pressure). 70-100psi on the low side won't directly affect the injectors but it will help the high side keep pressure up in the range it needs to be for the injectors. The FIC's flow 30% more across the board. So if you can keep your high side up around 3000psi you can cover significant power.

So what injector has the more potential with my setup, in your opinion? LT4 low side pump, DSX Aux Fuel Pump and LPE High Side Pump. Would the FIC 30% injectors hang with the LPE Injectors on E85, or will one fall off before the other? Or is it, more or less, as wash?

[EDFHOBBIES]

Wait about 10 days and lets see about the FICs

[KingLT1]

FIC injectors have already been tested by Ryne Cunningham. He was able to run a Whipple Heads/Cam ZL1 @ 16psi with 30% injectors, LPE DI pump, and his low side on E85.

[Hilltopper]

I am guessing without the Meth injection setup, no matter which injector set I go with, I will probably hit the limit of the low side LT4 pump before I get to the limits of the high side pump or injectors on E85. I have gone back and forth on this, but I am going to go with the LPE Injectors and see where we end up. I am expecting to take a big hit in power on the 93 Octane side of things, but should be pretty close to where I am now on the E85 side........that's the hope, anyway.

[EDFHOBBIES]

I asked Matt about them last night he said FIC he preferred over the Lingenfelter a lot better tables and he thought they idled better.. either way will be a good choice for more fueling..

[Hilltopper]

Originally Posted by EDFHOBBIES

I asked Matt about them last night he said FIC he preferred over the Lingenfelter a lot better tables and he thought they idled better.. either way will be a good choice for more fueling..

Interesting........as I have been told the exact opposite.

[EDFHOBBIES]

The research I did, Katech tested both lingenfelter's and FIC when they 1st appeared and they are using FICs with Katech branding. Like I said both are a good choice. I remembered your post and was going over my final list with matt to see if I should swap and he said he preferred them.. A lot better tables and support..

[Hilltopper]

If I was Katech, I would probably say the same thing if I was using the FIC private label injectors. I have talked to two tuners and got two completely opposite answers. One echoed your findings, the other told me LPE had better flow data/tables than the FIC. Who knows? Like you have stated, it looks as though both will do the job. I am going to do what my tuner prefers and has more experience with. Probably couldn't go wrong either way, although I would really have preferred to save the additional $1,000+ the LPE injectors are going to cost me.