LT4 Tuning for an LPE Big Bore HPFP

[TMS]

Asking the community for some info. I have a 2018 ZL1 (LT4). Running E-85. I just replaced the high side factory pump with Lingenfelter's Big Bore pump. My understanding is that Lingenfelter actually uses an LT1 pump and runs a bigger bore. They also state very clearly that the maximum operating pressure should not exceed 2,175 psi just like the LT1 stock pumps. So I have all the of that in the revised tune. Basically, I have an LT1 pump tune profile instead of my stock LT4 tune. Ever since I swapped the pump I now run lean in both banks and end up with a fuel rail pressure too low during engine cranking. These are showing up as DTCs with a lit CEL.

I've contacted Lingenfelter but can't get them to respond. Anyone know what changes need to be made to the tune for their pump?

[Beatme]

Did you ever figure this out? I have that pump on it's way, and just figured it came with any programming specs.

[TMS]

Well, not with any help from Lingenfelter. They have the absolute worst customer service and follow-up. I've been very dissatisfied with all of my encounters with them. I've chalked it up to them being a racing and engineering company first and a product sales and service company second or third. I think they sell product to support their habit. So take my information as just that, it isn't something that Lingenfelter cared to share by email or over the phone, nor did they provide any tuning instructions with their pump other than don't exceed 2,175 psi. Fortunately, I have a great tuner that figured it out. I will say that for their injectors, they provided a detailed characterization with all the tables that are required to be edited to work with their LPE DI injectors.

So first you must tune it as if it is an LT1 pump. What was missed in my initial tune setup for the pump was altering the pressure sensor offset/scalar. Once I did that, it came in line and solved the low fuel rail pressure during cranking. Subsequent data logs showed that I had not made any improvements and while my lowside was still hanging in there, my high side was dropping fuel pressure vs. commanded when running E-50 under WOT. I discovered on Lingenfelter's website that they want to see a constant low side pressure of 68 psi. My ZL1 is programmed for 52 psi under normal flow conditions. Once this was adjusted, the high side pump held to the commanded pressure all the way through the run on E-50. Then I was able to begin marching forward to see how far the pump would take me on the stock cam. It gained an additional 15% Ethanol.

Hope that helps.

[Beatme]

Thanks, I saw the 68psi requirement and was thinking that would probably have some kind of effect on it. Glad to hear that you have confirmed that.

[vortech]

Well, not with any help from Lingenfelter. They have the absolute worst customer service and follow-up. I've been very dissatisfied with all of my encounters with them. I've chalked it up to them being a racing and engineering company first and a product sales and service company second or third. I think they sell product to support their habit. So take my information as just that, it isn't something that Lingenfelter cared to share by email or over the phone, nor did they provide any tuning instructions with their pump other than don't exceed 2,175 psi. Fortunately, I have a great tuner that figured it out. I will say that for their injectors, they provided a detailed characterization with all the tables that are required to be edited to work with their LPE DI injectors.

So first you must tune it as if it is an LT1 pump. What was missed in my initial tune setup for the pump was altering the pressure sensor offset/scalar. Once I did that, it came in line and solved the low fuel rail pressure during cranking. Subsequent data logs showed that I had not made any improvements and while my lowside was still hanging in there, my high side was dropping fuel pressure vs. commanded when running E-50 under WOT. I discovered on Lingenfelter's website that they want to see a constant low side pressure of 68 psi. My ZL1 is programmed for 52 psi under normal flow conditions. Once this was adjusted, the high side pump held to the commanded pressure all the way through the run on E-50. Then I was able to begin marching forward to see how far the pump would take me on the stock cam. It gained an additional 15% Ethanol.

Hope that helps.

Thanks for this post, I have the LPE pump and it has been running at 2900 psi, I did not even notice the 2175 max pressure. Are you referring to the fuel pressure sensor offset under the general tab?

[TMS]

Thanks for this post, I have the LPE pump and it has been running at 2900 psi, I did not even notice the 2175 max pressure. Are you referring to the fuel pressure sensor offset under the general tab?

Yes, for the scalar adjustments you need to match to the LT1 on the general tab referring to the fuel pressure sensor offset and Pressure Sensor Gain. For the pressure settings, you need to adjust in the Fuel Pressure and Fuel Pump tabs. Basically it needs to match the LT1 profile with the exception of desired fuel pressure settings. Instead of an LT1 profile here, you want to set your Normal pressure to 68psi per Lingenfelter (I have mine set to 72.5). Then ratchet up your High Flow and Low Flow pressures accordingly.

[vortech]

What I find weird is that if I look up a 17 LT1 tune under general the scaler is 12.5 offset and 8.75 gain, then if I pull a 18 LT1 tune the scaler id -42.9 offset and 9.84 gain which is the same as a regular LT4. That kind of throws me off. So are you also saying that fuel pressure needs to be bumped up to 68psi versus 58 psi while running around normally as well. Would you mind posting your changed fuel tab settings. Thank you so much for sharing this-I would of never thought different.

[HeavyChevy305]

What I find weird is that if I look up a 17 LT1 tune under general the scaler is 12.5 offset and 8.75 gain, then if I pull a 18 LT1 tune the scaler id -42.9 offset and 9.84 gain which is the same as a regular LT4. That kind of throws me off. So are you also saying that fuel pressure needs to be bumped up to 68psi versus 58 psi while running around normally as well. Would you mind posting your changed fuel tab settings. Thank you so much for sharing this-I would of never thought different.

I think ones auto and ones stick because even my truck is set from the factory at -42.19 and 9.84

[TMS]

Yep. Set it to the 12.5 offset and 8.75 gain for the LPE HPFP. Yes, the 58 psi needs to go to 68 psi minimum. I run mine at 72.5 psi actually.

[lt1z350]

I know this is an older thread but have a question if still around to answer. I have seen these pump same as the stock lt4 pump pushed to 4000 psi with the larger cam lobe. Most tunes seem to be running 3800 psi if have a cam. So why not run the normal 3000 of the lt4 setup or 2900? I run a lot of methanol on my car so I have played with my pump settting just to see what it will do. On e50 I can hold 3200 psi all the way through the quarter due to my meth. I’ve got the blower back off and considering the pump again though now price seems to be up which sucks. But if running it at this 2100 you would think if can run 2900 and it sustain it with out it falling off your going to get more to the injectors and in the end mode fuel. I have fic 30 percent injectors in mine now and know with out a pump or cam lobe it is not a lot of help. It seems they can take a little more ms before it starts to run like crap. On this setup I have had it at 7ms and only had 1800 rail pressure before on a pass and it not gone lean and not lost any mph. So no power loss though rail was so low and injector ms up higher then I like to see. With the stock injectors after 6 usually it took to going to shit next would see rail to 800 and then it’s not tuning right. I have a ton of experience trying to make the fuel system work at different levels of ethanol and ran this setup where I didn’t think it was going to and car still pulled off a 9.90@139 back before I did port methanol and started getting more then enough to support it. I hate relying on so much and like to cut it to 50/50 and still run e65 plus on it so why considering the pump.
Thoughts ? Or anyone running it at 2900 with out issues and working well?

[HeavyChevy305]

I know this is an older thread but have a question if still around to answer. I have seen these pump same as the stock lt4 pump pushed to 4000 psi with the larger cam lobe. Most tunes seem to be running 3800 psi if have a cam. So why not run the normal 3000 of the lt4 setup or 2900? I run a lot of methanol on my car so I have played with my pump settting just to see what it will do. On e50 I can hold 3200 psi all the way through the quarter due to my meth. I?ve got the blower back off and considering the pump again though now price seems to be up which sucks. But if running it at this 2100 you would think if can run 2900 and it sustain it with out it falling off your going to get more to the injectors and in the end mode fuel. I have fic 30 percent injectors in mine now and know with out a pump or cam lobe it is not a lot of help. It seems they can take a little more ms before it starts to run like crap. On this setup I have had it at 7ms and only had 1800 rail pressure before on a pass and it not gone lean and not lost any mph. So no power loss though rail was so low and injector ms up higher then I like to see. With the stock injectors after 6 usually it took to going to shit next would see rail to 800 and then it?s not tuning right. I have a ton of experience trying to make the fuel system work at different levels of ethanol and ran this setup where I didn?t think it was going to and car still pulled off a 9.90@139 back before I did port methanol and started getting more then enough to support it. I hate relying on so much and like to cut it to 50/50 and still run e65 plus on it so why considering the pump.
Thoughts ? Or anyone running it at 2900 with out issues and working well?

I don't think our limit is the high side as much as the injectors. I have a 2019 ZO6 which comes with a ZR1 low side in the tank from the factory. I'm running e50 and while my low side and high side are keeping up just fine, my IPW creeps up to a max of 5.2 through a pull which suggest that i'm running out of injector before anything else...

[Tiffo60]

I don't think our limit is the high side as much as the injectors. I have a 2019 ZO6 which comes with a ZR1 low side in the tank from the factory. I'm running e50 and while my low side and high side are keeping up just fine, my IPW creeps up to a max of 5.2 through a pull which suggest that i'm running out of injector before anything else...

Thats good to know! I was just trying to decide which fuel upgrades Im doing next. Sounds like an in-tank pump and injectors might carry me a decent ways(15Z)

[HeavyChevy305]

Thats good to know! I was just trying to decide which fuel upgrades Im doing next. Sounds like an in-tank pump and injectors might carry me a decent ways(15Z)

I say 700hp max. There's a couple of tricks you still need to do with hard parts and in the tune to get to 700hp on e50.