High pressure desired Pump settings

[obd2]

has anyone had good results in tuning fuel system via HP tuners? tried raising High pressure desired to a higher number in the upper cylinder mass. the desired never change, the desired pressure remained at 2900 pis even after I up it to 4000 which surprised me. I realise by raising the desired may not do anything to real fuel pressure, but I never messed with the stock settings. did anyone have good results in tuning fuel pressure? my current setup has a low side fuel pump, just trying to see if commanding higher fuel pressure from the mechanical pump would get me more fuel.

[ahmedabri97]

Depends in the pump capacity.
Example in a L83 stock in table 2200 psi and I increase it to 2650 psi which actually raises 2650 psi.
If you are commanding 2900 psi in a stock L83 it will reach hardely 2700 psi at a max.

Maybe you need a bigger cam lobe to increase it more than 2900 psi.

[obd2]

Depends in the pump capacity.
Example in a L83 stock in table 2200 psi and I increase it to 2650 psi which actually raises 2650 psi.
If you are commanding 2900 psi in a stock L83 it will reach hardely 2700 psi at a max.

Maybe you need a bigger cam lobe to increase it more than 2900 psi.

totally agree this is an LT4 stock is 2900. so what you are saying is you raised the desired and confirmed via datalogging that the actual desired changed. did you perform a write entire or calibration. I ran out of time yesterday and got frustrated with datalogging. I downloaded the latest hp tuner version (Do this every week) which this time also contained a firmware update. going to open a ticket due to a few pids going blank on the chart even if they are being logged.

[Higgs Boson]

there are pump max limiters you need to adjust also so that you can blow out your seals.

[obd2]

there are pump max limiters you need to adjust also so that you can blow out your seals.

Thanks for the reply. what did you set your z06 pressures to? did you successfully raise DI pressure by raising desired. looks like both the z06 and ctsv have the same pump settings and looks like seal protection is disabled

[Ben Charles]

Max stated in the ECU on the lt4 is 27.5 mpa, I’ve routinley used 24mpa on the desired and hit it as well!!
Also just recently learned some changes that work well with cam lobes

[sevinn]

Max stated in the ECU on the lt4 is 27.5 mpa, I?ve routinley used 24mpa on the desired and hit it as well!!
Also just recently learned some changes that work well with cam lobes

I think alot of folks recently learned the same thing thanks to Mr. Banish lol

[Ben Charles]

I think alot of folks recently learned the same thing thanks to Mr. Banish lol

Smart fella!!

[Higgs Boson]

Thanks for the reply. what did you set your z06 pressures to? did you successfully raise DI pressure by raising desired. looks like both the z06 and ctsv have the same pump settings and looks like seal protection is disabled

All my DI stuff is set to stock but I am running port injection. On systems where I need to push the stock system I have raised MPa also, my comment was just tongue in cheek.

[ahmedabri97]

totally agree this is an LT4 stock is 2900. so what you are saying is you raised the desired and confirmed via datalogging that the actual desired changed. did you perform a write entire or calibration. I ran out of time yesterday and got frustrated with datalogging. I downloaded the latest hp tuner version (Do this every week) which this time also contained a firmware update. going to open a ticket due to a few pids going blank on the chart even if they are being logged.

Yes I confirmed with the actual rail pressure.
Write calibration.
I have no experience with LT4 but in a LT1/L86/L83 mech. pump maximum I tried with success is 2750 psi with a 32% cam lobe.
Without a cam lobe they normally max at 2650 psi.

[HNK]

My highside gets to 2300 on my C7Z, would going to 24 Mpa get me back online? or hardware is needed at that point?

[obd2]

Smart fella!!

WOW! are you saying his video is informative, and help you to get to the next level? I am sceptical of any new material, 2 years ago I got the tuning school guide and it was joke, the revised version was much better but the injection cycle is not 100 % correct. By the time they gave me the revised version was too late, had already figured most of it. I still have so much to learn

[sevinn]

WOW! are you saying his video is informative, and help you to get to the next level? I am sceptical of any new material, 2 years ago I got the tuning school guide and it was joke, the revised version was much better but the injection cycle is not 100 % correct. By the time they gave me the revised version was too late, had already figured most of it. I still have so much to learn

Banish puts out really good stuff. There were some tidbits in the video that I'd never seen discussed on these forums at all, and the SOI section was probably the best I've seen.

[obd2]

Max stated in the ECU on the lt4 is 27.5 mpa, I’ve routinley used 24mpa on the desired and hit it as well!!
Also just recently learned some changes that work well with cam lobes

you are referring to HP max pump, why would you drop it from 27.5 to 24. when data logging with stock settings lt4 run at 20 max. are you matching your desired also to 24?

[obd2]

Banish puts out really good stuff. There were some tidbits in the video that I'd never seen discussed on these forums at all, and the SOI section was probably the best I've seen.

Thanks for the reply

[obd2]

All my DI stuff is set to stock but I am running port injection. On systems where I need to push the stock system I have raised MPa also, my comment was just tongue in cheek.

the lt4 threshold is set to 27.5 = 3916 psi. I presume setting desired to around 3500 would be a good start, or am I missing something.

[Ben Charles]

you are referring to HP max pump, why would you drop it from 27.5 to 24. when data logging with stock settings lt4 run at 20 max. are you matching your desired also to 24?

We are talking about 2 different things... desires pressure is 20mpa stock, I usually jump it to 24

My desired and actual match

[Ben Charles]

Banish puts out really good stuff. There were some tidbits in the video that I'd never seen discussed on these forums at all, and the SOI section was probably the best I've seen.

In 2014 I used a 360 degree wheel that gave a visual ad in SOI, we had it mostly correct back then, but an OEM calibrator to help us fine tune that helped..
Going to do my cam cars a little different now

[Ben Charles]

WOW! are you saying his video is informative, and help you to get to the next level? I am sceptical of any new material, 2 years ago I got the tuning school guide and it was joke, the revised version was much better but the injection cycle is not 100 % correct. By the time they gave me the revised version was too late, had already figured most of it. I still have so much to learn

Not to say anything too terrible, but they get most of their info from the forums and capitalize on it lol.. just wait they will have a new book out soon..

Their is a couple of “yahoos” local to me that “learned” the tuning school way and think they know how to tune.... it’s very entry level

[obd2]

We are talking about 2 different things... desires pressure is 20mpa stock, I usually jump it to 24

My desired and actual match

Thanks Ben, maybe I should learn how to read lol. read it a second time made total sense. Cheers