Injector Pulsewidth

[Ghostnotes]

It looks like I might be running out of Fuel but I want to make sure I am logging the correct injector data since there are several. Can someone confirm which.I have the one highlighted in my channel list.

Also will this command my throttle to limit. To me the graph looks to agree with one another but my throttle will not open any further. The throttle is not closing down, it just will not go past 62%.

My Driver demand Axle does dip slightly below my commanded Axle

As I start to slowly open it, the TPS keeps pace with my input then suddenly opens up then levels out.


Thoughts?

[Ben Charles]

Log fuel presssure actual and desired
Log HPFP rail and desired
But based off your RPM and Injector MS you need some fuel mods

[Ben Charles]

For what it’s worth not logging correct TPS and needs to be in PE when making anyboost (open loop control)

[paulsmithsr]

Tune way off

[Ghostnotes]

Thanks Ben,

It might not show it here,but it is in PE, here is another shot.

It's at the bottom, and my fuel status shows open loop as well....just above it. My lambda reading is in the lower right part of the chart @.79/11.7. Now should i go a little leaner, I've seen a few opinions on that.

The throttle pedal/TPS really bothers me because that is part of the chart setup TTS supplied and what I have been battling against above everything. Relying on that,It kind of made sense to me as being "LIMITED". And the reason i say that is because in the screenshot, My Max En Tq vs. Eng Tq and my Driv Dem Axle vs CMD Axl Torque are off....but not always.

That and my Max Eng TQ and my Engine TQ are needs to be closer but are always the same % off after my adjustments. So i figured that might be part of it holding it back. Now if i see 5v @ 62%. I'm going to be a little P!$$#d.


If that's the case i need to readjust my tune accordingly and it might help with my fuel issue. I can go back to an earlier tune, this one was an attempt of getting my axle torques and torques in general as close as i can...along with my air. I undershot a little.

However I have a YSi-v7.Now I'm turning it as slow as i can right now with a stock dia lower and a 3.8 upper but according to a lot of people i should be making more than my EST TO/ EST HP are indicating. Somewhere in the 700HP/TQ hence the thought of it being limited again...

Going to set my fuel pressures up and do a careful run today. I know just by the DC alone i need more. Hoping i can get away with LSFP/ZO6 injectors and HPFP.

[Ghostnotes]

Here is a Log.

To me at least, the part throttle/cruise looks ok, I might try to tighten it up a little today.....no more WOT.

Whats kicking my butt is coastdown overshooting.

My whole situation revolves around the fact that i thought i was being limited.....not pulled.

[irun4cops]

Im NOT a tuner with knowledge more than the others above. However, assuming fuel pressure drop is your issue...

cold weather, all cars intake more air and request more fuel to match, so a tune that was fine yesterday in the warm, no longer performs well when it is cold because the fuel pumps no longer keep up with the new, higher demand in the cold.

If you have a 2018 or prior c7z, your low side pump is the weak link. I think c7 and grand sport, the low side pump is also the weak link. This does not mean that replacing the low side pump with a twin in tank setup like Fore, will solve all future fuel requirements, it just means, if you are running out of fuel, and your system is stock on a vette 2018 or prior, then it is the in tank fuel pump that needs to be addressed first. Everything else is a waste of time and will not solve it. 2019 z06 have the zr1 in tank pump, and as of yet, i do not know WHICH pump needs replaced first on the 2019 z06 if you managed to run one of those out of fuel... the high side or the low side. Assuming one runs port injection in the future or has a zr1 with it already, then it would still be the low side that needs to be addressed. People who throw money at the high side pumps and injectors, are wasting their money. Port injection, and be done. Addressing low side, and potentially port injection, and ignoring the HP pump and ignoring DI injectors is the most cost effective way to solve the problem.

Either way, start with a Fore double in tank setup as step 1.

Low side fuel pressure should be at or around 69 to 71psi. If it falls below that, then your low side cant keep up. The low side pressure drop throws code p228c on the vettes once it goes below 60psi on the fuel line up the tunnel, which feeds the high side pump.

Once the high side pump is grabbing from 65 or below fuel pressure, then that starts to manifest a lower high side fuel pressure on the high side as well. Most tuners only watch the high side, and think since they found a high side fuel pressure drop, it must be the high side pump.

On the vettes, i can tell you, it is not the high side, it is the low side. Same on the ctsv. Caramo i am unsure on, but my guess is its the same in tank pump, and thus if it were, it would be the same in tank pump and also the first to fail.

[Ghostnotes]

Im NOT a tuner with knowledge more than the others above. However, assuming fuel pressure drop is your issue...

cold weather, all cars intake more air and request more fuel to match, so a tune that was fine yesterday in the warm, no longer performs well when it is cold because the fuel pumps no longer keep up with the new, higher demand in the cold.

If you have a 2018 or prior c7z, your low side pump is the weak link. I think c7 and grand sport, the low side pump is also the weak link. This does not mean that replacing the low side pump with a twin in tank setup like Fore, will solve all future fuel requirements, it just means, if you are running out of fuel, and your system is stock on a vette 2018 or prior, then it is the in tank fuel pump that needs to be addressed first. Everything else is a waste of time and will not solve it. 2019 z06 have the zr1 in tank pump, and as of yet, i do not know WHICH pump needs replaced first on the 2019 z06 if you managed to run one of those out of fuel... the high side or the low side. Assuming one runs port injection in the future or has a zr1 with it already, then it would still be the low side that needs to be addressed. People who throw money at the high side pumps and injectors, are wasting their money. Port injection, and be done. Addressing low side, and potentially port injection, and ignoring the HP pump and ignoring DI injectors is the most cost effective way to solve the problem.

Either way, start with a Fore double in tank setup as step 1.

Low side fuel pressure should be at or around 69 to 71psi. If it falls below that, then your low side cant keep up. The low side pressure drop throws code p228c on the vettes once it goes below 60psi on the fuel line up the tunnel, which feeds the high side pump.

Once the high side pump is grabbing from 65 or below fuel pressure, then that starts to manifest a lower high side fuel pressure on the high side as well. Most tuners only watch the high side, and think since they found a high side fuel pressure drop, it must be the high side pump.

On the vettes, i can tell you, it is not the high side, it is the low side. Same on the ctsv. Caramo i am unsure on, but my guess is its the same in tank pump, and thus if it were, it would be the same in tank pump and also the first to fail.

Mine is a Z51 so I would have to assume if this is true it would apply to me as well at this point. I am already planning to get LSF supplement for starters.Being a non ZO6, the pump and injectors are at a disadvantage already, so ZO6 pump/injectors for now. I will absolutely not use meth. I'm shooting for 800hp(crank) for the near future.If I need more after that then dual injectors it is.

[Ghostnotes]

I'm sure it's been asked a 10000000000000000 times but what is the max HP for a non Z C7 before their injectors run out???

[paulsmithsr]

Depends how u tune it. - every body runs diff AFR - and more timing
I like to be safe so probably less
Stock LT1. Prob 650
Stock Z06. Prob 850

[irun4cops]

Depends how u tune it. - every body runs diff AFR - and more timing
I like to be safe so probably less
Stock LT1. Prob 650
Stock Z06. Prob 850

he's right.

Also depends on cam and supercharger or turbo and exhaust restrictions, etc.

And even then, it is still a trick question, as I explained in the first post. Lets say you make 700rwhp on a dyno in colorado on a hot day, and your car is fine...

then lets say the next day you drive to a coast line and it happens to be cold out... you will be making MORE HP, or at least, bringing in more o2 per cylinder intake cycle, but where is the extra fuel going to magically come from this new day with more o2?

Its not going to come, and thats why these questions you are asking have no real answer, as environment temp and altitudes change as you drive and as seasons change... and since extra fuel hurts nothing, and only keeps an engine from going boom... better low side setup and pump(s), is a must have upgrade.

Make sure your tuner does NOT disable p228c when they tune your vehicle. Some tuners do disable it as they are running lower fuel pressure as they tune your car at high rpm. If they disable it, then your car no longer has a fail safe to throw it into limp mode when it sees the low side fuel pressure fall below 60psi, and the high side low fuel pressure code is p0089, they might disable it or lower its thresholds for the same reasons... so make sure they do not do this, nor remove or lower your fuel pressure minimums. p0089 does not put a car into limp mode. p228c does.

[irun4cops]

im not savvy if the z06 in tank pump can be used on the c7 z51, i believe it can, and Im 90% sure it is larger. However, don't mix match with 2019 pumps, while the 2019 pumps for the z06 are larger than the 18 and prior, i have not heard of anyone having success running this pump yet in a 2018 or prior vehicle, the pump controller and computers seem to be different.

If anyone has had luck with the 19 z06/zr1 in tank pumps in an earlier year car, let us know.

If it were me, and i was going to drop the tank, i would get the fore double hanger pump setup with twin pumps. Have the second pump boost activated. Then it is not always running. If you are not running boost, and are all engine making those power levels, then you can still reference VAC and have it come on at a certain threshold i believe.

If you are stopping at 800 crank, i don't think you will need port injection. You may need the z06 hpp and z06 DI injectors.

If you know you will want to pass 800 crank, then i would skip the z06 hpfp, and skip the z06 di injectors, and instead i would keep the base c7 high pressure side, and just invest into the port injection systems that chris at crawford racing offers. Port injection and the double pump in your tank, and your car will run 1000hp should you decide to. Your bank account will thank you and me later for skipping the high side upgrade and jumping straight to port injection.

[Ghostnotes]

I'm not looking for absolutes.

It's raining here in Houston so the streets aren't great for any WOT pulls now, but I did log both sides of it last night and stabs for 5-7 sec showed stable pressure at around 1584 psi desired and 1764 actual rail with 60ish on the low side.

[irun4cops]

I'm not looking for absolutes.

It's raining here in Houston so the streets aren't great for any WOT pulls now, but I did log both sides of it last night and stabs for 5-7 sec showed stable pressure at around 1584 psi desired and 1764 actual rail with 60ish on the low side.

60 on the low side is too low. Chances are, if your car is down there, and you arent throwing codes, your tuner may have intentionally or inadvertently disabled the p228c warning... but either way, You are out of fuel on the low side and your car is no longer going into limp mode when this happens, thus, regardless which direction you go on the high side, the low side MUST be addressed, you need an additional low side pump.

I re read over your thread, and I noticed some things i did not the first time. Long story short, I would not touch the high pressure side components on your car, instead, i would do a double fore pump in the tank, and invest in port injection from crawford racing immediately. Crawford also has another external low side pump alternative, but i like them both in the tank personally.

Either way, my perspective is, if you invest in a z06 or higher flow HP pump, and higher flow injectors, you are still going to have to address the low side pumps...

well, the port injection will cost less than messing with the HP pump and DI injectors, and it will have longer legs to take you up past 1000hp, no problem. Forget the HP pump and cam and lash caps and injectors, etc etc etc. Its not worth it IMO. Port injection will pick up where your current HP side is limited.

Port injection, and put this fuel problem to bed for the rest of the time you own the car.

[Ghostnotes]

Mine is a Z51 so I would have to assume if this is true it would apply to me as well at this point. I am already planning to get LSF supplement for starters.Being a non ZO6, the pump and injectors are at a disadvantage already, so ZO6 pump/injectors for now. I will absolutely not use meth. I'm shooting for 800hp(crank) for the near future.If I need more after that then dual injectors it is.

This^^^

60 on the low side is too low. Chances are, if your car is down there, and you arent throwing codes, your tuner may have intentionally or inadvertently disabled the p228c warning... but either way, You are out of fuel on the low side and your car is no longer going into limp mode when this happens, thus, regardless which direction you go on the high side, the low side MUST be addressed, you need an additional low side pump.

I re read over your thread, and I noticed some things i did not the first time. Long story short, I would not touch the high pressure side components on your car, instead, i would do a double fore pump in the tank, and invest in port injection from crawford racing immediately. Crawford also has another external low side pump alternative, but i like them both in the tank personally.

Either way, my perspective is, if you invest in a z06 or higher flow HP pump, and higher flow injectors, you are still going to have to address the low side pumps...

well, the port injection will cost less than messing with the HP pump and DI injectors, and it will have longer legs to take you up past 1000hp, no problem. Forget the HP pump and cam and lash caps and injectors, etc etc etc. Its not worth it IMO. Port injection will pick up where your current HP side is limited.

Port injection, and put this fuel problem to bed for the rest of the time you own the car.

[irun4cops]

This^^^

I haven't owned or upgraded a stingray, ive always started at the z06 level, so forgive me. If others were chiming in, I would be all ears, but since they are not, i just want to point out why my gut says what is it saying...

https://www.corvetteforum.com/forums...fuel-lobe.html

Will you have to swap the cam in your engine to address the fuel lobe going from an LT1 to an lt4 pump? I did not find the answer quickly. But even as I was searching for the answer, the above thread told me what my gut said was true, that you will still be out of fuel at 750hp.

So again, lets go back to my original point about cold weather at low altitude... myself and several others have successfully lemon law'd STOCK z06, because we have figured out a situation where they run out of fuel. This is with the stock blower, no pulley swap, bare bones stock. There are environmental circumstances GM did not account for when they released the LT4 in its current configuration.

So my point is, if we can run the stock z06 out of fuel on the stock tune, well then, if you intend to make more power than a stock z06, there will be circumstances when the stars align, where your "z06" fuel system WILL come up short for what you need it to do.

Again, rather than invest money in the HP high side, instead, just add a low pressure port injection to the high side, and be done. I wouldn't waste your money on the z06 HP pump and z06 DI injectors, unless you can get them at a steal and not have to mess with the cam at all...

and I say this, as I'm 99% sure you are still going to have to get port injection anyway once you find out the z06 HP system is short of where you want it to be. Most people patch with meth, etc, but you, like me, don't want to mess with such a patch. If nothing else, give Chris Crawford a call, he's a great guy and I can't help but learn things every time I or my close friends speak to him. He is ahead of the game for sure.

I'll leave you to it, ultimately it is your car, and i know its no fun having strangers give advice on what you SHOULD do, so i don't want to overdo it. Let me know if you have anymore questions.

[Ghostnotes]

For me right now its about $$$. I can do the LPF and ZO6 hardware for about half the cost of a port job

Again like I said, I plan on the low side first. I have a cam with the 32% lobe. First will come the low side and we will see how that does. If I have to go further I will add the Z06 hardware. If those 3 together can not satisfy ~800 crank HP, I will keep what's on and add port in the fall and be better off still in the end. Regardless and in the meantime it will still be drivable. I just cap it off at 4000rpm but based on the link I will be close. They are talking rwhp, I'm talking crank.....

I fully understand air density and its effects on anything that uses combustion, I have adjusted plenty of instrumentation for high/low altitude and Hot/Cold weather, form simple pressure transmitters to GE LM series Gas Turbines.

[Ghostnotes]

So who sells a reasonable intake capable of the injector port. Years ago I adapted an Oldsmobile PFI to an Edelbrock performer(pre TPS) but this is different.

[irun4cops]

So who sells a reasonable intake capable of the injector port. Years ago I adapted an Oldsmobile PFI to an Edelbrock performer(pre TPS) but this is different.

that pro charger metal intake manifold that is usually black with red text, is the one most use.

Or this...
https://www.crawford-racing.com/prod...ntake-manifold

Who has it for the best price, with the port injection, I am not sure. Which blower are you running?

[irun4cops]

so have you considered that the HP pump going up and down an extra 30% adds to potential wear and potential failure on both the cam lobe and the pump itself? Plus now you are messing with lash caps, etc... another loose bit to jam up or install not perfectly. I always like the KISS approach for my cars. One less thing to break, is better for me in the long haul. HP pumps aren't cheap. Nor is pulling an engine to swap a cam if not needed. Delamination of the cam lobes, etc. I say no thanks to that potential mess.