[2023_ZL1-AUTO]

It was pointed out to me that my HPFP duration is pegged at 130 (the max for stock) and HPFP psi is dropping by 400psi while data logging a pull and running E33. This is after Kong did my SC X-port/polish. I'm wondering what others are seeing for their HPFP psi and what E mix is being ran. Anyone with X-Port or similar SC porting and flex fuel.

Thanks

[KingLT1]

That is normal for stock high side fuel system. +30 injectors and a Big Bore HPFP will get you up into the E50-60 range....add a 38% cam on top and likely be able to run full E at the same boost......or Drum Roll.... go Port Injection.

[Megahurtz]

Normal for stock hpfp and that much extra airflow. E20-E30 depending on conditions is all you will get out of your setup as is.

[2023_ZL1-AUTO]

Originally Posted by KingLT1

That is normal for stock high side......or Drum Roll.... go Port Injection.

The more I look into port injection, the more it makes sense for me as a do-it-yourself mod and with out touching oil (pulling engine and installing CAM). Meaning, if I were to do the CAM myself (I probably would never attempt this). It would require pulling the engine, installing cam, lifters, pushrods etc. I contacted TooHighPSI and they put together a complete list of items I'd need and add port injection to my ZL1. It was bad, all under $3100. Then, depending on what I do to address the low side fuel (I have JMS Fuel Booster currently), it would be either a aux pump (DSX style) or drop in dual pump.

[2023_ZL1-AUTO]

I see a lot of XDI Injectors talk here on the forum. But, any good or bad with these from TooHighPSI: FIC Extended Tip 1090cc/min (105lb/hr) USCAR Fuel Injector for "SC" or "R" port plates (Set of 8)

[radz28]

Originally Posted by 2023_ZL1-AUTO

I see a lot of XDI Injectors talk here on the forum. But, any good or bad with these from TooHighPSI: FIC Extended Tip 1090cc/min (105lb/hr) USCAR Fuel Injector for "SC" or "R" port plates (Set of 8)

What do you mean? If you are asking what I think you're asking, you are comparing port injection (PI) injectors to your direct injection (DI) injectors - well - you referenced DI injectors when stating the XDI injectors. You are looking at two different things. If I am interpreting wrong: my apologies. In the case I am wrong - there is nothing wrong with tuning for any of those PI injectors. All the compensations are in the REFLEX controller that was likely part of the quote for your kit. You, pretty much, just tell the REFLEX how much the injectors flow, and it does the rest. There could be a little polishing, but it's minor. There's nothing wrong with adding the FICs, in conjunction with the REFLEX controller from THPSI

The FICs are the PI injectors for PORT PLATES from THPSI. Those FICs are what are ADDED (the whole kit you were quoted by THPSI) to the DI to give you more headroom. The XDIs I believe you are talking about, would be direct replacements for your OEM DI.

What it seems like you are asking for is how to compare your options: upgrading the OEM DI system (injectors and maybe a pump) which look like lists for ~ $5900 for the 50% injectors and LPE HPFP; OR - ADDING PORT INJECTION, which is the $3100 kit from THPSI that you were quoted above.

There's a good chance you'll need a low side ($1100 [DSX] to $1700 [Katech bucket and add-on fuel filter kit]) that you should think about adding into the budget. You'll also have to think about another $200-$300 in plumbing to add to the THPSI plate kit. If the XDI HPFP mounts the same as the OEM LT4 pump (wasn't there a kit out there that ADDED ANOTHER HPFP, run off the serpentine belt?...), I think that might be more straight forward than adding PI, but tuning becomes more complicated if I recall (though - I thought I remember XDI injectors being one of the better ones out there to tune). The THPSI requires some special tuning, too, but there are lots of people that have been doing that for a long time.

The point is to make sure you're thinking in correct terms and using those terms so you don't get conflicting information

JMHO

[2023_ZL1-AUTO]

Originally Posted by radz28

What do you mean? If you are asking what I think you're asking, you are comparing port injection (PI) injectors to your direct injection (DI) injectors - well - you referenced DI injectors when stating the XDI injectors. You are looking at two different things. If I am interpreting wrong: my apologies. In the case I am wrong - there is nothing wrong with tuning for any of those PI injectors. All the compensations are in the REFLEX controller that was likely part of the quote for your kit. You, pretty much, just tell the REFLEX how much the injectors flow, and it does the rest. There could be a little polishing, but it's minor. There's nothing wrong with adding the FICs, in conjunction with the REFLEX controller from THPSI

The FICs are the PI injectors for PORT PLATES from THPSI. Those FICs are what are ADDED (the whole kit you were quoted by THPSI) to the DI to give you more headroom. The XDIs I believe you are talking about, would be direct replacements for your OEM DI.

What it seems like you are asking for is how to compare your options: upgrading the OEM DI system (injectors and maybe a pump) which look like lists for ~ $5900 for the 50% injectors and LPE HPFP; OR - ADDING PORT INJECTION, which is the $3100 kit from THPSI that you were quoted above.

There's a good chance you'll need a low side ($1100 [DSX] to $1700 [Katech bucket and add-on fuel filter kit]) that you should think about adding into the budget. You'll also have to think about another $200-$300 in plumbing to add to the THPSI plate kit. If the XDI HPFP mounts the same as the OEM LT4 pump (wasn't there a kit out there that ADDED ANOTHER HPFP, run off the serpentine belt?...), I think that might be more straight forward than adding PI, but tuning becomes more complicated if I recall (though - I thought I remember XDI injectors being one of the better ones out there to tune). The THPSI requires some special tuning, too, but there are lots of people that have been doing that for a long time.

The point is to make sure you're thinking in correct terms and using those terms so you don't get conflicting information

JMHO

You are correct sir! I honestly think when I was editing my post for a misspelling, I wiped out a complete paragraph of my post, my apologies ! Yes, I was referring to "Is there a preferred mod between the two if your staying with stock CAM? Either upgrade DI and replace the OEM's injectors and add HSFP pump etc. vs port injection system, plates, injectors, reflex controller, aux pump.

Thanks and sorry for that!

[cajunzl1]

It seems there is a fixed HP running stock fuel system, its how you get there?

King- if he can only run E30's with a X port, headers and Big Gulp with a 2.3 Pulley, is it more cost effective to not port the supercharger or run it at 2.5 with more ethanol to achieve the same horsepower on the stock fuel system. Dollar per Dollar?

[2023_ZL1-AUTO]

cajunzl1 - So it looks like my E30 will be more like E20 or E25 at this point. I'm second guessing if the X-Port was the right move with the mods I have. It looks now like I need to consider yet another major mod.

1) Port Injection which will include: Port plates, Reflex controller, (8) injectors, and a low side aux pump or a dual drop in fuel pump (stock CAM)

2) DI - LPE Big Bore v2, XDI 30% injectors and High Pressure fuel lines (stock CAM)

3) Terminator CAM Package with Rough Idle from JRE, transport the car 9.5 hours one way/9.5 hours back, leave the car with Ted for a week, but pick it up ready to haul A$$ down the track ! (No fuel system changes)

Decisions decisions, I'm too much of a newbie to know what would work best with the current mods I have. so feel free to fire in your opinions!

[radz28]

Originally Posted by 2023_ZL1-AUTO

You are correct sir! I honestly think when I was editing my post for a misspelling, I wiped out a complete paragraph of my post, my apologies ! Yes, I was referring to "Is there a preferred mod between the two if your staying with stock CAM? Either upgrade DI and replace the OEM's injectors and add HSFP pump etc. vs port injection system, plates, injectors, reflex controller, aux pump.

Thanks and sorry for that!

No biggie! I just didn't want to come across as a know-it-all-jerk

There are some guys who've been in the game a long time that have taken a stock LT4 (I think valves prings, too)to 1000 WHP. It likely took a lot of fueling manipulation, PI, low side, ported blower/pulley, and all the bolt-ons, with meth', but you can make a lot of power with a stock LT4. I wouldn't comment more than that, because there wasn't a lot of shared info'.

The cam is probably what would make it easier because of the fuel lobe. If you don't want chop, BTR has an almost cheater cam that's essentially an LT5 cam (it has lift and duration similar to an LT1 cam) but with a bigger pump lobe. But if you're stabbing a cam in, you might as well have some chop

I think it depends on your situation. XDI-stuff isn't a lot more (if any) than port, and, IMO, it's a little simpler. You don't have extra fuel lines and injectors, nor another controller you have to piggy back. BUT - the sky's the limit with PI, AND you get the benefit of cleaning the back of the intake valves. Adding plates on a ZL1 requires a shorter lid if you have a Maggie 2650, but that also gives you some whine, which is pretty nice.

Not having done XDI/DI improvements, I can't comment more than with what I've read - I have no experience (I now have a little tuning experience, but that's stock stuff for my combination). Having added PI from THPSI, and doing all the work myself, I can claim some experience and some lessons learned. I'd still do PI, even if I didn't have to because of my situation.

JMHO

Originally Posted by 2023_ZL1-AUTO

cajunzl1 - So it looks like my E30 will be more like E20 or E25 at this point. I'm second guessing if the X-Port was the right move with the mods I have. It looks now like I need to consider yet another major mod.

1) Port Injection which will include: Port plates, Reflex controller, (8) injectors, and a low side aux pump or a dual drop in fuel pump (stock CAM)

2) DI - LPE Big Bore v2, XDI 30% injectors and High Pressure fuel lines (stock CAM)

3) Terminator CAM Package with Rough Idle from JRE, transport the car 9.5 hours one way/9.5 hours back, leave the car with Ted for a week, but pick it up ready to haul A$$ down the track ! (No fuel system changes)

Decisions decisions, I'm too much of a newbie to know what would work best with the current mods I have. so feel free to fire in your opinions!

This is going to be the easiest way to go fast. It's the least complicated, and most expensive, but the foundation will be laid to make even more power down the road, if you want. You'll still be limited by fueling, but you could address that later. I don't think you'll be able to run much, if any, E', but add a low side and you'll be able to stretch it further down the road, whenever you want.

[2023_ZL1-AUTO]

Not that this matters since the tuning process has literally just started. For what ever reason, the data log didn't seem to record AFR. So it's a re-do, but also, I was instructed to lower E to E25 for next data log. Here is what HP Tuners showed (4th gear pull): Max torque was 621 (at 4264rpm), max boot was 16.52psi (at 6050rpm), the screen capture is the highest calculated HP during the pull and right before it fell off. I know the torque and HP are calculations, but there for reference.

[KingLT1]

Turn the boost down, run more timing, and ethanol. You are not gaining anywhere near what 16psi should be doing with 16.5 degrees of timing. Put the stock pulley back on which should push around 14psi, up the timing...should be 21-22 degrees on E30 and 23-24 degrees on E50.

[Megahurtz]

you should log SOI and EOI as well

[radz28]

DSX is coming to market, soon, with their own PI and controller, that doesn't require any of the cheating that everything else out there does (I have heard it won't be the only option, but I don't know more than that, and I do not know when). Their latest FB post shows their only physical connection to the E92 is cam and crank signals, and the rest will be software communications (for lack of correct terminology) between their controller and an updated OS for HPTuners, essentially. I'm cheating the fueling side with the REFLEX (which seems to be limiting me to where I am now), but the convention is to cheat airflow MAF, PE, and TORQUE models with little limitations when calibrated by someone who knows what they're doing. If someone like me could catch on (and I've had a good bit of help), pretty much anyone could, too, IMO (all the information, really, is out there). It's still not perfect, but I change stuff too much to ever "finish" anything, so that's mostly my fault. The point is, is I would advocate for adding PI over upgrading the DI now. A couple of years ago, that would not be the case, but it fits, perfectly, within my needs, and will go as far as I would ever need to. I would still LOVE to see the other option ( ;-) ) come to market, for sure, but at least DSX will be there soon. The only downside I see, which may be meaningless in the grand scheme, is technically - PI fueling gets in the way of airflow (the fuel in the ports take up space that airflow would otherwise be able to occupy), so theoretically - you would not make as much power as you would on DI (among atomization attributes of the DI, and other stuffs I can't think/know of). BTR did a dyno test on a Gen V wherein it had PI and DI. He ran with the PI only and then did a pull with the DI, and there was a HUGE difference in power favoring the DI. Blah blah blah...

Personally - I'd go with adding PI, in light of all that. It's a little more complicated, but it keeps the intake ports pretty clean, and can give you all the headroom you need.

JMVHO.