[LT4 650]

Nice numbers for easy mods!

Question...how are tunes loaded in the ECU for the ZL1?

I am coming from an AMG C63 that was tuned with catless dp's and the tune gets loaded through the OBDII with a handheld device. I had my AMG tuned for pump gas and 100 octane for 1/2 mile racing and I could very easy switch my tunes back and forth with the hand held device. Is it the same type of thing with the ZL1?

Thanks.

[KingLT1]

Tunes are flashed with Hptuners via a laptop computer. EFI live also exists but is the least popular of the two on GM stuff. There is some handheld stuff out there like SCT but imo it's garbage.

[Bangkok_ZL1]

Originally Posted by KingLT1

Nice gains, but it's leaning over up top for sure.

What is the best fuel modification to ensure that the fuel doesn't lean out? Because this fuel delivery system is really foreign to me. Huge fuel pressure and still leaning out. especially if you wanted to run E85 and a decent pulley (nothing huge)?

[Camaro1973]

Originally Posted by Bangkok_ZL1

What is the best fuel modification to ensure that the fuel doesn't lean out? Because this fuel delivery system is really foreign to me. Huge fuel pressure and still leaning out. especially if you wanted to run E85 and a decent pulley (nothing huge)?

Its not, hes judging by that off the HP curve. Up top the stock lt4 blower is kinda shitty. Its all in the tune, there's nothing for you to mod on the fuel system.


Anything above 680-700Whp a cam will be needed to make more power which drives the HPFP lobe on the cam (32% is typical). Or you can add meth for higher octane and more power. You cant run E85, its more like E50, and once you start adding more boost E content drops drastically.


Leaning out and running out of fuel are 2 different things

[Bangkok_ZL1]

Originally Posted by Camaro1973

Its not, hes judging by that off the HP curve. Up top the stock lt4 blower is kinda shitty. Its all in the tune, there's nothing for you to mod on the fuel system.


Anything above 680-700Whp a cam will be needed to make more power which drives the HPFP lobe on the cam (32% is typical). Or you can add meth for higher octane and more power. You cant run E85, its more like E50, and once you start adding more boost E content drops drastically.


Leaning out and running out of fuel are 2 different things

OK, I was under the impression he was talking about leaning out his air/fuel ratio as in Too much oxygen not enough gas. As for juice, I'm not sure they have Meth here. They do provide 95 straight Unleaded, or 95 gasohol. I on the other hand, was considering E85, but if what is needed is E50ish, I can do half 85, and half E10 for E47ish or half E20 for E53ish, Both are readily sold here so that can be made, as that was pointed out to me before. I'm liking all this new material, interesting.

[LT4 650]

Originally Posted by KingLT1

Tunes are flashed with Hptuners via a laptop computer. EFI live also exists but is the least popular of the two on GM stuff. There is some handheld stuff out there like SCT but imo it's garbage.

Thanks for the info...so then I assume you load the tune from the computer into this device while it is plugged into the OBDII port? Just curious...

[gtfoxy]

Originally Posted by LT4 650

Thanks for the info...so then I assume you load the tune from the computer into this device while it is plugged into the OBDII port? Just curious...
Attachment 1050984

That’s the interface module. The tune gets downloaded through that from the PC/laptop.

[KingLT1]

Originally Posted by LT4 650

Thanks for the info...so then I assume you load the tune from the computer into this device while it is plugged into the OBDII port? Just curious...
Attachment 1050984

The wireless BT function is flaky from my understanding. I run it wired via USB directly from Laptop -> MPVI -> OBD-2 port. The MPVI is the communication bridge between the HPt software and the vehicles on-board controllers. The files are flashed directly from hard drive of the laptop. HPt does make a Nguage that you can store tune files on and flash directly but it only works on the 2016 cars with the E92/T87 controllers. In 2017 when everything went E92a/T87a that feature was broken.

[LT4 650]

Originally Posted by KingLT1

The wireless function is flaky from my understanding. I run it wired via USB directly from Laptop -> MPVI -> OBD-2 port.

Thanks and that's what I figured after doing a bit of reserach...so then my assumption in my post was correct.

So then I assume my tunes actually stay on the laptop correct? Would the tuner put them on a stick for me to keep? Is that how that works because on my AMG all the tunes were loaded on the hand held device including the stock tune.

[MakCamaro]

Nice gains. I am also interested in this. My question is whether it is better to change the upper or the lower pulley. Would the gains be the same after tuning? It seems that people prefer to change the lower pulley for some reason.

Also, how easy is it to change the upper pulley? Is it as simple as unscrewing a bolt and then putting on the smaller pulley? I am asking this because I will do it on my own and then I will do a remote tuning given that I am in the UK.

[arpad_m]

Originally Posted by MakCamaro

Nice gains. I am also interested in this. My question is whether it is better to change the upper or the lower pulley. Would the gains be the same after tuning? It seems that people prefer to change the lower pulley for some reason.

Also, how easy is it to change the upper pulley? Is it as simple as unscrewing a bolt and then putting on the smaller pulley? I am asking this because I will do it on my own and then I will do a remote tuning given that I am in the UK.

I think people/shops prefer changing the lower pulley when possible to improve belt traction. With a small upper pulley, the belt has even less surface to grip.

[Z OH 6]

Originally Posted by MakCamaro

Nice gains. I am also interested in this. My question is whether it is better to change the upper or the lower pulley. Would the gains be the same after tuning? It seems that people prefer to change the lower pulley for some reason.

Also, how easy is it to change the upper pulley? Is it as simple as unscrewing a bolt and then putting on the smaller pulley? I am asking this because I will do it on my own and then I will do a remote tuning given that I am in the UK.

Lower pulley is always recommend compared to an upper pulley. The stock upper is so small to start with that using a smaller upper increases the chances greatly of belt slippage. Swapping the lower pulley also means you get to use a good harmonic damper too. The upper pulley swap is not easy either so there really isn't any point in changing compared to a lower pulley.

[Z OH 6]

Originally Posted by KingLT1

Compare the power curves on the dyno graph. power peaks about 500rpm earlier with the pulley. The curve is shifted left. I don't mean anything negative by it, but a larger or even ported supercharger would likely keep making power out further is all.

Correct, my OEM ported blower keeps going all the way to 6500rpm. Blue line is stock with AWE catback exhaust and Rotofab. Red line is Vengeance Stage 3 package (all bolt-ons with OEM Kong ported blower) on 93 octane.

[Getnlwr]

Why is SCT the least preferred method?