[dbs1]

As I recently noted in dec 2021 we leaned out the engine in our 17 ZL1 using too much ethanol and ended up having to rebuild it.
We added a cam, bigger injectors and high side pump as well as porting the LT4 charger and installing a larger tb and bg cai.

I was a little dissapointed in the mustang dyno results of 693hp/741tq, expecting at least 725 rwhp.

Car already has a 9.17 lower pulley and kooks LT's. Wondering if it's worth dropping one size smaller pulley up top (running stock pulley) or if we've maxed it out and then instead of 55% ethanol we run 75%?

I know the suggestions of the 2650 but that was Not in the cards at the time.

Next fall I may consider putting the LT4 sc on my 2018 denalli 6.2 and dropping a whipple on the ZL1 but for now is there any other things we can do with the current sc?

[dbs1]

As I recently noted in dec 2021 we leaned out the engine in our 17 ZL1 using too much ethanol and ended up having to rebuild it.
We added a cam, bigger injectors and high side pump as well as porting the LT4 charger and installing a larger tb and bg cai.

I was a little dissapointed in the mustang dyno results of 693hp/741tq, expecting at least 725 rwhp.

Car already has a 9.17 lower pulley and kooks LT's. Wondering if it's worth dropping one size smaller pulley up top or if we've maxed it out?

I know the suggestions of the 2650 but that was Not in the cards at the time.

Next fall I may consider putting the LT4 sc on my 2018 denalli 6.2 and dropping a whipple on the ZL1 but for now is there any other things we can do with the current sc?

[JSH]

Yeah, something's not right. Mine made 722 with stock tb and sc and fewer mods. Next it made over 800 hp corrected with a ported 1.7L sc.

[Camaro1973]

Originally Posted by dbs1

As I recently noted in dec 2021 we leaned out the engine in our 17 ZL1 using too much ethanol and ended up having to rebuild it.
We added a cam, bigger injectors and high side pump as well as porting the LT4 charger and installing a larger tb and bg cai.

I was a little dissapointed in the mustang dyno results of 693hp/741tq, expecting at least 725 rwhp.

Car already has a 9.17 lower pulley and kooks LT's. Wondering if it's worth dropping one size smaller pulley up top (running stock pulley) or if we've maxed it out and then instead of 55% ethanol we run 75%?

I know the suggestions of the 2650 but that was Not in the cards at the time.

Next fall I may consider putting the LT4 sc on my 2018 denalli 6.2 and dropping a whipple on the ZL1 but for now is there any other things we can do with the current sc?

What was the baseline on the same mustang dyno? Mustang Dynos can read up to 15% lower I’ve seen. If you want most accurate dyno numbers get it on a dynojet.

[radz28]

There are guys that are using a lot of meth and E' to get power well into the 900s (and a couple even further). I think these are mostly race-type set-ups, though, and probably not long for this world in those configurations. I'm not sure the 1740 is long for this world in those applications, either, according to some. It's probably too early to tell right now.

I forget what Joker calls it, but Kong has their X-Port, which is going to take the 1740 to (maybe even past) it's limits. Again - that's what some conjecture is, and it's probably too early to say for sure, but that's one of the opinions that are out there. It IS effective though, and seems like a cost-worthy way of max'ing out the stock blower.

You'll have to address fueling, and again, there's meth', and PI kits out there (TooHighPSI is getting stellar reviews and showing it's definitely doing great work), so that and a low-side upgrade will definitely have you ready to max' out the 1740.

[KingLT1]

I agree with Camaro1973, when dealing with Dyno's especially Mustang dyno stuff you really need a base line to compare gains instead of worrying about a peak number. They are the worst of all dynos to try and cross compare numbers on the internet.

The X port really changes the capabilities of the 1.74 supercharger. I would do that before spinning it any harder. You will gain 3psi minimum from just the porting. Or go to a larger unit, but with the current 2650 prices, the X port is a more economical way to get really good gains. I see stock upper/lower X port setups hitting 13.5-14 psi.

[Smokin19]

Yes, the Mustang numbers can dissapoint but, it is just a tool. The before and after comparison on the same dyno will give you actual results of your mods. I went with a 2.70" upper pulley as the Xport should be spun faster to get better results. Of course it's all in the tune and my tune is conservative because I don't track it. As has been stated the Mustang dyno can be as much as 15% difference in numbers than a Dynojet. What fuel lobe did your cam have?

[dbs1]

Not sure of the cam specs. The shop that did the engine work doesn't do much GM stuff. After talking to a few folks they said that particular shop does good work but their tunes are not stellar. Took it back to the former shop ice used to retune it and they got another 40hp.

I will say I've got a spot near me that's quite rural and has a rolling spot to a fixed sign that I've previously got up to 137mph. The other evening it showed 144mph so quite the gain.

I think I'm gonna try a 2.38 pulley on it for the next 1/2 mile and see how it does along with about 20% more ethanol.

[CW3SF]

Originally Posted by dbs1

Not sure of the cam specs. The shop that did the engine work doesn't do much GM stuff. After talking to a few folks they said that particular shop does good work but their tunes are not stellar. Took it back to the former shop ice used to retune it and they got another 40hp.

I will say I've got a spot near me that's quite rural and has a rolling spot to a fixed sign that I've previously got up to 137mph. The other evening it showed 144mph so quite the gain.

I think I'm gonna try a 2.38 pulley on it for the next 1/2 mile and see how it does along with about 20% more ethanol.

Hopefully you are logging and retuning for those changes. Pulley and higher ethanol will take a lot more fuel.

[dbs1]

The factory sc has been ported by Kong, but we didn't do the xport. I'm debating on just going to the 2:45 pulley or instead going to a 2.38 pulley and running it back to the tuner with the increased ethanol to check it out.

The tune was done in Phx at 1200' elevation and I live at 6600' elevation so I'm guessing there would be no problem running the 2.38 pulley here as I lose about 2-3lbs of boost but hardly any events up here to run the car.

If I just went to the 2.45 pulley I'm guessing we'd add just 1lb of boost and with additional 20% of e we'd be good?

Tuner has said we now have the capability with the new cam, bigger injectors and upgraded pump to run to 850whp without leaning it out for safety's sake, but what does that do for us performance wise without additional tuning?