[FoundNemo]

Originally Posted by wnta1ss

I keep seeing this stuff on the forum about losing boost. You seem to understand that less restriction can produce lower 'boost' numbers, good so far. But why would you think that he needs to now speed up the blower to find out what these headers and the tune and the lid and the crimp delete and the axleback were worth? The blower is still spinning the same rpm as it did before, which means pushing the same amount of air as before, so therefore nothing was actually lost with the blower. So the real gain from all this $$$$ was indeed just 19.9 STD hp.

At lower boost yes. I didnt say supercharger rpm was lower, i said lower pressure. Up the pressure back to stock and more power, at higher rpms.

[Rodslnger]

You will enjoy the maggie setup. I tried the 80mm blower pulley but ran out of fuel at 4krpm But it made over 740 FPTQ would have been over 800rwhp if I had the fuel. Boost Psi was 21 with the 80mm.

[FoundNemo]

Originally Posted by Rodslnger

You will enjoy the maggie setup. I tried the 80mm blower pulley but ran out of fuel at 4krpm But it made over 740 FPTQ would have been over 800rwhp if I had the fuel. Boost Psi was 21 with the 80mm.

Cheers sounds epic!

[FoundNemo]

More sound clips added to the other thread, including 3rd gear WOT roll on:

https://www.camaro6.com/forums/showthread.php?t=595879

[wnta1ss]

Originally Posted by FoundNemo

At lower boost yes. I didnt say supercharger rpm was lower, i said lower pressure. Up the pressure back to stock and more power, at higher rpms.

Supercharger displaces x amount of air per revolution, and spinning it at y rpm means that z amount of air is being displaced. You are focusing on the wrong thing here with boost pressure, because it's a by product. Note how the 'boost' number on this car changed with the headers and exhaust mods, with no pulley change, and it would likely change again with porting or a different camshaft. What really matters is how much air the supercharger is pushing, because that additional air allows additional fuel to be burned, which is the reason for the supercharger in the first place. Not disputing that adding an overdrive pulley on the blower should increase power, just was pointing out that installing it would not honestly be restoring anything, it would really just be an additional mod.

[Z OH 6]

Originally Posted by wnta1ss

Supercharger displaces x amount of air per revolution, and spinning it at y rpm means that z amount of air is being displaced. You are focusing on the wrong thing here with boost pressure, because it's a by product. Note how the 'boost' number on this car changed with the headers and exhaust mods, with no pulley change, and it would likely change again with porting or a different camshaft. What really matters is how much air the supercharger is pushing, because that additional air allows additional fuel to be burned, which is the reason for the supercharger in the first place. Not disputing that adding an overdrive pulley on the blower should increase power, just was pointing out that installing it would not honestly be restoring anything, it would really just be an additional mod.

Good explanation, a good example is when I had my Hellcat, it made 854whp with a 2.65 upper blower pulley, then I had the blower ported and changed to a 2.85 pulley would have normally been a 40whp drop, but I actually gained around 80whp and ended up at 892whp without having to spin the blower as hard because the blower was so much more efficient after the porting.

[FoundNemo]

Originally Posted by wnta1ss

Supercharger displaces x amount of air per revolution, and spinning it at y rpm means that z amount of air is being displaced. You are focusing on the wrong thing here with boost pressure, because it's a by product. Note how the 'boost' number on this car changed with the headers and exhaust mods, with no pulley change, and it would likely change again with porting or a different camshaft. What really matters is how much air the supercharger is pushing, because that additional air allows additional fuel to be burned, which is the reason for the supercharger in the first place. Not disputing that adding an overdrive pulley on the blower should increase power, just was pointing out that installing it would not honestly be restoring anything, it would really just be an additional mod.

Doesnt matter really anywho what it made, its a prep mod for the Maggie.

[radz28]

Less boost and same-to-better-power is more efficiency, which seems reasonable with LTs, like it looks like you're seeing. I am a little lost on everything, but if the changing the tires placement on the dyno drums differently can change readings, too, from what I recall (among other things, too). If that's the case, that could account for differences in expectations of gains, but opening that exhaust will help make more power down the line, so all is good. I doubt the lower-than-expected gains have anything to do with the headers themselves.

This is a great start to a 2650. You'll be out of fuel before you know it, HAHAHA.

[FoundNemo]

Originally Posted by radz28

Less boost and same-to-better-power is more efficiency, which seems reasonable with LTs, like it looks like you're seeing. I am a little lost on everything, but if the changing the tires placement on the dyno drums differently can change readings, too, from what I recall (among other things, too). If that's the case, that could account for differences in expectations of gains, but opening that exhaust will help make more power down the line, so all is good. I doubt the lower-than-expected gains have anything to do with the headers themselves.

This is a great start to a 2650. You'll be out of fuel before you know it, HAHAHA.

Fuellll gahhh lol

[FoundNemo]

So the reason the numbers are lower is that total timing is capped at 21 for the target to be conservative. There is more on the table if 24 were to be used like stock. Reviewed the tune file in detail. So 20whp and 20 to 40rwtq, less boost on 21 degrees of peak timing on 93 octane. Makes sense.

[KingLT1]

If anything Smaller wheels and tires could help numbers if the the new setup is lighter. Drag radials will lower numbers.

Boost is just a measure of restriction. Less boost doesn't mean less power if flow was increased. The Supercharger is still spinning the same RPM.

It bet it don't gain much more power on 24 degrees vs 21(at least on 93 octane). Stock timing map is pretty aggressive on the LT4 stuff and I have read reports of some making more power with less timing. Don't know first hand being I haven't directly compared it.

I have my brothers C7Z targeting 21 degrees but it's higher compression on E.

Either way it gained about what it should for Catted headers.

[Joshinator99]

Originally Posted by KingLT1

If anything Smaller wheels and tires could help numbers if the the new setup is lighter. Drag radials will lower numbers.

Boost is just a measure of restriction. Less boost doesn't mean less power if flow was increased. The Supercharger is still spinning the same RPM.

It bet it don't gain much more power on 24 degrees vs 21(at least on 93 octane). Stock timing map is pretty aggressive on the LT4 stuff and I have read reports of some making more power with less timing. Don't know first hand being I haven't directly compared it.

I have my brothers C7Z targeting 21 degrees but it's higher compression on E.

Either way it gained about what it should for Catted headers.

Agreed. I don’t think 93 octane will want 24 degrees, I’d bet money you would start knocking and actually lose power. Being able to run E50 or so would be a different story.

[FoundNemo]

Originally Posted by Joshinator99

Agreed. I don’t think 93 octane will want 24 degrees, I’d bet money you would start knocking and actually lose power. Being able to run E50 or so would be a different story.

I agree with you and KingLT1. Wont be increasing timing as there is no point. The goal is prep for the Maggie, not maximize headers install only for his car so we'll leave as is for now.