[JSH]

Originally Posted by ZL1Atlanta

Let me put it a little differently, I was able to crack the stock LT4 cylinder wall without ever worrying about the placement of the filter or bell mouth. LME rates the stock block built short blocks at 1400 RWHP on turbos, which doesn't take into consideration parasitic loss of blowers. It happened the first time I tried to run the all in pulley and intake setup, thus the reason it has a different engine now.

From the setup in the picture we changed pulley's for an additional 1.5 psi, added the bell mouth 1.5 psi more, and then went to a larger intake with integrated bell mouth for another 1.5 psi. So from when it ran that pass, its already making ~4 psi more in worse air - same location of intake, albeit the headlight is now removed.

Here's all I'm saying: Air density is lower at the front grille than in the engine compartment, which is why the pro stock guys take air from the front a few inches above the track and route it to the engine w/o taking in any engine compartment air. Same for NASCAR and that LeMans ZL1 we have posted about. So all I'm trying to do is minimize engine compartment air consumption and maximize front grille air. Perhaps drawing air from the wheel well might even work (?)

I have a 6" inlet bellmouth that I'll try at the track. And yes, my current outlet tube starts at 6" and reduces down to say 5.5", and then a coupler makes further reduction to 112mm.

I really enjoy these challenges.

[KingLT1]

Originally Posted by JSH

Here's all I'm saying: Air density is lower at the front grille than in the engine compartment, which is why the pro stock guys take air from the front a few inches above the track and route it to the engine w/o taking in any engine compartment air. Same for NASCAR and that LeMans ZL1 we have posted about. So all I'm trying to do is minimize engine compartment air consumption and maximize front grille air. Perhaps drawing air from the wheel well might even work (?)

I have a 6" inlet bellmouth that I'll try at the track. And yes, my current outlet tube starts at 6" and reduces down to say 5.5", and then a coupler makes further reduction to 112mm.

I really enjoy these challenges.

Not once you are moving...stick your hand out the window at 40mph, then 60..etc. That is the same air density that's in the engine bay at that point. Ram air has shown to make a difference on NA stuff because if done right you can see positive pressure at the manifold above 50-60mph. It's not going to make as much difference on a PD application. All you need to worry about is not having any restriction in front of the supercharger so it can pull air in. The whole thing about cold air has been a marketing tool from day 1. Once a car is moving the engine is getting ambient air. Especially on a ZL1 that has a massive grill opening. Josh just posted he took the seals off his BG and it went faster. Jason just has a massive filter open to the engine bay. Enclosing the filter and trying to block it off from engine heat is only going to help at idle. Again, once you start moving all the air pressure going through the grill and coming up under from under the car is flooding the engine bay with ambient air.

[JSH]

Originally Posted by KingLT1

... under the car is flooding the engine bay with ambient air.

I'm going to disagree on engine bay temps, King. All of the temps in my engine bay are 120F+, even the rear surface of the BG. I put an air temp sensor in there to confirm this. On my current build, my engine bay is 120F+, the engine side of the BG is 120+, and the front side of the BG air filter is ambient plus a few degrees. I'm also considering heat extractors, although their appearance could be better.

[ZL1Atlanta]

Originally Posted by JSH

Here's all I'm saying: Air density is lower at the front grille than in the engine compartment, which is why the pro stock guys take air from the front a few inches above the track and route it to the engine w/o taking in any engine compartment air. Same for NASCAR and that LeMans ZL1 we have posted about. So all I'm trying to do is minimize engine compartment air consumption and maximize front grille air. Perhaps drawing air from the wheel well might even work (?)

I have a 6" inlet bellmouth that I'll try at the track. And yes, my current outlet tube starts at 6" and reduces down to say 5.5", and then a coupler makes further reduction to 112mm.

I really enjoy these challenges.

I 100% understand what you are saying and trying to do, my point is just that you are looking past what has proven to work for something that is highly unlikely to make much of a difference being that the air is still going to get filtered through the cooling bricks after passing through the heat in the rotor pack. NA cars are completely different for those reasons.

[Z OH 6]

Originally Posted by KingLT1

Not once you are moving...stick your hand out the window at 40mph, then 60..etc. That is the same air density that's in the engine bay at that point. Ram air has shown to make a difference on NA stuff because if done right you can see positive pressure at the manifold above 50-60mph. It's not going to make as much difference on a PD application. All you need to worry about is not having any restriction in front of the supercharger so it can pull air in. The whole thing about cold air has been a marketing tool from day 1. Once a car is moving the engine is getting ambient air. Especially on a ZL1 that has a massive grill opening. Josh just posted he took the seals off his BG and it went faster. Jason just has a massive filter open to the engine bay. Enclosing the filter and trying to block it off from engine heat is only going to help at idle. Again, once you start moving all the air pressure going through the grill and coming up under from under the car is flooding the engine bay with ambient air.

Bingo

[Z OH 6]

Originally Posted by ZL1Atlanta

I 100% understand what you are saying and trying to do, my point is just that you are looking past what has proven to work for something that is highly unlikely to make much of a difference being that the air is still going to get filtered through the cooling bricks after passing through the heat in the rotor pack. NA cars are completely different for those reasons.

Bingo! We have two winners!

[JSH]

Originally Posted by ZL1Atlanta

I 100% understand what you are saying and trying to do, my point is just that you are looking past what has proven to work for something that is highly unlikely to make much of a difference being that the air is still going to get filtered through the cooling bricks after passing through the heat in the rotor pack. NA cars are completely different for those reasons.

I believe the engine will make more power as the intake air (TB air) temp decreases. It seems to me that you're saying something different.

I think of it as getting maximum oxygen into the cylinder at WOT. As atmospheric pressure goes up so does air density. As air temperature goes down, density increases. And if cooler more dense air is at the TB it also tends to suppress detonation. Thus my goal is to help ensure that the air to the TB hasn't been needlessly warmed by the engine bay.

This is not some miserable thermodynamics class than all of us hate to be in. Instead this is website chat which should be fun and engaging, e.g., we don't have to agree on everything.

To me, this data says it all:

As temperatures increase, so does density altitude (DA). As DA increases, air density decreases as does engine power.

[ZL1Atlanta]

Originally Posted by JSH

I believe the engine will make more power as the intake air (TB air) temp decreases. It seems to me that you're saying something different.

I think of it as getting maximum oxygen into the cylinder at WOT. As atmospheric pressure goes up so does air density. As air temperature goes down, density increases. And if cooler more dense air is at the TB it also tends to suppress detonation. Thus my goal is to help ensure that the air to the TB hasn't been needlessly warmed by the engine bay.

This is not some miserable thermodynamics class than all of us hate to be in. Instead this is website chat which should be fun and engaging, e.g., we don't have to agree on everything.

To me, this data says it all:

As temperatures increase, so does density altitude (DA). As DA increases, air density decreases as does engine power.

Naturally cooler air affects air density and will have some impact on power. My belief, and what we have proven on the dyno with back to back, same day testing, is that it isn't as significant as the internet makes it out to be when we are talking ~30 degrees, or in my case 92 degree vs 125 degree MAT.

We had the car on the dyno for a couple days testing different pulley's, playing with tuning, etc., so they weren't icing it after every pull. They got to the final combo, did a pull, and with no ice and no heat exchangers in the car, it was down only 19 RWHP from the next pull where they added ice. Now this is at ~1400 RWHP, so when you look at % gains, it isn't much. That said, changing the upper pulley from 2.95 to 2.75 gained 50 RWHP on it's own, bellmouth gained 50 more, all while not icing at all. This new intake hasn't been on the dyno, but it gained 1.5 psi in 3300 DA, so another 50 seems possible in good air.

So, when I see a bunch of emphasis put on the air going into the filter, especially on what is a modest build relatively speaking, it's hard to believe there is enough to gain to make it worth the time vs looking elsewhere. But hey, it sounds fun... I'd love to see some track passes or maybe manifold pressure with and without these changes. In my case, we have done almost everything there is to do and can't spin the blower faster, so we have in fact discussed shielding the bell mouth from the engine as a next box to check. I'm not sure if it'll make a huge difference, but with nothing left to try, it's worth a shot.

[JSH]

Originally Posted by ZL1Atlanta

Naturally cooler air affects air density...changing the upper pulley from 2.95 to 2.75 gained 50 RWHP on it's own, bellmouth gained 50 more... it's worth a shot.

I agree that the laws of thermodynamics affect both of us equally. I recently changed to a 2.625 upper and will try the bellmouth next time out. I agree, It's all worth a shot.

From my perspective on your car, you've probably taken the Magnuson as far as it can go.

[CamOnlyJabroni]

Unlike what everyone uses alky/meth kits for on DI stuff, you could just spray a little water in the intake and you won’t have to make your engine bay look like it’s getting ready for the Apollo 13 space launch.

[KingLT1]

Originally Posted by JSH

I'm going to disagree on engine bay temps, King. All of the temps in my engine bay are 120F+, even the rear surface of the BG. I put an air temp sensor in there to confirm this. On my current build, my engine bay is 120F+, the engine side of the BG is 120+, and the front side of the BG air filter is ambient plus a few degrees. I'm also considering heat extractors, although their appearance could be better.

If you log the temp sensor in the maf the temp is usually less than 10 degrees difference from ambient when the car is moving. Every car I have ever seen logs from tracks this way.

When the car is moving at speed the air going into the engine has very little time to heat up from the engine bay.

[JSH]

Originally Posted by CamOnlyJabroni

Unlike what everyone uses alky/meth kits for on DI stuff, you could just spray a little water in the intake and you won’t have to make your engine bay look like it’s getting ready for the Apollo 13 space launch.

Which kit?

Do meth cars have a vapor cloud under their hood?

[JSH]

Originally Posted by KingLT1

When the car is moving at speed the air going into the engine has very little time to heat up from the engine bay.

I hope you're right because I'm going to put probably double the amount of air on my air filter starting next week. If I become sufficiently desperate I might just pull the headlights out!

[Z OH 6]

Originally Posted by CamOnlyJabroni

Unlike what everyone uses alky/meth kits for on DI stuff, you could just spray a little water in the intake and you won’t have to make your engine bay look like it’s getting ready for the Apollo 13 space launch.