[Evolvedx27]

Originally Posted by ZL1 1LE

I can see it. I don't see anything out of the ordinary that would cause any problems. It's meant to flex there from engine torque.

well yea it is flexing but you can see it slightly getting pinched as well. keep in mind that its what? a 7th gear pull? could it be more drastic in 1st? also hood is open. you have to keep a very close eye on the smooth section of the intake tube. about a second or so before redline you can see that section gets slightly pinched. it may or may not be enough to cause problems... just worth considering...

[cwebster]

Originally Posted by Evolvedx27

well yea it is flexing but you can see it slightly getting pinched as well. keep in mind that its what? a 7th gear pull? could it be more drastic in 1st? also hood is open. you have to keep a very close eye on the smooth section of the intake tube. about a second or so before redline you can see that section gets slightly pinched. it may or may not be enough to cause problems... just worth considering...

Hood open or shut should not matter. The air box gets cool air only from a snorkle outside the engine bay (like a cold-air-intake). You can see it through the grille, deep on the driver side.

I could not see any collapse in the video either but I'd be interested to see similar GoPro footage from a dyno run on either of the problem ZL1s discussed here. A 7th gear pull may not generate enough vacuum to illustrate the problem. As the OP described, the problem occurs primarily in 1st & 2nd gears WOT.

[Sven59]

Originally Posted by cwebster

Hood open or shut should not matter. The air box gets cool air only from a snorkle outside the engine bay (like a cold-air-intake). You can see it through the grille, deep on the driver side.

I could not see any collapse in the video either but I'd be interested to see similar GoPro footage from a dyno run on either of the problem ZL1s discussed here. A 7th gear pull may not generate enough vacuum to illustrate the problem. As the OP described, the problem occurs primarily in 1st & 2nd gears WOT.

With the hood open you now have air flowing in from above the CAI which with the hood closed would be sealed so there should be a huge amount of more air.

[cwebster]

Originally Posted by Sven59

With the hood open you now have air flowing in from above the CAI which with the hood closed would be sealed so there should be a huge amount of more air.

Sorry but I have to disagree. Only so much air can enter the snorkel and that snorkel is pulling from well below, in front of, and outside the engine bay. Sealed or not, intake air is not going to come from the engine bay.

Edit: You do know that the air box is closed, right? Not trying to be a smart-@$$ - just not sure if you're familiar with the 6th Gen ZL1 intake.

[Sven59]

Originally Posted by cwebster

Sorry but I have to disagree. Only so much air can enter the snorkel and that snorkel is pulling from well below, in front of, and outside the engine bay. Sealed or not, intake air is not going to come from the engine bay.

Edit: You do know that the air box is closed, right? Not trying to be a smart-@$$ - just not sure if you're familiar with the 6th Gen ZL1 intake.

My bad, I saw one of the dynos and they had a CAI in it. Factory you are correct.

[Sooner Cole]

I am the OP. I got the data recording box installed on the car today. Unfortunately , it is raining here today. So, it will be tomorrow before I get a chance to take the car out and duplicate the issue. The data recorder actually transmits the data directly to GM realtime, so a resolution should be relatively quick. As a side note, the service techs and engineers have been very cordial and seem genuinely interested in solving this mystery. I will follow up ASAP.

[cwebster]

Originally Posted by Sven59

My bad, I saw one of the dynos and they had a CAI in it. Factory you are correct.

No problem. Just trying to keep the facts straight.

Originally Posted by 17ZL1Camaro

I am the OP. I got the data recording box installed on the car today. Unfortunately , it is raining here today. So, it will be tomorrow before I get a chance to take the car out and duplicate the issue. The data recorder actually transmits the data directly to GM realtime, so a resolution should be relatively quick. As a side note, the service techs and engineers have been very cordial and seem genuinely interested in solving this mystery. I will follow up ASAP.

Good news! Thanks for keeping us in the loop.

[Evolvedx27]

Originally Posted by cwebster

Hood open or shut should not matter. The air box gets cool air only from a snorkle outside the engine bay (like a cold-air-intake). You can see it through the grille, deep on the driver side.

I could not see any collapse in the video either but I'd be interested to see similar GoPro footage from a dyno run on either of the problem ZL1s discussed here. A 7th gear pull may not generate enough vacuum to illustrate the problem. As the OP described, the problem occurs primarily in 1st & 2nd gears WOT.

it's not a collapse... it slightly gets pinched about a second or so before redline. You might have to watch the video a few times.

[cwebster]

Originally Posted by Evolvedx27

it's not a collapse... it slightly gets pinched about a second or so before redline. You might have to watch the video a few times.

I saw a slight change in shadows but even if that's deflection of the intake tube, it's not enough to make a difference. I believe it's possible for that rubber intake to partially or fully collapse but it seems to me more likely to happen at WOT in 1st or 2nd gear when there is maximum vacuum.

[NitroCamaro]

I do mechanical engineering work and own a 17 ZL1 A10... Perhaps the installation of a digital or analog manometer between the throttle body and filter would illustrate the point much better than the video.

Heck with black boxes and such....

I'd guess with the deflection I'm seeing in the video is probably 10" in of Hg or more. Whatever filter or air box combo that remove the restriction will make more power.

[hairtrigger]

Could be dropping fuel pressure at higher load. Direct injection in the lt4 needs around 2900psi I think.

[Evolvedx27]

Originally Posted by cwebster

I saw a slight change in shadows but even if that's deflection of the intake tube, it's not enough to make a difference. I believe it's possible for that rubber intake to partially or fully collapse but it seems to me more likely to happen at WOT in 1st or 2nd gear when there is maximum vacuum.

This is what I'm saying.... If it's doing that in 7th gear I'm sure it's worse in 1st....

[vtirocz]

Have you confirmed it's not this issue? http://www.camaro6.com/forums/showthread.php?t=490819

It doesn't sound exactly the same, but easy enough to check to rule that out.

[hawk02]

Found this over on the HP Tuners forum. It's a 2016 SS with a magnuson supercharger that repeatedly hits a limiter at 5700 rpm. The cause turned out to be the rubber inlet tube collapsing.

https://www.hptuners.com/forum/showt...r-at-5-700-rpm