Intake Turbulence w/ Turbo

[Steve@HPE]

I've been battling an upper RPM hesitation my Camaro is having. After having tried re tuning, ignition parts and other things I'm beginning to think it's turbulence in the intake manifold.

I replaced the stock plastic intake with a Victor JR fitted with an EFI "hat"; I'm wondering if that EFI hat and intake combination might be causing turbulence, thus causing hesitation.

Anyone familiar with intake air dynamics on turbo systems?

[Steve@HPE]

Originally Posted by SC2150

We have had issues using the same set-up and it was a bear to tune so I think you are on to something. This was a few years ago and we havent used the vic jr because of the heat soak the AL created but I think you just hit on something we were also experiancing.

The other issue is over powering the MAF but I suspect your tuning SD? let me know what else you find......am interested.

We're tuning MAF. This morning we replaced that intake setup with a FAST 102 intake, re-tuned it and the car is running much better. What seems strange is the MAF curve was WAY off on the re-tune, I'm talking upwards of -25% in the 2400 to 3000Hz range. Of course we had to build a new intake tube to fit the lower FAST intake, so the MAF delta could be do to a slightly different location of the MAF sensor.

As far as why the Victor Jr didn't work well, it's hard to say, but my guess is turbulence and heat soak as you say. One odd thing we noticed was the car idled well and had decent street manners UNTIL the engine reached full operating temperature (i.e., the Victor Jr. became heat soaked). Then it sounded and felt as though the engine was missing.

[jay@redline-motorsports]

Went thru this before, what did the maf hertz look like? was it erratic? put the car in sd and see if the issue smoths out.

[xx_ED_xx]

Never understood why any body would run a carb intake with efi. Different runner lengths, stupid elbow, and then the intake is aluminum.

I wish gm would of made the intake plastic on the vortec 8100's
50 pounds of aluminum