Turbo Mod

[AH64ID]

I'm not exactly sure what you are referring to with the DP. Do you have a pressure gauge in the exhaust system or am I way off. :banghead: I know that with the VGT on the 6.0 powerchoke would actually spool at idle with something as small as the a/c compressor clutch kicking on. When they would spool they would close the vanes and raise exhaust back pressure but increase the velocity. Atleast thats how the engineer explained it to me. So until you actually reached around the peak torque range of that particular engine with the VGT the back pressure was higher than the boost.

Yes I run a pressure gauge in my exhaust manifold. In very general terms that is a correct statement. But there are several variable. Under normal acceleration DP is generally at or higher than boost, but not much unless the turbo is really too small for the application or was designed to have higher backpressure for spool/emissions reasons. Once the rpms stabilize and power stabilizes the drive pressure will normally drop while boost stays constant. But drive pressure does not have to exceed boost for the turbo to accelerate.

[ISX]

Got it done today. Only the water temp gauge, RPM, A/C compressor don't work. I put 15 miles on it and I really can't tell a difference with that hole in the wastegate. I think my wastegate actuator is a little stuck because I was hitting 45psi or so. I think my 35psi gauge tachs out around 40-45 and I was still going when it just stopped so it might have hit 50 for all I know. I will check the actuator out and see what the deal is. I have a pressure relief setup that lets the wastegate see pressure and that little thing that does it is what is sticking. I have a 12V air solenoid that I want to make work one of these days. The turbo does have a little more whistle to it, though I haven't heard it in months so maybe thats why it sounds louder.

[dorkweed]

Bump to the top.................any updates ISX?????

[ISX]

Why do I keep forgetting about this. I have pulled the trailer several times and I can say that.....I can't tell a difference. My wastegate opens instantly when I get to 35psi and stays shut any time before then because of a special overflow valve I put in and I haven't got enough boost to tell if it is working or not. But as for drilling the hole in the turbo, during nonwastegate opened conditions, I can't tell any difference at all. My EGT's are really low but they were low before so I can't say the crossported hole did it. Pulling our trailer at a constant 70mph I cannot break 900F egt even at 85F ambient up 7% grade hills, nothing will make it break that temp. Passing people with the trailer I can get above it but driving sane at a constant 70 will just not go over it. Got 17mpg pulling it the constant 70mph for 300 miles so it's still on top of it's game This trailer.. http://forum.mopar1973man.com/attachment.php?attachmentid=210&d=1259508018

[ISX]

Figured it out. They are split off because of a thing called pulse turbocharging which uses the kinetic energy of the pressure pulsations caused by the expulsion of the exhaust gas from the cylinder. It achieves higher torque at lower engine speeds. This is why the exhaust manifold is split into the front 3 and back 3 and why my turbo was split as well. So no clue why the HY isn't split. I didn't notice much of a difference if any but I guess the principle is there

[AH64ID]

The HE's found on CR's aren't divided either. I wonder if the housing is so small that it's not needed for low end flow. My Garrett is divided.

[ISX]

I thought those were variable so they wouldn't really need any kind of fancy pulsations?

[AH64ID]

The HE's found in 5.9 are not variable, HE341 and HE351CW. The HE351VE found on the 6.7 is variable.

[ISX]

You're telling me those trucks just have a regular turbo with a 9cm tiny housing?

[AH64ID]

You're telling me those trucks just have a regular turbo with a 9cm tiny housing?

And now you see why I wanted to ditch it! According to Hoslet a 9cm undivided flows about the same as a 12cm divided... but???? Anything with a fixed housing size is not variable, the HE351VE is something like 3-26cm3.

[ISX]

Hmmmm, wonder if whoever tested that is the same one giving all this other inconsistent data I keep finding lol. I'm gonna win the lottery and start buying my own test equipment. Fix the world's data consistency issues

[War Eagle]

Hmmmm, wonder if whoever tested that is the same one giving all this other inconsistent data I keep finding lol. I'm gonna win the lottery and start buying my own test equipment. Fix the world's data consistency issues

Good luck with that one!