LMM: Drive Pressure?

[jckleewein]

I just installed a drive pressure gauge. I am seeing a rapid flutter at any pedal position, but gets worse at 100% pedal position. The gauge goes from 40 to 60 psi (rapidly back and forth). It is moving so fast that I can't focus on any particular number. Could this be a wastegate issue?

 

[bullfrogjohnson]

If its a manual gauge it is normal. You can put a needle valve inline with the guage to slow the exhaust pulses to the gauge. The best way to measure drive pressure is with an electric pressure gauge.

 

[jckleewein]

Yeah its a manual gauge. I will order a electrical gauge monday.

Thank you!

 

[hondarider552]

I crimped the copper line and it stopped fluttering. with my radio off I could hear the needle bounching around.

 

[jckleewein]

How big of crimp did you put in the line? Did you put it where the air line hooks up to the copper tube?

 

[Subman]

I've had drive pressure gauges in every truck I've modded. Always used manual pressure gauges and never had a problem. What size copper line are you using and how much if it did you use?

 

[jckleewein]

I used 1/4" tubing and about 9 ft of the stuff.

 

[hondarider552]

I used 1/8th" copper line, and crimped it about a foot before the guage.

 

[jckleewein]

Where did you get your copper line. The home depot by my house only has 1/4.

 

[hondarider552]

Autozone in the guages isle lol. comes with like 5 feet of it coiled up with some adapters. it was like 8 bucks.

 

[BlkMax]

I have 1/8" copper tube going to a transmitter and it is coming off. I have had issues with the tubing freezing in the winter (and I have no traps or dips in the line to hold the water-the 1/8" is small enough to pick up the moisture from combustion and freeze up).

I will be going to 1/4" for this winter.

 

[Chaseum]

I just installed a drive pressure gauge. I am seeing a rapid flutter at any pedal position, but gets worse at 100% pedal position. The gauge goes from 40 to 60 psi (rapidly back and forth). It is moving so fast that I can't focus on any particular number. Could this be a wastegate issue?[/QUOTE
Save the $$$ on an electric gauge, Get a pressure gauge snubber. http://www.tpub.com/content/engine/14105/css/14105_137.htm

I think this one would work. I need one also. http://www.ocdiesel.com/Fuel-Pressure-Gauge-Snubber-p/issr7798.htm

 

[CurtisEmery]

Where do you have the line hooked into the exhaust. If you are too close to an exhaust port you will get gauge flutter. I run mine up in the turbo pedestal, and its smooth as silk.

 

[JD4440]

What electric guage are you'all using? Could I tap the exhaust where my EGR used to be and get an accurate measurement?

 

[hondarider552]

I just have a random 60psi boost guage in my BD manifold. works well enough for me.

 

[jckleewein]

Where do you have the line hooked into the exhaust. If you are too close to an exhaust port you will get gauge flutter. I run mine up in the turbo pedestal, and its smooth as silk.

I am running RDL headers. The headers are tapped and ready for a EGT or drive pressure gauge.

 

[durafarmin]

What do you all see for drive pressue at wot?

 

[hondarider552]

Stock turbo was a nightmare, 60+ PSI.

HTT is a lot better, 1:1 ratio from 20-40psi of boost.

 

[durafarmin]

ive got an lbz turbo on an lb7 its doing about 90 bp and 42 boost. ive got to get it tuned better.

 

[Smokin LB7]

ive got an lbz turbo on an lb7 its doing about 90 bp and 42 boost. ive got to get it tuned better.

How did you get the vvt to work?