Drive Pressure

cumminsbus

cumminsbus

Reconstruction Era
Joined
Mar 2, 2008
Messages
661
So it is time for me to be concerned with drive pressure for my turbo.

What are yall doing to measure your drive pressure?

I had thought about using my egt probe port and a copper line going to an air compressor gauge to measure the drive pressure.

Any other ideas?
 
i have seen people hook the drive pressure guage up using another port using a coil of cooper tubing to cool it down then connecting to regular line used for boost and run it to the guage
 
kjpcummins said:
i have seen people hook the drive pressure guage up using another port using a coil of cooper tubing to cool it down then connecting to regular line used for boost and run it to the guage
Click to expand...

Ya I thought about doing that and using my gauge but with 55 lbs of boost and a 60 lb gauge my drive pressure is more than 1to1 Im sure with the nitrous
 
yeah you would prolly need a 100psi gauge since 55 is already close to 60
 
I am interested in where mines at also. Your over 700hp with a TIB so might be time. :hehe:

I think I am going to buy the Lazarsmith kit. Little on the high side, but don't need another hole in the manifold and it looks nice. I am sure I could make one look pretty lame. :bang

ProtoTIP.jpg
 
im sure you could find that t fitting cheap somewhere never thought of doin that
 
I dont think you are going to get a good egt reading with that set up.
 
to be honest, with a single turbo and at the hp level you are running, I wouldnt get too worried about drive pressure. But if you are planning on spraying on that turbo, dont do it without an external gate, you will overspeed it in a hurry
 
the Isspro datalogger from Vulcan is awesome!!!!

check this graph out of my pressures found below. i need a bigger turbo asap. my top turbo is done after 50psi.


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cool logger.

but somethings messed up w/ ur truck, near 2:1 ratios at 50psi. i was at 1.1:1 w/ an hy35 over s366........
 
You got to email me that excel form, I got performax logs too, but just looking at the numbers isn't the same.

You've got primary left on the table, I was seeing 43-45 out of mine.

Boost numbers do seem low, seen 65 psi on the stock tune, flux 5's on this new build.
 
Rollin Coal said:
cool logger.

but somethings messed up w/ ur truck, near 2:1 ratios at 50psi. i was at 1.1:1 w/ an hy35 over s366........
Click to expand...


messed up? lol. brand new marine motor. runs better than ever. the spool from the new fletcher cam hits HARD and FAST. Fletcher did a great job with this build.

the top turbo is a 62/14 over a s480. thats whats wrong with my truck! I will be much better with a 66/16 when the dough comes in.
 
Joesixpack said:
You got to email me that excel form, I got performax logs too, but just looking at the numbers isn't the same.

You've got primary left on the table, I was seeing 43-45 out of mine.
Click to expand...


huh?

what you see is a comparison of me adjusting the wastegate in the same day.

one run is with the top wastegate opening at 20psi (before runs) and the other is with the top wastegate opening about 12psi (after runs). it made a signifgant impact on how the turbos ramp up boost, but drive pressure suffers just the same.
 
Joesixpack said:
You got to email me that excel form, I got performax logs too, but just looking at the numbers isn't the same.

You've got primary left on the table, I was seeing 43-45 out of mine.

Boost numbers do seem low, seen 65 psi on the stock tune, flux 5's on this new build.
Click to expand...



LMAO!. this is level 1 smarty! trust me... i'm not breaking my **** WOT trying to tune the turbos. i have alot more graphs but they the site says its too big.

i'm running lowered compression and a very aggressive cam which will account for some of the lower boost numbers IMO.
 
No sweat, LMAO I'm almost seeing more boost out of my primary than your combo, but what ever.
 
Joesixpack said:
No sweat, LMAO I'm almost seeing more boost out of my primary than your combo, but what ever.
Click to expand...

yeah, don't know why. what kind of drive pressures are you seeing on your setup?

the drive pressure worries me though.

we aren't apples to apples either. you've got that bigger top turbo and better flowing wastegate! :rockwoot:
 
morkable said:
to be honest, with a single turbo and at the hp level you are running, I wouldnt get too worried about drive pressure. But if you are planning on spraying on that turbo, dont do it without an external gate, you will overspeed it in a hurry
Click to expand...

Well I hope not too high, because I am going to give the :nos: a try soon and I am pretty close to the same configuration. :ft:
 
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