ill see if i can take care of that<br>

 

here it is, hope it helps

 

geeze.... ......sorry the pic is so big<br><br>

 

Picture's great. Thanks cfm.

 

I could have swore that I read somewhere that the pressure was higher from the turbo than what it is at the manifold. Like the turbo does 21.5stock but it is only 19.5 at the sensor? Wont a light come on if it is over 20? Also can you tap into the Map sensor for the pressure like on a PSD? this whole cummins with the cooler deal is new to me.<br>Chase

 

I actually just got back fro north vernon indiana where jim jessup lives. he tuned up my truck, but anyway, he helped design the 12v and 24v. he told me that the ecu on the 24 v will alow pressure up to 30 psi. and yes you loose almost 1 psi after the intercooler

 

So does this mean no light at 20psi or am I just lost on this?
Also it says something to the terms of &quot; Boost pressures are slightly less at the manifold than they are at the turbocharger outlet due to cooling and expansion of the air charge as it passes through the intercooler.&quot; I knew I saw it somewhere.

 

I took my 50 hp box of at urging of jim ( he doesnt like them) then he computer tuned my truck. I am running 29.9 psi and no light, without a box ( i.e. edge, vanaaken, etc.) which &quot;tricks&quot; the computer not to pick up on high boost the 24v will go to &quot;limp&quot; mode if over 30 psi. so no light at 20 this is all information i got from a designer of the engine so i trust him wholheartedly with my truck. My goal is not to BOMB my truck anymore, but to have a fully functional &quot;million mile&quot; truck, and the mods that i have have me very happy. <br><br>.....but i do need to go fast so that is why i am going to buy a 97 12v, cuz anyone who knows those engines knows that that will pull the 24v backwards through town but as i said i love my truck to death, it is perfect for me

 

The argument that pressure is constant throughout the entire intake tract isn't true, Superduty... unless the air wasn't moving.

The intercooler's affect on the intake charge will cause a reduction in pressure on the outlet side. If you want verification, take a pressure reading at the compressor outlet and compare it at the same time to an intake manifold port... you'll find it's always a few pounds less on the aftercooler's exhaust side. At least it is on mine. I learned a LOT about boost this year, we built a supercharged/intercooled 396cid EFI '94 camaro (LT-1 block) that goes 9.55 in the 1/4 mile, and a 383 mustang (351W-based) with a PT-88 Turbo, intercooler, Speedpro EFI, and it's running 9.25s all year long... gotta love boost.

 

I think old Mr. Bernoulli proved the point about delta-p across an orifice.

 

Remember that there is a difference between psi, and psig, psi being absolute boost pressure, and psig being what we see in the gauge.<br><br>Andrew

 

[quote author=TxDieselKid link=board=8;threadid=5633;start=15#69115 date=1037700044]<br>Remember that there is a difference between psi, and psig, psi being absolute boost pressure, and psig being what we see in the gauge.<br><br>Andrew<br>[/quote]<br><br>To clarify what TDK said, psia or &quot;absolute pressure&quot; includes the ambient atmospheric pressure in the reading. Basically, it is the pressure reading above a perfect vacuum. <br><br>Gauge pressure (psig) is the pressure reading above the local barometric (or ambient) pressure. It considers atmospheric pressure as being -0- on the gauge. Almost all (non absolute) gauges are pressure compensated to atmospheric so that you don't have to worry about calibrating to zero all of the time.<br><br>Whether you are using psia or psig, you will STILL see a pressure drop across the aftercooler during boost conditions. Pascal's law states that pressure in a STATIC fluid is the same in all directions. Our intake system is static only when the engine is NOT RUNNING.<br><br>The intake air from turbo to manifold not only loses pressure due to friction and flow restriction but also heat transfer. Blow up a balloon in your house and put it in the freezer. You'll see what I mean.<br><br>If you want a true indication of Intake Manifold Pressure, you need to tap the MANIFOLD. I tapped the air-horn, because the delta P from there to the manifold is negligible. Also, I had heard of some people having problems with manifold pulsation.

 

Thanks for posting that me4, I was WAY to tired to go into that much detail last night. <br><br>Andrew