Engine/Transmission (1994 - 1998) Twins and Pressure Ratios

[biggy238]

I was reading a 2001 post about building twins and I wanted to ask this.



Are twins much more sensitive to ambient or barometric pressure? What I mean is with one turbo, the pressure ratio to ambient pressure will be consistent as far as engine performance is concerned. A weather front or elevation change wouldn't prove as noticable a change in engine power. But, with twins, you're compounding those ratios, and thus compounding the affect ambient air pressure would have on the engine at a given rpm.



I've noticed with the onsent of fall weather that my truck has a noticable increase in power due to the cooler, more dense air charge availabe to it.

I can't help but think that twin turbos would compound this situation.



Somebody with twins tell me what you've noticed.



Thanks.

 

[Jim Fulmer]

The difference could be felt in most any truck Twined or no, to has to do with the air temp at the hat and that is were it counts, the increase wouldn't be allot but would be some, now having said that the difference between 210 degrees at 80psi and 145 degrees at 80psi is a different world.



Jim

 

[biggy238]

That's the answer i'm looking for. I just was thinking that if the change is noticable in a stock truck, that it should be plainly evident in a truck running higher psi.



I just wanted to ask because twins might be on my truck in the far off future. Weather fronts move through about once a week and so far air temp/density has made the difference in whether or not my truck can turn the tires over from a dead stop or not. (among other perfrormance changes)