Not to seem dumb, but what are these drive pressures with the turbos you guys are talking about. I may already know maybe just don't understand by how your saying it. stuff like 1:1 at 40 lbs.

 

The 1:1 is the ratio of drive pressure to compressor output. So 40 psi at the intake takes 40 psi drive pressure at the turbine inlet. I doubt there are too many that are that effecent but that is what the numbers you posted means.

 

DP is is pretty much like boost (for a lack of a better term) coming out of your eninge on the exhaust side. When it says 1:1 at 40 lbs, you are see 40 boost PSI coming into the engine and 40psi coming out of the exhaust. You can find this out my mocking up a gauge and hooking it up on the exhaust manifold.

 

I am going to do this to my truck.. what is the fix if the drive preasure is Low on exhaust side and also to High??

 

Low DP will spool slow from a large exhaust housing. High DP will spool fast usually due to a exhaust housing thats too small. So if you have high DP you need a way to relieve the pressure IE bigger exhaust housing bigger wastegate or an external gate

 

I will have to rig up that other boost gauge. I wander if the numbers will be different cuz of winter?? (diff Fuel)?

 

It will be on the low pretty much all the time until you are at full throttle/boost then at peak boost is when you want the ratio to be 1:1

The fix for high DP is back off the fueling or bigger turbo or an extra turbo

 

Back off the fuel?? I never herd of such a thing!! I need More More More. lol thanks for the info I just have to find a gauge to check the DP I do not wan't to buy a new gauge just for that or mabe it would not hurt to have it on there all the time. I am constantly messing around with my truck to get more power out of it.