Attention: TDR Forum Junkies I have been messing around with this some more and I got some data with loaded and unloaded running at about 60 MPH.
Measuring the turbo side of the BHAF. When pulling a grade my post turbo EGT can go to around 800F (+ or -). During those times I saw OAT + 30F to OAT + 50F. Typically running down the highway flat and level I would see OAT + 10F, with my turbo running in the mid to high 600F range.
Measuring the cold air side (fender) and the top of the BHAF. Just about at any time I would see OAT - 1 (a little error in my set-up). Pulling grades the top of the BHAF measurement might go to OAT + 2F.
I am going to assume that the bottom measurement would not be significantly different than the top or side. So I am estimating that 66% of the BHAF is getting OAT + 1 and that 33% is getting OAT + 50F (pulling a grade loaded). I can only guess that the average compressor inlet air temperature (worse case) would be about OAT + 18F. Running loaded flat and level it would be OAT + 4F. Running unloaded would be OAT + 1F.
Just about anywhere you place the temperature sensor with the engine idling or right after shutdown, I saw OAT + 40F fairly often and generally very rapid temperature rise. Especially after stopping, running loaded. The turbo is still often 400F to almost 500F for a few minutes.
Another thing for sure is that when OAT rises, the under hood temperature + OAT difference gets bigger. With OAT 80F or more the difference in the spread really got noticable. I am going to assume that is when the engine fan clutch is engaging.
Anyone know off the top of their heads how much Hp (CFM) the stock air box is good for?
Jim
Measuring the turbo side of the BHAF. When pulling a grade my post turbo EGT can go to around 800F (+ or -). During those times I saw OAT + 30F to OAT + 50F. Typically running down the highway flat and level I would see OAT + 10F, with my turbo running in the mid to high 600F range.
Measuring the cold air side (fender) and the top of the BHAF. Just about at any time I would see OAT - 1 (a little error in my set-up). Pulling grades the top of the BHAF measurement might go to OAT + 2F.
I am going to assume that the bottom measurement would not be significantly different than the top or side. So I am estimating that 66% of the BHAF is getting OAT + 1 and that 33% is getting OAT + 50F (pulling a grade loaded). I can only guess that the average compressor inlet air temperature (worse case) would be about OAT + 18F. Running loaded flat and level it would be OAT + 4F. Running unloaded would be OAT + 1F.
Just about anywhere you place the temperature sensor with the engine idling or right after shutdown, I saw OAT + 40F fairly often and generally very rapid temperature rise. Especially after stopping, running loaded. The turbo is still often 400F to almost 500F for a few minutes.
Another thing for sure is that when OAT rises, the under hood temperature + OAT difference gets bigger. With OAT 80F or more the difference in the spread really got noticable. I am going to assume that is when the engine fan clutch is engaging.
Anyone know off the top of their heads how much Hp (CFM) the stock air box is good for?
Jim
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