RowJ

Finally got to do some turbo air temperature testing I've wanted to do for some time.
I welded bungs or mounted ports on my Primary Turbo (bottom) outlet..... my Secondary Turbo Outlet and my Airhorn!
And thanks to Quads latest updates for the Adrenaline Box, I can also read temps at IAT sensor!!

Very interesting info that left me surprised twin turbos work as well as they do, with air entering the CAC at over 500* at 50 psi boost on a hot day.
Came away impressed with how well CAC (intercooler) works. That 500* air can be cooled down as much as 300*...to 200* at Airhorn.
It's 40* higher at IAT Sensor. This fact was surprising,at first, but not so much after reflection... maybe?

This last finding leads to my question, Anyone know if IAT sensor is a grounded K-type like my others? Any info in IAT sensor is appriciated.
Also, would love to see comparison temps for single turbos ..... factory or aftermarket. Anyone?
If interested in all my test findings, send your e-mail address for copy of the Word.doc. rj@netcommander.com

XLR8R

I'm also interested to see single turbo delta temps across the OEM CAC for a 2nd Gen... since I have plenty of data for the HPCR OEM CAC's efficiency, and wonder if there's a measurable difference in performance between the two.

Big Blue24

Rowj, I have noticed that IAT sensor readings go down when I am idling and then raise rpm up to 1500 or so. It seems that incoming air gets heat soaked in the head at idle due to slower moving air and low volume etc.

I have also noticed, just on the IAT sensor readings that when I'm winter driving 20* outside, IAT would always be about 30* warmer at cruise 6-9 psi boost than ambient but as temp dropped lower like 5 below zero at 70mph cruise, IAT would never dip below 38-40*.

In less words, IAT=Ambient + 30* when at cruise till temps dip below freezing and then IAT would have a greater temp differential, almost as if the head was warming the air more.

RowJ

Thanks, Makes sense. If you can hold coolant temps and oil temps in much colder weather (therefore internal block temp) then... IAT temp should also hold steady. JMO.
I also noticed the +30* at cruise, empty, level ground....... but under heavy load the delta can get as high as 100* for my setup!
Interesting to note the 50-50, H2O/meth lowers the heavy load IAT reading 30 - 40*.

RJ

Number47

just a side note the "perfect" temp for charge air should be about 100 Entering the horn. once a again that would be the Perfect temp. that is the temp you would see the most power

XLR8R

??? Cummins recommends optimum intake air temps of 60-90*F... too hot reduces charge density while too cold reduces efficiency by excessive cooling of the combustion chamber (especially the piston crown's bowl).

Big Blue24

So has anyone done testing to see where maximum HP is made with regards to intake air temp?

Obviously this would change with different turbo setups.

What I'm getting at is do you think my truck would dyno more if I opened the gate at 40 psi and had lower IAT readings, or would I make maximum power holding the gate closed entirely and running drive pressure way high and pushing the charger way out of it's map to say 50 psi?

RowJ

I would never second guess the turbo Mfg!
Always wisest to stay within the Map. Outside it you get expansion boost pressure from overheating, instead of compression boost pressure.........
and less than max attainable HP!
I dynoed my B-1 single (an earlier S300), four yrs ago, and got 6 more hp at 42 psi than I did at 51 psi. That turbo was bullet proof at 50 psi....
suspect your 3rd gen may not be?

RJ

Joker12valve

I would love to take air temps but on the old 12v i can't use a box to get iat. So what other gauge setup could i get, any part numbers would help out.

XLR8R

Just insert an unsheathed grounded type K thermocouple through the 1/8"NPT boost bung in the intake airhorn and use any compatible gauge or meter for real-time monitoring. Takes about 5 minutes to setup a meter you can see while driving, lodged between the dash & windscreen.

Big Blue24

Next time I dyno, I'm going to have to play with the wastegate a little and see what my curves do. It would be neat to figure out the shaft speed and or associated boost number that equates to maximum mass flow of air. I suspect that this number would have to be very dynamic based on ambient temp, and exhaust back pressure limiting incoming fresh air charge.

RowJ

TTT
Anyone else got charged air temps leaving the turbo....pre CAC?

How about all you Adrenaline guys with a Pulse, that can read IAT temps. Would like to hear your max IAT temps at WOT, please.

RJ