Hi all, thanks to BahamaBart, we now have some data from the GTT IC as well. There were issues with BiM-COM, so the data set isn't exactly the same as the testing I did, but we do have IC thermal efficiencies and back-pressure measurements.

The GTT has the lowest backpressure, and the lowest thermal efficiency of all units tested. The HP numbers don't compare, as the tests were run on different cars, and BahamaBart didn't get to run the stock set up to compare.....

But here's the data.......



For the thermal efficiencies, at redline in 2nd gear,
GTT = 41.5% with a standard deviation of 4.4% Ambient temp was 78.5 Degrees F
Stock = 63.1% with a standard deviation of 0.7% Ambient temp was 65.3 Degrees F

Thanks to BahamaBart for the data from the GTT!

Matt

 

Why ALTA has a greater pressure drop?

 

and I don't design them, I just test them.

Matt

 

Our Current TMIC, has a denser internal fin which causes pressure drop in trade for cooling. But the graph makes it look much worse than it really is. 1-2psi isn't that bad at all(compared to much larger cores). But the better way to look at it is, that .5psi is very good!

 

So the question is - where is the line between pressure and thermal reduction? At what point does IC pressure work against the SC?

A question for Doc O - since we have the stock IC data - what would the data look like if 2 stock IC units were put together? would pressure be cut in half? and thermal efficiency rise? to what degree?

PS - Matt - my pleasure, thanks for allowing me to give back to the board.

 

1) If you stack them, it has half the back pressure, but not the same thermal efficiency as warmer air hits the second IC.

2) if you put them in line, with charge flowing through one then the next, you get twice the backpressure, but air entering the second unit is cooler, so it doesn't get cooled as much. Overall thermal efficiency is higher though.

3) if you put them in parallel, you halve the back pressure, and maintian (or slightly increase) thermal efficiency IF you can have the same cooling air per square inch.

It really comes down to a packaging game, as there is little space to work with.

Matt

 

Doc ,

The Stock IC example was for discussion only - ignoting any notion of fitment.

Attempting to purse the thought - what is the correct balance between Thermal Efficiency and Pressure.

My layman thought is that IC back pressure should not be greater than the pressure at the throttle body (i.e. what it can take) if there was no IC in place. So if IC pressure is greater than what the inlet manifold can take then your IC is bottlenecking prior to the inlet manifold? fair logic?

So if one were to increase the size of the TB then an IC with less back pressure should be more complimentary? true/false?

CAN? a we devise a simple formula containing both components that would give us some insight.

taking to easy examples -

stock 63.1 TE w/ .6 pressure @ 5000 rpm
GTT 41.5 TE w/ .4 prssure @ 5000 rpm

any formula suggestion?

Bart

PS - Andy could be helpful here - anyone willing to help me dig him up from the grave? I've got the shovels, if you care to help meet me at the grave yard at 12 night.

 

I thought the throttle body was before the IC? Isn't the path: intake filter, TB, SC, IC (with bypass valve back to TB at low vacuum), inlet manifold with fuel injectors, head.
If I'm right, then the IC can't bottleneck the TB.
I stand to be corrected.
phil

 

I meant to say "inlet manifold" - so I will edit the above - thanks.

 

this is an interesting subject - wanted to keep the thread going.

 

Can someone please explain these numbers. I thought after a while they would make sense if i kept reading posts, but im lost!

 

Hello guys,

I would like to thank all of you for this great thread,
I am like many of us a little lost, so can't wait for more information.

Victor

 

test

 

Matt,

do you have the capability to do a graphic with some explanation as to what all this means and how it goes together...... I'll admit, I am a bit lost too.

I think pressure drop is bad...loose boost.... I also think cooler is better... but honestly, I am having trouble connecting the dots and as you all know that my hobby is stamping out ignorance..starting with my own...... can you help.....please....

 

If I recall correctly, I think Matt might be out of town, on travel this week... I'm sure he'll chime-in soon though.

 

Hi all. The way an IC woks is by moving heat from hot air to cold air. They way it does this is having the air run into little metal fins (called turbulators) that act as heat exchangers. So on the inside and outside of an IC, there are all these fins (looks like a radiator) that act as heat exchangers.... But the air has to bump into them to exchane the heat, so it retards the progress of the air, and you get some pressure drop.

So there is a natural trade off between how well something exchanges heat, and how much it impedes airflow..... Sad, but true....

The ways to try and improve this are to increase flow area (number of IC tubes, flow area per tube) and this is the philosophy of larger ICs....

The new Alta and M7 units try to improve the amount of cooling air that flows through the core as another way to improve heat exchanger efficiency.

So, what's this all mean? An IC can be characterized by two things... It's backpressure, and it's thermal efficiency....

Baby is crying... Back later to close....

Matt

 

Loosing boost alone is not always a bad thing. Example: TonyB and others have noted a drop in boost after an exhaust mod. Better flow will gain you the hp even at the expanse of some boost. PSI by itself is not a measurement of performance.
Opening up the head would have the same result. Less boost, better flow and more hp.

 

Not sure if it's the same thing, but Andy posted a formula for Intercooler Efficiency, where:

Ei= (inlet-outlet)/(lnlet-ambient)

This might be close to the thermal efficiency formula. However, I used Andy's formula on Randy Webb's test of the stock i/c, and got a result of 79.3. So maybe they are not the same calculation. Randy's test results are here: http://store.webbmotorsports.com/ind...products_id=37

 

Yr calc of 79 from Webbs figure is correct for stock and using the same formula and webb numbers the GRS is 83% efficient.

What doesn't make sense is the inlet temperatures (262 / 270 ) . I recently did testing w/ Matt's help on the GTT IC unit and it was done with similar ambient temperatures (78- 80 degrees F) and the inlet temp hit a high of 200 degree F on the last run when i did not allow the car to cool down or stabalize.

I did 10 Gtech HP/RQ runs - after each one I drove the car lightly at 35-40 mph until the temps in the inlet and outlet dropped and stabalized. I the would do another run. It was only on the last Gtech run that I did not allow as much cool down time and the inlet temp hit 200 degrees F.

I need the webb numbers explained to me - I cannot but at 80 degrees ambient that your inlet temp reaches 270 degrees unless you have done numerous runs and built up heat soak.

 

The formula was discussed extensively with regard to the new M7 DFIC, and lots of ratios were calculated. I think you're right about the stock IC number--well below 100%. It is possible to get an index above 100, and the preliminary figures posted by M7 suggest 114%.
BahamaBart: I too, thought the Webb IC temps were way too high--especially compared to the IC temps M7 read from the bungs on their new IC.

 

What SC pulley do you have?
Randy had something going on though. 10-11 psi of boost yet 190+ hp means it was not a stock setup.

Either way though the thermal efficiency should be the same. Inlet temps alone won't change the TE.

 

Still puzzled by the bit in bold.
TEs above 100% are unheard of. Maybe it's the "index" word that confuses me.

 

His numbers might well have been taken on a dyno. Even a CAI would be drawing "hot" air from around the engine bay, on a dyno.

Of course, dynos have much less airflow through the IC, just as the operating conditions in general are very different for the car. However, with that figured, I really can't imagine that it is very good at all to do IC efficiency runs on a dyno, exactly because of the low airflow compared to street driving. It would seem to me like, in that proposed setting, whichever IC was bigger [clearly the GRS!] would just prove to be a better heat sink.

The numbers do seem confusing, and my own experience would say that intake temps aren't that high when I'm [or anyone I know of if!] moving at any rate of speed.

M7's intake temp numbers were lower because of the airflow at speed, I'm thinking.

 

Dyno - didn't think of that and would agree that might explain things. I would agree that a Dyno is no place for IC efficiency testing if that was the case. The inlet temps via Webb blew my mind when I saw them.

Hopefully, Matt can test more or we find volunteers (like I did) to perform tests in a controlled manner so we all learn the true benefits of the various IC units on the market. Matt was super, he lent me the equipment and provided install pics, even a pair of used boots, and the data he was looking for. I had a ball because I made it a father and son project.

 

much clearer now...thank you