that would be 88% eff.

 

something doesnt seem right with the numbers.....

 

Oops ... looks like I copied and pasted too much.

Let's try this again:

Here's Caddman's numbers:

Idle 68 76 111 79 -31

inlet - ambient = 111 - 68 = 43 F
outlet - ambient = 79 - 68 = 11 F
efficiency = 75%

Hwy (80mph)68 72 149 91 -45
cruising

inlet - ambient = 149 - 68 = 81 F
outlet - ambient = 91 - 68 = 23 F
efficiency = 72%

Hard ACCEL 68 80 191 101 -90
from stoplight

inlet - ambient = 191 - 68 = 123 F
outlet - ambient = 101 - 68 = 33 F
efficiency = 73%

_________________
SHOW ME THE NUMBERS!

...How Fast is Your MINI?...My Mods...

 

no offense but something still doesnt look right....

-31 diffrence = 75% eff
-45 diffrence = 72% eff
-90 diffrence = 73% eff ?

im confused

 

>>no offense but something still doesnt look right....
>>
>>-31 diffrence = 75% eff
>>-45 diffrence = 72% eff
>>-90 diffrence = 73% eff ?
>>
>>im confused

Caddman,

Remember, efficiency is defined here as the difference between adjusted intlet temp and adjusted outlet temp, divided by the adjusted inlet temp. Therefore, the efficiency calculations are correct.

[(Inlet T - Outlet T)/Inlet T] x 100 = % Efficiency

Of course, we must consider the margin of error in the readings from the probes. If the errors aren't too bad, then the efficiency calculations shouldn't be too far off.

HTH

 

RECOOP is right. Caddman, if you'll turn to page 247 of our textbook ... ...

Ei = (Tco - Tio)/(Tco-Ta)

where:

Ei = intercooler efficiency
Tco = intercooler inlet temp
Tio = intercooler outlet temp
Ta = ambient temp

Using Caddman's Hard ACCEL data:

Ei = (191 - 101)/(191 - 68) = 0.73

I'm not sure of the accuracy of the gauge that caddman is using, but it should be at least as good as mine (it better be at 10X the price ).

Anyway, the specs on the $25 gauge are:

+/- 1C from -50C to 150C (I really hope the gauge never sees either of those extrema)

As mentioned earlier, I tested mine in ice water and boiling water and concluded it displayed very close to those values (0 C and 100 C). I have my outlet gauge now so I'll test it in water tonight and hopefully gather some data tomorrow. I have some highway driving planned, so I should be able to get some steady state figures.

 

>>Using Caddman's Hard ACCEL data:
>>
>>Ei = (191 - 101)/(191 - 68) = 0.73

Yes, I agree with the calc here. I wonder whether there'll be a significant air temp difference within the swirl. Do these temps move up and down very quickly? If so, the temps might vary a lot depending on boost level at that very moment when reading is taken?

Andy, when will you install the IC outlet temp gauge and do some hard acceleration tests?

Do you think you'll be able to get hold of the large Alta air-to-air for testing?

 

Anyone have an Alta intercooler they'd like tested?

 

Yes now that have run the calcs myself, you are right, but im baffled on why im less efficient than stock......even though i have found two problems in the system, still alot of air in water, and two kinks since i redid it this pass weekend, i must not have cyled it enough to get the air out, kinks were and easy fix............

Also i found a better deal on the guage but still not as cheap, i mean inexpensive as yours

ill have redo some runs once i get all the air out of the system, but the more flow from the kinks out should help alot, i was wondering why the water temp was going up.........it was dribbling....not hauling@$@ like it should be...

 

ok now that ive found the problems .... i made another run.....


Ambient 52
intake 281
outlet 79

open highway about 140.......

also i think i wasnt on the gas before taking the temps, so the intake temp was droping fast while the outlet wasnt as fast......as well the probes didnt have enough times to react to temps so they were not the actual temps.....zooming around in second gear is not a good way to check effientcy numbers.... Well i learned somethin new again today!!

by being in a taller gear it slowed the reactions so that i could document more correctly..... as well as the kinks and air...... My goof......

 

You guys lost me...

anyway since our cars come with an outside temp gauge, why not get two more factory temp sensors and mount them before and after the intercooler somehow. Have them all switched to a 3 position toggle switch attached to the tach display. That way you could just use your "stock" display to read them all.

 

BC28,

I actually thought about that, well, about relocating the ambient temp sensor to the intercooler. The problem with doing that is the range of temperatures encountered. Unless MINI is using a really unusual sensor, it only has a range up to maybe 50 C. I don't know of anywhere in the world that gets hotter than that (at least any place where one could drive a MINI)

But, I've seen manifold temps hotter than that just doing runs on the street.

Caddman's newest data:

Ei = (281 - 79)/(281 - 52) = 0.91

Out of curiousity, how hot was the water?

 

the water guage doesnt read below 70, so im not 100% sure, but it was below 70...

 

i think the main diffrence is the fact that i wasnt allowing enough time for the probes to get heat, there for i will be doing all future testing in 4th or higher gear, allowing the rpms to be slower to rise, giving the probes time to heat up, with the temps that was the first i saw the inlet temps that high, but i did that type of run three times with same results.....

 

What RPM did you take it up to in 4th?

 

7200... or so but i took the readings after i shifted in fifth and stayed on it

 

So, what RPM were you at when you took the readings? That makes a big difference.

 

around 6800-7000, i was trying to stay under load as long as possible, but at the point i took the readings the numbers were not scrolling fast like they were originally, they slowed and almost were stopped but not quite therefore i felt the probes were closer to actual temp....

 

I just installed my second $25 in the IC outlet and did some runs.

Ambient = 8.5 C

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

Run 1: 2nd gear, 2000 to 6500 rpm
Ei = (75.2 - 29.7)/(75.2 - 8.5) = 68 %

Run 2: 3nd gear,cruising at 3000 rpm
Ei = (33.1 - 16.0)/(33.1 - 8.5) = 70 %

Run 3: 2nd gear, 2000 to 6500 rpm
Ei = (89.5 - 32.9)/(89.5 - 8.5) = 70 %

Run 4: 2nd gear, 2000 to 6500 rpm
Ei = (93.5 - 36.1)/(93.5 - 8.5) = 68 %

Keep in mind, the acceleration was done in 2nd gear. I'd expect higher gears (and therefore higher speeds) would show better efficiency. Ignoring differences between intercoolers for the time being, we should all be thankful that we have an intercooler at all. Peak temperatures coming into the intercooler just on these few runs reached 93.5 C. The stock intercooler dropped that to a MUCH more combustion chamber friendly 36.1 C. Many supercharged vehicles (the GM 3800 for example) do not have an intercooler at all!

 

Here's some pics:

 

i would agree very much, the only reason i have such a higher effecientcy is because i put alot of time in to getting it right, thats why i was confused on the original results, but when i found the reason, the effiecentcy went up, as well i thin kyou need to do some high gear runs to see where your are at....it should go up for you as well....

 

Here's lots of graphs from my closed-course test-track runs yesterday and today:











Here's the raw data:

ambient= 6.5 C,ic inlet= 37.9 C,ic outlet= 15.7 C,RPM= 3500 ,Speed= 70 mph Gear= 5 Boost= 11.3 psi
ambient= 6.5 C,ic inlet= 110.1 C,ic outlet= 46.3 C,RPM= 6500 ,Speed= 110 mph Gear= 4 Boost= 16.0 psi
ambient= 6.0 C,ic inlet= 74.4 C,ic outlet= 23.7 C,RPM= 4000 ,Speed= 100 mph Gear= 6 Boost= 12.5 psi
ambient= 6.0 C,ic inlet= 90.7 C,ic outlet= 31.1 C,RPM= 5000 ,Speed= 100 mph Gear= 5 Boost= 14.0 psi
ambient= 6.5 C,ic inlet= 44.7 C,ic outlet= 17.0 C,RPM= 3600 ,Speed= 90 mph Gear= 6 Boost= 11.5 psi
ambient= 8.5 C,ic inlet= 73.4 C,ic outlet= 23.5 C,RPM= 4000 ,Speed= 100 mph Gear= 6 Boost= 12.5 psi
ambient= 7.5 C,ic inlet= 61.6 C,ic outlet= 21.5 C,RPM= 3600 ,Speed= 90 mph Gear= 6 Boost= 11.5 psi
ambient= 7.0 C,ic inlet= 53.3 C,ic outlet= 20.0 C,RPM= 3500 ,Speed= 87 mph Gear= 6 Boost= 11.3 psi
ambient= 4.5 C,ic inlet= 44.5 C,ic outlet= 13.9 C,RPM= 3300 ,Speed= 80 mph Gear= 6 Boost= 11.0 psi
ambient= 4.0 C,ic inlet= 78.1 C,ic outlet= 22.7 C,RPM= 4000 ,Speed= 100 mph Gear= 6 Boost= 12.5 psi
ambient= -2.5 C,ic inlet= 84.6 C,ic outlet= 30.3 C,RPM= 6500 ,Speed= 90 mph Gear= 3 Boost= 16.0 psi
ambient= 2.5 C,ic inlet= 94.5 C,ic outlet= 32.1 C,RPM= 5000 ,Speed= 120 mph Gear= 6 Boost= 14.0 psi
ambient= 2.5 C,ic inlet= 101.3 C,ic outlet= 37.4 C,RPM= 6000 ,Speed= 120 mph Gear= 5 Boost= 15.2 psi
ambient= 2.5 C,ic inlet= 91.0 C,ic outlet= 31.3 C,RPM= 6000 ,Speed= 100 mph Gear= 4 Boost= 15.2 psi
ambient= 3.0 C,ic inlet= 64.6 C,ic outlet= 18.9 C,RPM= 4000 ,Speed= 100 mph Gear= 6 Boost= 12.5 psi
ambient= 3.5 C,ic inlet= 96.6 C,ic outlet= 35.2 C,RPM= 5000 ,Speed= 120 mph Gear= 6 Boost= 14.0 psi

_________________
SHOW ME THE NUMBERS!

...How Fast is Your MINI?...My Mods...

 

Is it just me not understanding the numbers, or is our stock intercooler more than adequate for the 19% pulley? The Inlet temps seem to be fine according to the numbers. Not even close to 175deg F.

 

Well, keep in mind these runs were done in Winter temps (I know it's April, but it's still Winter ).

Let's say the IC efficiency is 60% (the worst of the runs I measured) and the supercharger is heating the air 95C hotter than ambient (the worst of the runs I measured), we can estimate how hot the charge will get in the summer:

82F (28C) ambient
123 C intercooler inlet
66 C intercooler outlet (150 F)

100 F (38C) ambient
133 C intercooler inlet
76 C intercooler outlet (168 F)

120 F (49C) ambient
144 C intercooler inlet
87 C intercooler outlet (189 F)

 

Ahh, yes. I remember winter..But here in florida those intake temps will get pretty high. Does effeciency remain about the same as ambient intake temps increase? Or do we loose even more in hotter weather?