That is what I thought I had seen with your previously posted numbers. With nearly 200degrees, I can see Randy being concerned about the 19%, but of all the numbers I have seen with the 19%, he must be living in a supernatural physics vortex or something else must be going on, because no one is seeing temperatures that high.

In fact I would think that an air to air intercooler such as the one from GSR with it's increased efficiency would offset all temperature differences between the 19% and 15%.

 

Temperature, possibly. But the intercooler cannot help the drive power increase seen in the 19% versus the 15%. At redline, the 19% is eating up quite a bit more engine power than the 15%.

 

How is the 19% eating up more power, Because of the extra heat or what?

 

As I stated, that number is on the track only, and peak at that. Around town, I can hit 160 on the stock intercooler.

The 19% is using more power because you are encountering more drag - the faster you spin, the more air you are trying to move. That ends up taking power to do.

I'm happy to show anyone out at the track that 195F with a stock intercooler - it isn't hard to reproduce.

Randy

 

By design, a Roots blower has drive power requirements that increase as the blower speed increases. In fact, it's not a linear relationship, but an exponential one, so spinning a little faster can require a lot more power.

 

I'd really like to see testing data for the stock and your aftermarket intercooler under the same conditions. If you'd like to send me one of your cf units, I'd be happy to test it for you. :smile:

 

Which redline? The redline of the 19% should be about 700 or more rpm lower than the 15%. From your Eaton graphs it is about 10hp at 16,000 rpm, which is lower than the 17,000+ rpm redline of the Eaton unit. Since we can't see the limits of the graph and can make a guess on extrapolation it looks like maybe a guess of 14hp at 17,000 rpm. If we modify the redline of the engine to match the redline of the SC for each pulley, than the power loss should be about 14hp (if it is truly a 5psi difference between the two, which I don't think it quite is, maybe about 4psi).

 

lets set up some track measuring standards so we can sort this out:

for example:
1. the car has to be moving at least 40mph? and have been moving for long enough for heat soak to be stabilized (as opposed to just starting moving after a heated run and a slow down that let the heat soak build while the cooling stopped)
2. no restrictions to the cooling air flow;
3. optimized cooling flow through intercooler (no removal of rubber between hood and intercooler top or removal of intercooler top cover, for example)
4. peak measurements are ok, consistent with the above.

the statements that: "195F with a stock intercooler - it isn't hard to reproduce." AND "Around town, I can hit 160 on the stock intercooler." need some filling in.
I can hit 160 after coming into NY from the highway and slowing down for 15 minutes of funky traffic, but that isn't really what we want to measure.

 

I was referring to the redline of the engine.

 

Also, ambient temp is quite important, I would think. I will log IAT's this weekend with some spirited canyon driving and report back. I will upload logs that will show this in relation to speed, and among other things like coolant temp, timing adv and maninfold pressure... all recorded in 5 second intervals. I'll also note ambient temp.

 

Knowing the ambient temp, the intercooler inlet temp, and the intercooler outlet temp are critically important. Without all 3 of those pieces of data collected, there is no way to compare one intercooler to another. Luckily, efficiency calculations done in very cold weather match up very closely with those done in very hot weather.

 

I'm going to try to upload an Excel doc of a 12 min run this evening. As you can tell by the initial IAT and coolant temp, she was already warm from my commute home. The temps driving home were in the low to mid 90's.

After a couple minute rest, I fired her up again, and the MINI was reading the ambient temp as 88. I installed the CarChip E/X and went for a semi-spirited drive in the canyon where I live. Folks were coming home, so i really could not dig into it. I got 145 for a high (IAT). I got this figure, as you can see, when flooring it. I was really only able to do so just that one time. So, I can certainly see going higher on the street, especially with an ambient in the 90s to low 100s...

No Excel upload possible... So, I'll try Word...

 

O.K. I have a few numbers for you all.

Ambient = 80 degrees F
Before intercooler = 150 degrees F
After intercooler = 90 degrees F

This was during normal driving " for me" spirited through trafic with hard accelerations between lights and periodically for passing. These temps were the average during a 1 hour test period. Peak temps under hard acceleration were:

Ambient = 80 degrees F
Before intercooler = 200 degrees F
After intercooler = 110 degrees F

Also we have made a design change to the air tube as the previous tube had too much flex and was continually breaking clamps. With the new tube the issue has been resolved.

 

just today, ambient about 65 F, recorded 240 F in, 110 out after a 3rd-4th gear WOT blast, probably hitting 80mph. stock intercooler.

 

Last weekend on a run thru and up mountain road that got up to 4000 ft in elevation on a 95 degree day. My intake temps got to 128 degrees with stock intercooler. I have the Alta air diverter with sprayer and when I used it, my intake temps would drop to 105-110 degrees.

Mars, glad to see some test results onthat intercooler, thanks. I do prefer the stock one with a sprayer though. take care