2007 Exige S Intercooler Air Flow Study

[apk919]

Originally Posted by dmh

Not as long as it is valid.
But what is being done here has already been done by neumerous people numerous times. What information do you think is missing or needs to be answered?

I could be wrong, but not everything that's been discussed here has been done previously, or at least, discussed openly and publicly. Many claims have been made about the efficiency of different a/a or a/w intercoolers, but not much actual data has been disclosed. Furthermore, some of those claims have been made by vendors, which is subject to bias, either intentional or unintentional.

Most of us are not professional automotive engineers (although I worked as an engineer for more than a few years), but are interested in this topic because it's our hobby. I see it as a kind of enthusiast's peer review, where we can feel free to share our techniques, data, and results, perhaps learning something new in the process. If I wasn't enjoying it, I wouldn't be doing it. I'm sure I'm not alone in this sentiment.

[Smoky]

Direct comparison Stock vs RLS. and those variables across roof type (cup vs Exige S). Has that been done already? If so, linky please. I haven't seen a direct comparo yet.

[moc]

Hi Guys, there is some data over here that you might find relevant to this thread.

[dmh]

Originally Posted by moc

Hi Guys, there is some data over here that you might find relevant to this thread.

Just as the Brits led me to believe! Go figure.
Most importantly, who won the race?

I take it water spraying the intercooler is allowed by the rules?

[apk919]

Originally Posted by moc

Hi Guys, there is some data over here that you might find relevant to this thread.

Thanks, and yes, very relevant.

[Monsi]

I'm really interested to see Mag's data of RLS vs Stock in a real world scenario

[dmh]

So...has anybody flowed the stock or rls intercooler at 28"?

[Thomasio]

Originally Posted by dmh

So...has anybody flowed the stock or rls intercooler at 28"?

I assume you mean 28" of mercury? About 14 psi? (Atmospheric pressure is about 14.7 psi at sea level.)

Wouldn't it make more sense to flow test the intercooler at 6 psig (about 20.7 psi), which is where it will be "working" while in service?

Any non biased parties have access to a flow bench? I'll provide one Lotus Exige S intercooler and one rls Intercooler (both to be returned) for testing.

[Thomasio]

This graph (below) is non-scientific, but please see this thread for more details:

Really Light Stuff Water / Methanol Injection

This graph compares the IATs for four 10 to 60 mph pulls (no injection) with four 10 to 60 mph pulls with injection, all 8 back to back. Top green line is IAT's for first four runs (no injection), lower green line is for last four runs with injection.

Injection occurs at two points. See thread (linked above) for details.

[dmh]

Originally Posted by Thomasio

I assume you mean 28" of mercury? About 14 psi? (Atmospheric pressure is about 14.7 psi at sea level.)

Wouldn't it make more sense to flow test the intercooler at 6 psig (about 20.7 psi), which is where it will be "working" while in service?

Any non biased parties have access to a flow bench? I'll provide one Lotus Exige S intercooler and one rls Intercooler (both to be returned) for testing.

No, water.
No, industry standard of 28; if not then 10".
I'm gathering the numbers as it seems Bell was not asked to flow the intercooler but rather just build it.

[apk919]

I finally got around to measuring IC cooling flow with the top off. Same course, a bit breezy, and 90 degrees F ambient. At moderate speeds, it looks like you lose about 19% airflow going topless as opposed to running the Cup Roof. At higher speeds, the data is a bit noisy, but there's some indication that it's even less of a difference.

Note that fettling alone increased flow by about 25% from stock... decreasing that by 19% is (1.25 * 0.81) or 101.25%... which means that running topless with a fettled clam gives you about the same flow as a Cup Roof without fettling.

[Mag]

Installed an oil catch can. Appears to make a difference.
1) when took the inlet side pipe off, it was dry inside. In the past there was always oil inside.
2) Notice the max preIC temps when hard driving, high rpm, this is when the most oil would come through. Shows in the comparison between MAX temps at pre IC. However, RLS IC effectively takes out most of the heat from blowback according to data with or with out catch can. Didn't run the w/o can + stocker test.



Prior to current run, car hot from sitting after previous run to gas station & parked for about 30mins: roof 29C, pre 50C, post 50C

Compared to previous test with out catch can:
Ambient 26~28C, Relative humidity 87%
Prior to run, cold car: roof 28C, pre 30C, post 30C

(To mimick the previous test, I drove the car around for 15 mins on hwy to get similar base temps/conditions on both runs. Interesting to note RLS test was in late afternoon. Stocker at night. It was cooler at night. I couldnt work fast enough )



Tests with oil catch:
RLS
Ambient 30C
Humidity 74%
Stock
Ambient 28C
Humidity 78%

Hard drive top speed 117mph, 5mins, 2nd ~4th to 8krpm (same route last test). Didn't do the hwy test again as difficult to mimick a similar run with traffic. In anycase we are probably more interested in how the IC performs during spirited driving. Heat soak properties can be inferred from the data and applied to efficiency in stop and go conditions. Later when I get the fans on, will do a comparison for stop and go.



Here is an overlay of pull #2 of each hard drive log file. The shift points are almost identical, so the overlay is for the two VSS traces over time, rls vs stock. Same road, similar temps (see details above).

You can see that the rls Intercooler VSS (solid) gets to a given speed faster than the stock intercooler does (dashed line).

[shay2nak]

wow nice work. I guess there's an added bonus by having the catch cans installed.

also, the shift point graph...where you show the RLS arriving at the given speed faster. That's because your engine has more HP, correct?

[Mag]

Originally Posted by shay2nak

wow nice work. I guess there's an added bonus by having the catch cans installed.

also, the shift point graph...where you show the RLS arriving at the given speed faster. That's because your engine has more HP, correct?

thanks, catch can yes, but note vented to atmostphere type was used here. The other type which claims to catch most of the oil still passes the hot gas back into the intake channel. On speed arrival: yes that would be the inference.

[apk919]

Originally Posted by shay2nak

wow nice work.

+1,000

[Monsi]

well mag you should get some money from RLS for the intercoolers you helped sell

so I guess I will be getting one eventually (and a catchcan of course because hot gases + coating the inside of your IC with oil is never good)

[shay2nak]

Originally Posted by Mag

thanks, catch can yes, but note vented to atmostphere type was used here. The other type which claims to catch most of the oil still passes the hot gas back into the intake channel. On speed arrival: yes that would be the inference.

ah, I have the the cans that run the line back into the intake. I wonder if it would make any difference. I suspect the hot oil would make much more difference that just hot air??

what's the X-axis on the gear graph? time? what's each division?

[Monsi]

Originally Posted by shay2nak

ah, I have the the cans that run the line back into the intake.

there is an easy way to fix that *yoink*

[apk919]

Originally Posted by Monsi

there is an easy way to fix that *yoink*

Nice sig!

[dmh]

Originally Posted by Monsi

well mag you should get some money from RLS for the intercoolers you helped sell

Then somebody buy mine. It's been for sale while a while in the parts forum.