2007 Exige S Intercooler Air Flow Study

[dmh]

I'm not suggesting DEs. Private testing is available at most all tracks. There are more than a few groups that are for just "tune & test".

Beside...who drives a Lotus on the street?

[qball]

Originally Posted by dmh

Who cares what an intercooler does on the street as there are laws to abide by. It is only about racing on a closed course of some sort that matters.

Why the **** do I care about your desire for intercooler data on a track???. I don't

I don't race my car on the track. If you don't want to look at my data... then don't.

I would say the percentage of S owners seeking better performance from their car that are regular street drivers far outweighs the number of S owners that race.

At least I am willing to share the data. I distinctly recall a thread where someone was requesting your intercooler data and track times (after questioning your sale of the RLS intercooler) and you became snotty about sharing it.

The data I collected is for my own curiosity. I'm just willing to share my data and learn from others...

[Smoky]

Originally Posted by dmh

Beside...who drives a Lotus on the street?

Even though you are (hopefully) joking that is the oddest question I've heard all week. Maybe all month. This one's a keeper.

Lots of round here. I like reading data.. It's more funner.

[charliex]

don's a wag.

i've yet to find a track out here that'll let me tune and test for anything less than the price of a normal track day.

most of the time i spend a few hours tinkering with the car and 10 minutes running.

70 MPH up a hill for 10 or more minutes in 110+ ambient temps is a pretty good test, or even lower speed in a low gear producing high load.

we've also got abandoned desert roads that lead nowhere, just giant jack rabbits, except of course when you come across the OEM's doing their testing on the same roads, akward!

[dmh]

Wag -- very fuuny.

For the others who don't know I'm messing around -- I am. Relax. Have fun playing with your data.

Racers don't share information!

[jerrym]

subscribed

[ocelot27]

Has anyone measured the mass air flow through the IC roof duct vs speed? We could used a properly calibrated off-the-shelf MAF sensor but it would have to be placed in an area of the duct with laminar flow - somewhere between the roof scoop and the mail slot would probably be ok. I'd be very interested in knowing the cfm vs speed for the 07s, 08s, and with and without fettling the mail slot. Also some 08s have screens in the inlet of the roof scoop and some don't - mine did and I promptly removed it.

On another note those of you who haven't cleaned out your IC should take a look inside. When I installed the RLS IC I noted the factory IC which (had about 1000mi on it) had a pretty good collection of bugs plastered on the fins.

-john.

[qball]

OK fine.... my vagina was hurting today anyways.

[Mag]

Originally Posted by ocelot27

Has anyone measured the mass air flow through the IC roof duct vs speed? We could used a properly calibrated off-the-shelf MAF sensor but it would have to be placed in an area of the duct with laminar flow - somewhere between the roof scoop and the mail slot would probably be ok. I'd be very interested in knowing the cfm vs speed for the 07s, 08s, and with and without fettling the mail slot. Also some 08s have screens in the inlet of the roof scoop and some don't - mine did and I promptly removed it.

On another note those of you who haven't cleaned out your IC should take a look inside. When I installed the RLS IC I noted the factory IC which (had about 1000mi on it) had a pretty good collection of bugs plastered on the fins.

-john.

yea i found a lot of debris in mine too.

my guess is the only way we'd get accurate data is to drill a hole in the scoop and stick a sensor thru, otherwise the sensor itself would taint the results. I've heard of air speed sensors that race cars use like this one that might work. Racing Data Acquisition Sensors

[ocelot27]

Originally Posted by Mag

yea i found a lot of debris in mine too.

my guess is the only way we'd get accurate data is to drill a hole in the scoop and stick a sensor thru, otherwise the sensor itself would taint the results. I've heard of air speed sensors that race cars use like this one that might work. Racing Data Acquisition Sensors

Something like this would be ideal:

Traceable Hot Wire Anemometer/Thermometer with NIST Certification, Control Company - Mfg# 4330

All you need to know is the cross-sectional area of the conduit where the probe is to calculate cfm - assuming the probe is in an area of laminar flow.

Pricey though - that's one of the cheapest ones I was able to find...

-john.

[apk919]

Originally Posted by ocelot27

Has anyone measured the mass air flow through the IC roof duct vs speed? We could used a properly calibrated off-the-shelf MAF sensor but it would have to be placed in an area of the duct with laminar flow - somewhere between the roof scoop and the mail slot would probably be ok. I'd be very interested in knowing the cfm vs speed for the 07s, 08s, and with and without fettling the mail slot. Also some 08s have screens in the inlet of the roof scoop and some don't - mine did and I promptly removed it.

On another note those of you who haven't cleaned out your IC should take a look inside. When I installed the RLS IC I noted the factory IC which (had about 1000mi on it) had a pretty good collection of bugs plastered on the fins.

-john.

You mean something like this?



Airflow was measured downstream of the IC, but since there's no place for the air to escape, it's essentially the same flow in cfm as any cross-section of the scoop or ductwork.

[ocelot27]

Originally Posted by apk919

You mean something like this?

Airflow was measured downstream of the IC, but since there's no place for the air to escape, it's essentially the same flow in cfm as any cross-section of the scoop or ductwork.

So two 6.5in Spal fans would essentially double the air flow.... neglecting head loss across the IC - which is probably significant.

-john.

[apk919]

Originally Posted by ocelot27

So two 6.5in Spal fans would essentially double the air flow.... neglecting head loss across the IC - which is probably significant.

-john.

Assuming that their rated cfm wouldn't be compromised by the same bottleneck that affects the roof scoop's ability to provide air flow...

[qball]

I wonder if any cool air could be pulled from the wheel wells, through the wheel well liner?

Does anyone know if there is a decent amount of air flowing in that general area? Or does it simply skirt underneath the car and past the exterior of the wheels?

[ocelot27]

Originally Posted by apk919

Assuming that their rated cfm wouldn't be compromised by the same bottleneck that affects the roof scoop's ability to provide air flow...

I'm talking about ditching the roof duct entirely and putting the fans on the front of the IC - cool air would still come down through the duct towards the fans - essentially the rubber boot and the duct adapter that connects the IC to the boot would be replaced by two fans...

-john.

[Thomasio]

Mag - something is very wrong with your data. The intercooler (stock, rls, Lotus Cup, or other) most definitely delivers cooler air than that which it receives.

Are you huffing nitrous again?!

My guess is that you have your channels reversed, or you don't have each of your thermocouples in the air stream.

[Mag]

Originally Posted by Thomasio

Mag - something is very wrong with your data. The intercooler (stock, rls, Lotus Cup, or other) most definitely delivers cooler air than that which it receives.

Are you huffing nitrous again?!

My guess is that you have your channels reversed, or you don't have each of your thermocouples in the air stream.

haha yea the sensor install was incorrect. The thermocouple needs to be completely insulated from the pipe. Currently the sensor is taking the reading directly off the copper, which is the temp at the pipe surface. So if anyone is intersted in real time pipe temps there they are .

Trying to locate some bakelite. weld an alum mount on the pipe itself. the copper adapter to be threaded into bakelite only. And the bakelite attached to the alum mount. this would give an accurate reading.

Something like this but 1/8 thread tapped into bakelite instead of squarish opening in pic, then bolted into alum mount.


I'm having a hard time finding bakelite. If anyone has easy access to some, i need a small 6 x 3 inch sheet, 10mm thickness, can paypal for cost + shipping.

[robains]

As has been said, Air to Air is definitely more for street driving and/or drag racing with plenty of cooled down.

Having just got back from a miserable day at ButtonWillow, the air to air IC just isn't gonna do anything, just extra dead weight.

Don't know the street to track ratio for the Lotus, but there were A LOT of Loti at the track and they seem to be a very popular car for track days, even at other none Lotus related events.

[robains]

I'm going to experiment with home brew kit. It looks well thought out and the power draw is only 50 Watts (about the same as my Nav/Stereo).

The water spray kit

Take a look at some of the data readings that were taken with this setup. However it appears the pump will not do well in continuous operation. Max is about 1 minute then needs to cool down. Anyone have alternate pump solutions? Higher pressure the better.

[dmh]

FYI if you are planning on racing...
there are no road racing organizations and/or sactioning bodies that I have ever heard of that allows anything like intercooler sprayers. If the rules don't say you can do something, you can't.