intercooler efficiency - where are the experts?

[paulcundy]

Anyone got any idea what relationship there is between intercooler efficiency and BHP output. If for instance I was able to further cool the charge air coming out of my intercooler by another 10'c how much extra power could I expect?
Would I need to re-map?

Car is a Noble M12

Regards
Paul Cundy

[deltaf]

Intercooler efficiency= temperature removed divided by temperature rise(thru compressor).

Tco-Tio over Tco-Ta

Where Ta= ambient temp; Tco= temperature out of compressor; Tio= air temp exiting intercooler.

Havent got the calcs for power gain per degree drop to hand right now, will have a ferret round and post em later...if i can find em.... something like 17degrees for every hp iirc..?

[Pigeon]

I haven't looked it up either, but I think it's something like:

Power output is proportional to charge density
Density is proportional to 1/temperature
So a 10% drop in temperature gives a 10% increase in density which gives a 10% increase in power.

Remembering of course that temperature is in degrees Kelvin.

[pbrett]

Thinking of water spray maybe Paul? 2 small jets fitted into the sides of the intercooler 'trench' should do it.

Made a little difference on hot days on my EVO and totally zero on the perfect turbo car days (cold and damp in the air).

Phil

[matt_t16]

What you really want to do is replace the existing intercooler with a chargecooler setup, around 90% efficent and can exceed 100% efficenct with a chilled water supply.

Use the existing intercooler space to mount a pre-rad for the chargecooler, then you have a choice of using a single twin entry single exit chargecooler or a pair of single entry single exit CC's each mounted close to the the turbo's, you should be able to reduce the inlet length from the front bank's turbo by employing this method leading to an increase in boost rise rate.

I've considered putting an off the shelf kit together but doubt they'd be the demand to cover the development costs.

Matt

[pbrett]

matt_t16 said:

What you really want to do is replace the existing intercooler with a chargecooler setup, around 90% efficent and can exceed 100% efficenct with a chilled water supply. Use the existing intercooler space to mount a pre-rad for the chargecooler, then you have a choice of using a single twin entry single exit chargecooler or a pair of single entry single exit CC's each mounted close to the the turbo's, you should be able to reduce the inlet length from the front bank's turbo by employing this method leading to an increase in boost rise rate. I've considered putting an off the shelf kit together but doubt they'd be the demand to cover the development costs. Matt

Nice idea Matt. To be honest though the most cost effectly route to more power is probably just to run more boost. Assumnig is a 3L version it's only @ 0.7BAR (to get 352BHP, impressive). Nice remap and I bet about 1 BAR is a ok, with another 40-50BHP available.

Not sure what the CR is though so that may be an issue.

[matt_t16]

You would need to examine the capacity of the current intercooler setup as you could find (due to the size of the turbo's) that an increase in boost will lead to a rapid increase in charge temp as the standard turbo's operate out of their efficency envelope. Having said that the 2.5's with the power upgrade run 1bar'ish so everything being equal 0.85bar on the 3 shouldn't be a problem.

Would be worth keeping an eye on the pistons as well, although they have decent cooling via the oil sprays the 400bhp and 420bhp versions of the lump, which run around 1bar IIRC have forged items.

Matt

[Boosted Ls1]

I've used twin copper cored chargecoolers for my Rover v8 and fitted them into a custom plenum. They worked ok but my favourite choice was a simple water injection set up and that's what I shall use on the LS1. If you use any type of cooler core then it's acting as a heat soak some of the time.

[joust]

Just wandered across this.

Quick google gives

Intake Temp C Power loss Example
20 0% 200bhp
60 3.5% 193bhp
70 7% 186bhp
80 10% 180bhp
100 13% 174bhp

www.bellintercoolers.com/Pages/tech.asp seems to be a simple FAQ.

J

[GavinPearson]

Remapping should not be necessary as you should have a sufficient set of sensors to infer inlet charge temperatures. If you dove the car hard in cold rain with the current set up for example, the inlet charge would be lower, and the car would still run OK.

All you are doing by improving the intercooler is increasing the chances of running at a cooler temperature in hotter weather.

I saw the intercoolers on a Noble a couple of weeks ago - they looked intelligently designed (as was the rest of the car - I am a big fan), you might be able to get a similar effect to a bigger intercooler with some more heat shielding and ducting.

[tuttle]

GavinPearson said:

Remapping should not be necessary as you should have a sufficient set of sensors to infer inlet charge temperatures. I saw the intercoolers on a Noble a couple of weeks ago - they looked intelligently designed (as was the rest of the car - I am a big fan), you might be able to get a similar effect to a bigger intercooler with some more heat shielding and ducting.

Inceasing boost is definately the way to go IMHO ,lowering i/c temp a few degrees will not give you any 'appreciable' bhp.
As the existing i/c is probably capable of cooling some extra boost,(0.8-1.0bar)making its work more easy/efficient would be a cost effective route .Increased thermal insulation of unit & pipe work-keeps engine bay heat from seeping in.
An interesting alternative to water sprays (more cooling power IMHO)is either nitrous oxide or carbon dioxide spray cooling (co2 is less expensive than nos).Liquid gas,stored in a fire extinguisher type bottle (usually in boot) are sprayed ,thru ring jets onto the i/c ,lowering charge temps pretty quickly.A few members at a Japanese car club that I use are very happy with the system.



>> Edited by tuttle on Sunday 8th August 10:30

[ThatPhilBrettGuy]

tuttle said:

An interesting alternative to water sprays (more cooling power IMHO)is either nitrous oxide or carbon dioxide spray cooling (co2 is less expensive than nos).Liquid gas,stored in a fire extinguisher type bottle (usually in boot) are sprayed ,thru ring jets onto the i/c ,lowering charge temps pretty quickly.A few members at a Japanese car club that I use are very happy with the system.

How long do you get out of a bottle? It can't be a big on in the Noble!

The big question is how much air does the intercooler get on a Noble. It can't be great having the number plate blocking the airs exit. I think mine's going to be moving...front and back.

[eliot]

Although his site appears down right now,
www.not2fast.com/
Eric has a turbo calculator, that includes a section for the intercooler and you can see the gain/loss in power.

Eliot.

[tuttle]

Gazboy said:

Can someone translate this: R-SPL HG Type13 3 core. Stock Mount. 192 x 250 x 119 mm. make it bigger/better than a standard MR2 intecooler?

With 3 cores! almost certainly more efficient than the standard MR2 i/c,'fraid I dont have the MR2 i/c dimensions tho.

For ThatphilBrettGuy.The # of shots from a nos bottle.With an 11lb bottle(little larger than a standard type fire extinguisher) I would get 50-60 4sec shots,using 50bhp size jets