17 replies to this topic

[Engineer]

I've done boost drop before on the standard intercooler it came out at 1 psi, cool, but not tested over continuous heat sink runs where the intercooler becomes saturated by heat and can't recover as in the real world and not on a dyno where you give it a rest

I've now done some charge temp testing on my car under these conditions. There's still some work to be done, cue Tim but the initial runs indicate a minimum of 80% efficiency and a max of 89% not bad for a piece of plastic.

This is with a Ferrita cat back and downpipe, MTE map, dry intercooler and pipe work (no oil or sludge contamination) standard intake and JR filter, max boost during runs recorded between 1 and 1.2 bar to-day which also varies with ambient temps, max RPM as the auto trans dictates in 4^TH sport mode and locked 3^rd gear so between 5600 and infinity

Ambient temp to-day was 18c, max speed ? but enough to get some reasonable results. The standard cooler recovers quickly under short bursts back to 20/22c outlet temps but suffers under continuous usage as the figures indicate. This with a standard T turbo, which I know not what model number Irf

Ambient temp 18c

Inlet Compressor temp 20c.

Outlet Turbo 140c, 123c, 103.

Outlet Intercooler 44c, 39c, 29c.

[dooby]

Ooh, that's some helpful info - thanks!

So - Blackbeast, any chance you can give us an idea of what an aftermarket intercooler can manage?

Cheers, Pete

Edited by dooby, 05 September 2008 - 22:15 .

[Engineer]

dooby, on Sep 5 2008, 11:14 PM, said:

Ooh, that's some helpful info - thanks!

So - Blackbeast, any chance you can give us an idea of what an aftermarket intercooler can manage?

Cheers, Pete

Hi Pete 90% overall would be excellent mate not to be expected with a plastic one designed for 9 psi

Edited by Engineer, 05 September 2008 - 22:20 .

[irf]

VERY interesting, thank you gary.

[BlackBeast]

dooby, on Sep 5 2008, 11:14 PM, said:

Ooh, that's some helpful info - thanks!

So - Blackbeast, any chance you can give us an idea of what an aftermarket intercooler can manage?

Cheers, Pete

Aye, let me get the car running first

[Engineer]

irf, on Sep 5 2008, 11:22 PM, said:

VERY interesting, thank you gary.

Coming from a chat room pimp I'll take that as a compliment

[Tim Williams]

I will take some readings on a 16T with the same intercooler as mine and then some with my car running the same boost as the other two and at higher levels.

I always said that the Volvo cooler seems good but never had data for it before.

[Sir Drivealot]

What are you using to take the measurements?


This is bloody interesting stuff considering my issues.


I was about to order a bunch of K-Type thermocouples from RS to get a set of readings for mine.

I have a Fluke 89 multimeter that will take readings from them and log them to a laptop.

I really want to get a set of readings to confirm I get a positive effect from the Aquamist when I fit it.

The figures you have come up with are very close on what Fletch came up with regarding IC effieciency The Volvo IC aint that shabby at all.


Why the three sets of figures?

On each of those the turbo outlet temp varies... What caused that? Was there some boost variation?

[Engineer]

Sir Drivealot, on Sep 6 2008, 01:52 AM, said:

What are you using to take the measurements?


This is bloody interesting stuff considering my issues.


I was about to order a bunch of K-Type thermocouples from RS to get a set of readings for mine.

I have a Fluke 89 multimeter that will take readings from them and log them to a laptop.

I really want to get a set of readings to confirm I get a positive effect from the Aquamist when I fit it.

The figures you have come up with are very close on what Fletch came up with regarding IC effieciency The Volvo IC aint that shabby at all.


Why the three sets of figures?

On each of those the turbo outlet temp varies... What caused that? Was there some boost variation?

Its a very simple twin probe temp meter costs around �100, you will only need 1 probe as your ME7 records post intercooler temps already the 3 figures are based on different runs the highest being with a heat soaked intercooler (intercoolers absorb heat into the casing so quick recovery here is important if its way to small for the job it won't and your power output will suffer) after running full boost over a series of runs, the lowest a run after normal warm up of engine and the one in the middle speaks for it self, just that. Water injection won't cure your problem but it should help.

Edited by Engineer, 06 September 2008 - 16:29 .

[Lord B]

Engineer, on Sep 6 2008, 05:27 PM, said:

Water injection won't cure your problem but it should help.

I think only guarenteed answer is Viagra       

[irf]

may be a silly question but when were these temps taken? i have no idea how you've got the info from the probes so how was it done? put your foot down through the gears, come to a stop, open the bonnet and then take a reading? or somehow take a live reading?

[Sir Drivealot]

irf, on Sep 6 2008, 10:15 PM, said:

may be a silly question but when were these temps taken? i have no idea how you've got the info from the probes so how was it done? put your foot down through the gears, come to a stop, open the bonnet and then take a reading? or somehow take a live reading?

LOL..     

The probes (if they are like the ones I'm getting) have long wires on them, and you can feed them into the car where your meter will read them.

Best way to fit them is to undo the jubilee clip, pull off the charged air hose hang the probe inside and re-fit the hose over the probe. The probes are small and the wires very thin.

[Sir Drivealot]

Engineer, on Sep 5 2008, 10:46 PM, said:

I've done boost drop before on the standard intercooler it came out at 1 psi, cool, but not tested over continuous heat sink runs where the intercooler becomes saturated by heat and can't recover as in the real world and not on a dyno where you give it a rest

I've now done some charge temp testing on my car under these conditions. There's still some work to be done, cue Tim but the initial runs indicate a minimum of 80% efficiency and a max of 89% not bad for a piece of plastic.

This is with a Ferrita cat back and downpipe, MTE map, dry intercooler and pipe work (no oil or sludge contamination) standard intake and JR filter, max boost during runs recorded between 1 and 1.2 bar to-day which also varies with ambient temps, max RPM as the auto trans dictates in 4^TH sport mode and locked 3^rd gear so between 5600 and infinity

Ambient temp to-day was 18c, max speed ? but enough to get some reasonable results. The standard cooler recovers quickly under short bursts back to 20/22c outlet temps but suffers under continuous usage as the figures indicate. This with a standard T turbo, which I know not what model number Irf

Ambient temp 18c

Inlet Compressor temp 20c.

Outlet Turbo 140c, 123c, 103.

Outlet Intercooler 44c, 39c, 29c.

Engineer, on Sep 6 2008, 05:27 PM, said:

Its a very simple twin probe temp meter costs around �100, you will only need 1 probe as your ME7 records post intercooler temps already the 3 figures are based on different runs the highest being with a heat soaked intercooler (intercoolers absorb heat into the casing so quick recovery here is important if its way to small for the job it won't and your power output will suffer) after running full boost over a series of runs, the lowest a run after normal warm up of engine and the one in the middle speaks for it self, just that. Water injection won't cure your problem but it should help.

Ambient temp 18c

Inlet Compressor temp 20c.

Outlet Turbo 140c, 123c, 103.

Outlet Intercooler 44c, 39c, 29c


Correct me if I'm wrong... (not unusual)

Assuming that these figures are in reverse order..... (Hottest was last run)

Isn't the temp pre IC building up as well as the post IC temp?

Wouldn't this signify that the compression temperatures are rising?

Is the Turbo compressor heat soaking?

The cooling efficiency of the IC appears to be almost 70% on ALL those figures within about 3.5%.

29 is more or less 28.15% of 103 thus 71.85% cooler

39 is more or less 31.70% of 123 thus 68.3% cooler

44 is more or less 31.42% of 140 Thus 68.58% cooler


Try strapping the probe to the compressor housing......   

Considering my IC outlet temps get as high as 60 odd degrees that aint so bad!!     

If my IC is running at 70% efficiency I must be getting 200deg post turbo         

I need to do some measuring!

[Sir Drivealot]

The level of heat soak is relative to the mass of the transmission object.

A low mass object will quickly saturate either way. As such it will transmit the heat to the atmosphere quickly and loose the heat quickly. when the heat source is removed there will be little energy able to be stored in the mass of the intercooler

A high mass will act as a buffer and in effect sufer from lag It will soak the heat up from the charged air quickly when cold, but will not effectively transmit it untill it has become saturated. Once it has become saturated it will transmit effectively. When the heat source is removed it will continue to dissipate the heat it has accumulated.

Both types actually back conduct. with cool air on both sides they will emit heat to both sides effectively heating up your charged air. The severity of the efect is relative to the ammount of heat stored in the intercoolers structure, the more mass the structure has the more heat will be stored in it and back conducted.

The other factor is surface area. the greater the overall surface area relative to the mass the quicker the heat loss to the atmosphere.

Furthermore there is the temperature of the passing air. the "thicker" the intercooler is the more time the air spends passing a hot surface, The more time the air passes the hot surface the hotter it gets, and the lower the heat gradient (diference between air temp and surface temp)

For effective transmission of heat you want the air to be as cool as possible, and the gradient for transmission to be as high as possible.

A tall thin intercooler will disipate heat better than a short fat intercooler of the same overall surface area. This is because the air hitting the surface of the intercooler will be generally cooler as it will have not been heated up as much by passing over the vanes for as long.

Wildly strange example; if the heat conduction to the air is 10deg per cm of surface it passes over then by 5 cm it will have reached 50 deg Thus the temperature of the air at the rear most surface will be 50 deg higher than the leading edge. For a 3 cm thick IC it would only be 30deg hotter than the leading edge....Thus the 3cm intercooler (assuming that the overall surface area remains constant by increasing the height/width) will have a greater overall diference between charge air temp and outside air temp.

Fine.... But heat transfer doesn't work like that. It's not linear. The greater the diference (gradient) the faster the conduction. What you will really have is hypothetically 10 deg for the first cm, 8 deg for the second cm, 7 deg for the third etc etc in an almost logrithmic scale untill eventually they equalise.

From this you can see that for more centimeters of intercooler, you have a logrithmically less efficient conduction, it doesn't make any sense to have a really thick intercooler.

So we need a big tall thin intercooler!!!!.... Not quite.... Read on

Flaw!. There is a compromise (as always) A very big thin intercooler isn't going to flow well. The best flowing intercooler would be a straight through pipe. There must be a balance between heat loss and flow!

Most intercoolers are hoplessly ineficient at flowing air, the pipes terminate into plenums and the air is confronted with a flat surface with holes into the capiliaries. Having negotiated that the air again has to exit the capiliaries into the outlet plenum and find it's way to the 3" exit hole. Not good at all. there is much turbulance and restriction

What WOULD be efficient would be proper manifolds into and out of the intercoler. A system where there is no cross sectional change of area... Not cheap to make!!!


More food for thought!!!

[Engineer]

No you are working out the % wrong mate, its ICI-ICO/ICI-TIX100 = % so 103-29/103-20X100= 89%. If you cant get the TI then use ambient but its not quite accurate. The sizing and design/configuration of the turbo will obviously make a difference to its efficiancy its why some are better than others bar & plate etc. Yes the turbo does push out hotter air as it heat soaks that's why they glow red! Yours must be like the gates of hell

[volvorsport]

weve got dataloggers at work for recording temps , ill see if i can borrow one , it records upto 500 hours .

also some expensive multimeters can be fitted with k type thermocouples , to give you a reading , ive got one !

only trouble is k types generally have an olive fitting in a boss , so requiring drilling into the pipework .

and your right about the intercooler type largest surface area works for me (small ebay fmic for teh lose) , the volvo intercooler might have some pressure drop making the turbo work harder , but it is quite efficient , as we always knew !

[Sir Drivealot]

Engineer, on Sep 7 2008, 10:09 AM, said:

No you are working out the % wrong mate, its ICI-ICO/ICI-TIX100 = % so 103-29/103-20X100= 89%. If you cant get the TI then use ambient but its not quite accurate. The sizing and design/configuration of the turbo will obviously make a difference to its efficiancy its why some are better than others bar & plate etc. Yes the turbo does push out hotter air as it heat soaks that's why they glow red! Yours must be like the gates of hell

DOH!!!

How thick of me!

0Deg is not no temp it's an irrelevent mid way point.

Hence needing a reference temp (ambient)

Gone to the back of the class!

[Sir Drivealot]

volvorsport, on Sep 7 2008, 10:45 AM, said:

weve got dataloggers at work for recording temps , ill see if i can borrow one , it records upto 500 hours .

also some expensive multimeters can be fitted with k type thermocouples , to give you a reading , ive got one !

only trouble is k types generally have an olive fitting in a boss , so requiring drilling into the pipework .

and your right about the intercooler type largest surface area works for me (small ebay fmic for teh lose) , the volvo intercooler might have some pressure drop making the turbo work harder , but it is quite efficient , as we always knew !

Yep my Fluke 189 is a reasonably decent bit of kit.
It'll read up to 1400deg with the right probe.



As for the K-Types you can get the tiny bead type that are nothing more than a blob on the end of a pair of thin wires.