3.2 DID intercooler upgrade

[stigmata]

Hi guys

Dont know if anyone is intrested, but we began development at work on an upgraded intercooling system for the 3.2 DID yesterday. The test mule is an NP GLS with 180 000km's on board.

As we all know the standard location of the factory cooler is less than ideal as it has minimal airflow and is prone to damage and clogging with mud etc. The core whilst being quite long has a very small stacked height, this combinded with the small tube sizes means that the cooler would be very restrictive. It is a common misconception that restrictive coolers must cool better, but it is far from the truth. As the amount of flow area( number of tubes x inside diameter of tubes) of the OEM core is quite small it means that the air has to speed up through the core. This means that as the air speeds up through the core it has less time to transfer its thermal energy into the coolers tubes. A larger higher flowing cooler allows the air speed to slow through the cooler thus allowing the air more time to be in contact with the internal surfaces of the coolers tubes and thus more time to transfer its load of thermal energy.

Ok, so while we had a fair idea that the OEM cooler wouldnt be that great, we were quite suprised on thermal load testing just how bad it can be! The ambient temp today during testing was 18deg C. A good intercooling system will be able to keep inlet temps to no more than 20 degC above ambient. My old 700hp Turbo Commodore maintained no more than 10degC above ambient on full noise. The 3.2 Paj showed us quite quickly that temps out of the turbo would exceed 150deg C on full noise, about the norm for most turbo deisels these days. The dissapointing thing is that after the cooler, temps were 116degC on the first run and then 126degC on the second run and still climbing. Please remember these are just quick power runs on the dyno taking no more than 15 seconds. I would love to hook a trailer on and test it full load up a hill but feel that would be not very nice to the vehicle at all. For obvious reasons these kind of inlet temps are not in the vehicles best intrests.

We have begun fabrication of a much larger higher flowing unit that will be top mounted and fan forced. This will allow NO more thermal loads to be placed on the already "loaded up" engine cooling system and to do away with the damage the cooler cop's for being mounted so low.

I have no problems in posting the progress and pictures if you guys are intrested. I love build ups myself

Will keep you guys updated

[Aussie_Dan]

Please do keep us posted on the progress Stigmata.
This is an interesting topic!
I assume that you did you have a fan blowing wind up the front of the car as you did the testing of the factory cooler? Those temps on the outlet side of the factory intercooler do seem very excessive.....
Cheers, Dan.

[brianwanless]

Yes please. I would be very interested, I suspected the intercooler would not be doing much.

[Ranger J]

I'd like to see updates!

[stigmata]

Hi Guys, should have mentioned this before. The dyno runs were done without the massive fan used with normal vehicles as I firmly believe this lul's you into a false sense of security with 4x4 vehicles. Yes the fan pushes out air at high speed, but those speeds are not really atainable when off roading, times when your giving your vehicle heaps of right foot. There was airflow but not the massive unit we use with normal vehicles. On road testing is a lot harder due to speed limits, but we still recorded these preliminary findings before the dyno. Quick stab 30-60km cooler outlet spike to 74degC, 50-80km cooler outlet spike to 86degC. It is of my opinion that the small amount of airflow through the tiny opening on the bash plate will do not too much at all. The cooler is way too shrouded to recieve much benefit of increased air flow. It did not take long at all to do the speed increase testing and we quickly saw there were issues before we went to the dyno. I will for the sake of it do another power run with the large fan and record the temps for those intrested

Kind regards

[stigmata]

Oh and the NP made 84rwkw's in dead stock form. Quite impressive I thought

[psproule]

Just FYI - have done a little work with a Mitsu MUTT and a Bosch Diagnostic system (with Denco Diesel) when diagnosing an injector pump problem with mine (NP DID). Loaded it up with the ski boat, towed it up a steep hill at 100KPH - about 3100RPM in 4th. IAT according to the computer peaked at 110 degrees and coolant temp peaked at 89. Factory cooler but kept clean and straight (regularly removed for a clean out).

While a new cooler will no doubt be a good thing, wouldn't a water spray be fairly effective? The factory washer bottle is the size of a 44 and would make a good source.

Pat

[stigmata]

Just FYI - have done a little work with a Mitsu MUTT and a Bosch Diagnostic system (with Denco Diesel) when diagnosing an injector pump problem with mine (NP DID). Loaded it up with the ski boat, towed it up a steep hill at 100KPH - about 3100RPM in 4th. IAT according to the computer peaked at 110 degrees and coolant temp peaked at 89. Factory cooler but kept clean and straight (regularly removed for a clean out).

While a new cooler will no doubt be a good thing, wouldn't a water spray be fairly effective? The factory washer bottle is the size of a 44 and would make a good source.

Pat

Water spray is always a good thing, I have installed a really nice system on my mrs twin turbo Liberty when we put the boost up to 20psi. Works a treat! the only down side is the location on the paj and what happens to dust when it becomes wet = blocked cooler! Would be intresting to see though. I might do a run on the dyno for that aswell

[stigmata]

Ok guys, I started construction of the new cooler based on a PWR core I ordered last week after some measuring etc. We will be mounting the cooler on a frame so that it is isolated from the harmonics of the engine. I fabbed up some tanks and welded them into place and played around with cooler heights. We can just get the cooler to fit under the bonnet with a medium desity foam seal and a 10"Spaal fan with 5mm to spare. This is in no way going to be enough so I have orderd another core from PWR that is a step down in thickness. I have also made this new core an additional 50mm longer. The flow area of the new cooler is nearly 4 times larger than that of the factory unit and total surface area is over 3 times larger so heat transfer will be way up over stock. The down side is we will have to wait until at least next week to get the new core.

Here are a couple of pics of the first prototype I knocked up today. I will keep you posted of any more progress, especially if we get any more dyno time in to test water sprays etc.

Kind regards

[psproule]

I guess you're planning on a bonnet scoop?

[Angry]

Keep this going I'm very keen to get more info on this.

I have a mate extensivley involved with EFI/Turbo's on Evos & WRX's he nearly had me a Evo Intercooler, I was thinking about front mounting it.

I reckon I could just manage to snake a pipe each side of the Radiator, since I use mine as a tow vehicle I dont go slow offroad & not really keen to have a hood scoop, so front mount suits me.

Very interested to see how this goes, especially witha chip added.

[Ranger J]

I'm interested to see where exactly you mount such a big cooler

[brett]

Surely a top mounted intercooler would suffer more heat soak than a low front mounted one????

[stigmata]

Surely a top mounted intercooler would suffer more heat soak than a low front mounted one????

Not with a fan running from the underside! It means that the cooler is working at zero vehicle speeds, such as low range work and has no lagging pipework Plus it doesnt get clogged with mud or damaged. Not everyones cup of tea Im sure but I guess it depends what sort of driving you value most. The OEM cooler seems like an after thought given its position, I reckon you would run into overheating issues with it mounted in front of the radiator. Remember 4x4 vehicles are a different thing altogether and require a cooler that will effectively reduce intake charge temps at low vehicle speeds. To overcome this problem when I design a front mounted system for a 4x4 vehicle I make sure that the cooler is foam sealed to the radiator or AC condenser so it can have air drawn through it by the engine fan at low speeds. When your in low range a normally fitted front mount with no air flow from the engine fan will do zip.

Kind regards

[NT GLS]

Interesting thread. Do you have any images of the factory intercooler? Would it be possible to replace the OEM unit with an aftermarket one with a better core but place it in the factory position?

I agree with what you say about intercooler designs and efficiency. I have a FPV FG F6 sedan. When we data logged IAT's on the dyno with the stock cooler IAT's shot up from 36 C to 59C in one power run, running 15psi boost. Replaced the factory cooler with a Process West unit and IAT's are typically 8-10 deg higher than ambient now.