I have a very good customer/friend that comes to our shop for work and parts. He has a mix match of parts on his car, not all our stuff but all good parts. Very avid autocrosser, very good, intelligent guy.

His car was recently fitted with our EVO Green turbo. This was after switching from the 20g-9-5.

Anyway, the car has an AEM EMS on it so it is very easy to monitor boost and air temps after the intercooler.

This particular car had a turbo failure, freak thing and the turbo put a lot of oil through his intercooler. Oil in the intercooler is common on Mitsubishi vehicles because the emmision laws will not allow you to vent a crankcase to atmosphere. Use to be you had a nice big fat breather on the valve cover, not allowed anymore. So on the drivers side of the EVO valve cover is a hose that runs down to the rubber turbo inlet hose. There is a LOT of suction on that hose and it evacuates the pressure from the engine whenever the car is running. Even more when the car is under boost as the turbo is sucking hard and you have more blow by at that time in the engine. The problem with this is oil in an intercooler RUINS the efficiency of the intercooler. A light coating of oil in the intercooler can really ruin how well it can cool the intake charge.

Back to the story.......this particular car is fitted with AMS's FMIC. Now I know when I see an AMS part on our dyno, just like when it is our part, it is going to perform in XX manner. This particular car was gaining a lot of air intake temps on each pull on the dyno. I pointed out to Jarrod that he should consider going to either AMS's race FMIC or ours, whichever he chose. He told me he had monitored the air intake temps before and they didn't go that high.

The car was left at the shop and we did a boost leak check, changed the upper i/c pipe and upon his request we took the intercooler off the car and cleaned it out. I had forgotten how important keeping an intercooler clean was. When he asked us to do it both my brother and I said it was a PITA blah blah blah (to ourselves, not to Jarrod).

Well folks, I put the car back on the dyno and the air temps were freaking unbelievably better. The car was previously gaining 30 degrees F in a single gear pull, which is not good. After the intercooler was cleaned the car would only gain 2-4 degrees F on a single gear pull, that is very good.

This is a small thing that is overlooked. I even admit to overlooking it, I did testing probably 10 years ago on it and it had since then just slipped my mind.

Tip of the day, make sure you are NOT pulling oil into your turbocharger from the crankcase and if you have a car with high miles on it that has been, I'd suggest pulling off whatever intercooler you have and giving it a good douche job, lots of douche bags around so it should be easy to find the equipment to do it

BTW, we used a very strong floor cleaning/oil degreaser solvent we have at the shop to do it. I use to use gasoline back in the day but that probably wasn't the best thing.

You can get a good cleaner at Home Depot for doing this. We use Greased Lightning and some other stuff called Purple something. Greased Lightning is the best you can buy commonly. Don't get it in a cut on your hand and if you has "office" hands don't even get it on your hands. It's pretty harsh. Also, don't put it on your paint on your car or aluminum.

Great for cleaning floors, grease, oil, engines, under the car etc. It will take light undercoating off.

There's a free tip for you................if you don't like it help someone clean their intercooler, you are the tool they are looking for

Have a nice day.

 

very nice sat info..

 

David, on the subject of cleaning the IC......... for a intercooler that has bent fins does straightening the fins effect performance noticably?


Not that I have many bent fins on my BR Race IC (shameless plug)

 

David, that's good to know. Thanks.

 

so u just run the cleaner through it and then wash it out with water I take it.

 

Cool, so after I am done cleaning it, I should put a oil catch can on there?

 

Great post, thanks! Confirms some suspicions of mine... I learned long ago how important it is to clean that blowby oil off the maf sensor on our evo's. Doing so really eliminated some tuning problems for me. I did not have an oil catch can for a while and I've wondered what the inside of my intercooler looks like.

My evo is tuned for the track. When I datalog, and do individual 3rd gear pulls, everything looks great. When I do a wot pull, haul down on the brakes, and then another wide open pull (ie simulating track conditions), my afr's get really rich. I've asked around and attributed this to heat soak, but I wonder if the efficiency of my intercooler is way down. (55 k miles, 20+ track days). I guess I should log intake temps as noted above. Hopefully evoscan does this

Thanks again for the info! Do you think that what I'm observing above has to do with a loss of efficiency of my intercooler?

 

a lot of "degreasers" contain sodium hydroxide / lye, and it pits aluminum. A very good degreaser is toluene to dissolve all the oil/gum then followed by a acetone then water rinse.

 

nice info buschur!!!

 

dave,

if you have a "grainger" industrial supply near you (or use them online) they make some very nice citrus cleaners that we use on our floor (and parts cleaning) that is about 85% stronger than simple green in its non-diluted form, and it doesnt corrode finishes.

check it out if you get a chance.

brake clean rocks too lol we go through about 6 cans a day lol

cb

 

I <3 brake parts cleaner, non chlorinated. I always have a can near by, best stuff on earth IMO

 

DB, you are my hero

 

Good post dave.

 

bump for how exactly you cleaned it

 

If you have a bunch of bent fins in one area it can create a sort of "hotspot" or bottle neck. Get out the little phillips head and just straighten them back out.

As for cleaning the intercooler it is always a good idea to thoroughly wash it out with water after you clean it with any abrasives. Like SlowCar said it can deteriorate the aluminum to an extent.