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Mike Kojima posted on September 05, 2011 22:00 
Project EVO X, Keeping the SST Transmission and the engine oil cool!
By Mike Kojima
In the last editions of Project EVO X we worked to get our car's handling and stopping power up to world class standards and eagerly attended our first track event. However we were really disappointed when our car went tilt after just a few laps at Streets of Willow Raceway. When the SST dual clutch transmission in the EVO X MR gets too hot the engine's ECU automatically makes moves to protect the transmission and the car goes into limp mode killing all measures of speed until the temps drop. In our hot Southern California climate, this happens so fast that it’s a frustrating experience and probably not good for the transmission either.
Read More About Project EVO X Here!
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| The stock transmission oil cooler is a high quality part and seems large. However, it is vastly undersized for anything other than brisk street driving. For any sort of track use, even with moderately skilled drivers taking it easy, the transmission gets too hot and the car goes tilt into limp mode until temperatures drop. |
The EVO X like most turbo cars also runs high oil temperatures at track speed, especially in our often over 100 degrees at the track conditions. Oil temps of around 300 degrees are not uncommon. Since modern reduced heavy metal bearings start to soften at 260 degrees or so and degrade at 300 degrees, we felt that once we fixed our transmission's heating issues, that oil temperature would be the next item to give our car issues.
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| Although the stock engine oil cooler is also pretty big, the oil can still easily get into the 300 degree range during on track driving on hot days. Turbo engines add a lot of heat into the oil as the engine oil must also cool and lubricate the super hot turbo center section. To fit our large auxiliary cooler we decided to V mount another oil cooler in line with the stock cooler. |
The SST transmission found in the EVO X MR is an awesome piece of technology. It is a dual clutch six speed semi automatic transmission which shifts faster than a manual transmission without the slip associated with an automatic transmission. The SST transmission has two input shafts each with their own clutch. One shaft has 1st,3rd, and 5th gears while the other has 2nd, 4th and 6th gear.
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| A nice feature of the EVO X SST transmission is an easy to replace cartridge type external oil filter. No more dropping the pan and cleaning out the screen! This is a nice feature. |
Having dual clutches allows the transmission to pre select the next gear before the shift actually happens. This means that the transmission is capable of really fast shifts. Sophisticated electro hydraulic controls allow the transmission to shift in a fully automatic mode or with full manual control, complete with automatic rev matching on downshifts.
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| The filter was super dirty, a good sign of it doing its job. This was from one track day and some easy street miles. |
Tuesday, September 06, 2011 5:11 AM
How robust do you think this car is/will be?
Tuesday, September 06, 2011 8:04 AM
Why is it that some of our modern "fun" cars are having cooling issues? I know the 370Z has issues, and you pointed out the GTR and EVO have issues. Is this due to the increase in engine output and not compensating? Lack of forethought on cooling or "acceptable" losses in cooling for aero/visual body work?
Tuesday, September 06, 2011 8:57 AM
In most cases the amount of cooling is fine for totaly stock use.
Tuesday, September 06, 2011 8:59 AM
I guess there are some cases where it is obviously not good, like the EVO MR and GTR transmissions and the 370 and BMW Turbo engine oil. I suspect that any car with the dual clutch type tranny might go tilt on the track.
Tuesday, September 06, 2011 9:10 AM
@Jeff, I think the OEMs are playing a game of percentages. For street use with the occassional highway onramp blast, the cars are perfectly fine. It's just when they get driven hard for extended periods of time that the heat issues occur. So Nissan looks at the percentage of Z owners that track the car, see that it's a very low percentage, and deems an oil cooler unnecessary. No oil cooler means lower cost and probably better fuel economy (less parasitic loss from an the oil pump, less weight, less aero drag).
Tuesday, September 06, 2011 9:13 AM
I think in the case of the Z the cars can go tilt in normal driving on hot days.
Tuesday, September 06, 2011 9:23 AM
I think the OEMs (Mitsu specifically) are just looking at the bottom dollar, which is kind of tragic imho.
Tuesday, September 06, 2011 10:55 AM
@ Khiem: Not to mention less to warranty in the future, and lower insurance costs to repair collisions. @XArmy: Of course, they're looking at bottom dollar. Hard to keep a company afloat on just soul. Someone's gotta buy the large number of cars that keeps the lights on. Mitsubishi is building a car that works for 95% of its customers, and knows that the remaining 5% are content to spend their own money tailoring the car to their specific needs that are in the extreme minority. No need to spend lots of per-unit dollars on customers outside +/- 2 standard deviations.
Tuesday, September 06, 2011 11:44 AM
That pump you're using for the transmission fluid is quite interesting. Could that be used to cool transmission fluid on a tow vehicle (like a pickup truck), as well? Do you have a link to the website of the company that makes it?
Tuesday, September 06, 2011 12:18 PM
It's hard to tell the clearance just by that photo, but I would have some worry about clanging the new Setrab cooler on a tall kerb in a way that I wouldn't be worried so much about the radiator or intercooler. No?
Tuesday, September 06, 2011 12:37 PM
so the original orientation of the oil cooler was rotated 90 degrees from whats pictured? it sits vertical as pictured in this article on my Evo... Mine is a 2011 though... weird thing to change...
Tuesday, September 06, 2011 12:55 PM
@ Dusty Duster: as long as the fluid temps don't exceed the design tolerances of the pump, it should be fine. We use one on Project G20 to cycle fluid to/from the oil cooler and oil pan, since the SR20DE oil pump is overtaxed as it is. It's been going strong for years now, and this same pump was used on my "beast" SE-R before this. Mine's rated to 300* at looks identical to this one. @ warmmilk: From what I read, the original oil cooler was rotated a couple of degrees (not 90*) to a more vertical position, so it's likely installed identically to the way yours is.
Tuesday, September 06, 2011 1:20 PM
Mike - I love how Motoiq projects can seem like a feature! I never did see how much more volume capacity you were now getting for the respective oil/fluid coolers? It's too bad there are no after market larger transmission pans like they have for the old slushboxes. Mulry - I think the oil cooler actually sits higher than the IC. VW may have invented the DSG first, but Mitsu sure made it DIY friendly! It does suck that all the manufacturers seem to have their own oil for their dual stick style gearboxes :(
Tuesday, September 06, 2011 5:49 PM
I've heard a lot of stories about DSGs overheating and eating their tranny fluid. I don't understand why OEMs have such difficulty cooling them and it seems like the stakes would be pretty high. I would never, ever, buy a car that overheats and goes into limp mode with "enthusiastic street driving" and I can't imagine I'm alone on this.
Tuesday, September 06, 2011 6:12 PM
When I was a kid, all cars would just overheat driving on a hot day.... All of our Fords always did, bone stock even new in good condition. I remember us having to turn the heater on all the time, miserable on a hot day. I also remember that they used to sell desert cooler bags that dribbled water over the radiator on roadside stands in hot areas and about half the cars had these strapped to the front of the car. This was the late 60's and early 70's when I was really little. Only rich people had AC in their cars and more than a simple AM radio. The point is even cars with cooling problems are a million times better than before. Now we complain if they overheat on the racetrack!
Tuesday, September 06, 2011 6:21 PM
@Der Bruce: SSP does make a larger transmission pan for the Evo. I do believe the owner has one and just haven't had the time to install it.
Tuesday, September 06, 2011 8:13 PM
Is this going to be a kit that one can get installed? I have an MR X, and l like this setup. How much?
Tuesday, September 06, 2011 8:19 PM
The Genesis pump we used was referred to us by Billy Johnson (MotoIQ contributor, pro race car driver). He apparently had good experience with it in his grand am mustang for the diff. Product info: http://www.genesisparts.com. Genesis Technologies Viton Lube Pump. Part # GC1111. @Warmmilk: the OE cooler was moved forward to accommodate the oil cooler lines to be in series with the new Setrab cooler. A new bracket was fab'd to get slightly better placement. What is not shown here are the diverter plates to split the air coming in to force some of it down, and the hole in the undertray with extended side pieces such that when the lower pressure underneath can suck some of the airflow out.
Wednesday, September 07, 2011 4:53 AM
Great writeup Mike. It's good to see these before a bigger intercooler! The #1 mod we do for track Imprezas is a similar sized oil cooler as they are lacking any substantial oil cooling from the factory (besides the laminova type exchanger).
Wednesday, September 07, 2011 6:46 AM
That pump looks similar to the pumps used in the meth kits. You could probably find something comparable from Shurflo or Aquatec (it is probably one of them that makes that pump).
Wednesday, September 07, 2011 10:42 AM
Mocal makes a curiously identical pump as well.
Wednesday, September 07, 2011 11:25 AM
What kind of effect does lowering the crossmember have in this case? I've always heard it was a bad idea on a front wheel drive car because of how much it changes the geometry of the cv axles.
Wednesday, September 07, 2011 11:26 AM
It does not change the geometry of anything!
Wednesday, September 07, 2011 12:41 PM
I'm just going off what I've heard here, I'm definitely no suspension/drivetrain engineer much less a mechanical engineer. I've just heard bad things about axle length vs suspension travel, high shaft angles and all sorts of things which are absolutely meaningless to me unless dumbed down dramatically. If there really are no issues doing this then I might just have to do it to make room for a taller intake manifold.
Wednesday, September 07, 2011 12:45 PM
Is the engine not connected to the crossmember? On a FWD Nissan, lowering the crossmember would lower the engine/trans, increasing CV angle.
Wednesday, September 07, 2011 2:15 PM
If I read that correctly, they used washers as spacers to lower the member while keeping the engine/tranny in the same position while creating space and protection for the fitting and the hose.
Wednesday, September 07, 2011 5:55 PM
I didn't see anything about that, but looking at the pictures, I done see evidence of motor mounts on it, so it's likely moot. I was mainly trying to decipher SixCylinder's post for Mike. :)
Tuesday, January 03, 2012 12:33 AM
I am a little behind on getting to this article but I am glad to see someone is putting the TC-SST through its paces on the track and writing it up. I would like to second Der Bruce's comments on SSP (South Side Performance). They have done a lot to test and develop products to allow Mitsubishi's TC-SST to handle higher horse power under track conditions. You should really talk to them about their advancements and I would love to see the results of their technology in a future article here. I have talked to them off and on about building a TC-SST for my up coming 750+hp project. Mike I'll email you their contact details.
Wednesday, March 28, 2012 5:07 PM
That cross member looks like it is mainly a brace. How much extra fluid did you have to add to the trans to account for the volume in the lines and cooler? How much weight do you think was added to the front of the car with lines, cores, and fluids?
 
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