2G Manual trans oil cooler

[99redgst]

Wondering how many people out there are running one. I just picked up a Quaife center diff to replace my 4 spider, already have a front Quaife. I read somewhere that the Quaife tends to heat up the oil more than other diffs. Not sure if that is correct or not. I will also be switching over to the evo III gearset, so obviously there will be quite a bit of money tied up in this trans and would like to do anything possible to increase the longevity of the trans. My main question is where would the ideal place for AN bungs to be welded on the trans case for the oil feed and return. I have heard of guys just putting thread in fittings in the drain and fluid level plug holes. I'm sure that works but would like to know if there are better locations for them.

 

[1gDSM4g63]

It shouldn't matter which location the lines runs, but if you want to weld then why don't you do it like auto transmissions and make it look clean.

 

[Rockbmx1]

The lines shown above wont do any good on an m/t cause they are on the bell housing. You don't need an oil cooler on an m/t cause there isn't the same pressure in a manual as an auto. Autos use the fluid as pressure to shift the gears, since with a m/t we do the shifting, there is no need for the pressure. Also without the pressure in the gear box, the oil wont circulate.

 

[99redgst]

Which is why they make specific pumps for the purpose. Such as: Pumps - Mocal Heavy Oil Scavenge/Circulation Pump

Heat is usually considered one of the major causes of gear failure. Roadcourse conditions can easily generate high temperatures. Obviously the feed to the pump would have to be below the fluid level. I'm wondering if one spot is better than another, perhaps one area has less turbulence in the oil caused by windage from the rotating gears. As for the return, would it be beneficial to have it positioned to spray cool oil onto the gearset?

 

[WFO-TSi]

Wondering how many people out there are running one. I just picked up a Quaife center diff to replace my 4 spider, already have a front Quaife. I read somewhere that the Quaife tends to heat up the oil more than other diffs. Not sure if that is correct or not. I will also be switching over to the evo III gearset, so obviously there will be quite a bit of money tied up in this trans and would like to do anything possible to increase the longevity of the trans. My main question is where would the ideal place for AN bungs to be welded on the trans case for the oil feed and return. I have heard of guys just putting thread in fittings in the drain and fluid level plug holes. I'm sure that works but would like to know if there are better locations for them.

Have you seen this post on the DSMLink Forum? It might give you a few ideas as well and maybe even a few points of contact that have done this.

ECMTuning User Support Forums

 

[99redgst]

Ahh, that is about the only info I have seen on this subject. I saw that a while ago but forgot where I saw it. So he is just using the drain and fluid level holes and seems to have worked for him. I thought I saw Jack say someplace that he knew where the ideal location to place the feed and return.

 

[ACM]

If you want to protect the gears copy the guys who do it for a living.

Install spray nozzles to pump fluid directly at each gear pair's mesh point, use the drain plug location for the feed line to the pump and oil cooler, the return line feeds the spray nozzles. This setup increases the torque capacity of the gears significantly.

I may be wrong, but I think TRE has engineered this setup previously on a DSM transmission - email Jon and check.

 

[pboglio]

Oil spray would be nice, but the fact you can cool down the oil at all is a major improvement. I'm running the Amsoil MTG 75W-90 currently, with a built TRE tranny. The oil cooler goes in as soon as possible. Tilton makes a nice pump, and I'm looking at a nice Setrab 13 row maybe, nothing too radical with a thermostatic valve.

 

[Dallas J]

Lucas English use to run one on his old black car and said it kept the tranny together much longer than without it when making 10sec passes every weekend.

 

[drivemusicnow]

3rd and 4th are the most heat sensitive for road course and if possible, two inputs above those gear sets would be beneficial in keeping a road course transmission together.

 

[99redgst]

3rd is my biggest concern since it meshes with the center diff. That would be an expensive failure to fix. I'll probably have TRE do the trans work to get the shot peened and detailed gears, might as well do anything possible to increase strength or durability. I would rather spend an extra 1k now than lunch a trans in short order and spend 2k+ repairing it.

I currently have my trans torn down far enough to pull the center diff. I'll have to take a look at it and see if I can eye up a good location for the oil supply to feed the 3/4 gearset.

Edit* I should mention I will not be running an extreme amount of power. The current plan is to run a Evo X stock turbo. I'm not sure if massive amounts of torque or quick spooling instant torque setups are harder on the gears.

pboglio- I believe you have been through a couple transmissions with a smaller turbo now right?

 

[Ill-EagleTSi]

So if I get a pump, can I use an old auto trans cooler? Its off a 1995 Talon tsi auto

 

[Scrymerr]

Drew is runnig MTOC set up and it works great for him.

 

[jericho777]

Any idea what kind of temps a manual tranny reaches on the street vs the course you run?

 

[99redgst]

Who is this question directed to? I have never had a temp sensor installed in the trans so I really don't know what temps I'm reaching. I would be interested in hearing this info from anyone who has it.

 

[jericho777]

Sorry 99redgst this is a general question. I was interested to see what the real need is. If the trans really is truly overheating and shortening its life.

 

[UnsafeAtAnySpd]

Granted this is a completely different application, but my CTS-V which I track has a trans temp sensor. It does get quite a bit hotter than on the street but I end up having other fluid issues before it so I can't remember actual values off the top of my head. I'm headed back to the track next weekend and will try to make note of the actual numbers.

 

[Ludachris]

I thought I remembered Greg Collier running a tranny cooler... can't find the threads about it here though. I know I read about the Archer cars running transmission coolers. Try doing some searches specifically in this forum using different variations of the word transmissions.

I found this discussion:
http://www.dsmtuners.com/forums/road-course-autocross/256495-road-racing-transmissions.html

 

[MIdsm]

I believe that the cooling spray should be directed toward the exit of the gear mesh, otherwise the oil trapped between gears may cause pitting of the gear surface. The viscous coupler and the differential also generate a lot of heat and ought to be cooled. Truthfully, the transfer case and the rear differential should be cooled as well.

The engineering forums have excellent information regarding oil cooled gear boxes; check both automotive and aircraft forums.

Good luck.

 

[drivemusicnow]

3rd is my biggest concern since it meshes with the center diff. That would be an expensive failure to fix. I'll probably have TRE do the trans work to get the shot peened and detailed gears, might as well do anything possible to increase strength or durability. I would rather spend an extra 1k now than lunch a trans in short order and spend 2k+ repairing it.

I currently have my trans torn down far enough to pull the center diff. I'll have to take a look at it and see if I can eye up a good location for the oil supply to feed the 3/4 gearset.

Edit* I should mention I will not be running an extreme amount of power. The current plan is to run a Evo X stock turbo. I'm not sure if massive amounts of torque or quick spooling instant torque setups are harder on the gears.

pboglio- I believe you have been through a couple transmissions with a smaller turbo now right?

Power has much less of an effect on transmission life for road course applications versus drag racing. The failures arise from very different means. Think of it like this, in drag racing you're "shattering" gears based on shock loading which can overcome the strength of the oil film quickly in order to cause metal on metal contact which will quickly induce stress concentrations (or take advantage of ones that are already present) into the gear teeth until the gear shatters, typically only breaking 2-3 teeth off of one gear. In a road course application, longer and more constant high speeds, with lots of shifts creates heat in several ways. The gears shearing through the oil, the synchros meshing between gear shifts, the natural friction between gears all create heat. Add on top of this that we have an AWD transaxle so you have the same number of gears, + center diff + a front diff all in a smaller area. You end up having the gear fatigue and fail which will typically take out the entire gear.

Unlike an auto transmission, heat does not directly kill a manual trans. Heat causes several things to happen, 1) Oil thins. This is critical as the hotter the temp, the thinner the oil which indirectly increases the friction between gears increasing temp even more. 2) tolerances shrink. This effect is minimal, but many times gears are designed with specific oil film thicknesses being the only gap between teeth/bearings etc. Hotter=tighter 3) metal becomes less fatigue resistant. Also minimal, but still a factor.

Which gears are most at risk? Well, the ones you're using ;-) I would say 80% of road racing is in 3rd and 4th.

So if I get a pump, can I use an old auto trans cooler? Its off a 1995 Talon tsi auto

A cooler is a cooler. Like any system, more capacity, and more heat exchanging ability are always pluses.

Any idea what kind of temps a manual tranny reaches on the street vs the course you run?

DSM transmissions can easily pass 300* which is typically where even the best synthetic fluids will begin to break down. I've heard some people with temps above 350. You'd like to keep it about 220-250.

I believe that the cooling spray should be directed toward the exit of the gear mesh, otherwise the oil trapped between gears may cause pitting of the gear surface. The viscous coupler and the differential also generate a lot of heat and ought to be cooled. Truthfully, the transfer case and the rear differential should be cooled as well.

The engineering forums have excellent information regarding oil cooled gear boxes; check both automotive and aircraft forums.

Good luck.

The oil trapped between gears issue shouldn't be all that big of a concern on this type of application. Due to all modern transmissions gears being helical in nature, the gradual transfer of load from tooth to tooth should eliminate any of those issues. (obviously you're not looking for high pressure oil cooling either) A good filter however, would be critical.