IRS Differential Cooler

[BlackBolt9]

Rehagen Racing also has a full kit for I believe around $1000 or $1100, I don't remember for sure and they don't have it listed on their website for some reason. We have been using that setup on the Koni Challenge cars even though they have a solid axle because we were seeing diff. temps above 300 degrees at times. One suggestion I will make is to have a least a temp gauge no matter how you decide to turn the cooler on and off. We originally had a temp switch that would turn the cooler on and off but it kept failing. We ended up putting a temp warning light on our driver display and hard wired the cooler to a switch so that the driver has to manually turn the pump on when the light comes on. We can't figure out why the switches kept failing but the gauge sending unit didn't, it's just something to be aware of.

EDIT: I was wrong, it's about the same price as MM's cooler. I asked Dean to add them to the website though so here is the link if you are interested, this system has been proven in Grand AM racing FWIW.

http://www.rehagenracingproducts.com/product.sc?categoryId=14&productId=752

 

[brkntrxn]

I just turn mine on after the first warm up lap of the day. After that, I turn it on as I am headed up the false grid. If I let someone else drive the car, I turn it on before I even give them the keys.

 

[gregscott]

No problem.


(VIR was MOST EXCELLENT today, btw. 65, partly cloudy and plenty of track time.)

OK That's it I'm moving, wife or no wife, I been married for 30 that qualifies for a successful marriage, and I'm taking Dog.

 

[///m3]

Don't know if mine came up in a search since it was quite a while ago...
http://www.svtperformance.com/forums/driveline-216/253611-differential-oil-cooler-install-pics.html

Here are the pics that are missing...
Diff Cooler pictures by pjmbmw - Photobucket

 

[coctostan]

Just out of curiousity, what kind of LSD's are you guys running? I'm curious if the style of LSD is causing or affects the high diff temps (clutch pack vs torsen etc).

I'm planning to run a TrueTrac and I don't believe it should generate as much heat as the clutch pack style diffs. Is that sound reasoning?

 

[wheelhopper]

^You are correct. The clutch type LSD generates more heat and has been more problematic it appears than in straight axles. Many have posted the benefits that the Torsen T2R has provided. That is the route that I plan to go before I do an IRS cooler.

 

[ac427cobra]

Just out of curiousity, what kind of LSD's are you guys running? I'm curious if the style of LSD is causing or affects the high diff temps (clutch pack vs torsen etc).

I'm planning to run a TrueTrac and I don't believe it should generate as much heat as the clutch pack style diffs. Is that sound reasoning?

No question, a clutch style traction unit will generate more heat than say a Torsen T2-R.

If you're trying to avoid putting a diff cooler on your car I hope you don't plan on driving it too hard!??! ;-)oke:

FWIW

 

[coctostan]

No question, a clutch style traction unit will generate more heat than say a Torsen T2-R.

If you're trying to avoid putting a diff cooler on your car I hope you don't plan on driving it too hard!??! ;-)oke:

FWIW

I am piecing together a cooler now. This car will primarily see open track days. I was just curious if the excessive heat could be attributed to the specific LSD or if it is mainly R&P heat.

 

[///m3]

I'm in the middle of re-installing the diff with a TrueTrac. I was initially going to rebuild the stock clutch plates, but the actual LSD unit spun inside the carrier bearing, forcing a replacement.

I'll be able to give some real world evidence if the diff runs cooler with a TrueTrac after next weekend's event at Roebling Road.

 

[coctostan]

I'm definitely interested in your findings. I'm putting my TrueTrac together this weekend, but I won't have it on the track quite yet. A bit off-topic, but what fluid are using in the diff with the TrueTrac?

 

[///m3]

Royal Purple MaxGear 75w-140.

It's what I used on the stock diff and had a couple of quarts left. I'm not 100% sold on its effectiveness though...I did spin a bearing, though I'm not sure the fluid had anything to do with it.

I run Redline in the M3.

 

[ac427cobra]

I run Amsoil Severe Gear 75-140 and I'm not sure what's been the key to my success!?! The Torsen T2R or the Amsoil!??!?!

I will NEVER run ANYTHING in my track cars but a Torsen T2R with Amsoil! I AM that sold on both! No Doubt, it's been the most trouble free component in my car!

FWIW

:thumbsup::coolman::beer:

 

[brkntrxn]

Figured I would post this up in here as well since it fits with this thread...


Some background on why I made a diff vent can. I have a diff cooler in my car, but I am having an occassional issue of diff fluid being burped or slung out of the vent tube on the top of the case. This only happens on hard left hand turns such as T4 at VIR and T1 at CMP and this only started after I began running slicks on the car. So, I am led to believe that this is not a heat related issue, but a g-force related issue.

Here is my differential vent can setup.

- several feet of 5/16" hose
- couple of small clamps
- one large clamp
- small clamp
- metal soap dispenser bottle
- small air filter
- NPT to 5/16" barb
- JB Weld!!!!!!

The hose is secured to the vent nipple on the top of the diff with a small hose clamp. I cut a hole in the trunk pan using a small hole saw and lined the hole using some hose split in half. At no point do I have a low spot in the routing of the hose and that is what determined where I cut the hole in the trunk pan.

The setup is fashioned so that if any fluid is expelled out the vent at the top of the diff and happens to make it all the way to the vent can, it will drain right back into the diff... as opposed to staying in the can. I wanted to put the NPT barb in the absolute bottom of the can, but that would have forced me to have a low dip in the hose therefore preventing drain back. I also wanted to mount this in a location that would not force me to move it for when I install a roll bar at some point in the future (if we bring the rear tubes back this far).

For those of you that are unaware of my unabashed usage of metal soap dispenser bottles from Bed, Bath and Beyond, refer to this thread on my catch can: http://www.svtperformance.com/forum...555809-winter-mods-2-catch-can-panel-etc.html

 

[Maynor]

Yours is a more elegant solution... I like it. Any issues with fumes in the cabin with the open breather?

I went a very similar route but with a can of chicken broth and a second vent hose to the outside the car. Total investment about $5.

I think you positioned the can in the right spot in case you go to a roll bar down the road based on our similar locations too.

 

[brkntrxn]

John,

Fumes may be an issue, I have yet to drive the car but that thought did cross my mind more than once when I did this. I will be running on VIR South this weekend, so I will let you know. If it does get to be too much, I am thinking I will put a vent tube down to the rear baffle in the passenger corner of the trunk.

I should probably go ahead and fabricate something in case the smell is too much on Saturday. The bad thing about VIR South is there really isn't a hard left turn to test out my g-load theory. Other than T4 on South (which is really an uphill braking zone and then a hard off-canter left after you crest the hill), everything else is a right turn or a low-g left turn.

-Kevin

 

[///m3]

Here are a couple of points I noticed after the trip to Roebling this weekend:

- The TrueTrac gets every bit as hot as the stock without the cooler running. It pegged the diff temperature gauge past 250F. The diff cooler pump was not working as I neglected to properly prime the pump after putting the new differential in. So after learning the track and picking up some speed, the diff puked some fluid out of the breather. One of those catch cans would've been beneficial.

- After removing the bumper and priming the pump, the diff temperature never got above 210F. That was higher than I expected, especially with ambient temperature never getting above 65F. That is pretty close to the temps seen with the stock LSD, maybe 10 degrees cooler.

I can't say for sure that the TrueTrac runs cooler than the stock unit. It definitely still needs a diff cooler.

Overall I was happy with the TrueTrac, but I don't have a whole of seat time in the wife's car prior to switching.

PS - Roebling is a fantastic course! I was having blast. Seems to be a whole lot easier on the cars than Sebring. I thoroughly enjoyed so much time spent in the corners right on the limits of adhesion. I learned a lot about how the Beast handles.

 

[Lumpydogs]

Nice work to a solution, guys.

I have a couple of questions (not criticisms):

1) How much gear oil are you putting in the diff that it's burping fluid?

2) Wouldn't a longer vent hose be sufficient without the catch can?

3) Assuming no diff cooler, wouldn't the catch can method work to increase the diff temperature due more restrictive ambient air flow?

 

[BlackBolt9]

Nice work to a solution, guys.

I have a couple of questions (not criticisms):

1) How much gear oil are you putting in the diff that it's burping fluid?

2) Wouldn't a longer vent hose be sufficient without the catch can?

3) Assuming no diff cooler, wouldn't the catch can method work to increase the diff temperature due more restrictive ambient air flow?

1) More then necessary but once it pukes it's fine.

2) Yes, but determining the length of hose needed is more difficult than just adding a "catch can"

3) No, the really isn't airflow per se through the vent.

We have been running coolers on the solid axle Koni cars since last year sometime since they were running pretty darn hot. We still run the catch can but it hasn't seen anything in the past several races that I've been checking it. I assume this is because the cooler is keeping the fluid from expanding to the point of overflowing not because we aren't running enough fluid, otherwise we'd have more axle trouble.

 

[brkntrxn]

Nice work to a solution, guys.

I have a couple of questions (not criticisms):

1) How much gear oil are you putting in the diff that it's burping fluid?

2) Wouldn't a longer vent hose be sufficient without the catch can?

3) Assuming no diff cooler, wouldn't the catch can method work to increase the diff temperature due more restrictive ambient air flow?

1) Adding fluid until it comes out the fill plug... just like normal. Is that too much?

2) Yes, and that is a common solution posted up in various forums. I just like shopping in Bed, Bath and Beyond. Makes me feel good epper:. LOL, with the limited space above the diff and the floorpan, I just figured putting a vent can in the trunk was the best solution.

3) Not sure what you mean. Restrictive due to the filter on the top?




To follow-up on the concern of smell in the car with my setup, I did not have any issues this past weekend. I could occassionally get a whiff of it, but running with the windows down kept the air flowing anyway. If I still had a back seat, I am pretty certain I would never smell it. When I go back to VIR Full/North or CMP, I will be able to give better feedback.

 

[ac427cobra]

When you consider the volume a 1/4" diameter hose can hold I would step that vent hose up to 3/4" right at the diff cover and that will contain more volume in the hose on a boil over. :idea:

FWIW