[natedog7700]

Are there after market transmission coolers I can buy? Are they affective and how hard are they to install?

[big_ed]

Bump

[shadow191]

Think it was tried a few times and it won't work because of pressure drop issues. So it's a no go. A few members have said they've done it, but then there's never any follow up as to what's happened.

[big_ed]

There a group buy in the n54 forum.... But they want 750 at the intro price.....

And of course the guy selling it says its legit.

I'd be down for something that works but not at that price range.

[shadow191]

http://www.e90post.com/forums/showth...ooler+pressure

So it's possible, but requires a lot of work and probably isn't feasible. It also needs to be routed perfectly to avoid pressure drop.

[ferocity02]

Big discussion happening here: http://www.n54tech.com/forums/showthread.php?t=38254

You can do it yourself for cheaper obviously. However the hard part will be mounting the cooler; pre-made brackets for this would be worthwhile.

[Cloud9blue]

Gather your own data and do your own research, and you will see that all these talk about "overheating" transmission is absolutely non-sense, especially for a few back-to-back pulls on the street and drag stripes.

Of course, the guys selling the parts will claim otherwise and keeps on bringing up this stupid graph: http://www.txchange.com/heatchrt.htm, which has absolutely no research to back up the claim and made by the same website who are trying to sell you more parts.

[135Pats]

Some progress has been made in the data collection front since I originally investigated this with ABR Houston back in 2013/14, but it's still not where i'd want it to feel comfortable installing one (with or without the factory heat exchanger in place).

Frustrating too because my 6AT is just about ready to give up the ghost. In 4th gear @ 26PSI (630ish WHP/550ish WTQ) it came out of gear (again) right after the shift from 3rd. Motor rook a ride to 8K, albeit with no load. Scary when it happens...I'm starting to really consider a 6MT swap.

[135Pats]

Originally Posted by Cloud9blue

Gather your own data and do your own research, and you will see that all these talk about "overheating" transmission is absolutely non-sense, especially for a few back-to-back pulls on the street and drag stripes.

Of course, the guys selling the parts will claim otherwise and keeps on bringing up this stupid graph: http://www.txchange.com/heatchrt.htm, which has absolutely no research to back up the claim and made by the same website who are trying to sell you more parts.

I'm inclined to agree. I log the fluid temp all the time and it never gets out of hand, nor is the delta particularly concerning. I've had my 6AT come out of gear during a single 3-4 shift in the dead of winter (IE ambient temps in the 30s, fluid temps well below 200).

Heat contributes but it's a combo platter of line pressure and too much load for the hard parts (with existing software limitations).

[Cloud9blue]

Originally Posted by 135Pats

I'm inclined to agree. I log the fluid temp all the time and it never gets out of hand, nor is the delta particularly concerning. I've had my 6AT come out of gear during a single 3-4 shift in the dead of winter (IE ambient temps in the 30s, fluid temps well below 200).

Heat contributes but it's a combo platter of line pressure and too much load for the hard parts (with existing software limitations).

I think if people really wants to settle this matter, someone should just send in their fluid for some oil analysis before and after some "high temp" events (+220f) on a car with good transmission, a good tune, and not running a ridiculous amount of tq like you guys with single turbo.

I seriously doubt the synthetic fluid used in these ZF box will break down by any significant amount. From my own logs I have gather in the past month, I don't even see my trans temp go above 230F even after beating on it at the track, which involves more than a hundred or so WOT pulls in just 20-30 mins from 3rd to 4th gear and sometimes even into the 5th gear, depending on the track layout.

Hell, if you are really worry about it, just change your fluid regularly, like once a year or two, and swap out the pan filter every now and then. For the guys running high power, your trans will slip no matter what temperature the fluid is at, if your clutch pack and line pressure holding these clutches together are not up for it.

[natedog7700]

Originally Posted by 135Pats

Some progress has been made in the data collection front since I originally investigated this with ABR Houston back in 2013/14, but it's still not where i'd want it to feel comfortable installing one (with or without the factory heat exchanger in place).

Frustrating too because my 6AT is just about ready to give up the ghost. In 4th gear @ 26PSI (630ish WHP/550ish WTQ) it came out of gear (again) right after the shift from 3rd. Motor rook a ride to 8K, albeit with no load. Scary when it happens...I'm starting to really consider a 6MT swap.

630whp.... Thats asking for it! Lol i have 500whp 480tq and my second trans is slipping. Its pointless to go past 450-500whp IMO. Wont last long especially if you run the car hard. I notice mine grabs for the first few pulls and after that, it just starts slipping bad. I dont know if it has to deal with heat build up or what. Weird though.

[135Pats]

Originally Posted by natedog7700

630whp.... Thats asking for it! Lol i have 500whp 480tq and my second trans is slipping. Its pointless to go past 450-500whp IMO. Wont last long especially if you run the car hard. I notice mine grabs for the first few pulls and after that, it just starts slipping bad. I dont know if it has to deal with heat build up or what. Weird though.

Ya it's not super cool when it slips, the thing just comes out of gear. I've had to back off the boost to more like 23PSI which is frustrating. That's just barely getting into the efficiency of a 3586.

6MT swap is the only viable solution right now. Or built DCT if you like wasting money.

[Cloud9blue]

Originally Posted by natedog7700

630whp.... Thats asking for it! Lol i have 500whp 480tq and my second trans is slipping. Its pointless to go past 450-500whp IMO. Wont last long especially if you run the car hard. I notice mine grabs for the first few pulls and after that, it just starts slipping bad. I dont know if it has to deal with heat build up or what. Weird though.

You shouldn't slip at just around 450lb-ft at the wheels... I have been running that much tq for over a year, and had no problem. Perhaps it is a tuning issue with yours. What fluids are you running again?

And stop drinking the koolaid that is on the n54tech thread. Heat has nothing to do with the problems you are experiencing.

[07tundra]

Originally Posted by 135Pats

Some progress has been made in the data collection front since I originally investigated this with ABR Houston back in 2013/14, but it's still not where i'd want it to feel comfortable installing one (with or without the factory heat exchanger in place).

Frustrating too because my 6AT is just about ready to give up the ghost. In 4th gear @ 26PSI (630ish WHP/550ish WTQ) it came out of gear (again) right after the shift from 3rd. Motor rook a ride to 8K, albeit with no load. Scary when it happens...I'm starting to really consider a 6MT swap.

Well Pats I did no research and I've Been running mine with no issues since 2014. I think BMW guys tend to over think things quite a bit(my opinion). My shifts are crisp and fast never any hesitation

[135Pats]

Originally Posted by 07tundra

Well Pats I did no research and I've Been running mine with no issues since 2014. I think BMW guys tend to over think things quite a bit(my opinion). My shifts are crisp and fast never any hesitation

Ya, there's obvious value in results. We can theorize until blue in the face but if it works, it works.

My concern is that in my case, my 6AT has very likely suffered glazing of the clutches. Whether that's from heat alone or a combination of heat/lack of TCU control/load etc is largely irrelevant, the damage is done. So in my case a fluid cooler is highly unlikely to fix anything. I've gone out on cold nights and done a single 3rd gear pull; at no point do fluid temps exceed 200F. It still slips, which suggests that heat isn't the primary culprit (in my case).

[07tundra]

Originally Posted by 135Pats

Ya, there's obvious value in results. We can theorize until blue in the face but if it works, it works.

My concern is that in my case, my 6AT has very likely suffered glazing of the clutches. Whether that's from heat alone or a combination of heat/lack of TCU control/load etc is largely irrelevant, the damage is done. So in my case a fluid cooler is highly unlikely to fix anything. I've gone out on cold nights and done a single 3rd gear pull; at no point do fluid temps exceed 200F. It still slips, which suggests that heat isn't the primary culprit (in my case).

True very true I did fluid and sleeve change a little early 40k with redline and added the coolers at that time. I had RBs pushing 506whp 526tq my tranny has never slipped so it shld be good. Even with the ST its been fine with a bit more power and tq, which I think the coolers have helped as heat is never your friend.

[07tundra]

Originally Posted by 135Pats

Ya, there's obvious value in results. We can theorize until blue in the face but if it works, it works.

My concern is that in my case, my 6AT has very likely suffered glazing of the clutches. Whether that's from heat alone or a combination of heat/lack of TCU control/load etc is largely irrelevant, the damage is done. So in my case a fluid cooler is highly unlikely to fix anything. I've gone out on cold nights and done a single 3rd gear pull; at no point do fluid temps exceed 200F. It still slips, which suggests that heat isn't the primary culprit (in my case).

Why don't you just do the swap as a rebuilt AT will be a pretty dime, if you did the work a swap will probably be in the same price range

[135Pats]

Originally Posted by 07tundra

Why don't you just do the swap as a rebuilt AT will be a pretty dime, if you did the work a swap will probably be in the same price range

A 6MT swap? That's what i'm leaning towards.

Part of me is wondering how much money I want to continue throwing at this platform. It's an excellent motor but at this point there's so much better out there from a chassis/exterior/interior standpoint. I'm not sure if I feel like throwing another $5K at this car; part of me wants to just keep it for another year then move onto a used S63 car to start building that.

IDK! I'll probably end up doing the manual swap, this car has a lot of sentimental value for me.

[07tundra]

Originally Posted by 135Pats

A 6MT swap? That's what i'm leaning towards.

Part of me is wondering how much money I want to continue throwing at this platform. It's an excellent motor but at this point there's so much better out there from a chassis/exterior/interior standpoint. I'm not sure if I feel like throwing another $5K at this car; part of me wants to just keep it for another year then move onto a used S63 car to start building that.

IDK! I'll probably end up doing the manual swap, this car has a lot of sentimental value for me.

I'll pm you

[DirtKurt]

I'm the one who has put together the kit over on the other site. I guess I'm shady now. I'm a little baffled that people are smoking transmissions fairly regularly now but heat can't be the issue? I put together the kit for myself because nothing was available.
The pressure drop myth is complete and utter bs. The cooling circuit is a secondary pressure circuit, when it exits the cooler the fluid is going right back into the pan. The circuit is also pressure limited through a bypass. You could technically plug the feed port on the side of the trans and it would still function normally. Granted you would quickly run into temp issues.
There are several people running coolers now, all with extremely positive results. This isn't rocket science, auto transmissions have been built and raced for decades now. A effective cooler is a must. 200+ degree temps are not ok especially when your well past the transmissions engineered capabilities. I'm not trying to start a business here, I put together a kit that I believe is the best it can possibly be. It can be done cheaper, but I don't really see the point in doing it at all if your running the chance of a cheap ass core or line failing and taking out the trans with it. Same reason most people are smart enough to not run an eBay oil cooler. I'm not going to lose sleep if I don't sell any, just figured I might give a few others a chance to get a bolt on setup since there are no other options. That's all I've got.

[07tundra]

Originally Posted by DirtKurt

I'm the one who has put together the kit over on the other site. I guess I'm shady now. I'm a little baffled that people are smoking transmissions fairly regularly now but heat can't be the issue? I put together the kit for myself because nothing was available.
The pressure drop myth is complete and utter bs. The cooling circuit is a secondary pressure circuit, when it exits the cooler the fluid is going right back into the pan. The circuit is also pressure limited through a bypass. You could technically plug the feed port on the side of the trans and it would still function normally. Granted you would quickly run into temp issues.
There are several people running coolers now, all with extremely positive results. This isn't rocket science, auto transmissions have been built and raced for decades now. A effective cooler is a must. 200+ degree temps are not ok especially when your well past the transmissions engineered capabilities. I'm not trying to start a business here, I put together a kit that I believe is the best it can possibly be. It can be done cheaper, but I don't really see the point in doing it at all if your running the chance of a cheap ass core or line failing and taking out the trans with it. Same reason most people are smart enough to not run an eBay oil cooler. I'm not going to lose sleep if I don't sell any, just figured I might give a few others a chance to get a bolt on setup since there are no other options. That's all I've got.

I never said you were shady I spoke on my experience thus far is all I did. I haven't had any issues with my AT.

[DirtKurt]

Not at all referring to you 07tundra, on the contrary I agree with everything you have said here