DCT swap into S54 powered e36

[Cobra1956]

Thought I would start posting my efforts to swap a dct into my track car. Things I screwed up or things I am finding out and just the over all experience. My current setup is s54 to stock 328is 5 speed into a 3.64 rear diff. Car dynos out at 325 to the rear wheels. Been in this configuration for about 15k track miles. get about 30 days per year.
I take guests and friends to the track often and people that can drive manual are going the way of the dinosaurs. They all want to go fast and they all want to shift but lack of skills makes this a very ambitious goal for people that have never been to a track. Plus I am getting fatter, older and lazier. I was looking into a Porsche Clubsport but the cost just doesn't justify itself when you factor in all you get i the PDK and air conditioning. Since I had the cool shirt set up I thought this would be a fun project and done with BMW stuff. My wife and I built this car affectionately called Deathtrap as it looks like a shitbox until you strap in and fire it up.
So here we go:
Bought someones project off of ebay. Got the box, adapter plate, computer, and all of the required part from the donor car. Also came with park brake lock out oem plus permanent piece and trans cooler adapter fitting. The sellers build BMW race cars and decided to go with the current 8 speed auto instead. Look at his builds and shop and thought all good.
In true Deathtrap fashion I wanted to make stuff out of as much of the stuff I have or will have. First issue to solve was going to be the driveshaft. The output flange on the dct is the large disk and the current is the small. Custom driveshaft was an option and then you still need adapters to bolt the shaft up to the box.
Adapter was about $160 and I figured a shaft would be similar to oem price so I thought about $700 or more. I thought about the splines on the driveshafts and if they were the same. Turns out that they are. Guessed at that and found a DCT shaft for sale delivered for less than $100. Machine shop cut off 2.75 inches, welded and balanced for less than $120. So that part is ready to go.

Will cover the box itself later. We swapped the old 5 speed for the 7 speed DCT friday. Ran into the first of what I thong will be many little issues. You will need a hammer, large. The idiot in me did not address the clutch master cylinder. I run an e46 m3 master and booster as part of my e46 abs installation. The line for the clutch is pretty low and a new reservoir is needed but I will try to plastic weld the port closed when I get that far. Can just cap it off and that might be the end solution.
The adapter plate forces the box back about 12mm and this makes the fit even tighter than it would be with a normal box as the dual clutch carries the width farther back. Cannot get the top two bolts to thread and spent hours on this to no avail. Should have pulled the engine mounts to lower the engine. Removed the rad so I can slide the whole mess forward to work on it from the top. Did buy a steel bracket for the e36 chassis that uses 6 bolts versus the aluminum bracket with 4.

[BimmerBreaker]

I had a friend who looked into this very deeply recently. Calling shops that install these conversions, talking to owners who have them, e-mailing or calling companies that sell adapters and those who sell the TCU's. He was dead set on having a DCT with his S54, but everyone he talked to said there were problems with the DCT controllers. Some would not rev-match on downshift. Some would cause the ABS to lock up the tires during moderate braking. Some wouldn't downshift at all (as in, literally getting locked in the upper gear, had to turn the car off to reset it). Some had slow shifting and unpredictable shifting behavior. They all had varying problems, none ran as intended.

It's interesting seeing how many people start DCT conversions then ditch them for 8HP's, DCT swap kits come up for sale all the time which to me is rather telling. The DCT was deeply integrated into the M3 it came in, the 8HP is a much easier transmission to work with, it requires less inputs, and does more of the processing internally. It can be run on a standalone TCU with stock DME pretty effectively. The best way to get the S54 to work with the DCT will be standalone engine management and while those give the best results, they don't seem to work 100% either. Standalone or not I've yet to hear of one that worked completely as intended. You can find videos of cars with them installed blasting through the gears, but that's only one part of getting it to work. The more in-depth reviews always seem to reveal some sort of issue. Many builds end up ditching the system completely after spending a lot of time trying to iron out certain kinks. It often seems that when you fix one problem, you introduce another.

I'm subscribed though, as I do genuinely hope it can be made to work correctly. I would just recommend spending some time verifying the electrical/TCU aspect before spending too much time and money with physical fitment. Of course to some extent, you won't know until its put together and on the road...

[Cobra1956]

No doubt the tool that will be getting used the most is the checkbook but this car is track only
I read a lot of those type of threads. issues seem to be people wanting street cars with different stuff
Most of this is stand alone abs works off the sensors on the calipers so hopefully that won’t be an issue
Did reach out to the engine software guys prior to even thinking about it and they said they have this covered. Hope they are right
Not getting ride of any of the parts coming out until it works. I will update as we go along. If I can’t get the damn bolts in we could be done already. Kidding of course

[aeronaut]

Have also heard of constant overheating problems. A pretty committed and ingenious racer friend worked hard at it. I need to reach out and see how things are going, but I think, think, he gave it up. But, also subscribed, always up to learn somethng and a challenge.

[Cobra1956]

BW says to overfill and sells a dry brake kit to allow that. Should be able to over fill via cooler, I think
Will definitely share what I am doing

My original plan is to run a big trans cooler mounted in the car with either a dedicated fan and or placed where the tag would normally be in a street car. Noticed window vents on a track car being pushed open I the rear window. I currently donor have the block off plate installed

Areas of heat that do concern me. Wider trans brings exhaust closer to the box. Need a heat shield with an air gap. Most people don’t gap correct and the insulation become a heat sink Need to modify my current exhaust set up. Running euro headers track and track pipe but the box is about 6 inches longer so that brings it towards the heat. Will need to figure out what gets what? Wrap the exhaust , shield the box or what? Trial and error. Monitor fluid temps

Dual clutch race cars are very common on the Porsche scene with the Gt4 and Cup
Maybe it works better for the based on the heat of the engine being all the way back. I will figure it out but I can assure you the cooler I will run is much bigger than an oem

[Kondata]

I've been looking over DCT swaps for the past 4 years, so I'm very interested to see how you sort this. I recently sold my 335i DCT box and gave up on that dream. Only thing I can comfortably recommend is if you have the HTG TCU, sell it right away. The only way I would even attempt to start this project is with a MAXX ecu for everything and all the factory CAN modules (shifter, harness...etc). Hoping you make better progress than I ever did.

[olemiss540]

Mike (325isBimmer) has one behind 700hp racecar I believe. Hoping he would chime in.

[AJLM34A]

a MAXX ecu for everything and all the factory CAN modules (shifter, harness...etc)

I picked up a DCT after 325isBimmer posted up about his 2 years ago. If you look on Maxx Ecu website, they have a very informative DCT section. They also have S54 base maps.
When I go Simple Jack with my HPDE car, it will be with an S52, with S54 ITBS, a Maxx ECU and DCT.

[Cobra1956]

Stubborn and stupid would be the theme since the last post. I am 66 years old so some of the items I thought I would leave to the checkbook versus doing them myself. The lesson learn here is that things don't always fit as promised or there is a reason and you have to find it. The first big distraction was when the plug for the transmission did not fit. I took for granted it would and this would be a habiger of things to come. So from now on everything gets test fit before work gets done. I spent about 4 hours on the plug to get it to fit sanding it down. It I would have test fit it prior I would have known it was too large and sanded it down prior to pinning the wires.

The next big issue waas to remove the old transmission and put in the new one. The shop manager was worried about how to bill out this job so we agreed to bill for a removal and installation. This came up when one of their mechanics took forever to install something on my car and rather than give me a huge bill they ate a big portion of the bill. The owner is a friend and I don't like that set up as I don't work for free and he shouldn't either. Everything went great and we had the old out and the new one in by two and then we hit a snag. We could not get the two large bolt to thread through the transmission the block and the adapter plate. We struggled with that fr another 5 hours and finally I said put it in the trailer and I will take it home and figure it out. We pulled the transmission out three or four times trying to figure out why it would not fit. It fit through the new trans and the adapter and the adapter and the block but when you put it all together it was not happening. We ground down the threads of the bolts in hopes of getting then to start and still no joy.

So I take the car home and spend about 30 hours messing with it trying to figure this out, while the car is in the trailer. I pulled the radiator and the engine mounts off and moved the whole thing forward . I could get at the issue but still not solve it. I ran a threaded rod back though from the block into the adapter but the shape of the block limited the length of the rod. I then planed to cut a short piece of rod threaded in to protect the threads and use a grinder to enlarge the bore. That did not go as planned so I finally decide to remove the transmission. That came off and then I removed the adapter and enlarged the the top two holes. Put everything back together and was shocked that it still would not bolt up. I decided to give up and head back to a local shop I have had luck with on tricky issues. Was cooler this evening so I decided to pull the transmission off again as it was going to have to come out anyway. It was at this point I discovered the issue and why it would not thread!
I keep reminding myself that there will be issues along the way. You are taking parts from 3 different chassis and slapping then together. While it's a pain in the ass it is also what makes the projects fun for me.
The s54 block is different than the n55 block. The biggest difference is the s54 requires the use of the covering plate to seal the front of the transmission whereas the other block is cast that way and seals without the additional piece. When you take the plate and put it on the dowels you clearly see the obstruction
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[m3bs]

You’ve pretty much convinced me I don’t want to try this….

[Cobra1956]

Actually don’t think it’s a big deal. Just not well thought out on my part. Issues left to solve are the exhaust modifications. Driveshaft is done. Thought that would be harder than it was. Thought I was dealing with one less bore than I was. Hope to lift the transmission back in tomorrow and start working on the exhaust and var heat shields and decide where I want the cooler

[Cobra1956]

Update time. It took me 50 hours of hot frustrating work to get the DCT to bolt up properly....only to find in my notes the issue I was fighting and forgot that I had the information. This is where a lifetime of being disorganized came back to bite me in the ass. The issue is simple. The bell housing for the DCT needs to have the top two lorg bolt holes clearanced. On the back side of the housing they are an oval. On the front side they are a circle. You need to oval them out or as on my case a little meat needed to come off the upper, inner side to get the bolts to thread in. I did use a washer over the bore to make sure there were no issues and ordered a few longer bolts as we had previously beveled the edges of the bolts to try to get them to thread. 65mm was long enough. It was super slow going sliding my fat ass under the car more times than I care to count. As an added bonus I dropped the trans off the jack twice and it was a chore to get this beast up high enough to get the jack back under it. All bolted up, torqued and moving on to the next little issues. My driveshaft bolted right up but I should have cut it shorter. I took the front half of a large flex disc shaft and cut it and had it welded by a machine shop. I would have to verify but I reduced the length of the front section by 3.25 inches. I do have a small bit of splines exposed but a little more would not hurt.
WIll start to look into whatever problems the exhaust will bring as the transmission is about 6 inches longer and it is wider so I will be making some heat shields. I did read up on issues of the pans warping and fluid starvation. I did see where Bimmerworld deals with the starvation issue by over filling with a dry break kit. My plan was to fill the system and then I can add additional fluid via the cooler lines which will be run to the rear of the car. The warping issue is a non starter for me so I decided to get an aluminum pan. Found what I thought was a good price on a pan but the lack of a deeper pickup make the design useless to me other than the added volume in the pan so I opted for the Slon pan. I will bolt that on last as there still might need to be some messing around with the box due to shielding or something similar.

Side note, I did see the comment about issues with the swap and abs not working properly. This is a track only car. Fuel pump is on a switch as is ABS and steering from a Volvo. The ABS is the e46 unit wired as a stand alone. Hope it all works but not much is in direct communication. Will be upgrading to an e46 purple steering rack as the current one is leaking. Apologies for the lack of pictures and do plan to get some posted but the quality time spent under the car cussing my stupidity was not conducive to photo taking..

[Cobra1956]

Couple of while we are in there jobs. Converted the oem plastic res to the Moroso aluminum, long overdue.
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Swap out leaking steering rack to e46 purple rack. Hate leaks!
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Solid center bearing support. Hybrid driveshaft, DCT front shortened and balanced, e36 rear section
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Figuring out what to do with the exhaust. Combining e36 chassis, e46 m3 exhaust, DCT transmission creates clearance issues due to longer wider transmission.
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[Cobra1956]

Looking at the exhaust issue, the section one needs to be modified to get around the box. I have a 4 foot piece of stainless tube on the way. I also have an old section two sitting here and have cut it up a bit to get parts I want or might need. I want the flanges as they will match up to the section one. My first thought is to lengthen the part along side the transmission. To keep it simple I do have access to a hydraulic tube expander and can make slip fittings for this piece. This should allow me to weld the stainless as a lap joint instead of a butt joint eliminating back purging the tube, I think. Use the current bend and shorten the rear section of section one by the length added to the front half. This will require the elimination of the resonator. This is where the flanges come in as I might consider using two stainless flex joints. This allows for maximum adjustment both in length and side to side if needed. The rear lange has a thin metal coupler that holds the two tubes together. Mine is broken. So I made a new one sans hole for a jig to make sure the flanges and bolt holes will match up. Hole will be drilled later of convert over to stainless. I thought about getting a section one from a dct car but they mostly have turbos or bends that would require more head scratching.
Flanges
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Broken connector
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Mild steel bracket/jig
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Old section two that has been under the knife. Don't think I will get what I need out of this other than the flange
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[golgo13]

If you are looking for a resource, my buddy Jerick over at JMP in Canoga Park, CA swapped a DCT into his S54 powered E36.

He just recently switched over to an aftermarket engine management system as the OEM DME was causing some issues.

https://www.instagram.com/jerickjavier21/

[Cobra1956]

Thank you

I will be sure to reach out to him

My stainless pipe arrived yesterday and I want to get the exhaust mocked up this week if I can
Curious to find out what he did?

[golgo13]

Curious to find out what he did?

Not sure, I haven't been under the car.

[Feffman]

Nick in Wisconsin is swapping a DCT into his GTR clone with an S65. They had to switch to a stand alone ECU. Not sure if this was for the engine and DCT or just for the DCT. Lot of work, expense and frustration but he's almost done.

Feff

[Cobra1956]

That was rhetorical

My pipe arrived and created a bit of mission creep
Decided after measuring up all the different bends and believe it or not, thicknesses on the oem section one, I decided to make my own. Ordered 4 45 degree bends and two 4 inch flex pipes in stainless and they should be here Wednesday. To assist me in the mock up I cut up some pvc pipe to use as connectors. The od of the pvc is a perfect match for the is of the exhaust so I can hold the pipe together and mark for welding. The oem flanges will be used on the ends as they are stainless
Could have made this a bit easier if I went with mild steel but opted to go the stainless route. Hopefully some pictures for next week

[Cobra1956]

Feff
I checked with my tuner prior to even going down this road. He assured me no issues. My car is mostly stand alone as is since it has been cobbled together over the years. In the event I need to go to a stand alone I will explore that. Not short of cash but always short of brains and the planning sometimes comes back to bite me in the ass. Should have been on the exhaust when I was gathering the driveshaft information! I’m an idiot..

[ferrarif1]

I am running a MaxxECU controlled S54/DCT combo in my E46M3 racecar. Things are working pretty well though I am still doing some fine-tuning after a season in the car.

A few things I have learned that may help others:
You are likely fine with the factory DCT driveshaft and Guibo combination but the aluminum DCT flange to 1350 driveshaft adapters have a tendency to fracture and you end up with a driveshaft and adapter launching into the cabin at high speed (right next to your legs). I know of at least two examples of this happening. The workaround is to use the HPR output flange adapter which bolts directly to a 1350 adapter HPR GS7 DCT output flange – www.hpr-tuning.com

The DCT on track requires a lot of cooling, take what you believe is reasonable and double the cooler size. I am still struggling with this and can get the fluid temp down in the cooler (Using a Setrab FP360 SSTD) but cant seem to keep the trans under 225F after extended sessions. I may add a supplemental fluid pump and/or ducted fresh air to move more fluid and air through the cooler. E9x M3's use a fluid-fluid cooler with the engine coolant before the air to oil DCT cooler and this may ultimately be a solution on track for swapped cars.

[Cobra1956]

Good info. I am hoping the deeper pan will help with some of the temps. I did purchase a Derale cooler with a fan and am looking to put the cooler in the trunk assuming I can get decent cool air to the fan. Sidelined with social events and vacation with family but getting to the exhaust work now. That had been slow going. Assuming you have something similar under the car I was/am concerned about how close the section one comes to the transmission and have multiple insulation and heat sink items on the list to look at. Curious if the adapter for the driveshaft is too rigid or the angles are not done well enough. I don’t know enough o out those items but they are on the list of things to be checked. What was application of the guys that broke? I am just running stock engine putting out @325 to the wheels based on the dyno

[Cobra1956]

Making slow but steady progress with the exhaust issues. Waiting on some parts and clamps to insulate the pipe near the transmission pan. Cut up a section one that was given to me by my friends at Delta V in Richmond, VA. Found a local machine shop that cut the stainless tube I had to a few 10 and 12 inch sections. Then had him cut the flanges off the front and the resonator off the back. The parts of the section one were dropped off at a local garage here in West Point. Modr's Service does all types of repair work as well as towing. The owner, Michael, used his tube bender to expand the old section one pieces to the size of the 2.5 inch id stainless tubing. No charge! Thank you Michael!
I had a few different people that said they could tig weld stainless. So I mocked up the flange to the remaining "s" bends to figure out how they would work around the DCT. I need to get the flanges welded to the extensions so I can figure out the rest. I remembered passing a welding sign on the way to the local transfer station so I thought I would stop by and see if this guy could do what I needed as it would save me driving 50 miles multiple times. Turned out he could and he was a former maintenance man at the local mill. Huge shop on his property and an antique collection that was incredible. Saw some of his stainless work and it was perfect so this is moving a bit toward completion.
Original section one along with the cut up one.
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After the pipe expansion. Flanges and 12 inch sections are at the weld shop.
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When the two pipes come back they will be bolted up to the headers. Then I can fit the "s" pipe to them, bolt up the extra flanges off my old section two to my track pipe, cut and mark everything and take it back over to the welder for final fabrication.
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Cooler arrived while I was on vacation. I plan to mount this in the trunk and supply it with naca ducts if I need more cool air. With the lines this should hold around another quart. With the SLON pan and a slight overfill this should give me about 2.5 additional quarts of transmission fluid.
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On the way home from vacation I stopped at the engine shop and picked up the wife's Christmas present. She was thrilled! Said she has no use for it.....
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[m3bs]

It’s the thought that counts….

[Cobra1956]

Spent last weekend at the BMW club races at CMP. Got to speak with a couple of guys racing M2's with DCT's. Asked about over heating issues and both said they had none. One did say he had dif overheating issues and heat wrap or shielding of some sort worked better than a dif cooler so that as interesting. He said the spec for the transmission temp is 120c max. Think that is about 248 f so hopefully no issues. Based on what I told him I was planning he thought it would be more than enough.
Picked up the two flanges from the welder the other day and got under the car for a bit today to work on the exhaust. Should finish it next week if the welder has the time. Looks like all of the necessary welds will be lap welds which is similar to what was done by the oem supplier.

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Front flange bolted to the headers with the 12 inch section of stainless welded on. The hose clamp has the offsets for an aluminum heatshield that will go over an exhaust wrap. This should be double insulation if I get the air gaps correct.

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Back half of the splice with the enlarged tubing on the section one. This will be welded up last most likely as there is plenty of adjustment available here. The pipe will stay up there but I laid a piece of metal across the lift to simulate the low point so I have a reference to work with.

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Test fitting the outer pipe. The flange is from the old section 2 I chopped up. It is bolted to the track pipe and is a pretty tight fit on both ends. New piece will need to be trimmed before welding.

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The inner pipe had the resonator on it. It was too thick to fit inside the new pipe and too small to go the other way. The portion between the weld and the cut is actually 3 different layers of metal so I trimmed on of them off back to the weld and it created almost a perfect fit to slip the new metal over the old pipe.

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I will get the back ends welded first. You can see there is plenty of space for adjustment. I need the ends to match up with the next fitting in each direction so once done I just have to slide everything together, bolt the ends and mark the center portion for welding.