PROMO Guru Autowerks - ZF 6HP26/28 Transmission Adapter

GuruAutowerks

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Update tomorrow with new pictures of assembly in the car... My apologies for not getting it out sooner, this holiday season has been a blurrrr!

Do you happen to know how the gearing is in the diesel trans compared to the 6hp21?

Both transmission have identical gearing, everything will be exactly like your 6hp21. The 335D has a 2.81 differential vs the 335i Auto 3.46 ratio. Actual ratios below and link to website with information.

http://www.bokchoys.com/differential/GearRatios.htm
335iE90Sedanautomatic
4.17​
2.34​
1.52​
1.14​
0.87​
0.69​
3.4​
3.46​
7000​
335iE90xDrive Sedanautomatic
4.17​
2.34​
1.52​
1.14​
0.87​
0.69​
3.4​
3.46​
7000​
335dE90Sedanautomatic
4.17​
2.34​
1.52​
1.14​
0.87​
0.69​
3.4​
2.81​
7000​
335iE92Coupeautomatic
4.17​
2.34​
1.52​
1.14​
0.87​
0.69​
3.4​
3.46​
7000​
335iE92xDrive Coupeautomatic
4.17​
2.34​
1.52​
1.14​
0.87​
0.69​
3.4​
3.46​
7000​
335iE93Convertibleautomatic
4.17​
2.34​
1.52​
1.14​
0.87​
0.69​
3.4​
3.46​
7000​
 
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GuruAutowerks

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Guru Autowerks Product Update & Information
N54/N55 ZF 6HP26/28 Transmission Conversion Kit


Happy New Year!

First off I want to thank everyone for the astounding support and interest we have received over the past month. Its an honor to have the support of the community behind us.

We are pleased to be starting the year off with a bang. Today we bring our first official product update; one of many in the coming months. Our goal with these updates is to prove our products viability and bring everyone along for the "ride". From the current finishing stages of the project all the way through tuning, testing and product release.

During these updates I welcome everyone to contact us with any questions or feedback/suggestions. We will do our best to be transparent and informative. Please keep in mind any prototype products you see right now are subject to design/manufacturing changes. What you currently are seeing is not the final product and there will be several small revisions for our first official product release.

*Project Update*

Currently the assembly is installed in the vehicle and we are working on installing our own aftermarket transmission cooler setup and a Racing Diffs LSD conversion kit. Once those items are complete we will have the 6HP28 TCU coded to the vehicle and then have the transmission tune installed courtesy of Rod Sutphin and the amazing team at xHP; they are pivotal to our project as we do not want to run a standalone TCU! From there we will move into our road testing phase with dyno and track testing to follow. Ken Atkinson @ Wedge Performance will be tuning the vehicle during the entire process. He has been great to work with in the past and we cant thank him enough for his support.

*Product Information*

- Stock Driveshaft on our 2007 BMW 335i has been reused without any modifications. In time we will confirm if everyone can reuse their stock drive shaft but we believe the answer will be a resounding yes. Custom 1-Piece driveshafts for any LSD application will also be available but not be required. This is a win win for everyone!

- Stock M-Shift Linkage works without any modifications.

- Using E-Shift setup or converting from M-Shift is still being confirmed. We will confirm with 100% accuracy once we know more.

- Using stock 6HP19/21 transmission cooler lines is being explored by using adapters. We do NOT recommend anyone to reuse the stock transmission heat exchanger but we want to provide a solution for people to use their current aftermarket cooler setup with OEM lines. We will be running an entirely aftermarket transmission cooler setup for our test vehicle.

- Manual to Auto conversion parts/process is being explored and so far looks cheaper than converting from auto to manual. In time we will release specific information concerning what is required and help guide people who are going this route.

- 135i transmission tunnel is believed to be the same as the 335i and therefore our kit should work. 535i and other models are also suspected to work. We will confirm and keep everyone updated as we know more. Please contact us with other vehicle models for further information on using our kit. We have plans to support as many models as possible it will just take time. Even N52, N53 or other similar engines/models with similar bolt pattern are possible if requested.

- Last but not least, both starter mounting bolts will now be accessed from the engine bay side. This is just a simple byproduct of the adapter plate design. So rejoice, no more finagling with that pesky long bolt between the bell housing and firewall.

1 GW 6HP28 Adapter Assembly Installed Forward Crop.jpg
2 GW 6HP28 Adapter Assembly Installed Backward-Side Crop 2.jpg
3 GW 6HP28 Adapter M-Shift Linkage Crop.jpg
4 GW 6HP28 Adapter Trans Mount Crop 1.jpg
5 GW 6HP28 Adapter Starter Crop 2.jpg
 
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Coupes66

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Dec 26, 2017
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I was wondering whether the adapter would foul the inlet to the rear turbo. There is not much room to fit these at the best of times. The photos you have supplied don't show that area on the exhaust side of the transmission
.009.jpg
 
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GuruAutowerks

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I was wondering whether the adapter would foul the inlet to the rear turbo. There is not much room to fit these at the best of times. The photos you have supplied don't show that area on the exhaust side of the transmission
.View attachment 47801
Very good question and one we had to work on during our initial test fitting of the adapter ring. We scalloped out that area as much as possible to allow ample room. If need be design revisions will be made in the future to ensure as easy as possible fitment/access. Most likely through future revisions we will change the adapter to contour in that area better... and even slope/match the back of the engine closer. Our current prototype clears but not by much... and a little more room could be obtained easily.

Not the best pictures for that specific area but this should give you a better idea to answer your question.

6 GW 6HP28 Adapter Assembly Installed Turbo Inlet 1.jpg
7 GW 6HP28 Adapter Assembly Installed Turbo Inlet 3.jpg
8 GW 6HP28 Adapter Assembly Installed Turbo Inlet 2.jpg
 
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N54x4

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Jun 26, 2020
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Will these transmissions work with xDrive vehicles? Sorry if you’ve already addressed this. I didn’t see it. I would definitely buy one of these.
 
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GuruAutowerks

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Will these transmissions work with xDrive vehicles? Sorry if you’ve already addressed this. I didn’t see it. I would definitely buy one of these.
No problem at all, its a great question and one we cant fully answer yet. We have seen a lot of interest from xi owners and have plans to work towards figuring that out after initial development on RWD models. I believe its possible, as the transmission itself is the same... and there are xi version of the 6Hp26/28 that can be purchased to attach a transfer case/front diff to. The questions I have are related to tuning, possible variances/redesigns needed in the adapter kit for fitment issues and other unknowns. Its very high on our priority list though and we will be getting to the bottom of it in due time this year.
 
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N54x4

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Jun 26, 2020
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No problem at all, its a great question and one we cant fully answer yet. We have seen a lot of interest from xi owners and have plans to work towards figuring that out after initial development on RWD models. I believe possible, as the transmission itself is the same... and there are xi version that can be purchased to attach a transfer case/front diff to. The questions I have are related to tuning, possible variances/redesigns needed in the adapter kit for fitment issues and other unknowns. Its very high on our priority list though and we will be getting to the bottom of it in due time this year.
Ok great thanks for the quick reply!
 
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vonhassen

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Dec 4, 2019
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2009 E60 535xi
Hey, I am very interested in this conversion kit to put on a 650awhp 2008 535xi running pure stage 2 hi-flows. The car is 100% only limited to its current power, or torque specifically, by the 6HP21 trans currently in it.

It has gone through one stock trans on xHP & then even the PD clutch kit setup + xHP currently in the car has started slipping very slightly in 4th & then significantly in 5th & 6th.

I would love to get on board with helping test this with y'all :)

Whenever you are ready to start finding out how hard, or easy 🤞, getting everything to work on an XI E60 platform car is, then let me know here! I'll be following the thread anyway though, I have been waiting for something like this for a while. I am so hyped you are taking this project, and the subsequent development of it, on for those of us tired of frying stock transmissions!

(bonus points: we are willing to turn the car up for the sake of data, & smiles, until we find out the new weak point beyond the 6HP21. So that might fall into your classification of a "serious tester", but lets make it clear that I don't expect this for free like that other dude lmao. Just mentioning this because I assume you have a long list of people wanting to beta test & I assume this car would hit a few birds with one stone in the testing department.)
 
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GuruAutowerks

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Hey, I am very interested in this conversion kit to put on a 650awhp 2008 535xi running pure stage 2 hi-flows. The car is 100% only limited to its current power, or torque specifically, by the 6HP21 trans currently in it.

It has gone through one stock trans on xHP & then even the PD clutch kit setup + xHP currently in the car has started slipping very slightly in 4th & then significantly in 5th & 6th.

I would love to get on board with helping test this with y'all :)

Whenever you are ready to start finding out how hard, or easy 🤞, getting everything to work on an XI E60 platform car is, then let me know here! I'll be following the thread anyway though, I have been waiting for something like this for a while. I am so hyped you are taking this project, and the subsequent development of it, on for those of us tired of frying stock transmissions!

(bonus points: we are willing to turn the car up for the sake of data, & smiles, until we find out the new weak point beyond the 6HP21. So that might fall into your classification of a "serious tester", but lets make it clear that I don't expect this for free like that other dude lmao. Just mentioning this because I assume you have a long list of people wanting to beta test & I assume this car would hit a few birds with one stone in the testing department.)

Thank you so much for the posting, showing interest and offering your help towards this endeavor as well! All that hype gives us more hype and the community has been extremely welcoming. All of it just fuels the fire to push harder these coming years and deliver some real solutions to these issues.

Sounds like shes a rowddddy animal and needs a serious setup to see her full potential! I honestly cannot wait to see what an xi can do with a serious driveline setup that can handle the abuse time after time. Obviously to get there will take a village and require more than just the transmission. If I can help with 1 or multiple pieces of the puzzle I will. Twisted Tuning and Mfactory are also working on LSD for xi Front Diff which looks promising and very well could be one of those "puzzle" pieces.

Shooting you a PM to keep you in the loop as we work through this year with the RWD setup and subsequent research/development for AWD applications.
 
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GuruAutowerks

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Best of luck! Hope it will hold the power successfully.
What power will the tests be done?

We will initially be testing the car with a dyno and track day as it sits right now with 20T turbos, FBO, single 450 LPFP on E85 mix; car also has Carillo Rods/Pistons and a ported N54 head. After initial test we will be systematically adding mods and retesting each with a dyno and track day. The car is a great candidate for showing each mod before/after for great test data. The driveshaft and axles are both stock units with 130K miles so breaking something is a very real possibility but we will upgrade/replace and move forward regardless. I am not going to say we are going for 9s passes but I would like to crack some 10s off for sure. We also have several early testers with much higher horsepower cars lined up to test.

We plan on the following mods/steps throughout our testing. Not all of these will be completed before first production run but we will continue providing real world feedback from our test car and others as time progresses.

- Pi setup with Aluminum intake manifold, adding a 535 or 450 LPFP to go with our existing 450.
- Aftermarket torque converter, upgraded valve body
- Sticky Wheel/Tire setup at some point
- Possibly M3 or Ford 8.8 conversion at some point w/custom DS and axles.
- Other things like launch control, 2 step, line lock... built 6HP28?
- More boooooost? More fuel? Who knows!

Thanks for your interest!
 
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RuskiRacer

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Jul 17, 2019
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Whats done to the 6hp28? My friend just blew his 3rd gear on 19ts on his 2009 535xi. I'm pretty sure that car comes standard with the 6hp28. I was begging him to change his fluid seems like its to late for that now.
 

nyt

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Sep 15, 2019
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Whats done to the 6hp28? My friend just blew his 3rd gear on 19ts on his 2009 535xi. I'm pretty sure that car comes standard with the 6hp28. I was begging him to change his fluid seems like its to late for that now.
It does not. 6hp21.