Custom DSG Transmission

[aaronth777]

Hello all, I've been doing a bit of research and wanted to ask for your opinions on an idea I had.

I've been looking into various types of transmissions to use for my future build, which will eventually be a high powered daily driver. I realize there's many things to consider with that goal, but I want to focus on the transmission in this thread. From what I've read, my options are upgrading the factory transmissions, whether manual or auto, or going aftermarket with something like a dogbox. While many of these options are feasible, one idea got my attention: a custom DSG (direct-shift gearbox), aka dual clutch transmission. When designed properly, they're capable of insane hp numbers like the 1341hp Koenigsegg One:1, but they're also used in lower applications like the golf gti. The benefits are near instant shifts (around 8 milliseconds), while also being smooth and quiet enough to use for daily street driving. Also I would have it made to work with paddle shifters on the steering wheel. Obviously anything is possible with money, I just want to explore my options before committing to such an expensive project. So onto my questions:

Has anybody modified an existing DSG transmission to fit an eclipse or evo? If so then what car was the transmission originally from?

If I went with a custom transmission, what company do you think would be willing to help me make it a reality?

 

[Steve93Talon]

Just get an EVO X MR, they have the SST dual clutch trans.

 

[aaronth777]

I didn't know the MR had that type of transmission, that looks promising. I just don't particularly care for the Evo X. I'm set on using the 2G eclipse though, I wonder what it would take to make the SST transmission fit into the 2G?

 

[Canadian_CD9A]

You would need to use the 4B11 and essentially do an entire powertrain and electrical retrofit from the EvoX into the DSM. Or, have an adapter plate and flywheel made to mount the SST to the 4G63. It would still be a massive job with the electrical side.

I've looked into this before. There is a Chinese-market car that has a late-model 4G63 with AWD and a twin clutch. From my understanding, it is a 7 speed with a Borg Warner clutch pack, but I can imagine that the work would still be monumental to get it to work in another platform, not to mention the question of strength.

I am aware of a longitudinal AWD DCT swap into an early Evo underway, but it is going to be a massive undertaking, and I'm not sure it can be done. For reference, check what Garage Whifbitz did with a E90 DCT in a MKIV Supra.

The Mercedes A45 AMG has a transverse AWD setup with the same position as the DSM, but again - monumental work. Dual clutch units are typically 100lbs or more heavier than what we have, too. I don't see how this project gets done and functioning with any DCT for less than $10,000.

 

[aaronth777]

Thank you for the information, yes it is a monumental task but one that I am very interested in doing. After all, we've come this far with DSMs because of people constantly pushing the boundaries of tuning. I like taking on projects that nobody else is doing. I even have a few more ideas that haven't been done yet, but that's farther down the road.

I'll have to look into that Chinese market car. If I could find that then I'd at least have something to start with, then it'd just be a matter of mounting it in the DSM and ensuring it's strong enough to handle decent power levels. I'm set on keeping the 4g63 in there and not swapping it out, even if that means extensive fabrication.

 

[Canadian_CD9A]

Honestly, I would recommend staying as far from the Chinese platform idea as possible. Although it is a turbocharged 4G63 (with 190hp), the transmission is on the other side since it's a later engine, and I'm not convinced that the bellhousing is compatible with the Evo 4-9 engine. Plus you would need to buy the part from China, figure it out with absolutely no support or manuals, and pray that it's strong enough to sit behind 300hp (or more).

If you really, really want to go this route, the 4G63 with 6 speed DCT (my mistake) was found in:
-Zotye T600
-Zotye T700
-Zotye T800
-Zotye SR7
-Zotye SR8
-Zotye SR9
-Landwind X7?
-Leopaard CS10?

Possible source for a transmission:
https://www.yoycart.com/Product/560744234923/
https://www.yoycart.com/Product/560717849803/

 

[aaronth777]

Yeah you make really good points, and I wasn't aware the engine placement was reversed in the Zotye models. Thank you for the information, I may still check it out just for fun. Looking at the evo X and gti transmissions, I'd have to reverse the engine as well unfortunately. So it looks like I have the option of extensive work fitting an existing dual clutch transmission to the 4g63, or working with a shop to have one custom made which honestly might be less work.

 

[Canadian_CD9A]

EvoX doesn't need to be reversed, it sits on the same side as the DSM. The GTi is opposite.

A custom-made DCT will run in the hundreds of thousands of dollars. You're stuck with a retrofit, and the EvoX SST is probably the easiest to use, by far. It's been available for 10 years, it's common, there is a ton of knowledge online about it, and you can scoop an entire parts car to make it work. Keep in mind you would need the ACD transfer case (not a bad thing), but also the AYC rear diff, and rig up every single sensor that the computer wants to make the transmission shift, and for the diffs to do their thing. It would be easier to use the 4B11, so you could keep the EvoX computers and wiring system intact.

 

[pauleyman]

Yeah you make really good points, and I wasn't aware the engine placement was reversed in the Zotye models. Thank you for the information, I may still check it out just for fun. Looking at the evo X and gti transmissions, I'd have to reverse the engine as well unfortunately. So it looks like I have the option of extensive work fitting an existing dual clutch transmission to the 4g63, or working with a shop to have one custom made which honestly might be less work.

Bonus point for thinking outside the box but unless youre independently wealthy you will have a lot more fun with the car just dealing with things that are already available. What is your mechanical knowledge? Whats the biggest job you've done?

 

[aaronth777]

EvoX doesn't need to be reversed, it sits on the same side as the DSM. The GTi is opposite.

A custom-made DCT will run in the hundreds of thousands of dollars. You're stuck with a retrofit, and the EvoX SST is probably the easiest to use, by far. It's been available for 10 years, it's common, there is a ton of knowledge online about it, and you can scoop an entire parts car to make it work. Keep in mind you would need the ACD transfer case (not a bad thing), but also the AYC rear diff, and rig up every single sensor that the computer wants to make the transmission shift, and for the diffs to do their thing. It would be easier to use the 4B11, so you could keep the EvoX computers and wiring system intact.

The Evo X is mounted the same way as our DSM's? I'll have to look into that more. But yeah I realize the easiest way to accomplish this would be to swap the entire Evo X powertrain into the dsm, and if I do that then I may as well just buy an Evo X.

I fail to see how this will cost hundreds of thousands of dollars though? Maybe if I paid a team of engineers to develop it, but I would be designing it myself while occasionally asking experts for advice. My plan is to draw up a complete assembly in a 3D modeling program (I have 9 years of experience in Solidworks), then 3D print a plastic concept just to make sure everything fits together properly, like bolting up perfectly to the engine. Then have all the real pieces made at a shop. It won't work perfectly the first time, but part of the fun is tweaking the design. I have many ideas of how to make this work, like using existing clutches like maybe the ones off the Evo X. I'm just looking for ideas and seeing if anybody wanted to help contribute to this. I do appreciate all the information.

Bonus point for thinking outside the box but unless youre independently wealthy you will have a lot more fun with the car just dealing with things that are already available. What is your mechanical knowledge? Whats the biggest job you've done?

Thank you, I like thinking outside the box and coming up with ideas. I can take a car apart down to the frame and build it back up again. I also like researching and figuring out why engineers designed things the way they did, everything from the engine to aerodynamics. I have designed a few smaller things, but never something this intense. It's a challenge for sure, but a challenge I want to take on