Drivetrain Automatic transmission question
#1
#3
#4
So I have a 2015 automatic MCS that is all stock. I read somewhere that there is a concern that if you modify it and increase it to over 31lb-ft of torque you run the risk of the transmission not being able to hold under the increased torque. Has anyone with an automatic transmission added mods and increased the hp/torque to say 250hp range or more without any slippage or damage? Sorry if this has been covered elsewhere but searched and didn't find much.
Thanks!
Thanks!
#7
These are hard if not impossible to upgrade. For some transmissions sometimes a shift kit is available that upgrades the valve body to use more pressure so clutch packs don't slip from the increase in torque, but jore hydraulic pressure can put extra strain on other things, including the oil pump.
To handle the extra torque -- at some point -- might require installing a transmission intended to handle more power/torque but this may not be a drop in/bolt in job even if the transmission exists.
There is some margin so if you keep how much extra torque you extract from the engine within reason the stock transmission may be ok. Maybe. Even if you are below its threshold you are working it harder subjecting everything to more stress, more heat, and this can take its toll.
Best advice I can offer is to expand on what minidogger had to say. Keeping the transmission fluid healthy, changing it more often, is paramount. If Mini/BMW offers a heavy duty fluid, or a synthetic fluid, that is approved for use in the transmission, under severe service conditions, trailer towing, that may be the way to go. (Switching to this fluid may require a thorough flush of the transmission to remove remnants of the old fluid so the new fluid is contaminated by mixing with the old fluid. If there is any superior fluid availalble there probably exists a set of instructions on how to switch to using it.)
Also, you want to monitor transmission fluid temperature and if it gets too much hotter you may need to upgrade/add to the transmission cooling system to bring flud temperature down to reasonable levels. Do not forget that more torque to the transmission means more torque to the diff and this may need modification to help it withstand the extra torque. For instance a diff fluid cooler maybe.
The following users liked this post:
Goldsmithy (01-11-2019)
Trending Topics
#9
Join Date: Oct 2018
Location: Lehigh Valley & Harrisburg
Posts: 37
Likes: 0
Received 15 Likes
on
8 Posts
I am using the MadnessAutoworks MADNESS AutoFlash TCM Module which claims to update the maps of the TCU to allow the gearbox to improve shift times and bypass the torque limiter and put more hp and torque to the ground. I don't no if this actually would help the transmission handle more torque but should make extra hp a little gentler on the transmission by smoothing out and reducing shift times. I had to have mine special ordered for my 2018 Clubman S ALL4 8 speed automatic since it isn't a unit they stocked for that car. I don't know if this helps with the addition of everyone else's recommendations.
Thread
Thread Starter
Forum
Replies
Last Post
Jeff Wallen
R56 :: Hatch Talk (2007+)
13
01-03-2016 07:35 AM