2017 Update: Clutch setup is holding up great after 20k hard miles!
After adding my aggressive E85 flash last summer, the factory clutch started to slip. I decided it was time to upgrade so I could enjoy the car to it’s full potential this summer. From Spec to ACT, there are plenty of aftermarket options available. Then I found the 335is/550i clutch upgrade on ECSTuning, so I started to do some research.
This clutch comes factory in the F10 550i, which puts down 443 tq and weighs a whopping 4552 lbs. DINAN doesn’t offer a clutch upgrade for their different stages of 550i’s, so apparently they feel that it is adequate. Their Stage 3 550i puts down 580 tq and they kept the factory clutch. Also, someone on the forums is using this clutch and claims that it is holding at over 620wtq on aftermarket turbos. To me, it sounds like the clutch is severely underrated.
My 135i won’t see more than 500 tq anytime soon. I’d guess that it is currently around 420whp/465wtq, but only weighs 3300 lbs!
I decided to give it a try. Here is my parts list from ECSTuning:
- 335is/550i 6-speed Clutch Kit
- Clutch friction disc
- Throwout/release bearing
- Clutch fork lever
- Pressure plate
- Pressure plate bolts
- Manual Transmission Service Kit
- 2 quarts of Redline D4 ATF transmission fluid
- Drain plug with crush washer
- Fill plug with crush washer
- Flywheel bolts
- 8 bolts if you have 2007-2008 N54
- 6 bolts if you have 2009+ N54
- Downpipe exhaust gaskets
- You will need 2 of these
- Aluminum Transmission Bolt Set
- Pilot Bearing
- Rear Main Seal
- Total ECSTuning parts cost: $544.17
When replacing your clutch, I highly advise that you also replace the factory dual-mass flywheel (DMFW). The springs wear over time and will eventually let go. I chose to go with a lighter, single-mass flywheel (SMFW) from MFactory for $499.95 shipped. This brought my total parts cost to $1044.12, not bad.
DMFW vs. SMFW could be debated for hours, but it all comes down to what you want out of the car. If you care about noise, go with a DMFW. The SMFW chatters a little bit, especially with the A/C on. However, the DMFW is known for having issues at high horsepower levels. If you plan on upgrading to aftermarket turbos, you will want a SMFW. SMFW also rev faster because there is less rotating mass. OEM and aftermarket DMFWs are available on ECSTuning. I chose the SMFW because this is now a performance car. It is no longer stock and will never return to the car it once was from the factory.
Here is a video I recorded after install with the SMFW chatter:
Let’s get down to the dirty stuff… old clutch:
Still some life left on the friction disc, but some slipping spots with heat damage on the pressure plate. Everything else was ‘okay’. The new rear main seal was installed and the transmission was removed.
See those two bottles of Redline D4 ATF on the table? We drained the old fluid out and added about 1.5 quarts until it started overflowing. After that, the new clutch and flywheel were bolted on.
Lastly, everything goes back together in reverse order. Obviously I didn’t get pictures of everything during the install, but it all went together flawlessly. Big thanks to my buddy Kevin, who did an awesome job with the install. He took great care of the car!
Once the car was finished, I took it out for a test drive and it feels fantastic. The clutch pedal is slightly stiffer, but retains an OEM feel. The gear changes are nice and smooth with the new Redline fluid. Everything grabs like it should and I’m very satisfied with the new setup! It will be put to the test this summer…