Synchrorev match transmission reliability?
 

Hey guys,

I currently have a 07 350z 6mt and I am looking for another car. It's currently between the e92 M3 and the NISMO 370z (2013+). Reliability is a huge concern for me and I wanted to know how robust the synchrorev transmission is. I'm not one for advanced technology in my cars because I feel there's more that can break. The synchrorev transmission is perhaps the only negative thing I associate with the 370Z, though I know it can be turned on/off.

Since there's a good amount of computer input in this transmission, I just wanted to know how reliable it is. Is there anyone here with a 6mt that has racked on a lot of miles and not had a single issue with the transmission? Am I overthinking the complexity of this transmission?

I'm not worried about the engine at all. I know these HR engines are awesome. My 2007 Z with the HR engine has 100k miles and has never burned a drop of oil or has dropped in performance. It's just the synchrorev transmission that strikes me as an item that's more prone to fail since it's heavier on the electronic end. I could be wrong. If I am, let me know.

Thanks!

You can turn it off and leave it off anytime if you are worried about it.

You're overthinking it. SRM is a few sensors and an ecu that tell the car to rev the motor a bit when you shift. A failure of the SRM will not grenade your transmission, which is very robust.

What you should be concerned about is the clutch hydraulics system, which is fragile and fails without warning.

Also, if you're concerned about overly complex cars being unreliable, why are you considering a used BMW?

Yes, you are overthinking the complexity of the electronics and their impact on the transmission operation. The SRM function has nothing to do with the robustness of the transmission itself. The MT transmission is fairly robust (people are throwing 600 hp at it seemingly without issue), although it has some quirks that people are fond of complaining about. The CMC and CSC are notoriously prone to failure. It's not silent like a Lexus and it can be a bit clunky if you don't drive it perfect. However, SRM will help you drive it smooth. In fact, SRM will probably decrease wear on the transmission and especially the clutch for the average driver.

The AT is probably way more electronic and is still pretty solid. Its a really good transmission for a non-DCT. The AT's biggest drawback is its inability hold power - it's only rated to 295 ft-lbs of torque or something.

The e92 M3 is overall fairly reliable car (minus some rod bearing issues). Maintenance is more expensive, which I'm fine with, but overall it's pretty reliable. I spent countless days researching that car.

I appreciate everyone's feedback!

So the SRM is a separate unit from the actual transmission? Just trying to understand it better

As far as the SRM its one of the best thing I like about the sport package. So far have not heard anyone complain of it being unreliable.
You should be worried more about your CSC failure.
I bet your also worried about using the DSC?
I hope not.

All SRM does is blip the throttle a little. IIRC, the TCM and ECM compare engine speed and trans input speed and tries to match them. FSM (and possibly the OM) will have details on how it works. As has been said, if anything, it will increase the life of the transmission and you can always turn it off if you think it is a problem.

I didn't have an M3, but I had two 3 series BMWs and they were the most unreliable cars I owned. They reminded me of the domestic cars of the '70s and '80s but way more expensive to fix. Way back, I said no thanks to American cars and went Japanese and found the difference incredible. I always owned Japanese cars for many years, but always wanted a BMW. Expensive lesson learned, now I'm back with the Z and, knock wood, the reliability has been excellent. Don't get me wrong, the Bimmers were great driving cars, they just couldn't stay away from the dealership.

i'm no expert but to my way of thinking by correctly matching the revs of the engine and transmission shouldn't it reduce wear and tear on the transmission?

That seems to be the general consensus but I don't think anybody has any empirical data to back it up.

I just want to clarify something.

I know the idea of SRM is good for the transmission but I was talking about the SRM actual unit - since that's an electronic or computer operated, is it more likely to fail? It seems no, but that's what I was asking.

yah, the sensor switch in the gate could potentially fail in the long run... but im sure your csc will fail much sooner so dont worry about it, you're safe.

Other than the sensors (should last a lifetime), there is nothing added to the "plain" system. The throttle servo is already there. The ECM and TCM are already there. The code in the ECM/TCM is not going to fail (assuming it was tested properly).

So, to sum it up, the sensors technically decrease reliability (added parts to fail) but only on paper. Ie, not enough to even consider.

No more likely than any other computer on any other car, because it is just that... a computer.