[Craigito]

Hi All,

I've been lurking for a few months. I'll probably be picking up a 335i in April/May sometime...although reading all these fantastic reviews is making it pretty hard to be patient. I have an A4 Turbo and have done quite a bit over the years. It's a MT and I know for the Audi, having an AT limited what you could do as far as adding power via ECU/Upgraded turbo etc. as the AT couldn't handle as much power as the MT could. Do you think this will be the same case with the 335. I was pretty set on the MT anyways because my commute is mostly highway with not a lot of traffic and I do enjoy rowing through the gears but the step does sounds very good from all the posts i've read. I'll definately have to drive both. I love turbos because it allows you to do power additions at relatively low cost.

[ChineseGuy]

AT- PROs: Kickmode....feel that boost thing when you floor it and you get to be lazy sometimes, yet use the +/- or the paddles to shift if you want a little of your MT feeling back

MT- 100% control of your car, and enough said...haha

[Craigito]

Originally Posted by ChineseGuy

AT- PROs: Kickmode....feel that boost thing when you floor it and you get to be lazy sometimes, yet use the +/- or the paddles to shift if you want a little of your MT feeling back

MT- 100% control of your car, and enough said...haha

Don't think you understood the jist of the post. I'm wondering if the MT is better as far as aftermarket performance upgrades..turbo/ecu etc. Basically, can the MT handle more power additions than the AT can? I know it's a probably a little early to say since the car is brand new.

[ChineseGuy]

Originally Posted by Craigito

Don't think you understood the jist of the post. I'm wondering if the MT is better as far as aftermarket performance upgrades..turbo/ecu etc. Basically, can the MT handle more power additions than the AT can? I know it's a probably a little early to say since the car is brand new.

OO....haha....my bad, didn't read the whole thing

but....not sure.....but i doubt there's a difference though...

[stressdoc]

Tough call. The 335d is step only, reportedly because the clutch in the manual could not handle all the torque. I would wait and see what happens to folks that get the Vishnu xede set-up. My guess? It's a BMW, it's solid either way.

[Shinobi]

Originally Posted by stressdoc

Tough call. The 335d is step only, reportedly because the clutch in the manual could not handle all the torque. I would wait and see what happens to folks that get the Vishnu xede set-up. My guess? It's a BMW, it's solid either way.

I am very interested in seeing what the new Steptronic tranny in the 335i is capable of. The automatic tranny of the e46 could NOT handle more than the manual trannies. Its limit is somewhere around ~330HP or so. Some people tried pushing more power through and their trannies busted.

Since the 335 is already pushing ~320+HP to the crank, I imagine that it can run more, but I have not seen any specs on this. I'm sure someone here will push their car to the limit and then we'll know.

I can't recall off the top of my head, but is the tranny in the 335s made by ZF or GM? or some other manufacturer?

EDIT: I found it. Google is your friend. Its a ZF six-speed, but I still don't know what its max torque rating is.

[Taittinger]

Originally Posted by ChineseGuy

AT- PROs: Kickmode....feel that boost thing when you floor it and you get to be lazy sometimes, yet use the +/- or the paddles to shift if you want a little of your MT feeling back

MT- 100% control of your car, and enough said...haha

Just curious, as always, but how is the MT in more control than the AT? In manual mode it only shifts when I ask it to. I have read how there is more control with MT; is there something I am missing?

[scm6079]

Coming from the Audi S4 world, the Quattro was the limiting factor most often for performance jumps. W/O the "xi" on the 335 I would think there would be little difference in aftermarket limitations between the two. This particular auto seems to lock up the torque converter frequently, thus allowing more power. And in a manual you can always be more gentle with clutch release as a driver, thus saving your driveline.

_Scott

[scm6079]

Originally Posted by Taittinger

Just curious, as always, but how is the MT in more control than the AT? In manual mode it only shifts when I ask it to. I have read how there is more control with MT; is there something I am missing?

The automatic is only directly connected when the transmission decides to lock up the torque converter. You can not decide (even on this very good auto) when to lock the torque converter. In a manual, you always decide when the tranny is direct connected to the motor, or when it is slipping, and by how much by modulating the clutch.

For example, when desiring extreme engine braking, the manual driver can leave a gear fully engaged, while the auto driver may be in the same gear the torque coverter allows slippage and thus less control.

This is why a typical auto can be in "1st gear" and you will not be moving at a stop.

_Scott

[Shinobi]

Originally Posted by Taittinger

Just curious, as always, but how is the MT in more control than the AT? In manual mode it only shifts when I ask it to. I have read how there is more control with MT; is there something I am missing?

Manual Tranny is 100% in the driver's control. It will NEVER upshift automatically. At the limit, it will just bounce off the rev-limiter. The downside is that it doesn't protect you either...so its possible to do the dreaded money-shift and blow your engine.

Automatics will prevent any possibility of a money-shift, BUT it WILL also shift at redline (unless you have software) and kickdown mode overrides all other modes and upshifts no matter what. So, you do not have 100% control.

[Taittinger]

Ummm... I am not sure what you mean. If I do not apply the break in 1st, the car moves forward, even on an incline.

[Taittinger]

Originally Posted by Shinobi

Manual Tranny is 100% in the driver's control. It will NEVER upshift automatically. At the limit, it will just bounce off the rev-limiter. The downside is that it doesn't protect you either...so its possible to do the dreaded money-shift and blow your engine.

Automatics will prevent any possibility of a money-shift, BUT it WILL also shift at redline (unless you have software) and kickdown mode overrides all other modes and upshifts no matter what. So, you do not have 100% control.

The autos I have driven never shift at redline, they just bounce until I shift. At least in the 350Z. I will have to wait until break in is over to try it on the 335.

[Taittinger]

Originally Posted by Shinobi

Manual Tranny is 100% in the driver's control. It will NEVER upshift automatically. At the limit, it will just bounce off the rev-limiter. The downside is that it doesn't protect you either...so its possible to do the dreaded money-shift and blow your engine.

Automatics will prevent any possibility of a money-shift, BUT it WILL also shift at redline (unless you have software) and kickdown mode overrides all other modes and upshifts no matter what. So, you do not have 100% control.

I thought kickdown is a "special" mode that I do not have to engage.

[Shinobi]

Originally Posted by Taittinger

The autos I have driven never shift at redline, they just bounce until I shift. At least in the 350Z. I will have to wait until break in is over to try it on the 335.

I stand corrected...actually, I'd forgotten that I drove a Subaru wagon as a rental and it did indeed bounce off the limiter like a manual. Most of the ones I've driven though do shift...many way before redline no matter what I do.

Originally Posted by Taittinger

I thought kickdown is a "special" mode that I do not have to engage.

Kickdown is activated when you push the accelerator all the way down and you click a button. The tranny then downshifts to the lowest gear *possible* and accelerates at full throttle, shifting at redline until you let up. This mode overrides all other modes (Drive, Sport, and Manual).

[Taittinger]

Do you know if the AT in the 335 will shift at redline?

[Shinobi]

Originally Posted by Taittinger

Do you know if the AT in the 335 will shift at redline?

That...you will have to verify with someone who does own a 335i. From everything I've read, it sounds like the Steptronic behaves the same way it does on the other BMW models that I've driven, so I'm guessing that it does.

You know what, I really need to go test drive one of these babies already .

[yemski]

from what I know regarding AT's and Audi's, it is the torque that the tranny can't handle. With MT you can swap the clutch and you're good to go. With AT you could upgrade the torque converter and the valve body to allow it to take more..but at a cost

The auto in the 335i is a ZF 6 speed in a car making ~300lb/ft torque. Trannys can usually take more torque than their particular application, kind of like a buffer... but the question is how much...350lb/ft...400lb/ft...finding this out would definetly reveal the modding potential for the AT

If someone can find the ZF tranny model number, it would be interesting to look up the specs on this bad boy...from the reviews it seems to be quick and good even for a 'slushbox'

[alaloom]

Originally Posted by Taittinger

Just curious, as always, but how is the MT in more control than the AT? In manual mode it only shifts when I ask it to. I have read how there is more control with MT; is there something I am missing?

I don't know if you understand smc answer's but here is another attempt. The magic behind the manual is not in changing gears, it's in operating the clutch. In a manual you decide when to press the clutch, what rev the engine is in and how you release the clutch. Slipping the clutch can help with breaking, but can also help in acceleration, which means you rev the engine high which creates a lot of torque at the flywheel (much higher than what the engine creates by itself) and then modulate the clutch to transfer the energy to the wheels. Slipping the clutch does not require you changing gears, it just requires operating the clutch. A similar phenomenon can exist in the torque converter, but it's more limited. The 335i AT looses all "slipping" once the torque converter is locked, which of course compensates with a lot of engine torque.

Slipping the clutch is how a manual 1990 Nissan Sentra (for example) can burn tire, something it's engine could never do on it's own. The best way to learn how to drive a manual is in under-power cars which have a very fine line between gaining power and stalling, you really learn how to operate that clutch.

[Driv3r]

GET suspension!

[Driv3r]

everyone car drops need

[scm6079]

Originally Posted by Taittinger

Ummm... I am not sure what you mean. If I do not apply the break in 1st, the car moves forward, even on an incline.

Right -- but when you apply the brake, the car does not stall -- even though it is still engaged in first gear, not neutral. In a manual if you were in first gear, and the clutch and brake engaged the car would stall -- since there is a "direct connection" the engine would be forcefully trying to overcome the brakes with 100% engine power. If the engine had the power to overcome the brakes you would continue to move forward, even with full brake power.

The automatic transmission's torque converter is the "magic" component. This is actually a hydraulic fluid coupling, that sits between the transmission and the engine. In old automatic cars torque converters relied solely on the hydraulic fluid to "push out" to the ends to couple the transmission to the engine. Thus, there was little if any engine braking. In more modern cars (since the 80's), a locking torque converter is used. This allows the automatic to function like a manual transmission car (not the shifting gears part, the direct connection part) when the transmission decides that power should be routed 1:1. Now in this new transmission BMW has taken it to a new level. This automatic has 2 very intersting features. First, it has the steptronic function. This is nice, and allows you to force the auto to stay in a particular gear. The other feature is that the torque converter actually decouples from the transmission completely at a stop. This is an automotive first, and actually is solely for fuel consumption, since it uses less gas sitting still than having the hydraulic torque converter connected. Think of it as moving the transmission to neutral on a stop. This is the reason the new e92 has the "brake assist" function for starting on hills -- the auto can actually roll backwards since the engine and transmission are decoupled.

However, even with these advances, you do not control how or when the torque converter is locked, disconnected, or partially engaged. The transmission itself controls how much engine power is routed to the transmission. Hopefully it makes the right choice. However, let's say you wanted to do a huge smokey burnout. In a manual, you can choose to leave the clutch disengaged and then rev the engine, and then engage it fully. In the auto, the torque converter will choose to engage no matter what you do. You could also do other usefull things with slippage without the point of a smokey burnout, like as is common in AWD cars (my S4, the new 335xi, etc) -- which is slipping the clutch to keep the engine from bogging, or in 3rd gear disengaging the clutch, spooling up the revs, and then reengaging the clutch to have a quick jump in speed-- without changing gears.

Overall I think the 335's automatic is the best true automatic ever made, but it is still not a manual transmission.

DSG and SMG are a whole different conversation as well.

_Scott
Member of the Society of Automotive Engineers.

[Taittinger]

Thanks all for ejumicating me! :-) Good stuff!