[Mustard3]

I was just wondering how much power the auto box saps compared to the manual.

With the same quoted bhp figure at the crank does anybody have dyno figures at the wheels. I believe the auto box locks up earlier than autos of old but are the losses as bad?

I've owned an E46 328i manual and an E46 330i auto, they were a close match on acceleration, despite the 30bhp advantage of the330i.

[dxb335d]

It's not that bad mate. Only a small percentage which is only a small amount of HP. The Auto box in the 335's is great. Stronger than the manual aswell.

[zltm089]

i though they would be the same!...

[m1bjr]

Originally Posted by dxb335d

It's not that bad mate. Only a small percentage which is only a small amount of HP. The Auto box in the 335's is great. Stronger than the manual aswell.

What is the torque rating on the auto, I thought the manual was the tougher gearbox, and the same Getrag unit as fitted to the M car?

[Alpina_B3_Lux]

Originally Posted by dxb335d

The Auto box in the 335's is great. Stronger than the manual aswell.

Actually it's the other way round. With really high hp applications the torque converter is not strong enough. There are already a few threads on it, currently two members in the US forums have upgraded their automatic transmissions.

With the manual, all you need to do is getting a stronger clutch, which is far easier than upgrading the AT.

Alpina_B3_Lux

[dxb335d]

I thought the Auto was chosen for the 335d because the manual couldn't take the high torque output. Also most tuned Auto motors have been fine where as manual ones get notchy?!

I was also told this by several people in and out of BMW. But if you guys know different fair enough.

[MEGA]

diesel gearbox compleeeetely different to the petrol mate the ratios are slightly different..

[dxb335d]

Ratios?! We ain't talking about ratios mate. But about which is the strongest
'box.

[Alpina_B3_Lux]

Originally Posted by dxb335d

I thought the Auto was chosen for the 335d because the manual couldn't take the high torque output. Also most tuned Auto motors have been fine where as manual ones get notchy?!

I was also told this by several people in and out of BMW. But if you guys know different fair enough.

I think we're talking of two different things - the transmission or the gearbox. The MT will much sooner get problems with the clutch than the AT will with its torque converter, so it is fair to say that without a stronger aftermarket clutch the MT cannot take the same torque output that the AT can (which is probably what the BMW guys meant).

However, if you eliminate this weak point - the clutch - then the MT should be sturdier even with high torque outputs, beyond a point where you would have to rebuild the automatic transmission (which is also possible, but much more expensive).

That said, I'm running with 700 Nm of torque right now and still have the stock clutch, although everyone keeps telling me it will not hold up. Well, it's slipping right now I believe but I've had it on a FBO car for 60.000km.

Alpina_B3_Lux

[dxb335d]

"should be" that means you are unsure...

We need facts!

What's the factory ratings for both boxes.

[m1bjr]

Originally Posted by dxb335d

"should be" that means you are unsure...

We need facts!

What's the factory ratings for both boxes.

Indeed.

You said it first so get Googling

[willhollin]

Are they Getrag manual transmissions?

[seanblee]

335d and 335i have different auto boxes. The i uses the ZF 6HP19 (early) or 6HP21 (late) with a 450NM limit, whereas the d uses the ZF 6HP26 (early) or 6HP28 (late) with a 600NM max.

[MEGA]

Originally Posted by seanblee

335d and 335i have different auto boxes. The i uses the ZF 6HP19 (early) or 6HP21 (late) with a 450NM limit, whereas the d uses the ZF 6HP26 (early) or 6HP28 (late) with a 600NM max.

which is what I was saying Although with much more actual, you know: Fact. So cheers sean

[Alpina_B3_Lux]

Originally Posted by dxb335d

"should be" that means you are unsure...

We need facts!

What's the factory ratings for both boxes.

From what I know, the 335i MT has the same gearbox (different gear ratios of course) than the E60 M6 (which was only offered as MT in the US). I was told it is rated for 500 Nm initial torque, i.e. torque on the non-moving transmission. You won't reach that with the usual tunes sold in Europe - with bigger turbos, meth and nitrous that would be another story.

Alpina_B3_Lux

[seanblee]

Originally Posted by Diseasel

i thought the autobox in 3.0D was rated up to 700NM?

Next one up from the 6HP26/28 is the 6HP32/34, which is rated to 1000NM and is used in the X5/6M and the 760i. It's never been used in a 3er.

[dopper99]

So if BMW have a high torque rated manual 'box... why the heck didnt didnt they put it in the 335d?

[idnan]

Originally Posted by dopper99

So if BMW have a high torque rated manual 'box... why the heck didnt didnt they put it in the 335d?

Why increase the production cost and therefore the retail price when the current one is strong enough for the factory power output of the car? I'm guessing the torque ratings are fairly conservative anyway.

[seanblee]

Originally Posted by idnan

Why increase the production cost and therefore the retail price when the current one is strong enough for the factory power output of the car? I'm guessing the torque ratings are fairly conservative anyway.

I think the point was that the 335d doesn't have a manual option at all at present...

[seanblee]

Originally Posted by willhollin

Are they Getrag manual transmissions?

ZF on the 335i - GS6-53BZ (where GS6 is 6-speed manual, 53 is the model, B is benzin [petrol] and Z is ZF). Apparently the same box as used in the E60 M5, 545i, E9x M3 and a few others, so it's good and strong, though I can't find a manufacturer's torque rating for it...

[p1tse]

Interesting read

But even IF the manual had less mpg I'll still take the 335i in manual for pure experience

[DavS1]

To answer the posters original Q, manual probably loses about 20-25bhp from engine - wheels, auto prob loses 30-35..as an educated guess