[wareagle900]

so, ive read disputes on whether or not the tranny can handle a certain amount of power... but what is the max?

what is the maximum hp and tq a stock tranny, driveshaft, and rear end can handle?

[wareagle900]

you are correct, drivetrain strength really has nothing to do with hp.... well, if we know that the tranny is the limiting factor, what is the most anyone has put through it? anyone know?

is there any way to beef up the tranny to deal with more power?

[dmurray14]

Don't know, but I know the e60 M5 uses the same 6MT as the 335, but in a different bellhousing.

[AltecBX]

I would say 450-470lbs. Anything after that, I would agree that the housing would have to be change to handle the extra sustain power at loads over 4k rpm

[Former_Boosted_IS]

Originally Posted by AltecBX

I would say 450-470lbs. Anything after that, I would agree that the housing would have to be change to handle the extra sustain power at loads over 4k rpm

Wrong, I am running more than that now and have been for months. The fact is there we just don't know the answer. The clutch will blow first and mine did at about 480 rwtq.

[GaryS]

BMW restricts the PPK for 6MT to 317 ft/lbs (AT gets 332) because they say that's all the MT can handle. They warned Dinan that his tunes for 135i/335i exceed the 6Mt specs. And they put a HD flywheel in the 335is. But decide for yourself. Everyone here seems to be getting away with it so far.

[Former_Boosted_IS]

Originally Posted by GaryS

BMW restricts the PPK for 6MT to 317 ft/lbs (AT gets 332) because they say that's all the MT can handle. They warned Dinan that his tunes for 135i/335i exceed the 6Mt specs. And they put a HD flywheel in the 335is. But decide for yourself. Everyone here seems to be getting away with it so far.

I have to tell you that is a pile of garbage. The 6MT is the ZF Type G transmission. Since there is some refusal to accept reality, let me make if more clear from the spec sheet from ZF.

carmodel eng tq trans tq trans type
---------------------------------------------------------
318i-6MT 180NM ??? GETRAG I
318i-6AT 180NM 400NM ZF 6HP19
320i-6MT 200NM ??? GETRAG I
320i-6AT 200NM 400NM ZF 6HP19
325i-6MT 250NM ??? GETRAG I
325i-6AT 250NM 400NM ZF 6HP19
318d-6MT 280NM ??? ZF type H(weit)
330i-6MT 300NM ??? GETRAG H
330i-6AT 300NM 400NM ZF 6HP19
530i-6MT 320NM ??? ZF type H
530i-6AT 320NM 400NM ZF 6HP19
320d-6MT 340NM ??? ZF type H(weit)
320d-6AT 340NM 400NM ZF 6HP19
335i-6AT 400NM 450(530)NM ZF 6HP19 TU/21
335i-6MT 400NM ??? ZF type G
325d-6MT 400NM ??? ZF type G
325d-6AT 400NM 450(530)NM ZF 6HP19 TU/21
M3 -7AT 400NM 600NM GETRAG M DCT
M3 -6MT 400NM ???
M3 -6AT 400NM ???
550i-6AT 490NM 700NM ZF 6HP26 TU/28
550i-6MT 490NM ??? ZF type G
530d-6AT 500NM 700NM ZF 6HP26 TU/28
330d-6MT 500NM ??? ZF type G(weit)
330d-6AT 500NM 600NM ZF 6HP26
M5 -SMG 520NM 550NM Getrag SMG III/7AMI550
M5 -6MT 520NM ??? ZF type G
535d-6AT 580NM 700NM ZF 6HP26 TU/28
335d-6AT 580NM 700NM ZF 6HP26 TU/28
(from E60/E90 ACEA Technik 0307, Getrag, BMW)

So it is clear, that they are quoting the 520NM or 317rwhp from the ZF output for the M5, but ZF never says what the max capacity is. In fact if you look at other ZF trannies you can see their overhead is about 20%. The M5/6 weight 500-600 lbs more than many of our N54s, so these trannies in the N54 will hold a ton more power than they will on the M5/6. BMW doesn't want you to put more power in the car then stock, we know that. None of us care what BMW wants since they don't seem to care about our HPFP, we care about what its holding capacity is. I can tell you it is a ton more than 317 rwtq.

[CubanJJ09]

Originally Posted by Former_Boosted_IS

Wrong, I am running more than that now and have been for months. The fact is there we just don't know the answer. The clutch will blow first and mine did at about 480 rwtq.

any sort of other problems thats popped up?

[Former_Boosted_IS]

Originally Posted by CubanJJ09

any sort of other problems thats popped up?

Cuban, I blew my clutch pretty easily when I got the nitrous dialed in. I think 1 or 2 more runs and I would have demolished it, but I babied it until the change. Now I have a Clutch Masters Twin Disc with one ceramic disc and one segmented kevlar disc. Simply put it grabs and I am running a Quaife LSD, so the power is being translated. Up to this point, I have yet to see another issue. Everything still runs like stock to be honest. The gears engage the same as they did stock. I am eagerly pursuing colder plugs, but that is about it.

I have modded a lot of cars way beyond what the car was designed for and obliterated some transmissions. The 6MT on this car seems to be VERY strong. With most of the trannies I have popped, you could always feel the weakness before it let go, but honestly I have yet to feel that on this car. I am with everyone else here in that I don't know what the tranny will hold. In my opinion it will be north of 650 rwtq at least, but I have no info to support that. I have put about 515 rwtq through mine in long gears a lot to this point and it hasn't flexed. I plan to put more through it soon. I didn't get a clutch to hold 900 rwtq for just 500 rwtq.

[335e92tx]

The other thing that tends to get somewhat glossed over is BMW (as do most manufacturers) rate the trans durability on continuous engine output over generally 100K miles. Can you push 50 percent more output with the associated 50percent reduction in drivetrain life? Up to a point yes. But the case can crack at some point probably between 35 and 60 percent additional output - YMMV.

[Former_Boosted_IS]

Originally Posted by 335e92tx

The other thing that tends to get somewhat glossed over is BMW (as do most manufacturers) rate the trans durability on continuous engine output over generally 100K miles. Can you push 50 percent more output with the associated 50percent reduction in drivetrain life? Up to a point yes. But the case can crack at some point probably between 35 and 60 percent additional output - YMMV.

Again this is all speculation. We know that the has to be some trade off, but who knows how much.

[dmurray14]

Originally Posted by Former_Boosted_IS

I have to tell you that is a pile of garbage. The 6MT is the ZF Type G transmission. Since there is some refusal to accept reality, let me make if more clear from the spec sheet from ZF.



So it is clear, that they are quoting the 520NM or 317rwhp from the ZF output for the M5, but ZF never says what the max capacity is. In fact if you look at other ZF trannies you can see their overhead is about 20%. The M5/6 weight 500-600 lbs more than many of our N54s, so these trannies in the N54 will hold a ton more power than they will on the M5/6. BMW doesn't want you to put more power in the car then stock, we know that. None of us care what BMW wants since they don't seem to care about our HPFP, we care about what its holding capacity is. I can tell you it is a ton more than 317 rwhp.

+100 million

No one really knows, I don't want to be the one to find out, and the rest is speculation.

[335e92tx]

Originally Posted by Former_Boosted_IS

Again this is all speculation. We know that the has to be some trade off, but who knows how much.

Your right - my estimates of over rated output are just that. But there is no doubt that they provide those ratings at full output for very extended periods. That is part of all manufacturers drivetrain durability testing. What that can be extrapolated to is anyones guess. And there probably is no repeatability in those 'results' or individual empirical data.

Put it this way, for MY use, I seriously doubt that my drivetrain will see even the rated manufacturers levels of stress in 150K miles (IE, I don't spend 66 percent of my time at WFO or even 25%) even with a 30/35 percent increase in output (which is pretty common with the boltons). I don't have the ability to utilize the power available at anywhere near the frequency that durability tests subject the drivetrain to. Others seem to utilize the power much more frequently and durability is anything but linear when 30-50 percent additional output is frequently exploited.

[Former_Boosted_IS]

Originally Posted by 335e92tx

Your right - my estimates of over rated output are just that. But there is no doubt that they provide those ratings at full output for very extended periods. That is part of all manufacturers drivetrain durability testing. What that can be extrapolated to is anyones guess. And there probably is no repeatability in those 'results' or individual empirical data.

It will be interesting as we find the limits. Everyone is very interested in knowing the answers to these questions. At this point other than the major HPFP problems, it appears BMW has put together an engine with strong internals and a tranny that will handle some serious power increases. I am purposely building everything very strong with the hopes that the fuel issues will be solved. If indeed they are, I have the platform to push this car very far.

After enjoying the car for the summer, I will probably build the motor and move toward some large numbers.

[CubanJJ09]

Originally Posted by Former_Boosted_IS

Cuban, I blew my clutch pretty easily when I got the nitrous dialed in. I think 1 or 2 more runs and I would have demolished it, but I babied it until the change. Now I have a Clutch Masters Twin Disc with one ceramic disc and one segmented kevlar disc. Simply put it grabs and I am running a Quaife LSD, so the power is being translated. Up to this point, I have yet to see another issue. Everything still runs like stock to be honest. The gears engage the same as they did stock. I am eagerly pursuing colder plugs, but that is about it.

I have modded a lot of cars way beyond what the car was designed for and obliterated some transmissions. The 6MT on this car seems to be VERY strong. With most of the trannies I have popped, you could always feel the weakness before it let go, but honestly I have yet to feel that on this car. I am with everyone else here in that I don't know what the tranny will hold. In my opinion it will be north of 650 rwtq at least, but I have no info to support that. I have put about 515 rwtq through mine in long gears a lot to this point and it hasn't flexed. I plan to put more through it soon. I didn't get a clutch to hold 900 rwtq for just 500 rwtq.

how long do u intend on keeping this car for? seems like a while since your building it from the ground up. just wonder about the durability with those kind of power levels (almost double than stock). but i agree the only true way to tell is when some blows that tranny up. hopefully it never happens but a shit load of knowledge will be gained from it.

[Former_Boosted_IS]

Originally Posted by CubanJJ09

how long do u intend on keeping this car for? seems like a while since your building it from the ground up. just wonder about the durability with those kind of power levels (almost double than stock). but i agree the only true way to tell is when some blows that tranny up. hopefully it never happens but a shit load of knowledge will be gained from it.

I am not sure, but at least through at least next year. I have to say it is nice to have a high horsepower sleeper. I have always loved that kind of car and it is one of the main reasons I don't want to build an M3 or buy a GTR. People know those cars are fast and that has never been my vision. Driving a very classy car like the 335i with a beautiful interior and 500 rwhp right now is awesome. I want this luxury in a sleeper with a 10 second time slip and I think I am closing in fast on the goal.

[CubanJJ09]

yea i agree. something about building your own creation rather than going and buying it. not saying that i still wouldnt like a gtr or m3

[wareagle900]

So it is pretty much agreed upon that the tranny will be the first to go, but at what oint is the question?

What I gather is that the stock block and internals can handle upwards of 500rwtq just fine, The stock clutch goes around 450 or so and the rear end ?

also, What does a new 6mt cost?

[Former_Boosted_IS]

Originally Posted by wareagle900

So it is pretty much agreed upon that the tranny will be the first to go, but at what oint is the question?

What I gather is that the stock block and internals can handle upwards of 500rwtq just fine, The stock clutch goes around 450 or so and the rear end ?

also, What does a new 6mt cost?

No, it is my opinion that the 6MT will be the last to go. I think internals in the engine will be the first to go, but no one knows when.