[gtp900]

Has anyone here "built" their transmission here? What are the week points? Clutches, valve body, or input shaft? I've had friends in the diesel truck world build their trannys to hold well over 1000ft lbs, even the new trucks are coming with 900ft lbs stock.
With the latest hybrid craze, and now with the availability of transmission flashing, we could make better use of the power if the transmission could handle it.

[GreekboyD]

Bohl Diesel tackled and accomplished this a couple of years ago.

Contact them.

[Mark M]

I'm not aware of weak points. This transmission seems to handle much greater hp and torque than most of us had expected. I believe the only weak point some could say is the software as it's not tuned aggressively enough for those of us whom prefer greater performance.

[WreckerX5d]

Originally Posted by GreekboyD

Bohl Diesel tackled and accomplished this a couple of years ago.

Contact them.

This. According to him, our transmission shares very similar upgrades with a Mustang.

[Whitbread]

Yup, I've built a few now also. There's updated oil pumps, bushings, clutches, and billet shafts if you're really adventurous.

[bfunk04]

What about half shafts? Has anyone broken those yet?

[gtp900]

Originally Posted by Whitbread

Yup, I've built a few now also. There's updated oil pumps, bushings, clutches, and billet shafts if you're really adventurous.

Sounds like we're ready for a single turbo option
That would take care of our changeover valve problems too

[335dsleeper]

I think it'd be pretty hard to spool a big single without a smaller turbo. When the changeover valve fails to operate correctly, the M57 barley spools the stock LP turbo.

In order to run a larger turbo, I think you're going to be forced to retain the HP turbo and changeover valve unless you use another method to spool the turbo.

Originally Posted by gtp900

Sounds like we're ready for a single turbo option
That would take care of our changeover valve problems too

[BB_cuda]

Originally Posted by Whitbread

Yup, I've built a few now also. There's updated oil pumps, bushings, clutches, and billet shafts if you're really adventurous.

Speaking of bushings, I recall Bohl telling us the input shaft bushing was looking beat up. He went in to change the clutches and found the bushing not looking so great.

[Miko226]

Has anybody broken a stock transmission yet?

[tryingtobebest]

Originally Posted by 335dsleeper

I think it'd be pretty hard to spool a big single without a smaller turbo. ...
unless you use another method to spool the turbo.

Big single - VGT.

The only and huge problem wer facing is head flange and then 100% custom exhaust manifold, im afraid to ask Unobtanium how much something like this will cost!)))) Unless someone trace one from europe since n57 was on 3ser since e46! And they tune it heavily.

Dsm/4G63 notorious for using Vgts in their 2 liters!

Not that ive read all of them but here is some SERIOUSLY INDEPTH informative threads!

Newbie discussion about Holset HE351VE vgt

"As far as I know I have the 1st ever Holset HE351VE installed in my DSM with a working electronic controller..." - Holset HE351VE Installed in My DSM (pics)

Holset Turbos, RESULTS ONLY (COMPLETE INSTALLED SYSTEMS)



2JZ's using them too
"Holly shit, this turbo is amazing. The spool is FAST! There is boost everywhere, under 3k part throttle and the turbo starts spooling whenever you would want it too. The spool is fast and so smooth, the power and flow is great, the top end feels fantastic!" - http://www.supraforums.com/forum/sho...51VE-VGT-Turbo

I just did a quick search and there is no thread in diesel section discussing VGT's maybe i should gather all of my information together and start this thread?

[Whitbread]

Originally Posted by Miko226

Has anybody broken a stock transmission yet?

No one has outright broken one that I've seen. What I've seen and dealt with is valve body wear casusing shifting behavior issues, worn bushings causing hydraulic leaks, and worn clutch packs from high miles.

[335dsleeper]

Please show me a VGT that will have similar spool characteristics to the OEM setup and will support over 500whp on a 3 liter diesel.

If it were as simple as a VGT, BMW would be running them instead of 2 and now 3 turbos...

Originally Posted by tryingtobebest

Big single - VGT.

[tryingtobebest]

Originally Posted by 335dsleeper

Please show me a VGT that will have similar spool characteristics to the OEM setup and will support over 500whp on a 3 liter diesel.

If it were as simple as a VGT, BMW would be running them instead of 2 and now 3 turbos...

On the phone....
By the time ive edit my post you guys have new replies!
Look above, and not 3 but FOUR already, gotta be in trend man!)) Jk

[335dsleeper]

First off, you're using a 2JZ as a comparison. 2nd, you literally just proved my point. "on the freeway at 2900 I can get 5-7 psi of boost in under 1 second at part throttle!" 5-7psi by 2900... that'd literally be nothing on an M57. Stock the M57 is making what, 18-22psi in a similar highway tip in scenario...

It would be horrible! Spool would suck, lag would rule and it would absolutely kill the drive ability of the 335d, and even after you did the install, it wouldn't make much more power than the current hybrids available. Our hybrids run HX 35/40 components... So, all you'd gain is lag... serious lag, which is no fun.

There's a lot of info online regarding compressor maps, efficiency islands and pressure ratios. Check it out... you'll quickly see why those turbos won't achieve similar drive-ability or make much more power on our little diesel.

Full spool at 3800-4500 isn't a huge deal when you spin the gas engine to 7000-7500rpms but sadly, we can't spin to 7500 with our little diesel.

Originally Posted by tryingtobebest

On the phone....
By the time ive edit my post you guys have new replies!
Look above, and not 3 but FOUR already, gotta be in trend man!)) Jk

[Hoooper]

Many other manufacturers are using vgts in their small diesels. From what I can tell, their solution to lag is just to pick a turbo that is way too small on the top end so it's able to make full boost by 1500 but it's wheezing by 3500. Even with that approach they still lag way more than our setup in my experience.

[335dsleeper]

Yup and a VGT turbo that'd flow more than the currently available hybrids (500-520whp) would spool much, much slower than the OEM set up.

I think a larger turbo could be fitted with a modified compressor housing and a flange adapter but, IMO in order to maintain drive-ability, performance and overall enjoyment, you'd need to retain the HP turbo.

Originally Posted by Hoooper

Many other manufacturers are using vgts in their small diesels. From what I can tell, their solution to lag is just to pick a turbo that is way too small on the top end so it's able to make full boost by 1500 but it's wheezing by 3500. Even with that approach they still lag way more than our setup in my experience.

[tryingtobebest]

Originally Posted by 335dsleeper

First off, ... Our hybrids run HX 35/40 components...

Im not pushing my idea or saying that itll be better then hybrids!
I just thought (roughly, didn't do a calculation) that 2L revving to like7-8k rpm would be somewhat equivalent to our 3L revving to 5k

The information about sharing some Holset HX35/40 internals is new to me, and I am gladly surprise about it!!!) Can you please provide some info or where you got this info from!?

[335dsleeper]

My hybrids.

Originally Posted by tryingtobebest

Can you please provide some info or where you got this info from!?

[Asonchadwick]

Here is what i did on my vw. I took the vnt turbo replaced the entire vacuum control methods with boost based. So i just literally swapped out the vaccum wastgate actuator for a booat based one. Tightened up the vanes and literally was like 5 psi at idle on the 1.9

Essentially it would hit full boost all the time immediately and then the vanes would change position based on the internal spring once it hits the set spring pressure. The nice thing about it was there was zero overshoot. Once it hit tarfet spring pressure boost stopped. Of course the exhaust housing was to small so i had boost creep eventually for the power levels but it sure was fun. Best if all it was simple as swapping out the spring. I could put in a 3 psi spring and only get 3 psi lol. Also i could adjust the vanes for either lots of lag or no lag. Sometimes i found boosting at idle was kinda silly. And say just cruising down the road at 15 psi made heat.

Another nice thing about this setup is if you used a dual port wastegate you can use an electonic boost controller. This is where is stopped because only one or 2 controllers used a tps input and they were kinda pricey. But if someone could work out a controller i dont see why vnts cant be used. I still think i would use a vnt for the small turbo and then just use a regular large turbo.

The main issue i had on the vw tdi was simply the vnt vanes sticking. With the boost control methods they never ever got stuck.

[robnitro]

Tucson, it's dangerous to get full boost on a tdi vnt below 1900rpm. The same surge issue would come into play with a single on our 35d engines if they are set up for mid/high end flow.

With compounds, you get the best of both worlds, which is why I think the bmw setup has less issues than the tdi's had.