MyE28.com DEV

I am very interested in keeping my 535i an automatic. The problem is we are building a turbo charged system and I don't think the original transmission will take the Turbo Beating.

Are there any suggestions for an Automatic swap that could endure and rapidly handle 450/500 horse power? Oh by the way we are going to a much lower gear in the rear end so 5 speeds would do wonders.

Since most of the guys here are emphatic automatic transmission haters, I doubt you'll get any suggestions other then the 5 speed swap one.

Maybe drop these guys a note.
http://www.importperformancetrans.com/index.shtml

E23 745s were automatics. There are a few people who have kept their cars automatics for turbo. It's not an unreasonable expectation.

Good & Tight recently put a modded C4 in his E30. I believe he is pushing way more than 500 HP.

http://www.mye28.com/viewtopic.php?t=39 ... &start=425

Rossler did a 4L80E with an M30 bellhousing, that would be the way to go for some serious power handling. Grab yourself a PCS controller and their six speed valve body with a 2.98:1 low gear set in the trans. Well, if you need an overdrive.

A C4 will take all the abuse you could probably muster just fine.

IPT seems well known in the Taco/Lexus/Volvo circles, well at least on the A340 stuff.

I wonder how much power a 4HP22/4 could hold with performance clutch material. If you choose to go with the EH, you will need a controller such as the Compushift (only direct swap one I have seen available).

Hope it gives you some ideas to get those gears turning in your head.

+1 on G&T, problem is you are looking to shell out some serious $$ for a transmission that can handle the torque... I forgot who it was on r3v that ran a turbo on a 4hp and it died at like 250-300 whp/wtq

You need to contact Paul Burke, he made me the whole conversion.

1:06 has a 10 sec pass
https://www.youtube.com/watch?v=K-Uqwlsh7VI

RondoAcapriccio wrote:+1 on G&T, problem is you are looking to shell out some serious $$ for a transmission that can handle the torque... I forgot who it was on r3v that ran a turbo on a 4hp and it died at like 250-300 whp/wtq

Any idea what failed? EH or non?

@TurboRichard

I have been running a 4hp22 (non-eh) & TCD 3k stall tq converter on my boosted application for about 3 years now. Granted I'm pushing around 300hp, it has held up to everything I've put it through. I'd be willing the bet they can withstand 400 for a period of time if an effective tranny cooler is added & the temps were monitored.

*note* I've literally beat the piss out of mine & its still holding up. Of course nothing lasts forever.

Hit Man X wrote:

RondoAcapriccio wrote:+1 on G&T, problem is you are looking to shell out some serious $$ for a transmission that can handle the torque... I forgot who it was on r3v that ran a turbo on a 4hp and it died at like 250-300 whp/wtq

Any idea what failed? EH or non?

Don't remember.. but I just googled automatic turbo r3v, and tacomans thread came up, he posted that it was beginning to slip or something.

Thanks for the reply. If I can turn anything further up I will report back.

Nebraska_e28 wrote:@TurboRichard

I'd be willing the bet they can withstand 400 for a period of time if an effective tranny cooler is added & the temps were monitored.

*note* I've literally beat the piss out of mine & its still holding up. Of course nothing lasts forever.

Yeah about 12 passes at the dragstrip.

I know the 533i three speed can take quite a bit of power and seems to be the most reliable of the automatics that were offered in the e28.

So what exactly breaks on the auto trans?
Are there clutches in the thing that burn out or what's the deal?

I've ran my 5spd DRY before howling like straight cut. Still handles all the power after years of abuse.

Yes, friction material (whether clutches or bands, 4HP22 uses clutches only) is what always seem to go first when I have killed automatics transmissions. Hard parts tend to fail once you can get the power to stress them at their limits.

My guess direct clutches are what fails first, as the clutch material burns due to heat input and steel plates can and do warp.

Think of your Getrag, would you use a stock clutch for a boosted M30? Not if you have any sense, as the torque input will overwhelm the friction material. Will it last for a while? Probably a bit then slip like crazy, same with an auto.

Seeing how a stock 8:1 'green' B34 musters about 150rwhp and a stock 4HP22 seems told hold 300rwhp decently, I would say that is not all that awful all things considered.

Then why not put in a domestic one.
Are they domestic trans do they have bigger clutches or why u think they can handle all the power?


They can't be that much money right? Wonder who makes adapters for them.

ohhh shiiiiiiiiii... Never mind...
http://www.cjponyparts.com/g-force-new- ... fgod4mcA0w

Just tossing in a domestic unit sounds easy, yet you have to be able to adapt the thing to the M30 bolt pattern. Luckily the 4HP22 has a detachable bellhousing. There are some transmissions supported by the JW Ultrabell (which I think is what Rossler installed on the 4L80E to then allow any bellhousing to mount to the adapter plate). The Ultrabell is pretty much a billet adapter ring that allows various transmissions to be mounted behind various motors...saaaay you want a TH400 behind your Ford FE, you would install the ring then their bell. Or a C6 behind a Chrysler RB, same deal. It is how TCI offers their 6X package.

Once that is accomplished, one has to figure out the crank spacing for the flexplate to attach the converter accordingly. Of course the cross member is different, driveshaft also. Piles of minutia then you would want a TCU to control the thing unless you go for a different until.



Aftermarket supports most performance oriented domestic units and common import units. Performance clutches are around, billet drums that hold an extra clutch or two on top of revised clutch packs with more clutches, billet planetary gear sets, billet shafts, stronger sprags, etc. Blew my mind what was available when I built the 5R110W in my PSD about 18 months ago, took a while to research all what I wanted and needed.



I emailed Alto to see if they could line a set of 4HP22 or 24 clutches with their Red Eagle material as opposed to the standard stuff. Seeing as how they already make the plates, maybe it would be easy.