Bilsport's pics of modding M90- any comments/translation?

[Captain Bondo]

Just noticed looking through morley's pics in ot that pukema has the original "turbocontainern" article!

Anyways there are pics of what I assume must be the slipring you weld up. It actually looks pretty accessible.

http://www.pukema.com/bilsport/container13-3.html

From what I can tell they are suggesting you weld that ring to the gear in the bottom right pic.

Any help? Morely? Wagner? etc?

Thanks guys!

Anyways looks like they had a hard time with the M90... although it also sounds like they ran a 3 puck sintered clutch disc and were prett heavy-handed with it.

[JW240]

Originally Posted by Captain Bondo

Anyways looks like they had a hard time with the M90... although it also sounds like they ran a 3 puck sintered clutch disc and were prett heavy-handed with it.

yeah they were very hard on the gearbox I think. Somewhere in the articles you see one of the guys writing down 'Be easy on the clutch' on a whiteboard, a lot of times. punishment

Originally Posted by Captain Bondo

...Anyways there are pics of what I assume must be the slipring you weld up... ...From what I can tell they are suggesting you weld that ring to the gear in the bottom right pic...

That is absolutely correct.

They say: "With a little bit of luck you have saved the broken gearbox from being thrown at the scrap yard, or saved a perfectly healthy gearbox from future disaster."

[Captain Bondo]

wicked. thanks! So it looks like you can get at it pretty easily with the rear half of the case removed... that is cool.

And yeah that picture is hilarious. Says something like "I will not sidestep the clutch" or something. lol

[Alex Buchka]

it basically says place the sync-ring on the gear as shown and burn it in with a mig, one gear tooth at a time, rotating all the time for cooling purposes etc. it also says to leave the case full of oil to stop any welding splatters from getting jammed inside the gearset and to aid in cooling the shaft whie welding. then just drain the case and re-assemble it.

[Captain Bondo]

Sounds like a good plan.
Although it looks like they shredded the M90 anyways. :eek:
The bottom right pic here isn't confidence inspiring:
http://www.pukema.com/bilsport/container17-2.html

Something about they hope is was tired or old... next box will be a rebuilt one... or something..

[Dfer10]

so welding that slip ring allows for what? handle like 500hp?

[Captain Bondo]

It's entirely a function of traction I think.

The "Jesus' 242" uses an m90 and makes something like 700hp. Autotech is putting 700-800hp through the M56- which is pretty much the same tranny just with a fwd casing.

However, I was reading about some RWD S40 racecar that was eating M90's laft and right with a slightly modded t6 motor (388hp) I don't know if they were modding the M90's though. They also broke several getrags however so I think the were pounding it pretty good. T6 motors are apparently hard on transmissions.

That car in bilsport was 400hp on slicks, and from what I can tell they were beating the ever-loving piss out of it running 11's when it broke. there is the slipring mod and a mod to the selector as well. I've also heard Steffanson sell brass synchros for them.
I think you could build one to hold 500hp provided you did show it do much disrespect. You could potentially break just about anything with 500hp if you try hard enough imo.

[Boosted2003]

Is it saying on the white board. No more side stepping?

[Captain Bondo]

yes. check a few posts up.

[Wagner]

When i did that, i couldn't do it exactly the way they did it in bilsport. I had to dismantle the transmission completely to have acces to that ring. (because a gear made it impossible to remove something, which made it impossible to remove something else. I don't remember the details, i have pics of this though somewhere).

It was easier to weld it that way though.

I'll try to find those pics and scan them over the weekend. Anyone wanna host them?

They broked the m90 by giving it alot ov revs and letting the clutch up fast. It was the 1st gear that let go, which usually does not break down on these trannies.

[U.N.C.L.E.]

Originally Posted by Dfer10

so welding that slip ring allows for what? handle like 500hp?

It just allows more violent use of the stick, keeping the sync-ring in place. Power handling stays the same.

The m90 is over-rated here on the board. Get a 265 or higher instead

[Captain Bondo]

Ok thanks wagner! yeah if they broke first gear that was just due to be psychotic for sure.

I'm tempted to pull the rear part of the case off today and do some exploration...

Uncle, my understanding is that the majority of M90 failures occur from a partial/poor engagement into 3rd gear and then applying power, or breaking the selector fork again becuase of poor synchro engagement. The modification tends to ensure that 3rd gear engages correctly during a fast shift, so yes you can be more violent as you say, but I think that indirectly represents the box being able to hold more power as it is the shoddy engagement that creates a weak link most of the time.

As I mentioned with that RWD S40, they broke M90's and tried getrags and broke them too. I think if you're capable of breaking one, you're capable of breaking the other for the most part, but new m90 guts are cheaper at least for me. Although there are plenty of modifications around for both boxes so comparisons are tough.

But short of bilsport stripping 1st gear, the 7 or 8 M90 failures I've seen documented were all related either to the slipring on 3rd gear or the shifter fork itself (which itself may have failed due to a jam up caused by the slipring).


If you are breaking M90's independent of the shifter linkage itself, I honestly think a T56 is your only hope for a street car. Even tremecs that are supposed to be "street boxes" shift like garbage and are very expensive. T56 is about the only OE quality box that will hold the juice. But that is an expensive piece as well along with some seriously custom gear to fit it (It'd be shocked if it clears a 240 trans tunnel).

It might become the only option but they're just so huge and heavy.

[blu92in99]

Originally Posted by Wagner

I'll try to find those pics and scan them over the weekend. Anyone wanna host them?

If you don't have a pic host yet, email 'em to me. I'll host them on my pbase account.

blu92in99 (at) yahoo.com

-or-

jhinkley (at) alldata.com



-Justin

[acbarnett]

Originally Posted by Captain Bondo

It might become the only option but they're just so huge and heavy.

you're telling me lol

I helped a friend drop and reinstall the t56 on his +T'd 2002 WS6 trans am last wednesday for a clutch change, that is a seriously large and heavy piece of machinery...

I'm just going to plan on the m90 for now out of ease of installation, if I break it, hopefully an adaptor plate for a t56 won't be too hard to make, I'm thinking you could possibly use an AW30-40 bellhousing or something.

[Hank Scorpio]

Originally Posted by Captain Bondo

It's entirely a function of traction I think.

The "Jesus' 242" uses an m90 and makes something like 700hp. Autotech is putting 700-800hp through the M56- which is pretty much the same tranny just with a fwd casing.

However, I was reading about some RWD S40 racecar that was eating M90's laft and right with a slightly modded t6 motor (388hp) I don't know if they were modding the M90's though. They also broke several getrags however so I think the were pounding it pretty good. T6 motors are apparently hard on transmissions.

That car in bilsport was 400hp on slicks, and from what I can tell they were beating the ever-loving piss out of it running 11's when it broke. there is the slipring mod and a mod to the selector as well. I've also heard Steffanson sell brass synchros for them.
I think you could build one to hold 500hp provided you did show it do much disrespect. You could potentially break just about anything with 500hp if you try hard enough imo.

Actually Jesus isn't making 700whp and the M56 is not as similar as you'd think.

[Hank Scorpio]

Originally Posted by acbarnett

you're telling me lol

I helped a friend drop and reinstall the t56 on his +T'd 2002 WS6 trans am last wednesday for a clutch change, that is a seriously large and heavy piece of machinery...

I'm just going to plan on the m90 for now out of ease of installation, if I break it, hopefully an adaptor plate for a t56 won't be too hard to make, I'm thinking you could possibly use an AW30-40 bellhousing or something.

I think either using the AW bellhousing then adapter or adapter then a chevy/ford/bimmer/whatever bellhousing are about equally "difficult".

Doing a hydrallic clutch though with the AW bellhousing looks to be hte easiest imo.

[mAydAy]

Originally Posted by Captain Bondo

If you are breaking M90's independent of the shifter linkage itself, I honestly think a T56 is your only hope for a street car. Even tremecs that are supposed to be "street boxes" shift like garbage and are very expensive. T56 is about the only OE quality box that will hold the juice. But that is an expensive piece as well along with some seriously custom gear to fit it (It'd be shocked if it clears a 240 trans tunnel).

It might become the only option but they're just so huge and heavy.

Last picture is the car it resides in. Ask Ravennexus about it, he knows the guy and knows more about the car. The T56 does fit, not sure what it takes, but it does fit.

[Captain Bondo]

"Actually Jesus isn't making 700whp"

Oh, got me. "Only" around 600hk to the wheels.
The spirit of it was that it's enough power for the vast majority of projects out there.


"and the M56 is not as similar as you'd think."

Care to elaborate?
I've just looked at my M90, and I've had a couple M56's apart, and most of it looks the same- the mainshaft part is a bit decieving because it is seperate from the output shaft- the driveshaft output flange in the case of the M90 rides in a bearing in the rearward half of the case, and is then driven by the mainshaft- it's where the mainshaft on an M56 interfaces to the diff. The input shaft is different in a similar way, but the back end of the mainshaft and the front end of the countershaft sure look the same to me.

So they look very different, but from what I can tell the main and countershafts are identical except for the ratios (which are the important pieces unless the input shaft brakes- in which case you're SOL ). You can sorta tell by how the rear casing half of the M90 comes off in such a bizarre fashion as opposed to just about any "normal" tranny that volvo, being the typical cheapasses they are, did not change much at all, and it's modular in the same way the motors the m56 and m90 were bolted to.

I obviously can't be 100% on this as I haven't had them both apart on the bench side by each with a micrometer, but I have seen both sets of guts firsthand and they look like they interchange. But have if you have measured them or talked to someone who has, cough it up Dougie!


The AW bellhousing is nice in that it's a whole lot smaller than the t56 one which might mean less firewall destruction. However, as you know the AW BH is very "deep", typical of an auto BH because it has to house the TC, but the T56 has a very shallow bellhousing and a short little nubbie of an input shaft, so it might take some funy pilotbearing monkeybusines. The typical approach of using a motorplate insures that at worst you're only short by the plate thickness, depending on where the crank snout ends relative the the BH mating surface anyways.

Also sorry if I implied it wouldn't fit, I certianly didn't mean to I totally think it will I just meant it might take modding the tunnel some. Look at that big bastard! seeing it on a redblock gives a unique sense of scale. Pretty sweet.

[linuxman51]

HAHA anyone else notice in the pic where hes writing on the board the *other* broken part?

Goddamn torque rods!

[Hank Scorpio]

Im just going with who I've talked to in the know. Mikey @ Atech has dabbled with both. The m90's are only consistent for about 350-400whp according to Mike in stock form, the M56 with a LSD haven't broken for them yet.

I thought the 16vT car of Jesus was only putting down mid 5's and the I6 was undyno'd as far as I know.

[Captain Bondo]

Sounds pretty fair- although I'd imagine the gap in power threshold between m56/m90 might be the traction thing again- pretty different platforms between the FWD and RWD of course so IMO it's tough to say the M56 is stronger literally, although the ratios are different so maybe the gearset itself *is*- but even still it looked physically interchangeable design-wise at leats to me. That'd actually be pretty sweet if it were the case, as we got M56's up here in pretty ho-hum cars that get written off all the time.
Probably worth buying one just for a backup in the future, and if it's different I'm sure it'd sell to someone wanting to do a conversion.


Ah well I'll cross that bridge when I come to it- whenever that ends up being. Actually, hopefully I won't have to cross that bridge and it'll just behave.

There are two dyno graphs on Jesus' site, a low boost one and a high boost one, I think maybe the low boost one is mid 5's, but the high boost one is 595hk which I think is just over 600 north american horsepower.

[acbarnett]

Originally Posted by Snoop Dougy Doug

Im just going with who I've talked to in the know. Mikey @ Atech has dabbled with both. The m90's are only consistent for about 350-400whp according to Mike in stock form, the M56 with a LSD haven't broken for them yet.

I thought the 16vT car of Jesus was only putting down mid 5's and the I6 was undyno'd as far as I know.

so what about the shift gear reinforcements, what would that bring the power handling abilities to?

[Hank Scorpio]

I thought about that too, but the 800+ hp car was launching on wrinkle walls M/T's It stripped the splines off the axles but no real harm to the trans yet.

Course the wrinkle walls might absorb some of the harsness of a launch, but 800hp is 800hp.

[acbarnett]

yeah, I'm aiming for only 400 wheel for daily driving with the potential for 500 wheel. It's just that running at the absolute limit of the tranny's capacity gives me the bigtime willies.