MT2 six speed in my Fiero

355gonebad · Post by **355gonebad** » Fri Jan 13, 2006 6:05 pm

As most know I'm trying to get my hands on a G6 six speed and plan to tell how to put one in the Fiero. I would also like to make it a group effort and see how it goes. The MT2 six speed is made by opal and carries the 60-degree bell housing. I still cannot get one from GM yet but they told me to try out Opal. You can get all the Shifter hardware and cables at your local dealer at this time. Cables run about 120 bucks. I look forward to making this a easy alternative for the 4 or 5 speed and would like this thread to be a good info sharing one.

donk_316 · Post by **donk_316** » Fri Jan 13, 2006 8:22 pm

There was one for sale in the Old Europe mall maybe 2-3 weeks ago.

MNFatz · Post by **MNFatz** » Fri Jan 13, 2006 8:31 pm

I'm waiting on one of those to come through the local yard.

What's the deal with the gearing? I've heard 1st is worthless.

donk_316 · Post by **donk_316** » Sat Jan 14, 2006 10:25 pm

Dont get me wrong. I have nothing against the 6 spd tranny. I think it would be an awesome swap. All the acceleration of the 4.10 with the highway gears of the muncie-getrag

The Dark Side of Will · Sun Jan 15, 2006 1:06 pm

Sorry for letting that get out of hand. I was in Reno yesterday.
Anyway, I've pruned this thread back to its worthwhile content.

The MT2 (incidentally, this is formerly the RPO for the Isuzu 5 speed) is also known as the FGP-F40. FGP = Fiat/GM Powertrain and is a result of the late collaboration between Fiat and GM. I don't know about its European or Opal usage, but it first came to America in the Saab 9-3 Aero with Ecotec bellhousing pattern. It will, as we all know, be used in the Pontiac G6 GTP behind a 60 degree V6. This gives it the standard FWD bellhousing pattern that will allow it to bolt to V60/60's, 3800's, 4p9's and Northstars.

A good deal of discussion on this trans can be found in this thread on OE: http://www.fiero.com/forum/Forum2/HTML/059254.html

The transmission is rated for 300 ftlbs. This may or may not mean much. The 282 is rated for 200 ftlbs (or so I've been told), but handles 300+ without much trouble. Early T5's were rated at 300 ftlbs but broke if you put 301 through them.

The ratios as implemented in the Saab are a mixed bag. 3-6 are great and tightly spaced. 1-3 are terrible. The supposed "close ratio" 6 speed in fact has a significantly wider 1-2 split than the 282 and the same 1-2 split as the Isuzu.

Ratios:
1 3.77
2 2.04
3 1.32
4 .95
5 .76
6 .62

In the Saab I believe it had FD in the 3.91 range. That will change to 3.55 for the G6.

A.rchie has taken on the task of adapting this trans to Fieros and has laid out several of the technical obstacles here: http://www.fiero.com/forum/Forum2/HTML/059254-6.html

1) Axles......... No one expected this or who 'da guessed it. The axles & tri-pots used on the 6 speed are freekin' huge. The inboard Tpi-pot for example has a spline on it that is bigger than any other GM unit I've ever seen. This will have to be resolved to make ANY use of this trans. in a Fiero work.

2) Clutch Hyd. Line........ The G6 has a unique fitting (not like the one you saw earlier in this thread) that has to be adapted to the Fiero line. We also have to test line pressure to make sure the Fiero Master Cylinder can correctly operate the Hyd. T.O.B. the 6 speed uses.

3) Shift Linkage............ A Fiero shifter will have to be modified, shift cables found, brackets & levers designed & made. Then someone will have to make it all work together.

4) Trans. Mounts......... Yes transmission mounts will have to be designed that work with the 84-87 cradle & the 88 cradle.

5) Odometer Drive........ Just as it says. For an aftermarket speedo this will be easy, stock Speedo will be harder.

6) Clutch........... Guess what, the G6 transmission uses an Input shaft that has a different spline than any other GM car I've seen. So all applications of this transmission (except the 3.9) will require some clutch change. Also see #7 below.

7) Flywheel......... Remember the dual mass clutch I showed you earlier? Well because it is taller than a stock Fiero clutch it moves the spline on the trans input shaft farther away from the Flywheel. This will have to be addressed with a thicker flywheel. This will be easy to address on my V-8 swaps but much more difficult to address on the various other engines. But I have a plan.

Some of the things he says I don't think will be as much trouble as he thinks... the flywheel for instance.

355gonebad · Post by **355gonebad** » Sun Jan 15, 2006 4:08 pm

Thanks Will, I hope to get some diagrams from GM this week I think it will be not as hard to do also and do want this to be a helpful thread and not a trash one. I'm trying to find out the spline count on the axles and input shaft I do not see anything else being an issue. I will try to get some pictures also. We already know it will bolt up to most of the engine swaps and even the 5.3 in the future. I found a Pontiac dealer in FT Worth that is exited that I want to do this and I believe will give me all the help he can.

donk_316 · Post by **donk_316** » Sun Jan 15, 2006 4:54 pm

I think this is a way better idea than the NSX trany swaps.

crzyone · Post by **crzyone** » Sun Jan 15, 2006 7:10 pm

WCF rates the 5 speed NSX trani at 500hp+, so I imagine 400lb/ft or so? Who knows. It'll definitly be easier than the NSX trani, but I doubt it'll be as strong as the Honda trani.

I am interested in the 6 speed option, especially if it could live under 400-500lb/ft or so :thumbleft:

JamesCurtis · Post by **JamesCurtis** » Sun Jan 15, 2006 8:13 pm

Good job mods :thumbleft:

And best of luck with the conversion, it should be sweet!

txf · Post by **txf** » Sun Jan 15, 2006 9:37 pm

Mike and I spoke over the phone about this swap and the possibilities of shifter problems but with a cable system it really should be too hard to work through them. So we are eagerly waiting for information from GM to confirm our theories on the bolt pattern and spline count.

In all actuality Spline counts shouldn't matter too much as custom axles are almost a must in any tranny conversion. And using the Fiero outer joints with the 6 speeds inner joints with just axles made to fit should be all that's needed. The 6 speed clutch can be used and a flywheel can be drilled to match the 6 speeds pressureplate too. What else should be considered.

The Dark Side of Will · Mon Jan 16, 2006 1:21 am

355gonebad wrote:Thanks Will, I hope to get some diagrams from GM this week I think it will be not as hard to do also and do want this to be a helpful thread and not a trash one. I'm trying to find out the spline count on the axles and input shaft I do not see anything else being an issue. I will try to get some pictures also. We already know it will bolt up to most of the engine swaps and even the 5.3 in the future. I found a Pontiac dealer in FT Worth that is exited that I want to do this and I believe will give me all the help he can.

Use with the 5.3 FWD will require yet another bellhousing, as that engine requires a bellhousing mounted reverse rotation starter for FWD use.

355gonebad · Post by **355gonebad** » Mon Jan 16, 2006 1:53 pm

I did not realize that about the 5.3 what a shame I have one in my Avalanche and I love that motor and it gets 17 to 18 MPG in my big 4x4 on the HWY.
I got a GM part number for the six speed it is 12577789 and cost is $2,250.00 I was giving a number for the big boys at GM to call about getting some tech stuff I hope it pans out.

The Dark Side of Will · Tue Jan 17, 2006 12:38 am

GMPD doesn't list that. Not that that necessarily means anything.

355gonebad · Post by **355gonebad** » Sun Jan 22, 2006 12:35 pm

I had to get the part number from GM I'm still trying to get some tech info on it but for know I will have to run the five speed the Mutt laid down on me last night so I need to get it on the road again so I will hook the 3800SC up to the Five speed for now and hopefully get my harness built soon. I just hate to spend money on a motor that is coming out of the car soon anyway.