MA5 5-speed to 5.7 hemi?

Mopar to ya said
I am going to let my brother in on this post. He has a 5.7 Hemi project and he is rethinking it because the tranny is so expensive. This may be another way to get the job done, and it is going into a Little Red Express clone. Lots of room. Good info here!

The more the merrier!

DionR said
Couple of thoughts.

In regards to the gear ratios, The newer Mustang GT's with the 6 speeds (MT82, not the T-56 derivatives) run a 3.66 first gear, and a 3.55 final drive. That gives a 12.993 SLR, for comparison. The ratio spreads are better on that trans, though, as the GT get's a 1:1 fifth, so more spaces to spread the drop over. On the MA5, the splits are about 40%/40%/27%/27%. For reference, the standard A833OD has a 45%/40%/27% spread. So, in theory, a 1-2 shift and 2-3 shift on the MA would feel like a 2-3 shift on an A833OD. And the TKO-500 and R154 both have about a 40% drop from 1-2, too.

In regards to the flywheel, I know of one person that has relocated the pocket on the 3.9 bellhousing to work with a 130T flywheel. That is my plan for my R154 swap (if I ever get to it), and I got started on the layout for a jig, but haven't finished anything. I was working on building a plate based on a 727 bellhousing that would use the motor to bell holes to locate the starter pocket holes correctly. Then I was going to cut the pocket out, use the plate to locate it, and get it welded back together. Just an idea, but it would make it easier to find a flywheel. And it would solve some issues with the starter you will have to deal with since it is farther out into an area that is already way too tight.

Lastly, I would talk to Spec or someone about a clutch. They did a custom clutch for me when I was going to run my R154 behind a turbo slant. Built me a Stage 3 clutch that was the right diameter and splines to match up. Don't remember the price (it was a group buy on Slantsix.org), but seemed reasonable. Too bad it was a complete waste of money as the car and the project is long gone. Either way, they should be able to build you a 10.5" or 10.95" clutch to fit a standard 5.7 swap flywheel, and put the right splines in it, and I doubt you will need a Stage 3 to make it work, either.

I'm not really interested in relocating the starter just to use a slightly smaller/lighter flywheel, it seems like too much work for the payoff. The 11" will be fine and I can just make sure it is drilled for a 10.5" clutch.

DionR said
I might add that the AR5 in the Solstice (MA5 is a Colorado trans) has a slightly different gear spread with a 1.51 ratio for third. This makes the gear drops 40%/33%/34%/27%. Plus the AR5 is supposed to have a shotpeened 1st and 2nd gear.

Also, the Colorado MA5 has a different shifter setup than the Solstice AR5 and might be difficult to swap into the car. I looked at this once and wasn't able to figure it out for sure, but I think the MA5 shifter is right about where the crossmember is on the A-Body. (not the best location) while the AR5 is a divorced shifter (and might be too far back).

And the MA5 was considerably cheaper than the AR5 the last time I looked.

I'm aware of the different 3rd gear in the Soltice. The remote shifter I suspect will definitely be too far back and I don't really think the gearing of the Colorado trans is that bad. I understand it has some deeper rpm drops but the way I intend to use this car will be geared towards a flat torque curve and relatively low rpms(6k rpms +/-) as I don't intend to upgrade the shortblock and I want to be able to beat on the engine.

magnumdust said
I think you're shooting way too tall on the gearing. My DD runs 245/45/17s(25.8 tall tire). I've run 3.42s, 4.10s, and now 3.73s behind that transmission. At the track its done best with the 3.73s. It would never hook on street tires with the 4.10s.

Oh and just an FYI, these transmissions don't like powershifting, and grabbing 3rd at over 6000rpm is extremely hit or miss.(which is really frustrating when i'm winding the truck out to 7k in 2nd gear.

That's disappointing to hear about the issues with high rpm shifts but as I stated above I don't intend to take the engine much further than 6k. I'm certainly open to any suggestions on gearing, I just don't want first gear to be useless on the street.

magnumdust said
sorry, the Ma5. If you look at TKO builds, they all hack that center crossmember because the shifter comes up right in that area. The T5 is just slightly forward, but most of it needs to be notched anyways.

Any pictures of this? That does seem a ways back further than I expected and I'd like to be able to use a stock 4-speed console...

Greg55_99 said
This pic is from the Pirate 4X4 site of an AX15 input shaft on the left:

I think you'll be OK. Just grind the tip of the MA5 down a bit.

Greg

That's what I figured Greg, thanks for looking into it.