SR55S tranny

[justbob]

I've posted this before and no one really bit on it but in your opinion what would it take to get this 5r55s five sp. auto tranny from a 05-07 mustang GT to work in our cars? My Friends Gt is a blast to drive, no matter the speed there is always a right gear it seems. The tranny itself should bolt right up and i would imagine the stock flexplate from the mustang (if its not allready the same as ours), and probably the stock starter for our cars. The drive shaft i'm sure would have to be custom made which is no big deal along with some creative customizing for the crossmember. The part i definately don't know anything about is the computer and what it would take to get this thing into 5th gear. The shift points could be changed on our computers and the speedo, but no 5th gear. Am i on the right track? Would there have to be some kind of a stand alone computer just for the tranny? And last but not least the shifter???? This tranny would be killer behind a trilogy. This is a route that i'd like to try in the near future, but i'd like to research it as much as i can first so there won't be too much down time and to also try and have most of the parts ready to go. Any ideas???

[HotRodMercury]

trade your marauder in for a mustang problem solved, wish it dint have to go that
rout.

[justbob]

Family of five, a gear for each = five speed Marauder...
And oops i was tired when i wrote this, it was supposed be be in Alternative Auto's forum.

[rumble]

What are the gear ratios on the speed auto?

[justbob]

5R55S 1st 2nd 3rd 4th 5th
3.22 2.29 1.55 1.00 0.71

4R70 1st 2nd 3rd 4th
2.84 1.55 1.00 0.70

Basically you would be adding a hell of a launch gear and a strong second gear also but achieve nothing more or less for highway. This would make the perfect application for n/a or s/c with the right t/c and gear.

[Marawder]

I've wondered the same thing and would love to put this tranny into my own. It would be so much better at Mosport with the extra gear as I seem to run out of RPM at 3 different locations, where going from 2nd to 3rd would just be too much. It would make the car so much better around town too, by avoiding that huge drop on the 2-3 shift.

[ctrlraven]

My friend picked up a 2008 Mustang GT and said he loves the automatic transmission, it always feels like it's in the powerband and glad they geared it a lot better.

If it bolts right up I guess the next step would be figuring out how to control it. I would think that some stand along system would need to control it or piggybacked onto out current ecu. I would like to do this also cause I have a friend who already took his out and swapped in a 6 spd manual trans and would give it to me for free.

Zack you need to figure something out for this lol.

[justbob]

bump bump....

[Bradley G]

I hear ya on the ratios and the RAR but T/C?
splain that ?
5R55S 1st 2nd 3rd 4th 5th
3.22 2.29 1.55 1.00 0.71

4R70 1st 2nd 3rd 4th
2.84 1.55 1.00 0.70

Basically you would be adding a hell of a launch gear and a strong second gear also but achieve nothing more or less for highway. This would make the perfect application for n/a or s/c with the right t/c and gear.

[justbob]

Not sure what torque converter we would want to run for optimal power with a totaly new first gear in our 4200# cars.

[TooManyFords]

Baumann makes a controller for the 4R70, maybe they are working on one for the 5r55?

[justbob]

Would be worth looking into John, thanks. Bob