T-56 Update

[viperbluelx]

If you swap from a T45 which has I think a 3.35 1st gear ratio to a Viper or 03-04 Cobra T56 with the 2.66 1st gear ratio it's gonna KILL your track times unless you change the rear end gear. I guess if you don't take the car to the track ever you can live with it though. I have the 00R spec T56 with 2.97 1st and 4.10 gear and even it feels weak in 1st compared to a T45 or 3650.

 

[CY98Cobra]

I don't go to the track so the 2.66 gear doesn't bother me any. Probably would make a difference on a drag car, but the T56 isn't the best choice for the drag strip anyway.

 

[viperbluelx]

I hear ya, I was just stating that if you started out with say a T45 and a 4.10 gear like a lot of blown Cobra's and then you swap to a 2.66 geared T56 you would need a something around a 5.13 rearend gear to have the same effective gear ratio you had before the swap. Like I said, no big deal if you don't run the car at the track. But seen a guy with a 5.0 car make the mistake of swapping from a T5 to the new TKO600 which has similar 1st gear ratios as the 2.66 1st T56 and he lost 3 tenths in the 1/8th without any other changes. He pulled it back out the next week.

 

[notchstang92]

You guys are swapping both the pinion flange and the driveshaft coupler on the rear to make things work. I ran part #'s thru ford and the coupler is different, but the flange on the IRS is the same # for a 2001 & 2003 according to the dealer. Can anyone confirm this?

 

[Quadcammer]

what a coupler is, I don't know.

The pinion flange is what I changed, but then again, I have a 98 cobra rear.

The 03 flange is huge compared to the earlier models.

 

[notchstang92]

in the ford database they call the coupler the piece that attaches to the rear U joint of the drivshaft. The flange bolts to the IRS and appears to be held in by the pinion nut. I only have the 03 coupler because it is different than the 01. The part #'s are the same in ford for the part on the IRS.

 

[Quadcammer]

ah, so basically your saying that the coupler sits on the ds and bolts to the pinion flange.

I had a custom DS made, with the correct coupler installed, so all I needed was to swap pinion flanges.

 

[notchstang92]

do you know the diff between your 99 flange and the 03 one?

 

[Quadcammer]

it was pretty substantial.

The bolts failed to line up by about 1/4" on all sides

 

[notchstang92]

thats what I needed to know. thanks for your help.