3.27 or 3.42s?

[Packenstine]

Just wondering which ratio they used in the TTA?

 

[TTA984]

3.27 ratio. It is on the small tag. Jan's 4th pic.

http://www.turbotransam.com/forums/showthread.php?t=6789

 

[Packenstine]

TTA984: Those tags are not original to his car.

Was there any discussion with the guy from PAS why 3.27 was chosen over the available 3.42 ratio? The TTA would have been just a touch more awesome with 3.42s.

 

[robert lee]

TTA984: Those tags are not original to his car.

Was there any discussion with the guy from PAS why 3.27 was chosen over the available 3.42 ratio? The TTA would have been just a touch more awesome with 3.42s.

They where set-up more for top-end speed vs 1/4 mile...

 

[jarredsoon]

I have 3.42 in my new moser 12 bolt and it is a touch more awesome for sure.

 

[pont1230]

they should have gone with the 3:42 from the factory like the gn instead of th 3:27 my opinion

 

[TTA984]

They had two things in mind when they put the TTA together. To pace the 73rd INDY 500 and second to be a 20th Aniversary Trans Am. I am sure a lot of thought went into what ratio of rearend to use. Maybe other ratios were tested and the 3.27 was the most suited for the wide oval track.:beach:

 

[tta299]

3.55 's in the 9 inch with 33 spine axles

 

[TTA984]

TTA984: Those tags are not original to his car.

Was there any discussion with the guy from PAS why 3.27 was chosen over the available 3.42 ratio? The TTA would have been just a touch more awesome with 3.42s.

I have the original 2 differential tags on my TTA. Looks like they have never been removed. The smaller left tag has different numbers that the one Jan is showing, those I believe are off Jarredsoon's car.

On mine the numbers are: P/N 10079888 and the 4 digit number is 1007.

 

[jarredsoon]

yes I sent Jan some tags a while back.

 

[Jan Larsson]

Those photos are some I was sent years ago to have as reference when looking for some nice once for mine ... they should be off a TTA as well.

As the TTA had two different rears (due to the change of the design; dust shield and brackets) the part number on that tag would differ depending on which rear it originates from ... I have to look up the part numbers but any TTA up to no 1000 something have the first version and the rest have the second version.

So Mike's car being no 984 would have the first version so part number should match that one ... and possibly the photo I posted were from a later TTA ... I'll check and post up my findings.

 

[TTOP350]

I think there is a thread on the backing plates on .org someplace. Thinkn' it was narrowed down to a month or 2 of the switch.
Heck I have 2 89 formula 350s and they both have different backing plates on the 9bolts. Not very far apart on the VINs..

If they wanted more gear for the TTA in 89, I'd bet it would have gotten the 3.45 that the 305 5spd TPI cars got.

 

[Jan Larsson]

I think there is a thread on the backing plates on .org someplace. Thinkn' it was narrowed down to a month or 2 of the switch.

Here's the post I did on this topic and figured it all out some time ago:
Question on the TTA BW rear end .. two versions? - Turbo Trans Am Forum

 

[TTOP350]

I figured you had a better grip on it. I think the backing plates were swapped to the heavier design due to a TSB on light brake pedal psi while backing up making a moan thru the car..
Here is the link to the thread on .org
http://www.thirdgen.org/techboard/history-originality/593125-rear-dust-shield-question.html