Well guy's I been watching this thread with interest ! and some of the questions that 70MACH1OWNER has asked have come from a on going conversation we have about pinion angle on lowered S197's installing a one piece drive shaft . 2 days ago I installed the Shaftmaster 4'' aluminum drive Shaft with the adapter plate. I have Saleen Race Craft springs with a 7/8'' drop all the way around ! Understanding that are suspensions move in in arched motion verses a straight linear motion I felt that basically a 1'' drop would not have that drastic of a effect on the pinion angle. Side note: I do have J&M lower control( none adjustable) arms and believe me after removing the factory LCA's you do realize how poor these pieces are, the factory LCA that was on the passenger side was making contact with body at the body mount point! before I installed the Shaft I also installed a J&M adjustable UCA just in case I would need to adjust the pinion angle. The J&M adj UCA comes preset at the same setting as the factory UCA 8.3/8 '' so I left it at the factory setting. After I removed the Factory Shaft I took angle readings at the trans flange and the pinion flange, with a Craftsmen magnetic protractor trans flange was -4.0 degrees and pinion flange was basically -.5 degrees I installed the Shaft and did not adjust the pinion angle what so ever, then checked the shaft angle its self, it was basically 3.9 degree's. I have tested the car up to 95 mph with absolutely no vibration! I mean none, in fact over all drive line is much quieter than the factory shaft.

 

Good info STD. I never noticed the driveline being any quieter after my DS install but I guess I could see that it might get quieter because the factory shaft has that mounting point to the body and it could transmit some NVH. So in makes sense it could be quieter with a 1 piece DS.
Scott

 

Here's what I got which coincides pretty much with blackstang06's results:
lowering from my original stock ride height
-.5" = .25degrees or less(basically no change)
-1.0" = .5degree change
-1.5" = just under 1.0 degree change
-2.0" = 1.5 to 1.75 degree change
-2.5" = 2.25 to 2.5 degree change
these were all checked and rechecked several times to ensure accuracy and no other changes were performed.
My car is equipped with a steeda adjustable UCA and billet lowers and my traction bars were not installed for this test.
hope this helps

 

Hey Ron,
Thanks for taking the time and effort to get these numbers for us. You numbers are about 1/2 of my calculated numbers. I am glad you took the time to get anyone those pinion angle numbers for lowering these stangs. It is hard for me to believe with the numbers you are posting that these slight P/A changes could be that big of deal to anyone changing driveshafts. Regardless of brand. Thanks for all the hard work Ron!!
Scott

 

Ron, thats good hard data for anybody installing a one piece drive shaft on their Stang. Ron your thoughts on the possible benefits of increasing the negative ( down ) pinion angle to create some more drive shaft clearance in the drive line tunnel to avoid contact issue's like the one tacobill experienced on his 4'' drive shaft would be appreciated....

 

How much of a change can you have and not have to worry about it?

 

Ron also I noticed you stated you where running a adjustable UCA I was wondering what degree of pinion angle your running your Stang at...

 

I've had customers report that as little as 1/2 turn on the UCA made a noticeable difference in performance. I'm not sure why these cars are so sensitive but it seems the V6 cars aren't as prone to these problems (heck they have a one-piece from the factory) which leads me to believe most of it probably has something to do with the differential since they do not share the same unit as the GT. Mine is currently set at -2.5 degreees. I've had my car dropped over 2.5" with the coilovers using all the stock control arms and didn't have any clearance problems with the tunnel. However when i replaced the LCA's with an aftermarket set (which i believe were a little shorter than stock, not steedas) and still had the stock UCA it did cause a rub on hard launches with slicks. I switched over to the steeda UCA and LCA's set the P/A and it was fine...I did raise mine up an inch so my doors don't hit the trailer fenders when i open them after loading up but even with my buddies in the back seat it's fine now and they are short and fat.

 

Thanks Ron, Yep! the V6's come with the 7.8 differential and I have noticed the The V6 has a lower ride hight in the rear out of the factory ! but the GT Verts seem to have a lower factory ride hight than the Coupes do ! So your running -2.5 at the pinion flange, your current rear ride hight is 1.5 ?.........