For those running a getrag and 6-speed rear end
09-20-09, 08:26 AM
#1
Lead Lap
Thread Starter
For those running a getrag and 6-speed rear end
Greetings,
Through the 8+ years I've been working on my car, I've been through many different driveshaft combinations; some worked and some didn't. The common theme for all drivelines I've installed, however, is utilizing the flex coupler between the differential and driveshaft. It's a level of protection against breaking parts I believe works.
With that said, however, I bent everything at the drag strip on my last outting - including both rear axles and a modified GX470 DS. Fortunately, nothing actually broke.
Anyway, the point of this thread is that I'm going back to a modified TT 6-speed driveshaft, and I wanted to post up the measurement for extending the aft shaft. It should be lengthened between 5 1/2" and 5 9/16". I have an old one in the car now and just purchased a new TT driveshaft for comparison. Consequently, it's a direct measurement you can count on.
Just wanted to post the number for the record in case others might need to know.
Later!
-scott
Through the 8+ years I've been working on my car, I've been through many different driveshaft combinations; some worked and some didn't. The common theme for all drivelines I've installed, however, is utilizing the flex coupler between the differential and driveshaft. It's a level of protection against breaking parts I believe works.
With that said, however, I bent everything at the drag strip on my last outting - including both rear axles and a modified GX470 DS. Fortunately, nothing actually broke.
Anyway, the point of this thread is that I'm going back to a modified TT 6-speed driveshaft, and I wanted to post up the measurement for extending the aft shaft. It should be lengthened between 5 1/2" and 5 9/16". I have an old one in the car now and just purchased a new TT driveshaft for comparison. Consequently, it's a direct measurement you can count on.
Just wanted to post the number for the record in case others might need to know.
Later!
-scott
You must be launching pretty good to be bending some one pieces.
09-20-09, 10:45 PM
#4
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I'm using an TT Auto pumpkin, TT Auto axles, and a Getrag. When I did the swap, I used the stock TT driveshaft, but got it lengthened and retubed to deal with the additional power. I'm right at 700whp, and it's held up just fine for me both on the street, and at the drag strip. Now the pumpkin and ****ty *** Carbonetic triple disc clutch, not so much.
09-21-09, 04:18 AM
#5
I'm using an TT Auto pumpkin, TT Auto axles, and a Getrag. When I did the swap, I used the stock TT driveshaft, but got it lengthened and retubed to deal with the additional power. I'm right at 700whp, and it's held up just fine for me both on the street, and at the drag strip. Now the pumpkin and ****ty *** Carbonetic triple disc clutch, not so much.
09-21-09, 05:31 AM
#6
Lead Lap
Thread Starter
Also FWIW, I'll be replacing both tubes in the DS similar, if not identical, to this driveshaft: http://www.supraforums.com/forum/sho...6&postcount=10
TTSC3: Early on, I had the 3.73 gearing (TT auto diff) with the 6-speed, and the gearing was too high for my taste. I'm currently running the JDM ring/pinion (3.26 gears), and I'm really happy with the result. Have you tried a 3.13 or 3.26 rear end?
-scott
Last edited by motorheaddown; 09-21-09 at 05:34 AM.
09-21-09, 07:07 AM
#7
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i thought i remembered reading somewhere that its a bad idea to be using a 6 speed with an auto rear end, but for the life of me i can't remember why. lemme see if i can find a linky
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09-21-09, 08:49 AM
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The gearing in the car sucks with the TT Auto pumpkin and the 6spd. In fact, the TT Auto pumpkin just sucks all together. I already blew one up at the drag strip on the first launch, and had to replace it. I can't fine a 6spd pumpkin for the life of me, and I was in a massive time constraint, so I had no choice but to repair the one I had. I actually did all of this last week, and ran out of time, because the car got shipped to California for the TV show "Bull Run", on Speed Channel. That's actually where it is right now competing, and now in day 5 of the competition, so the SC is still representing! Try to win one for the SC's and CL. Haha.
Anyway, the gearing on the 6spd is much better. You have to shift into 5th in the 1/4 with the Auto pumpkin, and on the dyno, 4th gear only takes you to 117mph at almost 8k. The 6spd would be at 130+, so that's a big difference. When you couple that in with the fact that the 6spd pumpkin is just much stronger, there's really no point to the Auto when using a 6spd. I just got ****ed because I couldn't find one.
Anyway, the gearing on the 6spd is much better. You have to shift into 5th in the 1/4 with the Auto pumpkin, and on the dyno, 4th gear only takes you to 117mph at almost 8k. The 6spd would be at 130+, so that's a big difference. When you couple that in with the fact that the 6spd pumpkin is just much stronger, there's really no point to the Auto when using a 6spd. I just got ****ed because I couldn't find one.
09-21-09, 10:47 AM
#9
Also FWIW, I'll be replacing both tubes in the DS similar, if not identical, to this driveshaft: http://www.supraforums.com/forum/sho...6&postcount=10
I've seen that before. It always amazes me that you can modify the hell out of that d/s and never have a problem with the carrier bearing. I was trying to do something like this when I had a custom D/S made for the R154 swap, but for the life of me could not find anyone that could balance it after they did that. So I ended up having a custom companion flange on the rear diff made to fit your everyday Ford U-Joint, mated that to a one piece aluminum. Boy did I have some wobble though. Ugh.
09-21-09, 11:29 AM
#10
Lead Lap
Thread Starter
I've seen that before. It always amazes me that you can modify the hell out of that d/s and never have a problem with the carrier bearing. I was trying to do something like this when I had a custom D/S made for the R154 swap, but for the life of me could not find anyone that could balance it after they did that. So I ended up having a custom companion flange on the rear diff made to fit your everyday Ford U-Joint, mated that to a one piece aluminum. Boy did I have some wobble though. Ugh.
-scott
09-21-09, 01:17 PM
#11
Actually, my 60' was pretty good - 1.64s. Boost on the two-step with anti-lag was about 22 psi; so, there's plenty of room for improvement. I just don't want to trash the driveline getting there.
Try using a brand new driveshaft; that's what I'm resorting to. Most DS shops can't balance an old shaft because the u-joints are worn based on the u-joint angle. Once the shaft has some mileage on it, the u-joint develops a "notch" for any off-angle rotations. It's nearly impossible to balance an old shaft because of the notch. A new driveshaft won't have that problem.
-scott
Try using a brand new driveshaft; that's what I'm resorting to. Most DS shops can't balance an old shaft because the u-joints are worn based on the u-joint angle. Once the shaft has some mileage on it, the u-joint develops a "notch" for any off-angle rotations. It's nearly impossible to balance an old shaft because of the notch. A new driveshaft won't have that problem.
-scott
I meant that I wanted to make the piping larger on the stocker, and have it extended at the same time, still using the carrier bearing. I couldn't find anyone that could hook the stock d/s up to balance it, as soon as I said Lexus/Toyota driveshaft, it was instant no. So I had to resort to a one piece. Nice times on the 60' though, best of luck with everything and keep us updates. It's nice to have some serious performance discussion and modification around here once in a while.
09-21-09, 02:26 PM
#12
Nice info to have Scott. Appreciate the measurements!!
Ryan
Ryan
Greetings,
Through the 8+ years I've been working on my car, I've been through many different driveshaft combinations; some worked and some didn't. The common theme for all drivelines I've installed, however, is utilizing the flex coupler between the differential and driveshaft. It's a level of protection against breaking parts I believe works.
With that said, however, I bent everything at the drag strip on my last outting - including both rear axles and a modified GX470 DS. Fortunately, nothing actually broke.
Anyway, the point of this thread is that I'm going back to a modified TT 6-speed driveshaft, and I wanted to post up the measurement for extending the aft shaft. It should be lengthened between 5 1/2" and 5 9/16". I have an old one in the car now and just purchased a new TT driveshaft for comparison. Consequently, it's a direct measurement you can count on.
Just wanted to post the number for the record in case others might need to know.
Later!
-scott
Through the 8+ years I've been working on my car, I've been through many different driveshaft combinations; some worked and some didn't. The common theme for all drivelines I've installed, however, is utilizing the flex coupler between the differential and driveshaft. It's a level of protection against breaking parts I believe works.
With that said, however, I bent everything at the drag strip on my last outting - including both rear axles and a modified GX470 DS. Fortunately, nothing actually broke.
Anyway, the point of this thread is that I'm going back to a modified TT 6-speed driveshaft, and I wanted to post up the measurement for extending the aft shaft. It should be lengthened between 5 1/2" and 5 9/16". I have an old one in the car now and just purchased a new TT driveshaft for comparison. Consequently, it's a direct measurement you can count on.
Just wanted to post the number for the record in case others might need to know.
Later!
-scott
