When/how did your factory 2 piece drive-line fail?

[skaarlaj]

Hello all, I'm on the fence of either spending the money on a 2 piece drive-line safety loop, or an expensive aftermarket 1 piece shaft in conjunction with a loop for a 1piece. I'm a stalled auto application that has managed (2) sub 1.6 60' times and usually in the mid-low 1.6's without any trouble of any sort yet, (maybe 40-50 passes like stated above).

I'm not buying into the performance benefits of the 1 piece, but if I'm tap-dancing around a probable failure, I'll surely consider the aftermarket drive-shaft. Also why we're on the subject of drive-lines, can anyone give a decent reason that the ford racing one is only recommended for manual transmissions with no mention of the auto?

So if you've managed to break a 2-piece factory drive-line, was it on a hard launch, powershifting, or something else and please also mention wether or not you're a manual or auto transmission. Thanks in advance.

 

[stkjock]

I'm not buying into the performance benefits of the 1 piece, but if I'm tap-dancing around a probable failure, I'll surely consider the aftermarket drive-shaft. Also why we're on the subject of drive-lines, can anyone give a decent reason that the ford racing one is only recommended for manual transmissions with no mention of the auto?.

research more then

So if you've managed to break a 2-piece factory drive-line, was it on a hard launch, powershifting, or something else and please also mention wether or not you're a manual or auto transmission. Thanks in advance.

I saw one personally snap on a GT500 at the track, it was on a 1-2 shift IIRC with DRs

 

[07 Boss]

Reduction in rotational mass is many times more beneficial than your standard weight reduction. Driveshaft, wheels, brake rotor weight all contribute to slowing you down. Reduction in these areas will make you quicker.

 

[skaarlaj]

Thank you stkjock, and 07 boss. Anyone have a stalled auto w/o a transbrake with a failure out there?

 

[stkjock]

Considering the shock to the drive train is not the same with an auto, unlikely there are many failures to find.

 

[JUSTA3V]

Mine flew apart at 450 rwhp. But I'm a stick. Look, just run it. It sounds like that's what you are leaning toward doing anyway.

Worry about a one piece when and if yours breaks.

How many auto failures would you need to find before you purchased a one piece?

 

[skaarlaj]

Mine flew apart at 450 rwhp. But I'm a stick. Look, just run it. It sounds like that's what you are leaning toward doing anyway.

Worry about a one piece when and if yours breaks.

How many auto failures would you need to find before you purchased a one piece?

Maybe more than 1, and I'd probably worry more about replacing it if it let go anywhere aside from a launch.

 

[RocketcarX]

There is no down side to a 1 piece DS, we're talking about 20 LB reduction or more in rotating weight, it's a big deal.
I would replace it not because of potential failure, but to simplify the car and drop weight.

 

[ponys197]

I replaced my 2 piece with an Axle Exchange 1 piece aluminum driveshaft and it was worth the money to me. Less weight , car felt more responsive and I saw a solid 0.10 decrease in my times.

I have the 5R55S with Trick Flow Pan and a Circle D 3C 3500 Multidisc stall. I am getting 1.75's to 1.73's 60ft times on 255/60/15 MT ET Street Drag Radials. I am still NA right now with @320HP at the rear. The Whipple goes on tomorrow.

IMO the 1 piece is worth every penny in what it adds to the car.

 

[skaarlaj]

I've read where 5.0 Brian ended up swapping in his original 2 piece while trying to figure out a vibration problem and he saw absolutely No difference in track times, he tested it again after he swapped the 1 piece back in, and again, no difference. So if we're not even talking about a solid tenth, I'm not sold on an 800$ pipe with U-joints or couplers on the ends, especially if there's no autos breaking them. By what I've read, if I was trying to be quick with a manual, I'd be more than sold already

Yes, I agree with the rotational weight savings, and understand the effect. We're talking a pretty tight / small circle at the end of the day. 20 pounds of static weight would probably be just as beneficial as 20 pounds of rotational weight savings in a 4" circle. The performance gains just haven't been proven to me from what I've read so far, aside from advertising.

 

[RocketcarX]

I've read where 5.0 Brian ended up swapping in his original 2 piece while trying to figure out a vibration problem and he saw absolutely No difference in track times, he tested it again after he swapped the 1 piece back in, and again, no difference. So if we're not even talking about a solid tenth, I'm not sold on an 800$ pipe with U-joints or couplers on the ends, especially if there's no autos breaking them. By what I've read, if I was trying to be quick with a manual, I'd be more than sold already

Yes, I agree with the rotational weight savings, and understand the effect. We're talking a pretty tight / small circle at the end of the day. 20 pounds of static weight would probably be just as beneficial as 20 pounds of rotational weight savings in a 4" circle. The performance gains just haven't been proven to me from what I've read so far, aside from advertising.

Simply not true, and as a serious drag racer, which you are, you should be chomping at the bit to shed 20lbs in any form.
In racing they say; "shave the ounces and and the pounds will come".
That pig needs a diet, my friend. They all do.
Next I would be looking at "littles" for the front wheel/tire combo as well.
The difference in the way the car will react will blow your mind.
Did you do the drag springs yet?

 

[skaarlaj]

Simply not true, and as a serious drag racer, which you are, you should be chomping at the bit to shed 20lbs in any form.
In racing they say; "shave the ounces and and the pounds will come".
That pig needs a diet, my friend. They all do.
Next I would be looking at "littles" for the front wheel/tire combo as well.
The difference in the way the car will react will blow your mind.
Did you do the drag springs yet?

I already have the skinnys on the front. The drag spring will be considered along with other suspension parts for a winter project. I'd like to just get the rear drag springs from BMR, but you have to get all 4 according to their site. My front already sits low enough for me and gets plenty of rise at launch.

 

[RocketcarX]

I already have the skinnys on the front. The drag spring will be considered along with other suspension parts for a winter project. I'd like to just get the rear drag springs from BMR, but you have to get all 4 according to their site. My front already sits low enough for me and gets plenty of rise at launch.

You're killing me Smalls, just do the springs already, as a set.
That is a promised reduction in ET from one modification, which seems to be the criteria here.

 

[07 Boss]

I wouldn't think it would be an issue getting two springs from them. I just bought the front gt500 drag springs to replace the CJ ones. Keeping the CJ rears.

 

[JeremyH]

The physics says rotating mass takes squared the amount of energy as stationary to accelerate to the same velocity, in practice dropping rotational mass seems to have about a 2-3 fold benefit over dropping static weight and its less mechanical drag on the engine. Dropping 25lbs of rotational is like dropping 50-75lbs of static. Common rule of thumb is 100lbs of static is worth a tenth, so you could reason a driveshaft would be a gain in the .05-.075 range. Though most don't go out to specifically test this one mod and would be problematic to tell since that can easily be hidden in run to run variance. That's said its a piece of the puzzle just like dropping static weight here and there. With performance in mind dropping any rotational weight be it wheels, driveshaft, flywheel etc should def be taken advantage of. A stronger, lighter one piece driveshaft that eliminates the problematic mid bearing (which I have never liked) as you add power is a must do mod imo. I do agree it seems more noticeable on a manual car. I personally have done aluminum shafts on all my stangs and will continue to do so. The worry of failure was never a determining factor for me though, but I have seen failures on the forum over years. I don't know which shaft your looking at for $800 but mine (have had 2 for this car coast/shaftmasters for different trans) were in the $500-600 range. Would love to see ford put them in the stangs from the factory like the trucks are getting.

 

[fourdegrees11]

I replaced mine with a Shaftmasters because I was upgrading the clutch and I didnt see the point of putting the stock driveshaft back on after taking it off