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BMR Carbon Fiber driveshaft
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Posted by: OldFart

Having more $$ than good sense, I finally broke down and shelled out the exorbitant price for the BMR Carbon Fiber driveshaft.

I’ve been wanting one for a long time, and questioning the intelligence of the Ford engineers responsible for the two-piece, CV joint, must have been designed by a committee, monster that Ford calls a stock driveshaft.

The install is a pretty much a snap, even with a Bassanni X-pipe in the way. The only questionable issue is the lack of a dust cover to replace the stock dust cover at the rear-end pinion shaft. I’m not sure if this is going to be a long-term maintenance issue or not.

The BMR part is around 18 lbs. (I didn’t weigh it but you can easily pick it up with on hand and little effort and that’s what BMR says it weighs.) The stock unit weighs 46 lbs. (I weighed it on a digital scale.) Twenty-eight pounds is a pretty significant reduction in rotating weight and mass.

Although I could have gotten an aluminum driveshaft for less $$, the carbon fiber is a good vibration insulator and acts like a vibration isolator for transmitted vibration between the transmission and rear-end. Since I’m running upper & lower arms with heim joints instead of bushings, this transmitted vibration had become a real issue for me. (Distracting and annoying as hell.)

I can testify that this mod works and works very well. The engine winds up considerably faster and the annoying transmitted vibration (felt in the gearshift knob) has all but disappeared. Surprisingly, the car even felt lighter and more responsive in a turn. But that’s probably due to the fact that I race the car and am a bit more sensitive to the way it handles than most drivers would be.

The other thing I’ve noticed, is that every time I drive the car (after stopping and shutting it down), the engine seems to run a little smoother and wind a little faster. I think this might be some more of that "inductive learning" stuff going on, but that’s a wild ass guess at best.

I like it and if you’re willing to plop down the high dollars for it – I recommend it. Works good.

OldFart

Posted by: KartRacer39

Aiight , come clean and tell me what the cost of the BMR Driveshaft is. The aluminum one goes for near 800 bucks so I am curious just to see. Thanks In Advance, Richard

Posted by: Mustang5L5

Holy crap an AL driveshaft for an 05+ costs $800???

Posted by: OldFart

Quote:

Originally Posted by KartRacer39

Aiight , come clean and tell me what the cost of the BMR Driveshaft is. The aluminum one goes for near 800 bucks so I am curious just to see. Thanks In Advance, Richard

Ok, sit down and take a deep breath.

The carbon fiber drive shaft, with adapters, nuts, bolts, shipping, etc. (everything needed for the swap) = a hair over $1,100.00.

You can price it at www.bmrfabrication.com

Like I said, I've got more $$ than sense. But it really does make a hell of a difference.

OldFart

Posted by: Mustang5L5

Holy crap

Posted by: OldFart

After the experience I've had with the BMR Carbon Fiber drive shaft, I cannot in good concience recommend it to anyone else.

It appears to boil down to the design of the shaft connection at the rear-end. Rather than a flange, it has a more traditional male/female spline shaft and a U-joint.

First, you need to understand that I had a problem with the rear-end whining prior to ever changing the driveshaft. And my Ford dealer completely rebuilt the rear-end under warranty (beyond all expectations since I was already running much higher hp and torque than stock). It was fine for around 2,500 miles - and then I installed the carbon fiber shaft.

On my first shaft, right after it was installed, it worked great! (Which led to my original post recommending it.) But within a few hundred miles it developed a mild vibration that became increasingly worse with every mile. Unfortunately, I was on a business trip in the car (only 700 miles round trip), and it was not an option to just park it or take it to my mechanic. I did take it to a local performance shop, and the mechanic pointed out that he was able to deflect the spline connection by just pushing on it. I had to pass the factory on my way home, so I took the car by the manufacturers shop and they drove it and agreed there was a problem. They provided a new carbon fiber shaft and paid a local shop to install it.

All was well, no more vibration, except my rear-end was again screaming like a demon. So rather than argue with the manufacturer about it (and the day after the new shaft was installed), I paid my regular shop to rebuild a rear-end that had been rebuilt under warranty 3,000 miles ago. That came to $727.00 worth of bearings, seals, new gears and labor.

Now it gets really bad. Within 200 miles of having the rear-end rebuilt (and around 300 miles on the new carbon fiber shaft) it developed the same damn vibration. The bad news is I was again on a business trip and just parking the car was not an option. Within 500 miles - the &^%$#@#$%$ rear-end was screaming and shot to hell again!

So I took it back to my regular shop and they took everything apart and put the calipers on it. The feed-back was: The tail-piece of the U-joint that attaches to the pinion is too short and the male spline is not seating properly into the female splined receiver, allowing movement and wear, which just gets sloppier the more it wears and allows vibration, which causes more wear and destroys the bearings, allowing the pinion to move up and down and destroy the gears.

So, another $508.00 for new bearings, crush sleeve, seals and gears (he cut his labor price) and re-install the stock drive shaft, and I'm right back where I started, except I've spent over $2,300 and not had a damn bit of fun doing it. (The manufacturer has offered to give me a full refund upon return of the 2nd drive shaft. So I'll only be out $1,300 and a ton of agrevation over this little experience.)

Even though the manufacturer says they have over 80 of these shafts installed with no problems, I can only relate my own personal experience - and it ain't been no picnic.

If I don't get rid of the car, I may try the JPC aluminum driveshaft as I understand it uses a flanged connection at the rear-end, similar to the stock unit. But I am going to want to talk to someone already using it before I go there.

Being the beta test site for 05/06 Mustang parts is getting old really, really fast. The parts cost more than similar parts for earlier models and sure as hell don't always work as well. I may already have passed the point of "stick a fork in me I'm done".

Oldfart

Posted by: ExBamaGal

Thanks for posting that Oldfart! I was hoping you would to let everyone else know about the problems you had.

Posted by: KartRacer39

Thanks, OldFart for the great info. I agree with you on being the crash test bed dummy for the 05. Best of luck with the new ride!!! The only person I have heard that has tried the JPC aluminum Shaft is Justin himself in their project car. I definately want to lighten my driveline, but also don't want to shell out something else while doing so.

Don't be a stranger and thanks as always for your Expertise and Knowledge.

Posted by: Gixx1300R

$1100 !!!!! wow,I got my Aluminum driveshaft for about $240.00. It weighs 17lbs.

Posted by: Aussie XAXB

I am trying to find a tech article I saw once that confirmed my doubt about lighter drive shafts, without regards of going from a 2 piece to a single shaft.

Based on physics there is no gain to be had from a lighter driveshaft, unless you are talking about dropping 50 pounds from the car. As far was the engine being able to transfer more power to the rear wheels that is bunk. The shaft is merely twisting on a plane and is not being "slung" around. Since it is only twisting and is achored at both ends it does not develope inertia of rotating mass that people usually assume is significant. It is balanced. There is a direct and consistent transfer of energy through the two anchored ends and the weight of the shaft, especially with the differences in weight from stock to a light weight shaft, is not significant in this application (cars, except for all out race cars) to impart any effect such as to improve power transfer.

Just as underdrive pulleys are all the rage and one of the first "performance mods" to be done to a car, Mustang Monthly states that underdrive pulleys on the '05 and '06 Mustangs will add 11 HP. That is a maximum and is around 5,240 RPM. At street driving RPM's you can expect to see about a 5 HP gain. Is that worth about $450 for a set of March (Top of the line) pulleys? Is 5 HP worth $250? For $250 you can get a cam kit, gaskets, and fluids and put in a cam (old school V8) and increase power and torque by about 35 to 50. Even more with a better intake. Even more with a better exhaust.

I will continue to try to find that tech article about the drive shafts. Until then I just want to state that marketing and manufacturer claims are not always reality.

Steve

Posted by: Gixx1300R

Well I'm sorry to say that you Tech Info is incorrect. Installing an Aluminum driveshaft dropped my E.T by 2 tenths and I have the Time Tickets to prove it.

Posted by: Gixx1300R

Here are my Tickets before the Aluminum driveshaft install. My Stang ran consistant 13.30s

Posted by: Gixx1300R

Here are my Times after the Driveshaft install.

Posted by: Aussie XAXB

Do you have the track conditions, humidity, and temperature conditions for the runs? What time of year were the "before" runs and what time of the year were the "after" runs. Just looking for verification of variables.

Thanks,
Steve

Posted by: Gixx1300R

Quote:

Originally Posted by Aussie XAXB

Do you have the track conditions, humidity, and temperature conditions for the runs? What time of year were the "before" runs and what time of the year were the "after" runs. Just looking for verification of variables.

Thanks,
Steve

The 13.30 runs were done on a Wednesday. I installed the Aluminum driveshaft on Thursday and returned to the track on Friday of the same week. Track condition were about the same (see 60" times)These runs were done about a month ago. The weather for both days was

Humidity: 55%-60%
Dewpoint: 64*F-68*F
Barometer: 30.08 - 31.10inches
Heat Index: 83*F-85*F

The temp was about the same for both days around 88 degrees starting and as night fell the temp dropped to the lower 80s

Posted by: Gixx1300R

Posted by: Aussie XAXB

That's pretty significant info. Ok, just to eliminate other factors as well...

The shaft was absolutely the only change? None of the following:

1. New air filter or cleaned reusable filter

2. Rotate tires

3. Change sparkplugs

4. Cleaned throttle body

5. Windows up, windows down

Steve

Posted by: Gixx1300R

There were no other changes except for the driveshaft. I even had the same 93 octane fuel in the car.

Posted by: Aussie XAXB

Well, sounds pretty conclusive to me. If the atmospheric conditions were a little more different I would have to question it, but that seems like as similar conditions as you will ever get.

Ok, is .2 over a 1/4 mile "feelable" (new word) in the seat of your pants, beyond the placebo effect? I personally wouldn't know. I've never played with a car on the track yet.

Steve

Posted by: Gixx1300R

Quote:

Originally Posted by Aussie XAXB

Well, sounds pretty conclusive to me. If the atmospheric conditions were a little more different I would have to question it, but that seems like as similar conditions as you will ever get.

Ok, is .2 over a 1/4 mile "feelable" (new word) in the seat of your pants, beyond the placebo effect? I personally wouldn't know. I've never played with a car on the track yet.

Steve

Yes you can tell the difference whn you first install the driveshaft. The motor revs a little quicker.

Posted by: Aussie XAXB

That's cool. Thanks for all your input.

Steve