QA1 GT350 CF Driveshaft

[Epiphany]

I would be interested to see if you notice any vibrations at higher speeds like 120+

In past vehicles with 1 piece shafts I noticed all the same improvements as you until I got into the higher speeds then had very bad high speed vibrations that shook the car badly. Putting back in the 2 piece shafts corrected the issues.

I would like to know as well...... Have you had a chance to do a high speed test? A few years ago, I've installed a one piece driveshaft on my (LS3) SS. Although, it was not a CF shaft... it produced a very noticeable vibration. And it seemed proportional to the speed of the car.

Many thanks for such helpful and detailed installation info. I intend to use this during my installation. BTW, the pics are outstanding!

Pardon me for a cautious response but I indeed exercised the vehicle in such a way so as to test the CF shaft in the range you are curious about and did not experience vibration. When I removed the two-piece driveshaft from my '09 GT500 and bolted in a '13/'14 GT500 factory CF shaft I got the same result - no new or additional vibration and a much smoother feeling driveline. I cannot speak to the shafts you guys used or the experiences you had but in this particular case, I'm convinced of the attention to detail that QA1 imparted upon the shaft with respect to design/balance and the results appear to back it up. I'll continue to drive with a keen ear and note any deviation from these or any prior statements I've made.

And thanks for the comment on the photos. I have always used my Canon DSLR but due to limited room or access I used a brand new Samsung G8+. My previous cell bricked while down in SC for Mustang Week and I figured it was time to upgrade. The near $900 bill is a killer but it does take great photos and video. I should also mention the host I've been using for the past 7 years, Photobucket, has gotten extremely flaky as most know. I'm getting bombarded with ads for a service I paid a premium for and I'm rather disappointed about it. I won't be paying the $400 to do the same thing my current plan allows for. I honestly don't think anyone will. They are trying to kill the company and doing a great job about it. So if you see a photo you like - save it as the whole thing could crap out sooner than they publicly planned it to.

Very nice @Epiphany - vettttttty nice.

What I would also like to touch on a bit further, as I caught a mention of it in the review above; drive-ability.

People usually tend to base their DS upgrade around weight savings and acceleration improvement, but that is only scratching the surface.

As mentioned by Epiphany above, the GT350 front portion of the DS is mated to the transmission solidly with no "Giubo Joint" like the other model S550 cars have. (auto V8 cars do not have them btw)

Well this solid F/R mounted 2-pc driveshaft is without question one of the things I absolutely despise about the 2005-Current Mustangs. (I understand and accept why they chose to use them)

When you upgrade to a 1-pc DS like this one, the difference is immediately noticed. The engineering behind it, the fact is is CF with some "flex" and ridding of the sloppy harmonics is situation in which is IMO, totally winning.

One of the traits of the modern car's 2-pc DS that is very bothersome to me (especially if I dropped the $$$ on a GT350) is the clickity clackity clunkity that they emit through the drive-line. This sloppy oscillation prevents the driver from truly feeling the car working, and also prevents the driver from being able to "truly" drive the car. Many do not know this as they drive and get accustomed to their new vehicle and they love it, but we all cater our driving styles to our S550s whether we know it or not. My example for this would be, driving these cars for the first time you get that sloppy and jerky feeling that you end up changing the clutch release methods and shifting styles to make the car "behave" better - but once you install a good DS such as this one, you change your driving style as you do not have the driveline "wind up" and unloading anywhere near the level it was with the multipiece unit.

10lbs less rotating mass, MUCH stronger, smoother shifts and better driving characteristics...and just one AWESOME looking piece. This would be the first modification to my GT350 (just like a 1-pc was the first mod to my S550 GTs, both auto and my MT82 car)

Excellent!

Crazy to think back at how you (when you posted as Modern Speed) and I used to disagree. Maybe old dogs just give up barking at one another after a while.

Kelly, I've read with much interest most any post from you and greatly appreciate you sharing your experience and knowledge on a number of fronts. Especially driveline. The one thing I had in mind to do was to accurately measure driveline angles and I didn't. I simply forgot and I'm kicking myself. I like to have as much data as possible at my fingertips as I believe it helps if you ever need to diagnose an issue. I was prepared to play with washers/shims at the crossmember in order to attenuate any new driveline harmonics. Looks like I don't have to but I'm still curious about the numbers and if they match the typical '15+ Coyote/MT82 car. I don't know if you've measured the angles on a GT350 but I'm interested in your thoughts here.

As you hinted, any semblance of "clunking" has vaporized with this mod. The additional inertia imparted by the heavier stock driveshaft tubing, yokes, and additional joints, seems to work with the lash at the rear and encourages clunking with variation in rpm such as when shifting, etc. The CF doesn't have that flywheel effect and is extremely calm in this regard. That part I love. It is almost as if there is no driveshaft and the engine is connected directly to the axle, albeit in an elastic, non-jarring way.

When down at Mustang Week I studied the '18 Mustang GT up on its side at the Ford Racing Booth. The car was an automatic and while noticing that Ford now uses a composite transmission pan (as well as a composite engine oil pan similar to the GT350's) I saw something else. They are now bolting on a mass damper at the crossmember similar to the GT350. It made me wonder if it had to do with the power bump for '18 or if it was a mere matter of a more limp wristed, NVH noticing demographic. The guibo/non-guibo study is interesting as well.

Bravo. Excellent write up and detailed information. Great job making it understandable as well

You keep raising the bar and I have to learn to somehow jump higher. And I abhor ambiguity so my apologies if my explanations sometimes run amok.

So it's here, the instructional PDF from QA1 for this driveshaft.
http://www.qa1.net/tech/documents/DS_MUSTANG_9919-210_REV_5-1-17.pdf

Of importance from the above document:

Be sure to inspect all components regularly, especially following an accident. Do not use any components which may have been damaged.
Composite driveshafts are fragile and if dropped or damaged will be considered scrap and should be replaced.


They clearly agree with Ford on this one.

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[BMR Tech]

Here is a pinion vs trans angle for ya from a PP GT.

Do some measuring and lets see what you come up with ;)

 

[Offboost]

Originally Posted by Offboost
I would be interested to see if you notice any vibrations at higher speeds like 120+

In past vehicles with 1 piece shafts I noticed all the same improvements as you until I got into the higher speeds then had very bad high speed vibrations that shook the car badly. Putting back in the 2 piece shafts corrected the issues.

Quote:
Originally Posted by H6G
I would like to know as well...... Have you had a chance to do a high speed test? A few years ago, I've installed a one piece driveshaft on my (LS3) SS. Although, it was not a CF shaft... it produced a very noticeable vibration. And it seemed proportional to the speed of the car.

Many thanks for such helpful and detailed installation info. I intend to use this during my installation. BTW, the pics are outstanding!

Pardon me for a cautious response but I indeed exercised the vehicle in such a way so as to test the CF shaft in the range you are curious about and did not experience vibration. When I removed the two-piece driveshaft from my '09 GT500 and bolted in a '13/'14 GT500 factory CF shaft I got the same result - no new or additional vibration and a much smoother feeling driveline. I cannot speak to the shafts you guys used or the experiences you had but in this particular case, I'm convinced of the attention to detail that QA1 imparted upon the shaft with respect to design/balance and the results appear to back it up. I'll continue to drive with a keen ear and note any deviation from these or any prior statements I've made.

And thanks for the comment on the photos. I have always used my Canon DSLR but due to limited room or access I used a brand new Samsung G8+. My previous cell bricked while down in SC for Mustang Week and I figured it was time to upgrade. The near $900 bill is a killer but it does take great photos and video. I should also mention the host I've been using for the past 7 years, Photobucket, has gotten extremely flaky as most know. I'm getting bombarded with ads for a service I paid a premium for and I'm rather disappointed about it. I won't be paying the $400 to do the same thing my current plan allows for. I honestly don't think anyone will. They are trying to kill the company and doing a great job about it. So if you see a photo you like - save it as the whole thing could crap out sooner than they publicly planned it to.


Thanks for the info I am glad to hear on that long straight road some were out of the country you were able to test the 1.1 rpm of the shaft with the rpm of the engine. That is great news!

 

[BMR Tech]

Gotta love photobucket!

Also, it sure would be nice if the hosting size allowance on this site was a touch larger than 1900 pixels! With the newer cameras on the smartphones, it is an act of congress to host images to this site from your phone.

Something about having a 2048 pixel image get denied with the note: "your image cannot be uploaded due to it being too large. Maximum size is 1900" " " " " "

So close! Yet so far. I either just stop and do not waste any more time, or if it is very important I will then screenshot the image I took, crop it to make it nice, then host it.

Rant off/

 

[Greg35]

CF driveshaft combined with some lightweight forged aluminum wheels are sounding pretty good right about now. Pretty... pretty... pretty... good.

Yes sir.....you are heading in the right direction! Oh , and don't forget that MGW Shifter;
you'll love it!

 

[Epiphany]

I've spent some time the past few days under the car with respect to this modification. I wanted to be certain that the CF wasn't masking anything driveline related. I also spent quite a bit of time going back and forth with Kelly from BMR as he has a wealth of knowledge when it comes to the driveline on the S550/S197 cars. Easy to talk to, he shared quite a bit of data and information relevant to my plan. We both found the results rather interesting.

I started by leveling the car so that I could get some pretty accurate numbers with the car up in the air.

I gathered up a few straight edges as well as every angle finder I have. With the driveshaft in place it isn't easy to obtaining repeatable data unless you are rather careful about placement. However, with the shaft in place you can check its angle with any flange angle changes you make, hence why I did it this way.

I started by taking angle measurements at the transmission output flange, the driveshaft itself, and the pinion flange at the rear axle housing.

Transmission flange was at 87.2* (or 2.8* of downward slope)

Driveshaft was at 3.6* of downward slope

Pinion flange was between 85.8* and 85.9* or (4.2* of downward slope)

Armed with the above, I went to Spicer's site to use their driveline angle calculator, a great online resource. The driving member would be the flange at the transmission and the driven member would be the flange at the rear axle. Plugging in the numbers I recorded the driveline angles looked as follows...

My interest lay in seeing if I could get the angle of the front and rear flange closer to parallel. That would mean shimming at either or both ends. So I picked up some longer crossmember bolts as the factory ones have very little thread engagement. The plan was to use washers between the crossmember and the body to shim it down and get those angles closer. Spicer's calculator allowed for quick and easy verification once I had the degree increments for each.

So I placed a jack under the transmission, removed the factory crossmember bolts, lowered the transmission an inch or so and slipped in a couple of washers at each corner, inserted the new/longer bolts, torqued to spec, and removed the jack. I then checked all the angles again.

The angle difference between the front and rear flange decreased but that isn't all that happened. The front flange and driveshaft angles changed (rear stays the same as it was untouched) but most importantly was the .4* driveline angle at the front. According to most any driveline resource, this isn't enough angle. The minimum is .5* and you can see it mentioned from Spicer's own site...

Rule 1: Universal joint operating angles at each end of a driveshaft should always be at least one-half degree


Rule 2: Universal joint operating angles on each end of a driveshaft should always be equal within one degree of each other (one half degree for motor homes and shafts in front of transfer cases or auxiliary devices)


Rule 3: For vibration-free performance, universal joint operating angles should not be larger than three degrees. If they are, make sure they do not exceed the maximum recommended angles.

In the interest of science, I wanted to see what would happen if I placed four washers at each corner between the crossmember and the body. The result of which, looked like this...

The data plugged in...

The driving/driven flange angles became closer to parallel but the operating angle at the front u-joint is unacceptable at .2* which can cause a major reduction in long term durability. The driveshaft has to have some angle relative to the crankshaft or transmission main shaft centerline. Without any angle, the needle bearings in the u-joint may not get adequate lubrication if they don't move much. So while the operating angles front and rear are within 1 degree the front has to go back up.

Of note - I spent quite a bit of time studying the dampers Ford bolted to the transmission/crossmember on the GT350. I also compared crossmembers between the GT's MT82 and that of the GT350's TR3160. I noticed they were slightly different but wasn't sure why. Now I think I know. The GT350 has an rpm ceiling of 8,250 rpm. Based on typical data from u-joint companies I found, Ford had to be very careful about the front driveline angle such that it was near minimum. Pay attention to the following...

7 degrees working angle = 2100RPM max
6 degrees workign angle = 2700RPM max
5 degrees working angle = 3300RPM max
4 degrees working angle = 5100RPM max
3 degrees working angle = 6100RPM max
2 degrees working angle = 7400RPM max
1 degree working angle = 8500RPM max
0 degree working angle = Not recommended

In order to allow the rpm the Voodoo engine imparts, Ford was keen to near match the front u-joint driveline angle to allow a near maximum. Armed with this, I decided to try a suggestion Kelly made - to make an adjustment at the IRS pumpkin such that it reduced the driveline angle. Without any shims, I loosened the two front differential ear mount bolts as well as the pair aft of the differential that attach to the cradle.


From the factory service manual, the four bolt locations that I tweaked...

I basically loosened them all and preloaded the diff a little (pulling the nose down) and retightened. I was able to go from 4.2* to 3.9*. I also used only one washer up front at the crossmember so as to be safe with respect to the minimum operating angle there I mentioned previously. Measuring each angle and plugging in the data I ended up with this...

So I ended up with a theoretical improvement. Front and rear angles are better than when I started. The front angle, now at .6* would allow for a potentially higher rpm threshold compared to the original measurement of .8* I started with while simultaneously being above the .5* minimum. Yes, the fraction of a degree numbers are small as should be any commensurate improvement but I wanted to best optimize the combination.

Huge thanks Kelly. I learned quite a bit about this particular car that I would not have without your help.

 

[Goofball]

So I have a QA1 shaft in my garage that was just delivered and now I'm terrified to install it. Is there a chance that I can install it as carefully as possible and NOT have any issues or should I be expecting some NVH? I mean that is pretty scientific stuff there that I'm simply not interested in having to do if that's what it takes for this shaft to be running right.

 

[Epiphany]

As I mentioned earlier, my shaft was fine and an improvement over factory. I simply wanted to optimize my driveline angles, something few do.

On edit....I should add that the front angle with one washer is closer to 2.9 than 2.8 (driveshaft angle didn't change much). So the final numbers are even better. I'll post up the data when I'm back at my desk top.

 

[ThreeFiveO]

You guys are way above my pay grade but I do enjoy reading your posts! Keep up the good work. I think Ford could learn a thing or two from you.

 

[H6G]

[MENTION=19066]Epiphany[/MENTION], that answers a lot of my questions. You are a genius! A few years ago, I was dealing with a T6060... with vibration issues (one piece driveshaft). Unfortunately, It’s not easy to find someone that understand the theory and not just ‘nuts & bolts’. Your posts clearly illustrate your ability to try things that most would never even think about. All facts and non’fluff’..... outstanding work. Thank you.

 

[Goofball]

So do you guys think these numbers could vary a lot from car to car or would they be pretty close? I mean your measurements are in fractions of a C hair right?

 

[Epiphany]

So do you guys think these numbers could vary a lot from car to car or would they be pretty close? I mean your measurements are in fractions of a C hair right?

You can analyze til you paralyze.

Don't fall victim to it. I'm quite sure your transmission rubber mount has yet to sag or cold flow and while the rear diff rubber bushings aren't of the highest durometer you should be good there too. In essence, your car is fairly new and should be well within tolerance and that is exactly what QA1 designed the specs on this shaft to meet.

Put the shaft in and drive. If you have issue I'd contact QA1 as I'm sure they'd be interested in any potential issue. Beyond that, I'll gladly help if need be. Based on the reviews to date, everyone has been very pleased with the results. Just know that you can refine the installation even further if you want to.

:cheers:

 

[UnhandledException]

I am interested in this mod but reading Ephiphany's detailed angle measuring and my lack of understanding of mechanical engineering side of this particular issue, I m worried if this is a fairly involved mod that requires lots of measurements to line up everything perfectly or is it as simple as removing bolts and old DS and putting new bolts back with the new DS?

 

[Goofball]

I installed the MGW shifter and QA1 driveshaft in about 6 hours and it runs flawlessly. At all speeds I have no vibrations. Definitately a noticeable improvement over stock.

 

[Epiphany]

I am interested in this mod but reading Ephiphany's detailed angle measuring and my lack of understanding of mechanical engineering side of this particular issue, I m worried if this is a fairly involved mod that requires lots of measurements to line up everything perfectly or is it as simple as removing bolts and old DS and putting new bolts back with the new DS?

It is a simple bolt-on replacement part. What I went through was to verify driveline angles. Ford gives some angular dimensions for certain stock configurations in the service manual but there obviously isn't any data when a one-piece driveshaft is installed. I wanted to collect as much data as I could so I had something to work with in the event of an issue as well as to provide the same for anyone in the future that is looking to compare their own install.

I installed the MGW shifter and QA1 driveshaft in about 6 hours and it runs flawlessly. At all speeds I have no vibrations. Definitately a noticeable improvement over stock.

Good to hear you got it in and all is well!

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