benefits of aluminum driveshaft

Less rotational mass, no vibrations at higher speeds/ rpms.

I know alot of people put them on to get rid of some vibration they get at higher speeds after a gear install. Of course the aluminum weighs less and its always good to lose weight, especially on something that rotates. I'd like to know if anyone can feel an increase, SOTP that is.

It is stronger and lighter! Also is a good idea to look into when you are suffering from vibrations!

Jakob

I have a 1990, I too was getting vibrations at high RPM's as well as when parking my car in the garage which has a bit of an incline leading up to the openning, I'd cruise up to the openning and upon reaching it, I'd shift to neutral and brake slowly and I'd hear a clunk. I took my car in to my Mustang mechanic and asked him to check it out. It was still the stock driveshaft and when you pushed on it and released, you'd hear the internal's of the shaft clunk. Not only that, my u-joints were done and leaking. I said to heck with it and he installed a complete FORD Racing aluminium shaft in, labour free. Took him 5 minutes to install it.

My drive home was a totally different experience!!!!!!!!!!!!!!!!!

Oh, and the clunkings gone too

The vibration was what got me to buy one of these. Every time I'd back off the gas or push in the clutch it used to feel like I was driving on washboards... Now it's smooth all the time!

Yep, definately got rid of the truck feel on the interstate. Very smooth and quicker to boot. Even found one for my '68 ranchero out of a crown vic taxi. Made a huge difference there.

Jamie

Spanky - if your Mustang is basically stock, you'll probably actually GAIN top speed with a change to a 3.55 or 3.73 rather than lose top end. You don't have enough HP to pull that very long top gear (T-5 or AOD) up very high in the rpm band. With more gear, the engine will be able to access the higher part of the power band where more power is available to overcome aerodynamic drag. If you're looking for performance mods (and don't have some driveshaft problem you're trying to solve), save your money on the shaft, and put a set of gears in that thing. Gears are probably the single best mod you can make in terms of really feeling the difference.

spanky442 said:

Well my 93 is basically stock. I did cat back flows and H-pipe years ago. Its time to replace those as well. I've decided to do small simple upgrades. No vibration problems, but I figured the lighter wieght will help it get more power to rear wheels. Right now I my list is a x-pipe and new cat back system, possibly borla, I hear they sound good and don't have the drone that flows get. The driveshaft idea came about when looking into gears. Stock 3.08's are good, but a little more would be nice. I don't want to lose to much top end so I'll probably stay in the 3.23 to 3.55 range. Any opinions? Thanks

Click to expand...

As a minimum I would go with the 3.55. If you have the 3.08 and not the 2.73 nothing short of 3.55 will make a big difference. 3.55 is a very good all around gear anyway. I am going to go with a 3.73 for my stick vert cause of its extra weight. I will go with a larger tire diameter or better yet a six speed trany if it is too much gear.

Spanky - if you do the math, you'll see that at your current top speed with those gears, the car is nowhere near the power peak of the engine. Assuming 26" tires, and a .675 to 1 5th gear ratio you're only turning over about 3760 rpm at 140 -- and it would be a really good stock Cobra that would hit that speed. Putting the 3.73's in would have the engine turning 4550 rpm at the same speed - and it'll be making more power at that rpm than it would at 3760, so as I mentioned before, top end would likely be increased with the 3.73's, not decreased. It's exactly the same dynamic that allows most late model Corvettes/Camaros/Firebirds/Vipers with the 6 speed tranny to reach their top speed in 5th gear, not 6th. Not to mention how much more quickly it would reach the speed. You won't be losing a little - you'll be gaining acceleration, responsiveness AND top speed. What you'll lose a little of is fuel mileage on the highway - but it probably won't be too noticeable. You might gain a bit of around town mileage as it won't take as much throttle to get you goin' -- if you can keep your foot out of it.

My combo was designed to be cobra-like with alum. heads. My aero is worse than yours, and my 3.73's w/shorter tires are like 3.90's in your car. I get 16-18 mpg around town, 23-25 on the road. Put the 3.73's in there - you'll wonder why you waited so long. Don't forget to adjust the speedo - below is a link that will help.

http://www.geocities.com/mgnedell/notchback/tech/speedo.html