dodaniel

Ok...let's say, I know nothing about cars...or money...or anything.

Someone, please point me to an article that justifies the cost of these aluminum driveshafts for the S197 Mustangs? I have purchased 2 or 3 FoMoCo aluminum shafts over the years for my fox bodied cars, each costing $250-$300.

Sure, I understand they are stronger. I understand they are one piece. What am I missing?

And I am seeing "performance" increases by switching out to them? Some people saying .2 of a second?! There is that much loss in the 2-piece shaft? Seriously, a tenth of a second is what, about 10-15 horsepower? Using that equation...a stock driveshaft wastes 20-30 horsepower?

Sorry, just very skeptical .. I do believe they are better, most definately. I just do not see the cost justification versus performance.

n8rfastback

they are definately very expensive

especially being that they are just ranger shafts hacked down and balanced out.....

blkstang06

You find higher cost on just about every mod for the S197 compared to older Stang platforms !..Its called capatalism...
Not all aluminum drive shafts are from Ranger shafts the 4" are but most of the 3.5 are not ..... I noticed big difference from the stock and the Shaftmaster 4" rev's faster, quieter. 39lb verses 16.5lb a two fold win ! less rotation weight and 23lb of weight that the car doesn't have to drag around...

SoundGuyDave

Got a Spydershaft on mine, and yes it's worth it... The car does accelerate quicker, there's no shaft "clonk" noise, and it's a LOT lighter. Between the heavy weight of the OE shaft, the frictional losses from the mid-joint, and the inertial issues, I would say yes, it feels like about a 20HP difference. This is NOT one you'll see on the dyno, but you will see it on your time slips, and you can positively feel the difference when driving.

shaftmasters

Talking only about the 4" replacement shafts, which all start out as Ranger shafts before being cut-down and balanced. The shaft itself has an initial cost well above those for the fox body mustangs.

FoMoCo part# 3L5Z4602LA (4" Ranger shaft) was recently quoted here in Michigan by a dealer to a private individual for a cost of $447.88 add to that the price of modifications and either replacement pinion flange or custom CNC billet aluminum adapter plate and you start to get some idea where the selling prices are coming from.

Kluski

Why won't it show on the dyno. I realize the shaft is not making RWHP, but it is freeing it up. If you install pullies the difference shows. Wouldn't this be the same concept? The crank HP would be the same, but the RWHP would be different.

Not trying to be a jerk, but I have heard people say you can't see it on a dyno, but have not heard why not.

jayguy

You should be able to see it on the dyno, actually. Just like swapping the pulleys for an under-drive set, you're not actually adding horse power to the engine, but you are freeing it up to actually get to the rear wheels. A chassis dyno measures that, the horse power that actually gets to the rear wheels.

If the car can run the quarter quicker, that's a way of measuring what the rear wheels put to the ground, which is going to show up on a dyno, as the rear wheels spin the drum up quicker than they do with a stock 2-piece heavy shaft.

I don't have one, and haven't had my car on a dyno, but the physics don't lie.

Faber

I just put a spydershaft on my car and it is awesome. My wife actually noticed a difference in the feel of the car also. great mod, and definately worth it.

wallace

im in the same boat.... the driveshaft and water pump has been on my list for the past yr. i don't think i'll ever do either of these mods. sounds like a good mod if you track the car. my clunkyness seems to have gone away w/ the new shifter...dunno. maybe oneday when they are 100.00 bucks, not a penny more.

JimC

I have the 4" Shaftmasters and it is definitely worth it. The car accelerates quicker and runs smoother - I had vibration from the stock shaft but it is gone with my Shaftmasters. And, at the track I did hit a new personal best after swapping to the Shaftmasters.

I think that the reason you don't see it on the dyno is because you already have accelerated up to speed when you start to measure things. The dyno isn't going to pick up the quicker acceleration and difference in the feel of the car - everything is already spinning by that time.

dodaniel

If the car moves quicker down the track, and it isnt showing on the dyno, the only answer is reduction in weight. And a reduction of 20lbs does NOT equate to .2 of a second (it would take more like 200lbs to get that)...I dont care what kind of physics we engage to argue that.

Guys, thanks for clearing up the cost issue...considering all I am after with my late model is low 8s in the 1/8th mile, I'll stick with the stock shaft...if I were roadracing or going for broke I could justify the cost.

SoundGuyDave

20lbs of static mass reduced will NOT give you 2/10ths, agreed. 20lbs of rotating mass, though... I think I read somewhere (it may be with wheels) that rotating mass is roughly worth 10x the static mass. This is one of the reasons that 20" rims suck so bad for performance purposes. SO much mass, way out from the spindle, resisting acceleration, and once spinning, resisting deceleration. The driveshaft is much the same way. If you don't want to do the swap, cool, don't do it. But don't discount it until you experience the difference. See if you can find somebody local to you with roughly equivalent mods but with a 1-pc aluminum shaft, and go for a ride. It'll open your eyes. On my car, the top three "fun factor" mods were, in order, a Bama tune (throttle response, trans tuning), 3.73 gears, and the Spydershaft. All three were immediately noticeable, and really turned the car up a notch. I did notice improvements with the UDP setup, electric pump, and CMCV deletes, but nothing like the "big three." Jury is still out on the headers. They absoulely make a difference, the car pulls harder in the midrange now, and sounds freakin' awesome, but I don't think they made as much of a "butt dyno" impact as the shaft. Long tubes are easily worth 20HP, by the way...

RadBOSS

Its the static weight (lower) and less mass moment of inertia of the drive shaft to accelerate that makes the difference. If you are at 6,000 engine RPM on the dyno, steady state power, then none of this makes any difference.

But the time to get from say 4,000 RPM to 6,000 RPM will be less with the lower mass moment of inertia shaft because the power to accelerate it will be less, meaning more goes to the rear wheels to accelerate the car instead. Flywheel HP is unchanged..

That is the difference.

B00ST

Welcome to the club buddy...I've learned the exact same thing with my 06. The days of the fox body parts prices are gone....sux!!

dodaniel

Yes, but if you accelerate your wheels in the 4000 to 6000 rpm range, you will see it on a dyno.

No matter. As stated, it is a nice upgrade...in my mind that money spent on a nitrous oxide kit gets a "little" more bang for the buck.

70MACH1OWNER

Dave and I have done very similar mods. Check my signature. I have to agree completely. 4th best mod was the cams!!! But I still have stock gears and am considering going with the 3:73's
Scott

tom281

I own a Shaftmaster's 3.5" aluminum shaft and it is awesome- no regrets.

Buy one, then save your cash for a blower.

blkstang06

..+1 ...

habu

+1 Well said.

I put the shaftmasters 3.5 on my car and it definitely registered on the SOTP dyno. As far as is it quicker.. it's like adding a really lightweight wheel/tire combo. You are freeing up rotational mass. I don't know how accurate this is but I've heard that 1lb saving of rotational mass is the same as saving 10lb of dead weight.

Kluski

I read one comment somewhere that mentioned the saleen short shift adaptor interferes with the Spydershaft. Anyone else have this combo? I just want to confrim. I bought the shaft but need to know if I should buy a new shifter before attempting to install the shaft.