Wait for Carbon Fiber Driveshaft or buy Aluminum now?

[Dan Schoneck]

I have had a pst carbon shaft for over 7 years on my street car. Carbon fiber is the best strength out there. Also aluminum is the one that will flex, NOT carbon. Pst does carbon shafts 40ft long for boats. U can put a yellow line on a alum shaft and put it on a chassis dyno and video tape it and later look and see the line distort.

Later Dan

 

[Streetpwr281]

Dan - Thanks for the comments. It sounds like it may be worth my while to wait for PST to release their Carbon Fiber GT-500 driveshaft in late-January. I've got no reason to rush anyways so why not.

Thanks.

 

[LSR]

Carbon Fiber is the way to go, alot of people shy away due to cost. But after seeing PST website and cost, their cost is very reasonable.

http://www.pstds.com/custom_driveshafts.htm

I have a buddy that is making over 800rwhp with his Shelby drag car with slicks. He has broken a 3.5 Steel shaft from MCP which damaged his car severely. Now he is running a carbon fiber shaft. I will see if he can come over and give his $0.02 and whom he bought his shaft from

Debate all you want, but the best R&D proven info. on Carbon fiber driveshafts comes by way of NHRA Pro Stock cars run carbon fiber driveshafts and have never experienced a drivshaft failure with cars that make 1300+hp and leaving with slicks.

 

[LSR]

Steel Shafts

--------------------------------------------------------------------------------

Pros:
Extrememly strong
Extremely durable
Cost effective

Cons:
Lower critical speed
Larger rotaing mass


Aluminum Shafts

--------------------------------------------------------------------------------

Pros:
Higher critical speed
Corrosion resistant
Light rotating mass
Good strength to weight ratio

Cons:
Weaker than steel
Heavier than carbon fiber

Carbon Shafts

--------------------------------------------------------------------------------

Pros:
Best critical speed
Lightest rotating mass
Corrosion resistance

Cons:
Suceptible to road damage (such as offroad use)





Now for the big question, who will race their Mustang off-road ;-)

 

[HARLEYDEALER]

LSR, is correct about the carbon fiber DS, I have been running a PST DS since Sept this year with 898wrhp.The drive shaft has billet end at the transmission and the rear yoke was made to fit my 9" Carrie, the cost about $1300.00. After twisting my one piece DS, $1300.00 is real cheap! It broke the bell housing, twisted the main shaft, bang and dented the tunnel and put a hole in the fuel tank with 104 octane fuel and this was on a dyno at 5200 rpms, I was standing right there, there was no warning of any kind till she let loose, then it made both the tuner and I shit! Had a front DS loop but the rear was on BO, so no rear. At least with the carbon fiber if she goes there will be little to no damage, just a pile of dust and fiber, plus PST will replace it at min cost. For the piece of mine and safty the CF DS is the only way to go, but I do have a 3.5" Chromoly DS made by the Drive Shaft Company in NC as a back up, it took a while to totaly trust the CF. Both shafts are well made. Happy Holidays

 

[VNMOUS1]

So does that mean a 2.6, JLT/tune combo is too much for the stock shaft?
Thats about 550rwhp

Mine got tweaked with about 560 rwhp on a prepped track with stock tires. Couldn't freaking believe it. I think it was an anomoly.

I know what Evo has done with the specs on their shaft and I feel confident that it's the ticket for me.

I know a couple of people that are happy with CF, but having dealt with it in motorcycling racing applications I can tell you that it's great until something compromises the structural integrity (like a chunk being taken out by a rock or other debris). I've seen it unwind pretty quickly under stress.

To each their own, but it's not for me.

"Christine" is in shop even as we speak having a variety of things done and I decided to have them do the DS install since I wasn't shot in the butt about lying on my back near freezing concrete. Using the front and rear BMR loops.


bj

 

[Dan Schoneck]

also i have had 3 carbon d.s's and i also have one in my race car that runs 7.60's at 186. So they are pretty strong, i have also seen one break on a 7.0 flat car(2000hp) that had extreme tire shake and it broke at the york and then broke in another spot and that was it no damage.

 

[shakerb]

LSR, is correct about the carbon fiber DS, I have been running a PST DS since Sept this year with 898wrhp.The drive shaft has billet end at the transmission and the rear yoke was made to fit my 9" Carrie, the cost about $1300.00. After twisting my one piece DS, $1300.00 is real cheap! It broke the bell housing, twisted the main shaft, bang and dented the tunnel and put a hole in the fuel tank with 104 octane fuel and this was on a dyno at 5200 rpms, I was standing right there, there was no warning of any kind till she let loose, then it made both the tuner and I shit! Had a front DS loop but the rear was on BO, so no rear. At least with the carbon fiber if she goes there will be little to no damage, just a pile of dust and fiber, plus PST will replace it at min cost. For the piece of mine and safty the CF DS is the only way to go, but I do have a 3.5" Chromoly DS made by the Drive Shaft Company in NC as a back up, it took a while to totaly trust the CF. Both shafts are well made. Happy Holidays

So should DS safety loops be purchased with the CF DS or is it safe enough that if it breaks it will not cause any damage to the car?

 

[Streetpwr281]

Good question: Do you need driveshaft loops with a Carbon Fiber DS?

 

[Ry_Trapp0]

i would imagine it would still be a good idea. hell, they dont cost all the much and you could even fab them your self for next to nothing.

 

[Streetpwr281]

I was thinking more from a weight perspective. If the steel driveshaft loops are not necessary why add them. If they are necessary, even with the Carbon Fiber driveshaft, then I'll absolutely add them. Safety first and weight reduction second.

Thoughts?

 

[352Ford]

You guys are killing me…

Done properly CF is typically stiffer than steel and Al, but has a lower ultimate strength.

When looking at DS weight you also have to look at shaft diameter because of the polar moment of inertia. Just knowing the weight doesn’t give you enough data.

When you “ding” a metal shaft, or any shaft for that matter and you lose all strength. While it doesn’t splinter like a CF piece, it will fail. Look up hoop stress/strain, its all held on the outside of the shaft, that is why larger dia shafts of the same thickness are stronger.

OEM’s have proven CF is a viable DS material when designed properly, but as always aftermarket suppliers are hit or miss.

 

[HARLEYDEALER]

I never seen a CF DS blow, so I am not sure of the damage, I know it wouldn't be nearly as bad as a metal shaft, no way! But I do wonder about the ends swing around in the tunel and exhaust. I run the front but on the GT500 the rear loop comes in contact with the DS when lifting the car and thats not good! The rear of the CF shaft that I have which is made by PST out of FL. has the slip yoke which is longer on the rear of the shaft to help with the harmonics of the drive train, wouldn't mind controling that some on a fail DS, but due to the clearance problem no can do, but at least it will not take out the transmission like last time. Sitting here writing this I believe I will try a different mounting plate and maybe I can get it to work, heck its winter and its on the lift now and I just bought a new tig welder and plasmer cutter, I will work on this. Bill

 

[chuckstang]

good thinkin
take some pics too

 

[harley99fb]

I never seen a CF DS blow, so I am not sure of the damage, I know it wouldn't be nearly as bad as a metal shaft, no way! But I do wonder about the ends swing around in the tunel and exhaust. I run the front but on the GT500 the rear loop comes in contact with the DS when lifting the car and thats not good! The rear of the CF shaft that I have which is made by PST out of FL. has the slip yoke which is longer on the rear of the shaft to help with the harmonics of the drive train, wouldn't mind controling that some on a fail DS, but due to the clearance problem no can do, but at least it will not take out the transmission like last time. Sitting here writing this I believe I will try a different mounting plate and maybe I can get it to work, heck its winter and its on the lift now and I just bought a new tig welder and plasmer cutter, I will work on this. Bill

Your car is a beauty.;-) Nice choice in hoods also.:beer:

 

[Streetpwr281]

I'm finally about to order my one piece driveshaft. PST does not yet have the Carbon Fiber unit ready for release so it looks like I'll be buying the Evo/Dynotech aluminum unit for now. I can always sell and upgrade to the CF piece later if/when its released and user tested.