Carbon Fiber Driveshaft
04-18-2015, 03:48 PM
#2
I would stick to aluminum or chromoly depending on your power levels.
CF driveshafts are significantly more expensive, larger, and weaker them chromo, that is a lot to trade for the lightness.
They are safer if they break though.
CF driveshafts are significantly more expensive, larger, and weaker them chromo, that is a lot to trade for the lightness.
They are safer if they break though.
04-19-2015, 03:04 AM
#6
TECH Addict
CF is not weaker in pure strength. It will beat all other makes in that category. But it is fairly brittle in a sense. When it does crack it's done, it just takes a lot to crack it. There is no in between like chromemoly or most other structural metal. It doesn't bend, which is what makes it so strong. Now carbon fiber wrapped aluminum, that's a different story entirely.
04-19-2015, 07:24 AM
#7
CF is not weaker in pure strength. It will beat all other makes in that category. But it is fairly brittle in a sense. When it does crack it's done, it just takes a lot to crack it. There is no in between like chromemoly or most other structural metal. It doesn't bend, which is what makes it so strong. Now carbon fiber wrapped aluminum, that's a different story entirely.
A pebble kicks up from your front tire and you scratch or nick a CF driveshaft and you're done - it WILL fail on that same spot. You scratch a Chromo or Steel DS and its no problem, it will still last for years and years. CF wrapped aluminum are totally different, are are usually used in very high RPM applications where the CF is only used to increase rigidity over a standard aluminum DS.
Aluminum DS's are all you need for sub 1,000hp and a large percentage of most cars. Above that Chromo, and for no budget road racing/constant high RPM use then CF is a good option.
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04-19-2015, 04:04 PM
#10
TECH Addict
CF is indeed weaker depending on what force. All the highest HP money-is-no-object cars use chromoly because of its strength. CF resists flexing and harmonics, but in turn is very brittle. It properties make it good for stuff like body panels and intakes, but for things like rims and driveshafts they are not exactly tough street duty parts. They exist, just not a good choice for most people.
A pebble kicks up from your front tire and you scratch or nick a CF driveshaft and you're done - it WILL fail on that same spot. You scratch a Chromo or Steel DS and its no problem, it will still last for years and years. CF wrapped aluminum are totally different, are are usually used in very high RPM applications where the CF is only used to increase rigidity over a standard aluminum DS.
Aluminum DS's are all you need for sub 1,000hp and a large percentage of most cars. Above that Chromo, and for no budget road racing/constant high RPM use then CF is a good option.
A pebble kicks up from your front tire and you scratch or nick a CF driveshaft and you're done - it WILL fail on that same spot. You scratch a Chromo or Steel DS and its no problem, it will still last for years and years. CF wrapped aluminum are totally different, are are usually used in very high RPM applications where the CF is only used to increase rigidity over a standard aluminum DS.
Aluminum DS's are all you need for sub 1,000hp and a large percentage of most cars. Above that Chromo, and for no budget road racing/constant high RPM use then CF is a good option.
BTW CF is VERY VERY Strong when laid correctly. It makes for a great structural material and can easily best Chromo in pure strength (and it's significantly lighter).
But, as I said in my previous post, it doesn't flex. So when it does break, it breaks spectacularly. Where as Chromo will bend and flex instead. Chromo is also far cheaper.
04-19-2015, 05:09 PM
#11
How is your explination of CF and it's strength any different than mine? Ohh it's not, yet you come across as disagreeing.... Hmmmmm.
BTW CF is VERY VERY Strong when laid correctly. It makes for a great structural material and can easily best Chromo in pure strength (and it's significantly lighter).
But, as I said in my previous post, it doesn't flex. So when it does break, it breaks spectacularly. Where as Chromo will bend and flex instead. Chromo is also far cheaper.
BTW CF is VERY VERY Strong when laid correctly. It makes for a great structural material and can easily best Chromo in pure strength (and it's significantly lighter).
But, as I said in my previous post, it doesn't flex. So when it does break, it breaks spectacularly. Where as Chromo will bend and flex instead. Chromo is also far cheaper.
There are combos and times where CF or Chromo would make sense, but for most people at most budgets aluminum is the way to go. I've done my research and asked the big companies, since I am in the market for a driveshaft myself.
04-19-2015, 05:13 PM
#12
TECH Addict
The difference is, I did not flat out state that CF is stronger then chromoloy without clarifying how and when - it is stronger against rotational force like it experiences at RPM and resists flexing, but weaker against twisting force from torque like a high powered drag launch from a dig.
There are combos and times where CF or Chromo would make sense, but for most people at most budgets aluminum is the way to go. I've done my research and asked the big companies, since I am in the market for a driveshaft myself.
There are combos and times where CF or Chromo would make sense, but for most people at most budgets aluminum is the way to go. I've done my research and asked the big companies, since I am in the market for a driveshaft myself.
Originally Posted by hrcslam
When it does crack it's done, it just takes a lot to crack it. There is no in between like chromemoly or most other structural metal.
Come again? It was actually YOU who stated it was weaker without clarifying circumstances. I was the one who clarified. Then you disagreed while saying the same thing......I agree with you BTW, now that the confusion is clarified by circumstances. No way I'd ever run a CF driveshaft (too expensive and zero tolerance for error).
Last edited by hrcslam; 04-19-2015 at 05:20 PM.
04-21-2015, 05:04 PM
#14
Has anyone in here who is bashing CF ever actually owned one? I'm probably going to get flamed for this but heres my actual experience and answer.
The one on my car is my dd. I bought it 2ndd hand but was still new so I didnt incur the cost of a new one. But anyone who thinks this thing is getting hurt by rocks is smoking something. The roads by me suck with construction and plenty of gravel. Mine has no nicks in it whatsoever they're very tough even though the underside of the car constantly gets hit with small rocks or whatever other debris.
Mine is an acpt thats a 3.25" shaft and holds 700whp. Can anyone point me in the direction of a metal shaft that will do that in a 3.25" size? I refuse to add any weight to my car and take it out when I can. Most dont realize rotational weight is one of the biggest killers of hp and acceleration of the vehicle there is, much more than static weight at least. The cf shaft in my car is 5lbs less than stock, to my knowledge there isnt one shaft out right now the same weight as stock, they're all heavier with a larger dia making the moi larger....
CF doesnt like bending force, but seriously who is out there bending their shaft in a U shape? And even so these things still arent going anywhere. The torsional properties of CF are where the real magic is. The shaft will not give under torque like a steel shaft and due to its lighter mass it accelerates much more smoothly (I noticed that instantly). That DOES mean its more brittle but once again if you're not pushing 600+ hp I dont see a problem, and most people on here arent.
Bottom line is if you can get a CF shaft do it. I have yet to hear of one breaking due to road debris lol. If it ever does break carbon fiber will just "unravel" and wont do any damage to the car, as opposed to metal which usually breaks and puts a few vent holes in the floor.
The one on my car is my dd. I bought it 2ndd hand but was still new so I didnt incur the cost of a new one. But anyone who thinks this thing is getting hurt by rocks is smoking something. The roads by me suck with construction and plenty of gravel. Mine has no nicks in it whatsoever they're very tough even though the underside of the car constantly gets hit with small rocks or whatever other debris.
Mine is an acpt thats a 3.25" shaft and holds 700whp. Can anyone point me in the direction of a metal shaft that will do that in a 3.25" size? I refuse to add any weight to my car and take it out when I can. Most dont realize rotational weight is one of the biggest killers of hp and acceleration of the vehicle there is, much more than static weight at least. The cf shaft in my car is 5lbs less than stock, to my knowledge there isnt one shaft out right now the same weight as stock, they're all heavier with a larger dia making the moi larger....
CF doesnt like bending force, but seriously who is out there bending their shaft in a U shape? And even so these things still arent going anywhere. The torsional properties of CF are where the real magic is. The shaft will not give under torque like a steel shaft and due to its lighter mass it accelerates much more smoothly (I noticed that instantly). That DOES mean its more brittle but once again if you're not pushing 600+ hp I dont see a problem, and most people on here arent.
Bottom line is if you can get a CF shaft do it. I have yet to hear of one breaking due to road debris lol. If it ever does break carbon fiber will just "unravel" and wont do any damage to the car, as opposed to metal which usually breaks and puts a few vent holes in the floor.
Last edited by redbird555; 04-21-2015 at 05:10 PM.
04-22-2015, 10:59 AM
#15
A 3.5 inch PST 6061 shaft will hold 1000hp and is almost a third of the price of your CF DS was new. Thats a massive, .125r larger than yours. Splitting hairs here.
There is a place for everything but spending $1400 on a DS that a LT1 will never ever see gains or benefits for, is silly.
Between a CF and 6061 shaft, I would guess the CF would resist tearing from a puncture wound much better. But, there is a reason planes and things are made out of aluminum and not glass mat.
Edit: The real gain for CF is as I said previously, your critical speed is much better than 6061/steel. But, again, last I checked, no land speed guys run boat anchor LT1s.
There is a place for everything but spending $1400 on a DS that a LT1 will never ever see gains or benefits for, is silly.
Between a CF and 6061 shaft, I would guess the CF would resist tearing from a puncture wound much better. But, there is a reason planes and things are made out of aluminum and not glass mat.
Edit: The real gain for CF is as I said previously, your critical speed is much better than 6061/steel. But, again, last I checked, no land speed guys run boat anchor LT1s.
04-22-2015, 03:52 PM
#16
TECH Addict
A 3.5 inch PST 6061 shaft will hold 1000hp and is almost a third of the price of your CF DS was new. Thats a massive, .125r larger than yours. Splitting hairs here.
There is a place for everything but spending $1400 on a DS that a LT1 will never ever see gains or benefits for, is silly.
Between a CF and 6061 shaft, I would guess the CF would resist tearing from a puncture wound much better. But, there is a reason planes and things are made out of aluminum and not glass mat.
Edit: The real gain for CF is as I said previously, your critical speed is much better than 6061/steel. But, again, last I checked, no land speed guys run boat anchor LT1s.
There is a place for everything but spending $1400 on a DS that a LT1 will never ever see gains or benefits for, is silly.
Between a CF and 6061 shaft, I would guess the CF would resist tearing from a puncture wound much better. But, there is a reason planes and things are made out of aluminum and not glass mat.
Edit: The real gain for CF is as I said previously, your critical speed is much better than 6061/steel. But, again, last I checked, no land speed guys run boat anchor LT1s.
04-22-2015, 05:34 PM
#17
My acpt was no where near 1400 new. The Driveshaft shop who took over ACPT will make you one right now for 750 out the door with everything and hold 800hp iirc. I paid 400 for mine. A pst is still cheaper but not 1/3 of the price. PST carbon shafts are grossly overpriced compared to other shops.
.25" isnt much between the two if they weighed the same but the moi on the pst is still a good bit more because it weighs almost twice as much. Pst 3.5" stock length shaft is right around 15 lbs. my CF one is 8.5 and that makes for a pretty good difference in inertia.
My point with my post was mainly directed at those who say they fall apart on the street and are like glass when something hits them. Thats simply not true, but since price was also borught up the price gap is much closer now than it was back then.
.25" isnt much between the two if they weighed the same but the moi on the pst is still a good bit more because it weighs almost twice as much. Pst 3.5" stock length shaft is right around 15 lbs. my CF one is 8.5 and that makes for a pretty good difference in inertia.
My point with my post was mainly directed at those who say they fall apart on the street and are like glass when something hits them. Thats simply not true, but since price was also borught up the price gap is much closer now than it was back then.
Last edited by redbird555; 04-22-2015 at 05:41 PM.
04-22-2015, 06:11 PM
#18
My acpt was no where near 1400 new. The Driveshaft shop who took over ACPT will make you one right now for 750 out the door with everything and hold 800hp iirc. I paid 400 for mine. A pst is still cheaper but not 1/3 of the price. PST carbon shafts are grossly overpriced compared to other shops.
.25" isnt much between the two if they weighed the same but the moi on the pst is still a good bit more because it weighs almost twice as much. Pst 3.5" stock length shaft is right around 15 lbs. my CF one is 8.5 and that makes for a pretty good difference in inertia.
My point with my post was mainly directed at those who say they fall apart on the street and are like glass when something hits them. Thats simply not true, but since price was also borught up the price gap is much closer now than it was back then.
.25" isnt much between the two if they weighed the same but the moi on the pst is still a good bit more because it weighs almost twice as much. Pst 3.5" stock length shaft is right around 15 lbs. my CF one is 8.5 and that makes for a pretty good difference in inertia.
My point with my post was mainly directed at those who say they fall apart on the street and are like glass when something hits them. Thats simply not true, but since price was also borught up the price gap is much closer now than it was back then.
I said that they ARE more fragile then chromo or Aluminum,which is a fact. Any stress mark, nick, or crack will be catastrophic on a CF shaft while the same damage on an Al or Chromo shaft would be negligible and still work for years.
If you don't agree, take that up with Denny's because they are the ones that told me that when I was looking for a driveshaft. Weight difference is tiny, 2-3lbs.
04-22-2015, 06:20 PM
#19
I'm not sure what we disagree on? I never said if they get a nick they wont come apart. Wht I did say is that its HARD stuff and you're not nicking it with rocks in the road like people in here claim, that was the problem I had with the responses. When I wasinstalling my torque arm I actually pulled a brain fart, didnt pay attention and whack the shaft with the end of the TA. Nothing happend.
And no way, I weighed mine, the stock aluminum shaft and a PST 3.5". CF was 8.5 stock was 13.5-14 and the PST was 15.xxx.
And no way, I weighed mine, the stock aluminum shaft and a PST 3.5". CF was 8.5 stock was 13.5-14 and the PST was 15.xxx.