Changing out the DRIVESHAFT?

[jibbby]

Zuffen - 20hp for $600 sounds nice...sign me up... Does that also mean I can get 100hp for $3000... How about a bulk deal like 300hp for $7000?.... You know I am just kidding around with you...

Anyway, I am hearing way too many horror stories about the alluminum driveshaft failure...Lex I think I am going to pass on this for safety reasons alone for now...I am still planning on calling Jim to get his lowdown on all this crap......I get a little wheel hop at times too..

Curious, what are the top dragsters running on these day...Steel?

 

[Lextreme II]

First of all, I dont plan to run aluminum driveshaft anyway. I am just going to shorten the current stock SC400 driveshaft for about 175-200 usd. It will be balanced of course. That being said. Most lexus SC400 dont see more then 500 hp anyway. So for that amount of hp, aluminum will ok. High hp, i would stay away from it.

 

[cowboy bebop]

Jibby, if you've got wheel hop, then you want something that's stout. I have wheel hop in the 1st to 2nd transition, and it's gotten burly from time to time. FWIW, I've seen guys with less than 400 rwhp 400rwtq twist the driveshaft into a knot because of a seconds worth of wheel hop.

I'm pretty certain that the Th400 when applied to an SC300/400 and MKIV need a custom length driveshaft.

Eric

 

[jibbby]

Ok, still with that all being said I might very likely be seeing 500+rwhp one day in my sc400...I was considering a big block Chevy swap for a second just last week...So for me this Aluminum driveshaft may not be choice... I love the idea of losing weight on the shaft, but not at the risk of future failure.

Cowboy, I had crazy wheel hop and went sideways in first and just a hair in 2nd while under nos, but that was when I ran a Kaaz LSD with stock SC430 tires about a year ago. Now with the Torsen LSD and the Eibachs and tomico's broken in and fat rears...I now just get a hair of wheel hop in first at times...I also am now running lower profile tires in the rears then in the fronts and I believe that also has helped with weight transfer out of the blocks and has helped reduce wheel hop...

Cowboy - I thought your Supra was equiped with coilovers which eliminate or greatly reduce wheel hop? If your into handling and are not into dampening wheel hop is hard to eliminate with an almost weightless tailend...

 

[cowboy bebop]

There's a number of causes for wheel hop, but worn out bushings are the usual suspect. Titan Motorsports has solid aluminum bushings that I may try. A friend installed them on his SC300T, and his wheel hop disappeared.

Eric

 

[jibbby]

Really????? Bushings??? I guess if the arms are not fitting on tight from worn bushing I could see that happening...I never thought of that..Wow... So what do you think just the lower rear control arm bushings or all? I never changed out my rear bushings just my front end bushings and arms..I will give it a go and change out the rear bushings. I got a set of rear bushings handy and ready to go..., it's just alot of work changing out those rear bushings as apposed to the fronts....Cowboy Let me know if that helps with your wheel hop problems...interesting...

 

[cowboy bebop]

It'll be a while until I change them out, but if we go out to Titan late one night again, I may get a wild hair and press them in.

Thanks man,

Eric

 

[Lextreme II]

Gents... stick with the topic.... Driveshaft...

 

[jibbby]

Ok back to topic - How about these carbon fiber driveshafts....How much more $ can they be? Are they reliable? Again what are the Nascar, Funny car, and Top fuel dragsters, and monster trucks using in regards to their driveshafts? Alluminum, Carbon Fiber, or Steel?...I have never seen a driveshaft snap on the Nascar curcuit.....Anyone?

 

[xirforever]

You wont see one go in NASCAR because they arent doing stop go racing, its all very continual and boring IMHO. Top Fuel i think they just go straight from motor to clutch to rear diff. They have 1 gear. Not sure about Funny Cars but i suspect they run the same type of setup as they are close to topfuel cars just a different body and whatnot.

 

[DHBomber]

http://www.acpt.com/
I had a FD3S and these are the driveshaft to get. If i'm not mistaken, they weigh in at about 9lbs. Top notch stuff. The best thing about them is they kill harmonics, and take the shock loading very well. They are/were going for about $900-1000 and are able to make any custom driveshaft you want/need.

 

[Kiwi.in.aus]

Jibby I had a chat to the guy in the unit next door who currently runs one of the cars in the SuperCar support series and who was in the main game for over 10 years , read the guy knows whats what !!

The Supercar boys WILL NOT run alloy driveshafts as if you make them with a class of alloy and wall thickness enought to do the job they are almost as heavy as a steel one and are still weaker !!
To build one of these cars is at least $250,000 so money is not a problem and they have a lot to gain but reliability is a huge issue , alloy units are just not able to take any abuse at all , so they don't run them , so if those guys think that an alloy driveshaft is not an acceptable risk [ with all the money and engineering ability at their disposal ] I wouldn't run one either .

 

[jibbby]

DHBomber - Carbon Fiber shaft is the way to go by far...That is a great link... Estimated 5% power gain with CF shaft....9LBS approx....$1000 (ouch)... Reliable and strong but oh so costly.....The only thing is I could not find out what is the maximum HP rating on the custom CF replacement shaft for the SC's.... From what I am reading I am asuming close to 4 digit horsepower...This is good news....

I never knew Carbon fiber was so strong....

Kiwi - I am done considering the alluminum shafts...It is apparent they are weak and unreliable over the long haul...

5% power gain on 500hp is 25hp....

 

[skid]

Just a waste of time.

Most of you running street cars will go with after market rims and low profile and wide tyres (tires) for the bling factor which 99% of them weigh more than the original manufacturers spec. This increases the drive line effort to get it all moving. All those £$£$ to save a small weight on a drive shaft is irrelevant.

If you want to go faster junk all the crap you carry in the car. You need 1 lightweight seat, (2 if you're lucky enough to have an understanding woman ) no electrics, a fire extinguisher and a tube of tyre weld should you get a puncture.

I bet you can save 150kg, 300ibs, from the average gadget laden saloon.

less weight = free real world performance and better economy!

win/win methinks.

Mark

 

[jibbby]

It wasn't just for the weight reduction but for additional driveshaft strength from the stock driveshaft...The sc400 stock steel shafts have a breaking point and my thoughts were too reduce weight on the driveshaft and increase strengh by changing out......

If you arejust changing the driveshaft to reduce weight I agree it is a waste of money....

 

[cowboy bebop]

It would take some SERIOUSLY hard launches... I mean at 20psi on the two step with a 77mm turbo to pretzel the driveshaft. Wheel hop will kill it also, but that's if you get in the hop and stay in it until it breaks. Usually once the hop is felt, a driver backs out a hair.

Eric