I was wondering about this with you one piece driveshaft. With it being one piece I'm assuming it must have some give so that if you do a hard launch or do a hard downshift it doesn't break or possibly form a stress crack.

 

My engine is basically solidly mounted so I would have less movement or flex then most guys with stock or poly mounts. I have has the car upto 130mph and it is still dead smooth.

I'm just curious if it would be needed or not.

 

Had the protractor on it but did not write it down.

I am up in BC but come to Portland occasionally. Car is usually serviced at ER. Would be great to meet sometime. Always love your posts ...

 

Thanks. Shoot me a PM if you're ever in the area and want to meet up...

 

right. if you limit movement of engine and rear end you shouldnt have a worry at all. there are plenty of two piece shafts being run with no CV joint. and no reported issues that I am aware of. If there is an effect it would be accelerated wear on the input spines/yoke . but surely it takes a long time before its an issue.

here is a pic of the two piece shaft I made for the evo 4. original shaft weighs 41lbs. shaved 15lbs and it cost me less than 200 in materials since I utilized a factory mazda rx8 carbon shaft for rear section.. the evo 4 uses two cv joints. yikes. car drive much nicer with the two piece shaft





I have been planning but struggling for a driveshaft solution for my evo 1. would like to shave 8-10 lbs but will be a tall order as it already weighs 30.5 stock. the evo 8/9 shafts are 39.5lbs. funny a couple months ago found a guy in the UK that got his hands on some 2 piece titanium shafts from a evo x race team. he was converting them to work on evo 6 8 and 9. they weighed just 12.5 pounds!!. i wanted one bad but he was asking like 4500 for them.

 

Any updates on the driveshaft? How's it holding up?

 

Runs true, no vibrations, no clunk, no problems whatsoever.

Car is way more enjoyable as DD as it no longer needs dipping into the throttle for take-off. The rubbery driveline quality is gone and the stock clutch actually feels crisp now.

Car feels more lively and peppy at a wide range of speeds. Fuel consumption unchanged.

 

How did you adapt/connect the forward end of the rx8 shaft to the Evo 1 center cv joint?

 

there is a steel tube inside the end of carbon shaft. its long enough that it can be cut and welded without hurting the glued connection. you can weld any kind of end onto the shaft that is needed. its just the same as building a steel shaft.

 

Ok thanks, I think I've got it now. Do you recall the approximate weight on these units?

 

its not as light as some of the after market. its a factory piece so its over built so to speak. most of the weight savings comes from eliminating joints. especially when its a lobro joint

 

According to these guys, its about 10.5 lbs

http://www.ingearperformance.com/page/3