It arrives on Monday. I will let the forum know if it resolves the wobble feeling the first one had under full boost. I am praying it does.. The stock shaft feels like a piece of crap after you feel the aluminum shaft. (big detailed review pending if the new ones smooth all around)

This driveshaft is 25lbs. . making it the lightest aluminum driveshaft to exist for an evo right now. i just hope the next one i get is smooth under load / full throttle so i can keep it on the car. (it'll also be priced super competitive - that is if i can approve of it first on my car).

Exedy triple HD (i had a twin hd before, but it started to slip after around 8k miles)

Trans is a Shep trans with ultimate ratio (evo 9 1st, the rest is evo 8 gearing / billet output shaft etc)

Ya its fun to drive.. just need to get it back to the track. if all goes well ill have the shaft in by Monday and then will go to track Wednesday. (praying the shaft is 100% smooth in full boost this time)

 

Tom,

I may very well be wrong here, but maybe the issue with that aluminum shaft is the combination of the material and the length of it. Since you mentioned its happening only under WOT, you may be experiencing deflexion and vibration due to the flexibility of the material. Steel would probably not act this way, but then you lose the weight advantage. Just thinking out loud...

That thing looks quite a bit longer (just eye-balling it) than say an aluminum driveshaft made for a Mustang. Those guys are able, however, to get the strength and vibration issue under control by increasing the diameter of the DS. I don't know if we can fit a larger diameter under these cars or not?

 

Tom,

Good luck on the 2-piece driveshaft... they are not as simple to make work without vibration as many people imagine, especially when they have to spin fast enough for 150 mph. Two piece driveshafts using only u-joints need to have the u-joints at very specific relative angles to operate without vibration. The 3-piece design of the stock driveshaft using a CV joint is the reason its vibration-free. Someone needs to make a light weight 3-piece shaft utilizing the stock layout.

 

I hope you're wrong, but its definitely a possibility. however this driveshaft is on about 50-60 other evos including evo X's and no one ever mentioned any vibrations or wobble sensations like i noticed. i cant see myself being the only person to notice a difference.

I think it was the core that was sent in that caused this. I had my friend send in his core for me so i wouldn't have to remove the driveshaft off my car. Well after speaking to him more, his core had an issue just like this as well, so im thinking something was bad from the beginning and the shop did not catch the core being bad, and reused.. so now i have the same symptoms the core did that was used to convert it.. i would of thought it would have shown up in a balancing test, but maybe not.


Thanks Mychailo. I hope it is not something normal that comes with the two piece, if it is, i will not be able to live with it. according to the driveshaft guy though, its not normal and that he feels he can eliminate it. so he sent me another driveshaft over that i will receive on monday.

The shafts will come from a driveshaft shop that has made thousands, but only at best 100 for the evo world to date. they are new to making them for the evo, and he said he has a way to get them down to 22-23lb once his new stuff gets fabricated.

The next shaft hes sending me he mentioned he used bigger ujoints for testing so i am interested to see how this new one behaves.

The only driveshaft shop i know that does cv's in their shafts right now and offer aluminum are driveshaft shop.. and carbon fiber.

I will keep the thread updated so we can see how the new one turns out. i hope its smooth.

 

Myself and another forum member are running this 2 piece driveshaft-ZERO issues.

Like Tom said, I think that a bad carrier bearing from the core shaft that I sent in for him got mistakenly reused. Reason I say that is that Tom's problem is the EXACT same one that the core had. I only told Tom and the driveshaft builder that it had (at least 1) bad carrier bearing 30000 times. I guess it should of been 30001 times

 

LOL!

Not my fault.. blame Bill. I told him also over the phone 5x within 10minutes.

I hope the new ones good to go then i can get this POS down the track again one last time this year.. maybe i will speed shift it this time.

 

New driveshaft came today. I installed it around 10pm. This one was a little different then the other one I had received.

This one is noticeably longer. I think that may have been the issue with the other one. It was to short and binding up. (Just guessing)

This one also came in (2) pieces this time with arrows pointing to where it needs to be bolted up for proper balancing.

This one also has the same resistance at the ujoint flange / yolk end that attaches to the transfer case as my old oem (good / smooth) driveshaft has.The one that had an issue had no resistance, So potentially the u joint was bad there as well on the old one? (Again just guessing).

Below are two pics up for now. I will update the thread to let you guys know if its fixed or not tomorrow. I am pretty certain this one is going to be smooth (praying it is).

If this one is good / smooth, and passes my testing, Then I will start offering them to the community for a really good price that will beat any current pricing to date on an Aluminum driveshaft for the Evo.

These are available for the evo X and other manufactures as well.


They come from Bill's Englewood driveshaft shop in Colorado.

 

Thanks Tom

in for test results on this

 

ok just tested the new driveshaft. you can feel it turn under the car.. but i could feel the stock one also like this.. i only have 1 seat in my car the driver seat, and this is about the same feeling i got when i had the stock one in. you can feel there's something down there rotating but its smooth.

so the new driveshaft is smooth and fixed the pulse issue. its crazy how much smoother in general regular stop and go driving is vs the stock one.. i cant even get over that part.

ill make a review on the driveshaft, so i don't wanna say to much. it goes from something that feels like it "chugs" to a smooth luxury car type feeling on stop and go.. the lighter shaft really tightens the car up and releases all the restriction its so noticeable.. that's probably why i could not get used to the stock one after feeling this one. deceleration doesn't even feel like an evo.. it feels to smooth.

so its smooth now and the car pulls very very hard. noticeably harder vs the stock. i need to get it to the track now asap.. it should produce some really solid times.

 

^ do you still need to drill out for the larger hardware or is it oem size?

 

I used the old flange i drilled out. it still is using the bigger bolts for the rear diff flange. the flange is easy to swap out though ive done it twice now. with a makita impact it takes a few seconds.

a flange with smaller holes can probably be sourced, but theres a quick fix to the bigger bolts by using a sleeve in the flange. i think ill still test another driveshaft from the driveshaft shop yet then i will stop messing with the driveshaft. their new shafts use CV's like the oem shaft.

 

Tom,

How do you find the AMS F1-i Manifold? Are you running the Boomba 75mm throttle or stock throttle..?

Did you have to do much to the upper intercooler pipe to get it to fit? Do you think it has increased booth threshold / lag??

I have quite a similar setup except I run different cams, intercooler and my FP black is still the old style. My current intake is the MAP REV3 ported with MIL.SPEC flowed throttle, but Im thinking of going bigger.

 

Hi Tonba,

I'm running the 70mm full blown throttle body and it works great. It has really good idle and driveability characteristics.

I like the AMS F1i, it works great as well. It has opened up a lot of power throughout the powerband.

You will need a custom upper pipe like the ETS. If you need any parts feel free to msg me. Id highly recommend the ETS upper pipe with the F1i, it fits perfect and quality is very good.

It has not created any lag that i noticed and im a pretty picky person as you can see with the driveshaft stuff.

I had the rev 3 before also and the mil.spec tb. i sold it to my one local friend/customer, and he is making great power with it on his car. the only difference is, his engine is a 2.4 and mines a 2.3, and he has an evo 9, and i have an evo 8.

What cams are you running? i can give you some info regarding cams if you need any. i went from kelford 272 to gsc s3. ive noticed a good gain of power across the entire powerband with the camshaft swap, but have not gotten the car down the track again yet to actually see if i picked up mph or not.

The driveshaft feels like it made the car spool alittle quicker as well and it seems to have about 20whp gain maybe.. its noticeable. not playing with vd anymore though, i will let the track tell me whats going on. im making around 640whp according to vd.

 

VD or a dyno pull will be able to pick up differences in inertial mass.

 

Tom you aren't using VD anymore? or just not using it on your personal car?