Verus Carbon Fiber Driveshaft - New revision

[NoHaveMSG]

Originally Posted by FrickingReallySlow

Quite a lot of people have had the same experience. Do you also have trans/diff bushing / stiffer engine/trans mounts?

Current thinking is that the 2 shaft design was paired specifically with the potential NVH of 86 platform to remove vibrations and break potential resonance. Carbon fiber provided some dampening and people generally got better results compared to AL

It could be a self selection bias here where the only people that get one piece driveshafts are the ones that want stiffer response everywhere in the drivetrain by add stiffening, more NVH is added as input and the chassis + one piece driveshaft gives the resonant vibration transfer function. I also have a DSS aluminum without any bushing/mounts and its fine even to 105mph. Just a datapoint.

This is also assuming the tail bushing on your trans isn't wiped

Are you MT or AT?

[FrickingReallySlow]

2015 FR-S MT

[StraightOuttaCanadaEh]

Originally Posted by FrickingReallySlow

Quite a lot of people have had the same experience. Do you also have trans/diff bushing / stiffer engine/trans mounts?

Current thinking is that the 2 shaft design was paired specifically with the potential NVH of 86 platform to remove vibrations and break potential resonance. Carbon fiber provided some dampening and people generally got better results compared to AL

It could be a self selection bias here where the only people that get one piece driveshafts are the ones that want stiffer response everywhere in the drivetrain by add stiffening, more NVH is added as input and the chassis + one piece driveshaft gives the resonant vibration transfer function. I also have a DSS aluminum without any bushing/mounts and its fine even to 105mph. Just a datapoint.

This is also assuming the tail bushing on your trans isn't wiped

Yes I have Perrin engine mounts and trans support and the Whiteline diff bushings and shifter insert. The fact that it appears at precisely the same speed every time (unless I'm driving uphill or downhill - then it's sooner) kinda makes me think it's got an inherent flaw. Then again the previous owner didn't say he had any NVH issues. I don't remember who he was now, would've been useful to ask him if he had any bushings. Perhaps we should create a poll

[Turdinator]

I'd wait for Verus to come back to you before stressing too much.

Ok, story time! I bought a 2nd hand CF Driveshaft Shop one and had vibrations from the start. I ended up taking it to be balanced, which was difficult as here in Aus no one I spoke to had balanced a Cf driveshaft before. The first place just shimmed the unis which helped a little but I still had vibrations. The next place I found did a much better job but they weren't sure on how to attach the balance weights. They ended up just taping them on the shaft, leaving it to me to attach them permanently. I was ok with this as they didn't even charge me, in fact they nerded out quite a bit about the CF. I contacted Loctite about gluing steel to CF, bought the product, borrowed an applicator from work and here I am 3 years later with a light ass drive shaft that is as smooth as silk at any speed that I have been brave enough to drive at.

[Ohio Enthusiast]

Originally Posted by Turdinator

I contacted Loctite about gluing steel to CF, bought the product, borrowed an applicator from work and here I am 3 years later with a light ass drive shaft that is as smooth as silk at any speed that I have been brave enough to drive at.

Is the driveshaft clearcoated in some way? Or is it bare CF? Did you sand/scuff the CF before gluing?

[Grady]

Originally Posted by Turdinator

I'd wait for Verus to come back to you before stressing too much.

Ok, story time! I bought a 2nd hand CF Driveshaft Shop one and had vibrations from the start. I ended up taking it to be balanced, which was difficult as here in Aus no one I spoke to had balanced a Cf driveshaft before. The first place just shimmed the unis which helped a little but I still had vibrations. The next place I found did a much better job but they weren't sure on how to attach the balance weights. They ended up just taping them on the shaft, leaving it to me to attach them permanently. I was ok with this as they didn't even charge me, in fact they nerded out quite a bit about the CF. I contacted Loctite about gluing steel to CF, bought the product, borrowed an applicator from work and here I am 3 years later with a light ass drive shaft that is as smooth as silk at any speed that I have been brave enough to drive at.

What max speed?

I have one that may be a culprit of a harmonic vibration at around 130. Talked with Verus on it and with my gearing it was balanced at a speed of 165 mph. Have not worried about it, all the tracks I drive on 110 is about the max speed.

[billstock67]

Originally Posted by billstock67

Not unexpected, Verus has requested that I rotate 90° and retest.

Will report back.

Rotated 90°, no apparent change.
Verus has shipped replacement.

[orz]

In the 2nd picture the flange looks bent right where you see that burnt blemish mark. I suspect that if the mating surface isn't flush then that would cause severe vibration issues.

[billstock67]

Originally Posted by orz

In the 2nd picture the flange looks bent right where you see that burnt blemish mark. I suspect that if the mating surface isn't flush then that would cause severe vibration issues.

I believe that is an optical illusion, due to camera lens angle. The outside of the flange is scalloped, so anything other than 90° appears as less than flat.
Surface checked perfectly flat prior to install.

[FrickingReallySlow]

You can try to back out your mounts/bushings and inserts to see if the vibrations shift or go away. I suspect that it will but could be PITA to do again. if it does alleviate the problem, have to decide which of the two things you want to keep

Originally Posted by StraightOuttaCanadaEh

Yes I have Perrin engine mounts and trans support and the Whiteline diff bushings and shifter insert. The fact that it appears at precisely the same speed every time (unless I'm driving uphill or downhill - then it's sooner) kinda makes me think it's got an inherent flaw. Then again the previous owner didn't say he had any NVH issues. I don't remember who he was now, would've been useful to ask him if he had any bushings. Perhaps we should create a poll

[billstock67]

Originally Posted by billstock67

Rotated 90°, no apparent change.
Verus has shipped replacement.

Installed replacement shaft, unfortunately same at 80mph + as first one, plus experienced an even greater amplitude vibration when slowing, in the 75-65 mph range.

[Joveen]

Did you do the install or shop with experience did?

Sent from my SM-G998U using Tapatalk

[StraightOuttaCanadaEh]

Originally Posted by FrickingReallySlow

You can try to back out your mounts/bushings and inserts to see if the vibrations shift or go away. I suspect that it will but could be PITA to do again. if it does alleviate the problem, have to decide which of the two things you want to keep

Problem is - which bushing/insert do I target. And yeah the diff bushings, I'm not sure what those do, but the trans insert, shifter bushing and engine mounts I like a lot.

[billstock67]

Originally Posted by Joveen

Did you do the install or shop with experience did?

Sent from my SM-G998U using Tapatalk

I did.