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I am in a dilemma here. I swapped the stock diff brace for an HPI mount, however I was unaware of the consequences that would follow removing the harmonic damper as it will not fit with the HPI mount. The vibration has completely killed my enjoyment of the car, however the HPI mount has resolved much of the wheel hop so I am hesitant to go back. Is a solid mount (ex: double barrel AMT mount) with the harmonic damper more tolerable or are there other major downsides to consider? I am just so concerned with breaking something with all of the wheel hop and drivetrain shake that the stock diff mount/poly torque tube bushings produce and I don't want to throw the whole bank account at it trying different setups.
Just installed the HPI mount, defiantly not a plug and play install.
* Re-machined the counter bores to a larger diameter so you are able to get a socket on the bolt head.
* Had to modify the bracket to so the damper was able to be reinstalled.
That's kind of what I was thinking was going to have to be done to the bracket to make it work but I couldn't see well enough to confidently determine that was the case. Very happy to see other's solutions to this because the positives of the brace really are a lot to ignore. Did either of you (or anyone that's managed to make the brace and damper coexist) notice a significant change/reversal of the extreme vibration when you got the damper refitted?
Well it sounds like it will absolutely be worth the effort to get this thing back on there because as a 26 year old male who's had obnoxiously loud and uncomfortable cars my whole life, the NVH was unbearable to me. And the other guy wasn't kidding when he said the install was not plug and play. Carefully bending brake lines and cutting down washers to fit in the bolt holes so I could both tighten and losen the mounting bolts was not something I was anticipating.
Well it sounds like it will absolutely be worth the effort to get this thing back on there because as a 26 year old male who's had obnoxiously loud and uncomfortable cars my whole life, the NVH was unbearable to me. And the other guy wasn't kidding when he said the install was not plug and play. Carefully bending brake lines and cutting down washers to fit in the bolt holes so I could both tighten and losen the mounting bolts was not something I was anticipating.
did you end up Reinstalling the damper did it make a difference?
I had the HPI installed for a while without the dangling *****. I too, could not stand the NVH it introduced. Never tried the HPI with the damper but I removed it and went back to a refreshed rubber mount. The juice wasn't worth the squeeze for a road car in my case
I use a Double Barrel mount leaving the dingleberries in place. I can say there is a slight NVH change as I replaced an OEM 25 yr old mount with 129,000 miles on it. It is more sound than actual vibration.
I installed my HPI brace in 2020 at the same time I fixed my driver's side leaking differential seal and also installed a transmission brace while I had everything apart. I removed the damper at the same time. Not sure if the transmission brace is the key, but I have ZERO NVH with the missing damper. No wheel hop, no slop in the driveline, no noise/vibration. It is perfection! The transmission brace is a royal PITA to install with the transmission and diff in the car, but it can be done!
C5Z HPI Brace vs Solid Mount vs Stock
