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NVHPTSD would be a suitable license tag at this point.
That's pretty good. I could get some big ol' bumper stickers made slandering the driveshaft companies involved too. "INDY RACK & AXLE RUINED MY CAR AND MY LIFE".
Originally Posted by Fireindc
Hell of an update man, I love your posts. It's so much work and satisfying to see you knock it out like that. As usual I'm on the edge of my seat waiting to see what fixes your NVH.
Hey at least all these debacles are leading to decent entertainment for the peanut gallery right? Lol. I'm on the edge of my seat as well.
Originally Posted by SimBa
What's with the ground strap going to the diff? Does that replace the ground strap that would have gone to the PPF previously?
Dang man, who's making these driveshafts, Chiquita?
Yeah, that's the PPF ground. It's been in a myriad of different places now. First the PPF, then directly to the Miata diff when I deleted the PPF, and now directly to the Getrag diff where the OEM mounting brace would go. Luckily I had my bag of 500 random bolts with me and exactly one was the correct thread pitch.
Whoever's making these driveshafts obviously threw QC out the window completely to increase productivity. Whoever put my last two driveshafts in the balancer must have been blindfolded.
Originally Posted by OptionXIII
I'm not sure I trust any driveshaft shop that isn't in my area at this point. There are a few ones out there highly recommended by the Jeep forums I frequent, but when was the last time you heard of people that built off road XJs having particularly high standards for NVH and balance?
I replaced my stock driveshaft after finding a failing u joint while chasing a small vibration. The Dorman shaft was $200 and had a visible wobble. I returned it. The FM shaft was $300 and looked to be identical to the Dorman other than price and part number, down to the paint shade and sticker, location and size of the balancing weight, and the amount of wobble. Neither made a difference in the vibration I have.
Your experience is way, way worse.
I remember you mentioning this in another thread. That's annoying as hell finding that all these off-the-shelf components are likely the same part just tagged differently. At least you know a local driveshaft shop is going to put in the work to make sure you're taken care of, as opposed to a faceless supplier with a full degree of separation between them and the customer.
I spoke to my driveshaft shop this morning. I'm gonna pull the adapter plates off of my trans and diff and bring them in tomorrow so the shop can ID the bolt patterns and build an adapter-less shaft. The adapters are steel and probably 5-6" in diameter, and easily weigh 4+lbs each.
This is probably a stupid question, but does anyone think the weight of the adapters may cause them to act as vibrational dampers to a certain degree? I know removing them shouldn't be an issue but I'm gonna put my head through a wall if I incur any other vibrations during this swap.
I spoke to my driveshaft shop this morning. I'm gonna pull the adapter plates off of my trans and diff and bring them in tomorrow so the shop can ID the bolt patterns and build an adapter-less shaft. The adapters are steel and probably 5-6" in diameter, and easily weigh 4+lbs each.
This is probably a stupid question, but does anyone think the weight of the adapters may cause them to act as vibrational dampers to a certain degree? I know removing them shouldn't be an issue but I'm gonna put my head through a wall if I incur any other vibrations during this swap.
I can't imagine a fully metallic giubo offering any real dampening effect(?)
Yo! Yeah, I'm running the 7" core FMIC.EU intercooler that came with my Kraken kit still. Hasn't become a restriction on my setup at 300whp and IATs haven't gotten out of control on track at 270whp or hot canyon runs at 300. I should probably do some research on how far I can push the thing as I'll inevitably run more power...
Edit, just found what I believe to be the intercooler I have on FMIC.EU's site. They claim it's suitable for up to 400hp. Not sure if that's crank or wheel.
Thanks for the response. I figure I'll shoot for ~350HP in a season or two, but that's a ways away.
I could cobble something together now, but I'm leaning towards waiting and getting a kit that's designed to work together so I can forget about it and move onto other parts of the car. If Kraken's setup works then it seems like that's the easy button.
I've been covering this much more on my other thread about the driveline vibration, but here's the current long and short of it with the new driveshaft.
I received and tossed the new shaft in today. It didn't fix anything. Vibration at 50mph, maybe even a little earlier than before. F*ck. Spent a couple hours doing research on C5 and C6 Corvette prices. Went back and put the car in a lift and found that neither the driveshaft or trans adapter were perfectly centered on the pilot shaft, causing runout in both. Additionally, the front of the shaft wasn't centered on the trans adapter... causing more runout. See video.
I got real scientific with it and ran the car in the lift in first gear, marking the low points of each driveline component with a sharpie as the driveline rotated. I was low on time and the rear adapter and front driveshaft flange seemed to have the most runout, so I loosened each of those individually and kinda just pushed them in the opposite direction and re-tightened everything. The front adapter and driveshaft flange still have some runout, but are much better than before. Vibration doesn't start until 65mph now and is much more mellow than before. It's still pretty bad at 95-100mph. Not nearly as bad as the Miata diff with the poly bushings, but not quite as good as the Miata diff with rubber bushings. For reference, I have a rubber OEM bushing in the Getrag diff and the adapter brace has small diameter poly bushings in it. If I could put some rubber bushings in the Getrag adapter, the vibration might almost be acceptable for track use.
I didn't take an after video, but the front driveshaft flange and adapter still have some runout that I need to take care of. Who knows, maybe the vibration will be gone after that.
Jesus Zak, stay with us bud. You aren't a corvette guy, I can't see it!
I'm still stuck wondering what's the difference between you and Greg's setup. What driveshaft is he running, does he use the adapters?
After My runout issues with brofab adapters I'm definitely skeptical that they could be the cause, but it really sucks throwing money at something in hopes something sticks. Go ride your MTB and come back to it, I know you'll get it...
I'd hate to see this thing parted out in defeat but I am all about an American Miata. C5Z prices aren't terrible right now, considering what you're getting with that package.
I'd hate to see this thing parted out in defeat but I am all about an American Miata. C5Z prices aren't terrible right now, considering what you're getting with that package.
Blasphemy! Don't even say that.. I'm sure he'll get it sorted. Worst case just let it sit for a little bit and come back at it. With that said I do wonder sometimes if I shoulda just pressed the easy button and gotten a c5z. Performance bang for your buck it probably can't be beat but I prefer how a very light weight car feels.
Meh, I've caught C5Z's (plural) on the back straight at Sebring. And I've driven a couple and the steering is heavy, numb, and not very fun. And consumables are much more expensive.
This issue sucks but it is fixable. Just gotta find it.
Jesus Zak, stay with us bud. You aren't a corvette guy, I can't see it!
I'm still stuck wondering what's the difference between you and Greg's setup. What driveshaft is he running, does he use the adapters?
After My runout issues with brofab adapters I'm definitely skeptical that they could be the cause, but it really sucks throwing money at something in hopes something sticks. Go ride your MTB and come back to it, I know you'll get it...
I know, I know I can’t do it, it’d be too easy and I couldn’t transfer my ghetto digital dash over hahaha.
So mine and Greg’s setups are exactly the same aside from the ZF5/ZF6 transmission. He’s got adapters on both ends too. I’m assuming his adapters and shaft self-center much better, though. There’s no way you could bolt everything up and get lucky with everything being aligned on my current setup.
I’m actually headed up to Mammoth Mountain to hit the bike park and camp with some buddies this weekend. Lucky timing for a little mental reset on this thing lol.
Originally Posted by Stock
I'd hate to see this thing parted out in defeat but I am all about an American Miata. C5Z prices aren't terrible right now, considering what you're getting with that package.
Dude, don’t tempt me! I didn’t actually get close to messaging anyone but yeah, current bang for your buck on those is nuts.
Originally Posted by sixshooter
Have you tried turning it off and turning it back on again? -my IT guy
Are the adapter holes centered? Are the adapters out of balance? If you balance the dead center on a ballpoint pen, is it balanced?
There’s a little bit of adjustment in the adapter holes on both ends. I can’t tell if they’re perfectly centered, but the adapters themselves look to be round and true. I should be able to get them centered, just gotta play with it. If the vibe persists with everything centered, I’ll remove the adapters and have the balance checked.
Originally Posted by SlowTeg
Blasphemy! Don't even say that.. I'm sure he'll get it sorted. Worst case just let it sit for a little bit and come back at it. With that said I do wonder sometimes if I shoulda just pressed the easy button and gotten a c5z. Performance bang for your buck it probably can't be beat but I prefer how a very light weight car feels.
I know, I know. I’m taking the weekend off and will resume d*cking with it on Monday. I’m sure the C5Z handles sick but I’m with you, these little cars are just too much fun to drive. If I’d initially known how much money I was gonna dump into this car, I might have bought something else. The character-building alone, however, was worth it lol.
So I took Nate and Teg's advice and took a break from the car for the weekend. Headed up to Mammoth with some buddies and meditated here for 14 hours until I reached driveline elightement.
Just kidding. All I figured out was that I could probably toss a couple hose clamps around the front of the shaft to counterbalance it once I got the alignment near-perfect. I pulled the car into the lift on my lunch break today to further examine and experiment with the drivetrain.
I checked. The axle is fully seated. Disregard the hose clamps on it, that was me experimenting if I could get the vibration any smoother in the meantime by counterbalancing it. But... yeah... another warranty issue with parts from my kit. I've already messaged KP about getting a replacement axle.
At least popping in a new axle won't be too intrusive of a repair lol.
That's just wild. You keep on taking the punches with grace, friend. I hope they fix this for you quickly.
No joke dude! Mammoth mtn in the summer is awesome. Epic vistas and a 2,000 vertical foot gondola in the bike park. Too rad.
Lol, thanks Ricardo. The situation is honestly laughable at this point. Hopefully this issue is the smoking gun and I'm done having to mess with it after this.