I agree with ChaseZ. My car bucked and coughed and was barely drive able at all. I thought I had screwed something up. It was just the Stillen tune. It is not setup for the A2A configuration but Seb has a baseline tune that will have your car driving like stock once again except with a lot more throttle response and of course, power!

Check the clearance of the strut brace and the front throttle body. Mine was touching and required some 12mm spacers at the brace bolt locations to get rid of the interference.

You should not have ANY belt slip cold or hot. It sounds to me that something is wrong with the SC. Did it turn freely before you installed it? Mine was a little tight but turned smoothly with just a little effort. The serpentine drive belt is designed to handle a lot of power (the SC at 7500 rpm should be about a 60 hp load). Take the serpentine belt off the jackshaft pulley and see if the SC is hard to turn. You should be able to turn it by hand.

Something sounds BAD. You should only be able to hear the SC rattle at idle. Above idle the only sound you should hear is the intake whine. Did you check the SC oil? It should be red. It is very hard to check the level as the dipstick gets oil on it as you pull it out. Best to check it after the car sits for awhile.

Is this a new SC or a used one?

I shot an email to SpecialtyZ for tuning options.

If I recall right, it spun freely. I will take the belt off again once the wife is home and can give me a hand locking the tensioner into place.

I am a little nervous about the strut brace since I have a vented hood. It fit fine stock but I've gotta be careful as to just how far up I raise it. I was a little scared that one of the SC pulleys was going to rub, but when I shut the hood it didn't sound any different. Edit: Strut bar clearance is good with the Stillen kit spacers.

Well ****...

Oil is brand new. It is a used SC with about 12k miles on it. I verified it was empty of oil, put a full bottle into it and checked to ensure I had oil on the dipstick.

That is the best way to verify the correct oil level. Drain and install a full bottle.

Neighbor thinks it might be a bearing. I am torn on this one though because the seller said that he replaced all the bearings in the SC. With that said, he wasn't able to retest... Does anyone have any thoughts on this before I do the work to take the SC and replace the bearings? Or any tips/tricks/things I should do while I have the SC stripped if I have to replace the bearings? i.e. order different bearings from Vortech

If I do have to break it down to replace them, I do want to paint the volute. Any thoughts on that?

I wonder why he replaced the bearings if the SC only has 12K miles on it. Sounds fishy to me.

You might want to talk to Vortec and see if they can replace the bearings and get the Si upgrade while they have it.

Sorry you are having to deal with this issue this late in the build. Good luck!

Yeah, I feel like there's always an issue somewhere haha, mine just happened to come up near the end.

A quote from the for sale post, "In its time it was 99% daily driver with one trip to the Dragon and one track day at Summit Point. After the track day it was louder than normal. When I got home I pulled it apart and one of the bearings had failed. Input bearing if I remember correctly. I replaced all bearings and seals and intended to reinstall but while everything was out I came across a new project and decided instead to sell the Z(it was too boring driving around with no boost!)."

I feel confident in my ability to rebuild the SC and I'm looking at ordering the 928 high-speed rebuild kit for down the road should I find myself pulling the SC apart for repair.

Edit: I shot Vortech an email asking for some assistance if they wouldn't mind providing it.

Listening to one of the videos leads me to think that there may not be anything wrong with the SC and the other makes it sound not so normal.

Sounds like mine: https://www.youtube.com/watch?v=obZlz3kMr0I

Less like mine: https://www.youtube.com/watch?v=E3pHfwP-nn4

A few bad bearing vids:
https://www.youtube.com/watch?v=Gz4J7lfA2sk
https://www.youtube.com/watch?v=4Rif4gSMQXU
https://www.youtube.com/watch?v=IhbzZLDP0cA

I don't think the SC sounds like any of the bad bearing vids, but I also think it's a little louder than expected. Again, I've reached out to SpecialtyZ and Vortech as well to see if they have any insight into what, if anything, may be wrong with the SC unit.

If you guys have any videos for me to compare mine to, I would appreciate it!

It is going to be very difficult to diagnose a bad SC bearing using a smart phone video being that the "normal" sound is pretty rough sounding. What bothers me about this is that the sound doesn't seem to go away as the engine revs. It should stop the rattling noise as the rpms increase (gear backlash is removed).

While I was researching the Stillen kit, I did run across one person that had a bad bearing problem with a new SC. If I remember correctly it had the wrong bearings installed from the factory. It may have been JWillis72 on this forum. He has moved on to a C7 now but he might respond to a PM.

What's up with these Vortech superchargers? They should be fairly bullet proof if they are operated as they should be. I had a ProCharger on my Mustang and it gave me no issues for 50k+ miles.

The "Less like mine" video is what mine sounds like. Listen as the engine revs up, the rattle goes away. If the rattle does not go away then their may be some gear damage. The previous owner said that a bearing had failed but he didn't say if any damaged resulted from the failed bearing.

I'm gonna crank the car up and rev a little to see what the sound does. I agree that smartphone video/sound is nowhere near ideal for diagnostic, but it's what I've got right now... I'm still waiting to see if Vortech will respond to my request for them to take a listen or ask for more data. There are definitely people out there experiencing this sound, so there has to be some explanation outside of conjecture and maybe Vortech knows. Hopefully.

The other thing, could it be the tune? Or the lack of tune, I should say. Could the rougher idle lead to excessive backlash, which is causing the sound to be louder? Again, I feel like I've heard many different stages of bearing failure, and this sound seems too catastrophic for the SC to continue functioning the way that it is (no excessive back and forth play in the pulleys).

It Lives!!
 

Talked to Sebastian at SpecialtyZ and he was able to prepare and overnight me a tune before he headed out to Zdayz! I can't thank him enough! Ironically, he is literally flying 90% of the way to me, just as I'm about to go on vacation haha.

Flashed the tune and the car is definitely better! AFRs are higher than I'd like, but for the first iteration, that's to be expected.

AFRs are about 14 WOTish, 16 cruising and 18 under light load, light throttle conditions. Pretty high... I can feel the engine pull timing around the 16-17 mark. I will officially start the data logging process when I get back from vacation, but I'm doing a few drives to get dome prelim data for Sebastian to work with when he gets back from Zdayz and I'm gone.

I have a very small gas leak from the tophat. It's coming from the return penetration. I think it came loose during the final installation, so I'll have to pull it out some after I've run some gas out to tighten the connection. Fairly heavy gas smell in the cabin...

My rattle can isn't much quieter, but that's to be expected haha. The vibration in reverse, I think, is coming from the intake being pressed against the hole that it runs through in the front passenger side and the direction the engine moves when in reverse pushes it more against the car, causing the vibration. I'll widen the hole a little more and that should solve the problem.

I would say I'm about ready to be added to the FI builds! I don't have any numbers yet, but I'll post them up when I get a chance to get to a dyno.

Things upcoming (probably once they fail haha):
Headers (maybe)
Level 10 tranny
Forged internals (maybe stroke out to 4-4.2)
SC impeller, bearing, and pulley upgrades
CSF Radiator
Oil Cooler

The last thing... Stickers... My car is still a daily driver, I'm not rockin' any sponsorships, and I don't wanna make it look crazy, but at the same time, I'd like to give credit where credit is due. Did you guys put the stickers on? And if so, where?

Thanks again for all your help and input!!!!!

-Brett

Just say no to stickers
 

NO stickers, none, not one!