Earlier this year I blew up my VQ37VHR 7AT. It's got a Stillen kit, safe tune, 8 PSI boost, and I used to beat it mercilessly.
It was just too easy to mash the pedal and let it scream, and scream it did.
I let the oil run low and got some CEL VVT codes, and I assume there was some contact between moving parts at 7k RPM or so.
When I got it home I added some oil and cleared the codes.
It starts and runs (sounds like it's missing 2 cylinders) and smokes.
It's in the bay to pull the motor but I've got other projects I've been working on so I've had a lot of time to speculate about what I'll find.
Sucks because it's only got 34k miles on it. Too bad I'm a knucklehead that got too busy to check the oil.

I can get a 70K mile motor cheap enough but I've been working on my old cars.
Just pulled the 302 and trans from my 82 Foxbody, did HCI longtubes timing chain oil pump water pump clutch and swapped the trans.
Coming out and going back in was a few hour affair each way.
Not gonna be the case with the G37, installing the Stillen kit was a PITA, and I'm not looking forward to it (I hate doing body panels).

I'll check the VVT gaskets or orings (whatever the problem area is) on the "new" motor before it goes in and keep up with oil maintenance once it's running again.

Anyway I was wonding what you all think I'm gonna find met its demise when I tear down the engine.

 

So you installed a Stillen SC at roughly 30K miles and eventually blew the motor up, or its just misfiring and burning oil? How did the transmission hold up with 8lbs of boost?

 

Yeah I drove it for a few thousand miles and several years with the Stillen kit. Ran it at Maple Grove year before last, 12.96 1/4 mile.
AFR was pretty steady at 10.5 which is where my tuner insisted FI VQ37VHRs should be.
Trans held up okay. It was the weak link in the 1/4 mile, stalls at 1600 RPM and sluggish shifts (logged at around .4 seconds per upshift) and occasionally would tag the rev limiter before shifting which loses even more time.
With UPRev there's only so much the tuner could do, increased the hydraulic pressure and played with the 2 rev limits so it would hold gears to 7500 but not exceed 7800 RPM.
It would not shift manually fast enough from 1st to 2nd to keep off the rev limiter so runs from a stop were done in sport auto mode.
Manually it worked okay on twisty roads but then you lose the auto blip downshifts which work well in sport auto mode where it would downshift to 4000 RPM in the lower gear. It actually worked pretty good for that.
A few months back I got a built 7 AT so that's going in, too.

I was hammering it when it grenaded.
Mashed the pedal and ran through a few gears and it suddenly lost power with the pedal floored and probably at 6 or 7k RPM.
Threw CELs, smoked, idled rough (missing on some cylinder) when I pulled onto the shoulder.
Stopped and shut it off, looked under the hood for holes in the block or oil dripping.
Fired it back up and drove a few miles, stopped at a diner and called AAA.
Waited an hour and a half for the flatbead, said ****it and drove it home 20 miles or so.
I imagine I could still drive it today if I really needed a car (I have 7 cars and 4 of them run right now), it's just not right.
The amount of smoke has me thinking bent valve, dropped valve (although I don't think it would still run), holed piston from contact with valve...
I had considered tearing the top end off in the car and maybe I'd just find damage in the heads but that's not very realistic, as there'd have to be damage to a piston as well.
Being as I'm replacing the 7AT while I'm at it, I'll just pull it and tear it down out of the car out of curiosity.

 

So you didn't run into any AFR issues with the Stillen kit based on where they located the MAF sensors within the intake? I seem to recall Eugene (EAC) and others telling me that this is an issue since the sensors with the Stillen extension are too close to the intake.

I've considered the Stillen kit as well because centrifugal superchargers are linear and minimize damage to the transmission (7AT).

 

When stuff went south I drove the car home, parked it in disgust, and didn't mess with it for months.
I admit I figured it was the gasoline I got that day since it was the first time I had run it on anything other than Sunoco 94.
I was forced to buy some suspect gas that day when I got caught with an empty tanks in unfamiliar territory.
I figured I lost a ring land or holed a piston; it wasn't until I took a closer look that I realized I ran it low on oil, and those motors can lose VVT timing when that happens, and the CEL codes seemed to verify that.
I have not logged AFR since I got it "mail in" tuned years ago but I must have gotten 10 tunes before I was happy, so a lot of logging went on back then, and it responded predictably to the changes in tune, so I assume there was not a lean condition adding to the carnage that day, but I can't say for sure.

I know ideally MAFs are located in the center of a 10" straight section of intake plumbing, and the placement in the Stillen kit is a packaging compromise that is sub optimal. Unless someone has run downstream MAFs to compare with the Stillen located MAFs or run CFD modelling to prove there's a real issue with the MAF location in the Stillen kit, it's entirely speculation that the MAF location is problematic. There certainly are lots of people running Stillen SC kits on VQ motors.

But one thing is for certain in this hobby, you're gonna break some stuff if you mess with it, eventually.

After I installed the Stillen kit I saw this kit for sale
https://rotrex.com/centrifugal-super...rcharger-kits/
I'd never heard of it before that, and I was a little bummed out, as it seems like a pretty good kit, uses stock manifold, and air to air intercooling, with the postention to make more power than the Vortech V3 Stillen kit is capable of.
I also see Z1 is offering a kit with air to air.

I was pretty happy with my G37X for several years with the Stillen kit, and I'm pretty sure it's my fault I blew it up, cause I got lazy with maintenance.