Under Hood V-6 Action

As they say, I "had too much time on my hands". 15 mins too much, to be exact.

Here's what my 3800 SC V-6 engine looks like when being put through the paces. Of note, the belts can be seen 'dancing' as each enters resonance. Also, the SC tensioner magically gets tighter on the belt as RPM increases. If they designed the tensioner to do that, then props to GM engineers for going the extra mile.

Lamp on AC clutch circuit shows the clutch really does disengage at WOT.

And no, my engine/trans mounts don't need replaced. Front pucks and resin-filled rear are still in great shape. I was running in 1st gear lock-out toward the end, which puts immense stress on the OEM passenger side mount. What you see is the effect of 370 lb-ft multiplied by 1st gear, applied on & off at near 6k RPM. Don't try it unless your mounts can handle the twist.

I love the belt chirps at WOT shifts. For 1-2-3 WOT from a dig skip ahead to 5:40. Enjoy!

Awesome!

Wow, that tensioner really does look like it does its job!

That's pretty awesome to watch Aaron. It's pretty trick how you have a light wired in to observe the a/c operation.

Pretty thoughtful of them to think of that parasitic toll on acceleration by cutting out the A/C in engineering, or was that something that you programmed with a tuner?

The first big jarring motion had me wondering what happened to the engine until I realized it was the first big bump you hit!

The lamp was wired to the AC about 2 years ago to help diagnose a clutch issue. It's just a 12v test bulb ($3 at AutoZone). After I solved the problem, figured I'd leave the bulb in there so I could know when the AC clutch was on. Kind of forgot about it.

The AC clutch is commanded off during WOT from the factory. It's always been "known", but to actually see it in action is pretty cool, since I never turn off my AC for any reason.

Yeah, I ran over some really rough spots. The engine moves a lot more than you'd think!

Wow that looks like a pretty wide angle cam - is that the one you're sending over to me?

Very good video for information sake! I wanna see what mine looks like especially when I'm getting the ridiculous amount of squeal during fast engine decel from boost

No, sorry can't send out my HERO3! The Canon you're getting isn't wide angle, but it captures a nice 720p HD view of where it's pointed. I actually prefer a narrower angle for straight ahead and rear-view shots. Less fish-eye distortion. Just need to aim it carefully.

Huh. Thats a pretty quiet supercharger.

Pretty neat video!

That is sweet!
I never would have guessed the passenger side mount was under such stress. Guess i need to look into replace mine since its still original at 205k miles. Might solve some of my idle vibration.

Would be really neat to see if different belts (gatorback, delco, cheapo, etc) vibrate, move and sound different at WOT.

I agree the movement seems excessive, but remember this a worst case scenario at the very top of 1st gear = max wheel torque. 99.9% of the time the mounts don't move this way, and I see little drawback to it - unless you're looking to feel every vibration through the cabin and steering wheel 100% of the time. I'd rather keep what few comforts I have left, even if it means losing a few lb ft of torque for a 1/2 sec. Throttle response is more than awesome. I really don't care if the engine moves, as long as the mounts can take it.

Makes it easy to see why our OEM mounts crap out so easily, though!

That explains why I really feel the A/C tugging in my Si when I didn't feel it at all in the Riv. That, and the Riv having an extra 150 lb-ft...I'm so aping this video idea Aaron.

sweeeet! how many miles on that there rivi now?

262,107 on car, 15,431 on rebuilt engine, 111k on rebuilt transmission.

AA wrote:

262,107 on car, 15,431 on rebuilt engine, 111k on rebuilt transmission.

Dangggg.. Thats probably where mine would be at about now.. I think I got ride of it december 2011.. I would have blown at least 3 more motors by now though