Ok, this video is pretty nuts and not because something explodes, catches on fire, or crashes, but because get a great look at what exactly happens to a serpentine belt during a drag strip pass with a COPO Camaro. It is really freaky what goes on, especially for the second or two that the engine sits up on the two step before launching down the course. Remember, this is under hood footage only, we’re staring at the mighty LS engine the entire time. It is probably the first time in our lives we (and the entire group of people we were watching with) have been enthralled enough with a belt video that when we watched it, we immediately watched it again, and again. It is actually that cool.
If you have ever had to replace a belt tensioner in your car, you’ve probably done the job thinking, “What the heck is the purpose of this thing, anyway?” Well, after seeing this video you’ll not only understand what it is doing, but you’ll go out to your shop and thank it for the service it has provided! Pure gearhead coolness here. Only true car guys, gearheads, and BangShifters can sit and stare at a screen with the image of a belt deforming and love it. And you WILL love it…trust us.
Thanks to Grippo for the tip!
PRESS PLAY BELOW FOR A TRULY ENLIGHTENING LOOK UNDER THE HOOD OF A COPO CAMARO DURING A DRAG STRIP RUN –
Yup, had to watch it a few times, pretty wild.
Man, that rev limiter is the punisher of that tensioner spring.
I’d like to see what happens to a cam timing belt.
The most amazing thing about this video is that tensioner is taking up slack from the belt stretching under a load. Next time you have a serpintine belt in your hand, put your foot on the loop at the floor and then try to stretch it. You can’t really, at least not a measurable amount. Gives an idea of the amount of forces at work here. Especially the wide ones they use on supercharged engines. You can also watch this happen on most newer cars with serp belts and A/C, start engine, turn A/C on with blower on low and you can watch the tensioner jump as the compressor kicks on and off. Timing belts don’t stetch as much as serp belts do. they have more cording in them, although as they wear out they will get slack in them, sometimes enough that they will contact the covers around them and make slapping noises.
Sorry guy belts dont stretch (to the extent your talking) thats the tensioner actually being pulled over from the loaded belt. Sc takes a shit ton of power to spin and it increases exponentially. A supercharger can be leaching as much as 200 hp approaching redline. That’s a huge drag… if you belt is loose it did not stretch, the ribs wore out.
If the belt isn’t stretching then what is causing the tensioner to extend farther? How is the belt “being pulled over from the loaded belt”? Can you provide a more detailed physics explanation of this effect you’re talking about?
Looks to me like the belt is stretching and the tensioner is keeping constant pressure on the belt as it expands.
Its well known that belts expand quite a bit. For example its not uncommon for (cogged) motorcycle belt drives to jump a tooth or expand off their sprockets during hard acceleration… and thats only in the ballpark of 100hp, quite a bit less than the forces in this video.
Pause the video, measure the distance the belt travels at low load. Then pause it at high load and measure the distance the belt covers again.
This will show the belt has infact stretched.
The distance the tensioner moves is misleading to the amount of stretch that happens, however the belt does stretch as shown by the differing distances it covers.
That was the dumbest comment I’ve ever read. The only thing that can cause the tensioner to move like that is belt stretch. And really? A supercharger can leach 200 HP? I think you hit an extra 0, or you know nothing about boost. Take your pick.
I watched it a few times also – noticed the flying liquid on the left side of the video, also some climbing the fender. Awesome what that belt tensioner went thru – gives me more insight on what to watch for on the LS when I put the 327 in my S10 4×4 Blazer. “evil grin” xD
And it still can not beat a Mustang…lol
Only because the rustang broke down on the way to staging…
always wondered what kind of damage getting up on the chip did to an engine, you know it can’t be good… that tensioner just hints at some of it
Wow
That was wild and amazing.
There’s the reason tensioners are so important!