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Tensioner, Idler pulley weights...

Djason

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#1
Curios what everyone's thoughts are on reducing the weight of the heavy tensioner and idler pulleys by installing lighter "better" aftermarket pulleys. Especially those who are pushing well past the factory power levels.

Do parasitic losses come into effect or would it be so minimal you couldn't measure it? The force needed to spin a factory pulley is considerably higher than quality aftermarket pulleys that are also designed to withstand higher rpms over OEM before failure.

More importantly Is the belt slipping ever so slightly with the heavy OEM pulleys, at a WOT hit, which directly effects the life span of the blower belt? Premature belt failure is what I'm trying to avoid.

Any downsides to a lighter pulley over OEM?
 


Marc W

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Your main parasitic losses (that you can do anything about) are the accessories. Hpindy here has a underdrive accessory pulley made he sells that is a worthwhile investment. It however is for the ATI crank pulleys only and those have to be pinned. So nothing for the warranty weenie guys. 😝
 


Hpindy

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I have all three supercharger idler pulleys changed to the metco billet aluminum ones . That is a 5 lbs savings . I can neither confirm nor deny if it makes a notable difference.. I have done a lot of little things and they all add up .

Sent from my BBF100-2 using Tapatalk
 


vortecd

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I have the aluminum ones from TBA machine. I did all 3. They spin better, look better and weigh less. He only did the 2 in the video then did the 3rd later.
 


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Djason

Djason

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Thread Starter #5
I saw that vid as well, along with a couple others. Totally agree Hpindy. It's the little things combined. Figured it couldn't hurt. Pretty much what I did for my Z06 build. Even more being rotational mass.

I did order the Metco pulley kit last week but they are about 3 weeks out from production. The only thing I didn't like was the tensioner pulley being 3", slightly larger than OEM. This will take, ever so slightly, belt wrap off the blower belt which I really don't want to do. So from 180* wrap to ??? My math isn't THAT good. Lol. I asked Rick at Metco about the 3rd pulley down near the alternator. This was his reponse.

"I’d rather not sell you a pulley for the third location when I can’t be sure it will fit without modification. My suggestion would be to order the 2-pulley set, and try the smooth idler in the third location before installing it in the intended location beneath the supercharger pulley. If you confirm it fits to your liking, I’ll get another smooth idler together for you."
 


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Djason

Djason

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Thread Starter #6
Your main parasitic losses (that you can do anything about) are the accessories. Hpindy here has a underdrive accessory pulley made he sells that is a worthwhile investment. It however is for the ATI crank pulleys only and those have to be pinned. So nothing for the warranty weenie guys. 😝
Lol...my warranty went out at 2000 miles. As most of my performance cars do. It's a disease.

Not sure what power level you need to be at to warrant pinning the crank. I would think close to 1000 flywheel. I think the hellephant engine does come pinned from factory. I'll look into what Hpindy has. Thx!
 


vortecd

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I saw that vid as well, along with a couple others. Totally agree Hpindy. It's the little things combined. Figured it couldn't hurt. Pretty much what I did for my Z06 build. Even more being rotational mass.

I did order the Metco pulley kit last week but they are about 3 weeks out from production. The only thing I didn't like was the tensioner pulley being 3", slightly larger than OEM. This will take, ever so slightly, belt wrap off the blower belt which I really don't want to do. So from 180* wrap to ??? My math isn't THAT good. Lol. I asked Rick at Metco about the 3rd pulley down near the alternator. This was his reponse.

"I’d rather not sell you a pulley for the third location when I can’t be sure it will fit without modification. My suggestion would be to order the 2-pulley set, and try the smooth idler in the third location before installing it in the intended location beneath the supercharger pulley. If you confirm it fits to your liking, I’ll get another smooth idler together for you."
Sounds like way to much over thinking. The amount of belt wrap is very small.
 


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Lol...my warranty went out at 2000 miles. As most of my performance cars do. It's a disease.

Not sure what power level you need to be at to warrant pinning the crank. I would think close to 1000 flywheel. I think the hellephant engine does come pinned from factory. I'll look into what Hpindy has. Thx!
You should pin the crank if you change to any upper s/c or lower pulley.
And the TBA pullies are a nice weight reduction from stock.
 




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