lose accessory belts better fe

[yzfdallas]

I have a 03 civic and this weekend the i changed the timing belt along with the other accessory belts. well after i had everything together i turned no my ac and my new belt made a noise cause it was to loose, the noise when away after a few seconds, now i got to thinking, if taking the alternator belt off helps fe would having the accessory belts loose for the power steering the alternator and maybe the ac help with FE. Has anyone tried this? I know some cars have automatic belt tensioner but my Honda has a manual tensioners, so this may only work on certain cars. This may only be good for another 1/2 mpg to 1 mpg, at the most, increase (or even no increase) but every bit helps.

[cfg83]

yzfdallas -

That's the first I heard of that, but it sounds similar to an "underdrive pulley". I think the idea for an underdrive pulley is that it is smaller than stock, so the engine feeds less juice to the rest of the devices, including the battery.

Does this make sense? Is this right?

CarloSW2

[VetteOwner]

what?

how does a 2003 car still have manual belt tensioners?!?!? acuualy speaking of, how does a 03 car still have multiple belts?!?! first ive heard of this since it seem sliek every thing after id say 95ish has automatic tensioners...

new belts make noise from the sealant they put on em, it wears off, squeak goes away. having loose belts do nothing but eat up the belt (so you may save a quarterl on gas but spend $30 on a new belt) when it slips, theres friction, friction=heat, heat=bad for rubber parts cuz it leads to failure

the whole idea of an underdrive pulleys is its generally made out of aluminum, and usually a few inches smaller in diameter than the stock pulley. lighter mass, smaller diameter (works like gears, small gear driving large gear, lots of torue and dont need much power to turn the small gear. reverse the roles, it takes alot of force to turn the big gear thats drivign the small gear.) it frees up some wasted torque, thus more can go to the wheels so you have more available torque at a given speed/pedal travel/ rpm so you can do the same job as before but with less gas.

[yzfdallas]

[yzfdallas]

[Erik]

Yes - less tension would mean less spinning resistance.

The trick would be to find the least tension that would still keep the belt from slipping/wearing out quickly.

[Snax]

Seems like a bad idea to me. Get an underdrive set.

[Ryland]

Older civics had different belt tension specs for the fuel efficient model...

[VetteOwner]

Originally Posted by Snax

Seems like a bad idea to me. Get an underdrive set.

yea id go for underdrive... its askign for a bad time/noise when the belt slips/breaks...

that and temperature changes the elasticity and gripyness of the belt, so does reving the engine, (its why some cars belts squeal at idle but once they start accelerating it goes away, pulls the belt tight)

if it slips too much you can get a high speed glaze over the belt, which it coats the rubber in what feel liek a plastic layer, kinda like tryign to use a plastic shoppign bag as a belt...


huh i never knew they still use manual tentioners/multiple belts...you would think multipule belts would be worse for FE than single long belt...

[Hateful]

I think a loose alternator belt would deliver a weak spark and cause less FE and black smoke rolling out the exhaust.

[yzfdallas]

well i loosened the power steering belt a lot, no noise from the belt but its very loose. If i had a scangauge i could run a test but i don't have anyway of testing it. The engine did feel a bit lighter but it could just be me. didn't some people remove their alternator belts and it increase their fe quite a bit. I just want to loosen the belt enough where they don't make any noise but are loose. i'm not to worried about the belt they only cost $8 for my car, for the power steering pump.

[yzfdallas]

Originally Posted by Ryland

Older civics had different belt tension specs for the fuel efficient model...

i guess every bit helps

[holypaulie]

Originally Posted by VetteOwner

the whole idea of an underdrive pulleys is its generally made out of aluminum, and usually a few inches smaller in diameter than the stock pulley. lighter mass, smaller diameter (works like gears, small gear driving large gear, lots of torue and dont need much power to turn the small gear. reverse the roles, it takes alot of force to turn the big gear thats drivign the small gear.) it frees up some wasted torque, thus more can go to the wheels so you have more available torque at a given speed/pedal travel/ rpm so you can do the same job as before but with less gas.

I've read one day on civics forum that aluminium underdrive pulleys cause a lot of problems like overheating, undercharge of battery, decreased power steering and A/C efficiency and failure of the crank bearings (removed harmonic dampener)

[SD26]

An underdrive pulley is going to be better.

A loose belt is going to slip, but it is going to still produce heat through friction (power loss) and possible pulley damage with that friction (power loss).

A drive pulley shouldn't be a harmonic damper, but maybe some manufacturers are doing it.

[Snax]

I'm looking at getting a 50% underdrive pulley for my Escort - if it ever becomes available again. Supposedly for about $120 including shipping, it is worth a 15% fuel savings. By my math, that means it would pay for itself in about 10,000 miles at the current local price of $3.50/gallon.

[yzfdallas]

http://cgi.ebay.com/ebaymotors/01-05-HONDA-CIVIC-1-7L-LX-EX-UNDERDRIVE-CRANK-PULLEY_W0QQcmdZViewItemQQcategoryZ33626QQihZ016QQi temZ260226472823QQrdZ1QQsspagenameZWDVW

would this work for my car

[Ryland]

Smaller pulleys don't grip v-belts as well, so the belt is going to have to be tighter, if you moved to larger pulleys on both ends of the belt you would gain efficiently, you will also gain if you go with lighter pulleys.

[cfg83]

holypaulie -

Originally Posted by holypaulie

I've read one day on civics forum that aluminium underdrive pulleys cause a lot of problems like overheating, undercharge of battery, decreased power steering and A/C efficiency and failure of the crank bearings (removed harmonic dampener)

Were the Civic forums driving for performance or FE? The whole "take it easy" approach of Hypermiling makes me think that these problems would be less of an issue for us.

CarloSW2

[101mpg]

Loose belts will cause things like slipping in the water pump and more heat. Tighten belts to specified tension. Larger pulleys on accessories will slow things down - may need a little longer belt but will reduce engine load. Thermostat will open a little more for this and compensate. But a non-spinning water pump spells death on an engine. Better off with larger pulleys on accessories than smaller pulley on crank.

Get aluminum racing pulleys and you'll be better off.

[VetteOwner]

yes they can cause overheating because your water pump isnt pumping as fast. power steering may be less but still alot better than none(get some arm muscle :P ) and to not have underchargign probelms get a smaller alternator pulley so you kind of keep the same ratio between the crank and alternator.

just because it doesnt make noise doesnt mean its not sliping... when it starts making noise then theres a probelm and somehting needs replacing...

loos ebelts can fall off pulleys too, get caught on stuff once they do fly off and potentially do other damage...