K24.20A

Does the underdrive pulley make any difference in power for a K24A4? How about pulley kits? Do these allow more hp? Some say no.. Can anyone clear this up for me?

gianinline

It free up weight from the crankshaft.

I can't tell you specifically for a K24.... but as me and my friend have pulley kits on our cars... it was a slight difference, yet... noticeable (little).
My car has OEM size all aluminum pulleys, and it revs up quicker than my friend's car.

Tyte-S

I thought pulleys caused more wear on the engine? Tho they do free up weight from the crankshaft.

swappedaccord

if you change the underdrive pulley, you will end up damage your motor, you'll ruin the harmonic balance in the engine, basically throwing **** outta whack. i wouldn't do it, save your money, the other pulleys are fine to change out, but you won't notice any hp gains.

oem_certified_accord

so swapped...you mean to tell when perrin built their 500-600 whp STi which was featured in modified (5 page article), and they threw on their pulley kit. they were dumping thousands into an engine that was later on going to kick the bucket?

back your statement up with supporting facts. otherwise i'm buyin a underdrive crank pulley

cartune network

anything that isnt somekind of harmonic dampener has more tendancy to prematurely wear out bearings. all of the motors u see these "lightwieght pulley's" on are either owned by children who are ignorant when it comes to there car or are people who use the motor for one thing and are not building the motors for longevity. thea cars in magazines u see them on are all out drag cars or show cars. for street use with stop and go traffic i wouldnt use a p.o.s. pulley in place of my harmonic dampener.

F23Coupe

Where's proof of this? I'm running Unorthodx pulleys for close to 50k miles and only problem I can think of is that I have a bit more vibration at idle. But I know it's not affecting the engine hardly any because I submit my oil samples to Blackstone Labs regularly.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by swappedaccord &raquo;</TD></TR><TR><TD CLASS="quote">if you change the underdrive pulley, you will end up damage your motor, you'll ruin the harmonic balance in the engine, basically throwing **** outta whack. i wouldn't do it, save your money, the other pulleys are fine to change out, but you won't notice any hp gains.</TD></TR></TABLE>

F23Coupe

Sounds like the scare tactics worked on you, too. The AEM underdrive pulleys aren't great because they underdrive the alternator a bit too much for comfort but the UR pulleys are pretty good. The day I find out that my bearings are going is the day the UR pulleys are coming out and reporting to you guys. But going strong at 50k miles or so, I don't forsee any problems in another 50k miles.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cartune network &raquo;</TD></TR><TR><TD CLASS="quote">anything that isnt somekind of harmonic dampener has more tendancy to prematurely wear out bearings. all of the motors u see these "lightwieght pulley's" on are either owned by children who are ignorant when it comes to there car or are people who use the motor for one thing and are not building the motors for longevity. thea cars in magazines u see them on are all out drag cars or show cars. for street use with stop and go traffic i wouldnt use a p.o.s. pulley in place of my harmonic dampener.</TD></TR></TABLE>

swappedaccord

check this out:
http://www.toyotacelicaonline.com/pulleys.htm

oem_certified_accord

i just got off work so i wasn't about to read the above link (no disrespect) but i talked to a tech at my job and he said as stated above..don't run pulleys in your daily driver..if you're running a high-performance car i.e. boost. that's fine.

but he explained to me once he threw on his underdrive crank pulley (95 EG Hatch) he lost 6 hp. some would say "that's not so bad" but i was like "aww wtf hell no" .. he then explained to me that it does throw off the balance of your bottom end because the stock setup is adjusted to the specs of the oem crank.

somethin about a machine that spins the pulley and marks a spot on it where it's most centered at too. so if you look at your oem pulley (harmonic dampener) w/e you should see an impression on it. that is where it was scaled to be center balanced at by the manufacturer's equipment.

if anything i said was wrong do forgive it's been a long day

Note* i only jumped into this thread because my boy just threw a perrin underdrive crank pulley on his subaru

-oem