underdrive pulleys ka24de

[slipknot555_666_69]

ok ive searched and searched and cant find any actually answer just arguments.

how much hp does a ud pulley kit add and could anyone notice any big difference for what they cost and the pain to install them

thanks for any help

[Karateboy88]

ok ive searched and searched and cant find any actually answer just arguments.

how much hp does a ud pulley kit add and could anyone notice any big difference for what they cost and the pain to install them

thanks for any help

I don't have one.

But I did take pulleys off, clean them, paint them, and reinstall them.

You can expect a drive train gain of less than 5 hp- so you won't notice it. Most likely 1 hp since the stock pulley isn't that heavy.

[slipknot555_666_69]

any other opinions?

[Wc240]

lighter underdrive pulleys do not add power, the motor has an easier time spinning them so it takes less parsitic loss to run em. idf you searched for unorthodox racing, or looked at there site, they say what they have seen on a dyno

[QuicksilverFX]

do not get a unorthodox pulley, they have been known to break and destroy motors.

[slipknot555_666_69]

so good idea or bad?

[slipknot555_666_69]

but im running a na setup do u think it would be the same gains

[OutToWinPAHC]

Less rotational mass..... So its depends on the HP you make to determine a gain.

I don't recommend them, unless its a harmonic balancer.

[slipknot555_666_69]

well i already have 248/248 cams, intake, header, full exhaust with test pipe, ecu tune, the biggest plugs and wires i could find, and deleted all the emissions besides my butterflies

[nismoracingsx]

i've heard about some problems w/ the underdrive pulleys since they lack a harmonic balancer..aftermarket pulleys w/ the balancer cost a very pretty penny...

[GODCHSR]

You won't have any problems if you install them.

They don't 'add power' but they do increase the RWHP but reducing rotating mass... dynos don't lie.

[EliteGTR]

do not get a unorthodox pulley, they have been known to break and destroy motors.

you have no idea what you are talking about.

pulleys on a ka is the best way to gain power besides going forced induction

[EliteGTR]

i've heard about some problems w/ the underdrive pulleys since they lack a harmonic balancer..aftermarket pulleys w/ the balancer cost a very pretty penny...

there is no such thing as a harmonic balancer. its a damper. underdrive or not doesnt make a difference.

[dm-ka]

I had ebay underdrive pulleys on bot of my previous S14's and coupled with removed clutch fan I did notice a difference. Your motor becomes more alive. On my last 240 I had quite a few mods and my cams were 240/232 and pulley was the last thing I ever installed on it so the gain in power was good (do not have actual numbers but you really can feel the dif).So my advice go for it you'll like it.

[Wc240]

there is no such thing as a harmonic balancer. its a damper. underdrive or not doesnt make a difference.

exactly, thats why its called a Harmonic balancer, duh, didnt you get the memo?

[EliteGTR]

so how do you balance harmonics?

[soon2Bcool]

any time you remove rotating mass, you are bettering your setup. I've been looking at an UD pulley for awhile, but my car already has a weak charging system. Is it a noticeable drop in alternator output, power steering feel, and a/c compressor pressure?

[soon2Bcool]

so how do you balance harmonics?

hire a better vocalist than yourself...

[tegls1]

I never had them on a KA but I did have them on my SI and you do not see any negative effects. My car sharged properly and steering was normal. I am going to install aset on my KA whne I get it running right.

[soon2Bcool]

cool, thanks for the info

[driftneil]

any time you remove rotating mass, you are bettering your setup. I've been looking at an UD pulley for awhile, but my car already has a weak charging system. Is it a noticeable drop in alternator output, power steering feel, and a/c compressor pressure?

The alt is the same, but the ac and power steering are def diff. Takes a bit more to turn, but I like it. The a/c is just a bit weaker.

[OM3GA]

People are getting their crank pulleys confused with the harmonic dampers found on some domestic V6 & V8 engines. "Harmonic Balancer" is a term used loosely in the automotive industry. Technically, this type of device does not exist. The "balancer" part comes from engines that are externally balanced and have a counterweight cast into the damper.

The pulleys on most of the new import and smaller domestic engines have an elastomer (rubber ring) incorporated into the pulley making them look similar to a harmonic damper. The elastomer in the OEM pulley serves as an isolator, which is there to suppress noise from the engine accessories; the A/C compressor, P/S pump, and alternator. This is what the manufacturers call NVH (Noise Vibration & Harshness) when referring to noticeable noise and vibration in the passenger compartment. It is important to realize in these applications, the elastomer is inadequate in size and durability to act as an effective torsional damper. If you look at the pulleys on some imports there is no rubber to be found at all. We have samples of these, mostly from Acura/Honda B & D Series engines, Nissan Altima, 1.8L Eclipse, 2.3L Fords, Chrysler 2.2L's, and 1.8L VW's just to mention a few. Most owners who have installed our pulleys notice the engine actually feels smoother. This is result of replacing the heavy crank pulley with our crank pulley. NVH is variable and unique to every car. NVH will increase with the installation of an aftermarket intake and/or exhaust, for example. Think of OEM intake systems in newer cars, they use baffles and resonators in the intake to quiet all the intake noise. Aftermarket intakes eliminate these resonators and create dramatic increases in engine noise from the throttle opening and closing. So to most tuners, certain types of NVH can make the driving experience more enjoyable.

The purpose of a traditional harmonic damper is to protect against crank failure from torsional movement and frequencies of high amplitude. This is not necessary in most modern engines because of the many advances in engine design and materials. Factors such as shorter stroke length, smaller displacement, piston dwell time, piston pin off-set, power output, etc., do determine when and how these harmonics and torsional movements occur. More importantly the actual tune of the engine, espcially with modified vheciles, is the biggest factor in potential engine damage. Poor tuning leads to detonation which is an engine killer that no damper can stop.Again, there is a lot of internet hearsay about solid crank pulleys. When engine problems occur, too often people are quick to blame the pulley first, rather than taking the time to look logically into why there was a problem.

[dm-ka]

Amen to the above post.

[Wc240]

it doesnt have your"traditional" H/B. nissan calls it a crank pulley dampner and it serves the same purpose.