To be or not to be ! man talking about not sure now after reading all of the stuff on the pullys I dont know what to think . I understand how they work and rotating mass . but is it a yes or no . is it a gain with other mods? do you go for all three or just the crankshaft , what ? half say no half say yes . please ,im asking a question to know ,not to get reamed out ! thank you !

 

Not wanted on a street driven Z, they like to eat cranks. 3rd pulley is a joke, the idiots label it water pump, it is an idler pulley and the whole thing is easily removed.

 

They are not worth it…they'll jeopardize the well being of your engine and in exchange for a-drop-in-the-bucket performance increase.

 

Answers well given.

 

thanks guys thanks for the info I really appreciate it ! I will pass on that mod! and move on to something else. thank you again !

 

I'd just do the crank pulley. Stock sized. It could techincally destroy your engine, but so could an intake or plenum spacer. I enjoy mine. I thought it made the car lighter/younger if that makes sense. Perfect to do on a 60k service. Just .02 talking though. I noticed slightly bigger differences on other cars I've done though.

 

think your greatly misunderstanding WHY these destroy cranks, its nothing about power like a intake or plenum spacer its harmonics, the ati and fluidamper absorb them, stock helps a little and lightweight makes it worse. any gains you notice is purely in your head and they are questionable if they actually do anything due to being in a dynos margin of error so they cant be proven one way or the other.

the crank pulley is the worst one to do out of the bunch.

 

Oh I understand the harmonics of it all.....but as I said an intake and spacer will do the same per Nissan techs. For example...ecu talks to Maf and compensates. But during the learning period, is there not more volume then "normal" going through the cylinder? Point is....most mods "destroy" the car....just the nature of the beast. The car will rev faster. Faster revs don't equal hp on a dyno. I Think of it as more of a combination mod...this isn't worth the time if this all you do to the car.

 

Some mods make improvements , some just make changes, other can screw your car up. The pulley can screw your car up, fact. No myth to it.

 

Screwed my car up, not because of harmonics, but the crap aluminum opened the hole for the key and helped my motor start knocking, listen to good advice

 

Epic fail if you think swapping out your crank pulley will push you over the power-capacity of the engine...


going to an underdrive pulley setup is a drop-in-the-bucket when you really really really (really) look at the entire system of rotating mass.

under drive pulleys are slightly less weight (a kilogram or so) means less of mass and further more less rotating mass on your driveline.

Think of all the rotating mass that is on your driveline…(starting on the outside and working in) your tires, wheels, rotors, axles, final drive gearing, drive shaft (even though it's carbon fiber), transmission gearing, flywheel, crankshaft, camshaft/drive train, alternator/PS pump/AC, etc … all that rotating mass and you effectively reduce your combined mass by a fraction of a percentage...Just keep the OEM pulleys…

 

I don't think you understand at all.

The harmonic damper is a passive device. The air/fuel control, at least in closed-loop mode, relies on negative feedback. Negative feedback is used to create a self-regulating system. Even in open-loop, the knock sensor provides feedback to the system to make a drastic change if something is wrong.

The crank pulley is passive, and has no feedback. Its designed to be a passive device that damps known parameters that are based on the physical properties of the engine. The modes of vibration are determined by firing order, firing frequency, and mass of rotating assembly. There exists no system of self regulation to correct a vibration that can cause damage to the engine if the damper is removed.

Your ECU/MAF analogy doesn't even make sense.

 

you should not talk to nissan techs, they are mechanics not performance engine builders. you said yourself why those mods dont destroy the engine, the ecu compensates, not as good as a tune but it isnt destroying the engine.

 

you completely ignored what i said how do you go from harmonics to power capacity, thats some add or adhd from hell right there. that or your misunderstanding why im saying they destroy engines.

this has absolutely NOTHING to do with weight once again it has to do with HARMONICS, the underdrive pulleys have nothing, the stock pulley has a tiny tiny amount of elastometer bonding the hub to the actual outside of the pulley the belt rides on which absorbs harmonics, the ati and fluidamper which you should be using has either fluid or a large amount of elastometer. most of these dutys are handled by the stock dual mass flywheel but if you go to single mass then the only thing left is the pulley, if you then swap to one with absolutely nothing on it to absorb harmonics your just making the problem worse and this is what hammers bearings and destroys them.

stock is bad, lightweight is worse, fluidamper is good and works across all rpm ranges, ati is best but only works in a specific tuned rpm range(which can be retuned if you switch to cams or something for a different power band). stock is fine till about 500-550ish whp past that is when ati and fluidamper is a must.

 

thanks for all the post . I think im keeping stock and move on to something else. thanks guys for everything . I really want to get a supercharger but its the money . I would have to sell one of my bikes and I dont want to.

 

I wasnt referring you Jerry…just in general…I know where you're going with your statement and I agree with you here.

I don't have this info at my fingertips, but if I remember correctly, I was going through some technical info on my ATI and they are rated up to 500whp for their ~2year service period…running above 500whp they suggest getting the pulley recertified on a shorter frequency…I don't remember the entire specification but 500whp sticks out.

 

ahhhhh ok, im not sure on the ati i went with the fluidamper personally. it could just be that most people going above that use cams so they are figuring in retuning for a different rpm range but im not sure without speaking to a tech.

 

Lol...I think ya'll are getting too stressed out about this. YES we all know PULLEYS can kill. But with my point...so do most things we do to the car (so say the opposition). (The opposition being those who say OEM is the best, the "if its not broke don't fix it." crowd) We've said pulley could kill the car and even I've attested it's not a worthwhile $$$ mod either. I felt a small difference. So what. Not worth the money as a single mod. But is anything ever worth it? It's not to the insurance company or KBB value. We mess around because we want to. If we wanted OEM reliability we'd probably have 85% less traffic here and no for sale section.

 

well i dont think theres any more point here your not understanding the core concept, the things you pointed out dont kill the engine, period unless you purposely clog a injector or tune it to have 40+ degrees of timing and run 87 octane but then its not the intake or spacer that kills the engine its the tuning or other issues. intake or spacer DO NOT kill a engine thinking so means you really need to grasp the concept of how these things work. the pulley really does kill the engine due to not absorbing harmonics and hammering bearings. intake and spacer do absolutely nothing of the sort........................ like i said you need to quit talking to nissan techs they are feeding you bs information, half of them are nothing more then parts changers anyway that dont grasp the concepts themselves. they ARE NOT engine builders.

this is like engine modification 101 that you dont seem to be understanding no clue how to make this any simpler but plain and simple your wrong and spreading misinformation.

 

There you go again...listening with your mouth. Its OK...I really do know what you're saying. Plus...You're harping over specifics when it was used to make a point. Those are basic mods that have to rely on something external adjusting to them. I know you won't concede the point, but if you improve/mod/fix something that doesn't need fixed or replaced.....then you're adding another variable to the cars life. That does include improper installation. And last point....Nissan techs. Like anyone on a forum talks to freakin techs. It was a point of reference.