Buddy has these exact pulleys on his Z. Def revs a little faster and launches a little better but if its from a roll and not dig it didnt help him. Hope this helps you decide!

 

So in your own opinion, what are your thoughts on lightweight and or underdrive pulleys?

Thanks, that is what I was hoping for. I kinda figured not to see any gains in hp or tq. I was just looking for a cheap and easy way to make my car rev up a little faster.

 

Just some notes on my end, I never said I was expecting these to add hp and tq. My main reason for buying them was for a little faster revving engine. With s/h I paid under $230 for them and I'm doing the install myself. I have had under drive pulleys on my 2001 prelude I had 5 years ago so I know the effects first hand of under drive components which is why I did not buy under drive just light weight... I was looking into getting the Osiris engine management but don't have 500-700 plus install and tune/dyno. I really don't have enough done yet to go that route anyways. I don't even have headers and full exhaust yet. I will get the Osiris once I have enough done to actually see good results with a tune. Other than that, thanks again for the info.

 

A little more snap from a dead stop sounds good to me.

 

Thats all were all trying to do here anyway! lol t But yeah since you already got them.....Install those bad boys and enjoy the extra kick in the pants from a dig

 

the fact that it can START spinning it easier, by default is an increase in power. how meagerly measured or not...who knows. In all reality its probably only on the low end though.

Someone had dyno'd their pulley before and after...then again after nitrous. he made more power with the pulley, but when he used nitrous he made more power with the stock pulley. I wish I had the link..but i'm lazy and dont want to search for it right now. Cop out, i know...i shouldn't quote things I dont have reference to but I think I read it over on My350z

 

Personally, I recommend either. Standard size lightweight for someone who wants quicker revs, slightly more throttle response without compromising driveablity (less power steering input). And for a person that wants to milk every HP out of their car with plan for a tune (higher idle to compensate) I recommend going underdrive, since our cars do not have a belt driven water pump and a more than sufficient alternator.

As far as lightweight pulleys being non-harmonically balanced, you wouldn't believe how frequently we get a car in our shop with a failed Harmonically balanced OE Pulley, when they fail it appears they go out of balance (have no actually testing) and eventually slip. Aftermarket pulleys got a bad rep from some domestic platforms in which rotational assemblies were balanced as 1 unit (Crank pulley, Crank, and clutch/flywheel), when these platforms began changing pulleys they saw devastating effects.

For our platform we are fortunate that Nissan balances components individually, so as long as the aftermarket pulley is properly balanced the rotating assembly remains balanced. I still believe that high horsepower built engines need some sort of Harmonic Damper to slightly reduce the chance of destruction during slight detonation, but on NA and relatively low horsepower stock block setups I believe its fine to run a lightweight pulley, I did for several years NA and another year on my stock block TT makeing 470+rwhp without issues. Now on my Built block I do run a stock pulley, because I feel built engines need some sort of damper, however we have customers with High HP built engines who insist on running a lightweight pulley with no bearing issues to date. Its somewhat ironic how no one will question running a lightweight flywheel (which is much larger, and has much more dampening potential) vs the OE Dual Mass Flywheel.

This is purely opinion based on our experiences, to date we have yet to see bearing failure in a VQ35 directly linked to a lightweight pulley. In fact (as i've pointed out before) all bearing failures I am aware of have been using some sort of Harmonically Dampened pulley (OE or ATI).


Sorry for such a long post.
-Rob

 

pointless argument with no proof of any real gains outside of it "feels" like it helped

 

i installed my ams set 2 days ago and love it throttles better and pull feels better i have an 5at think its one of the best mods i put on my car

 

No prob on the long post. Some nice info throughout. Thanks for the opinion.

That's nice to hear. If you don't mind me asking, what other mods do you have done to your car?

 

test pipes plenum spacer churches tb spacer rev up box hr y pipe

 

Good stuff.....

 

Ok, so I finally got around and did the install of the AMS pulley set. Took way longer than I had planned but its done. After trying to take the radiator fan assembly out and couldn't cuz of the upper radiator hose being in the way I said screw it and took out the radiator, fan assembly, intake box, and overflow tank. Also had to remove the plastic under cover to get to the tensioner bolts easier. The idler pulley was the easy one. The alternator and crankshaft were the hardest of course. Once they were off it all came back together much quicker and easier. Once I got all the air out of the cooling system I went for a quick spin. Things I noticed from a quick drive are: in neutral the engine does rev up quicker and when driving along it seems like the engine does rev up through gears a little faster and smoother, better throttle response through the whole power band, and from a dig you can tell the biggest difference. (I'm not saying that I gained 10+ hp/tq, I'm simply saying that it does "seem" like they made a difference) I weighted the three stock pulleys together and they came out to 7.4 pounds compared to 2.5 for the AMS set. I'll post some pics once I have the time to upload them.

 

Were you able to resuse your belts? If not what did a new set cost? Also do you feel the difference in performance was worth the investment for both parts and labor?

 

When I bought the pulleys I also choose to buy new belts with them. It was an extra 30 on to the price of the pulleys. Its good I did cuz the old belts were close to needing replaced anyways plus I used one of the old belts and cut down two sections to fit around the crank and alternator pulley so I could use my chain strap wrench to keep the pulleys from moving while taking off and putting on the crank bolt/ alternator nut. I didn't pay for labor as I did everything myself. IMO it was wroth it for me. I'm sure other people would say its useless and a waste of money...etc. It depends on what your thoughts are on things. If you feel that the said results are wroth it then go for it. If not, then I wouldn't.
I just enjoy working on my car so thats another reason why I think its wroth it. If I do something to my car and it does absolutely nothing when it comes to better performance thats fine with me cuz I still was able to do something myself and learn even more about things and how to do it.