bradleykit Posted February 24, 2010 Share Posted February 24, 2010 I am planning to change my 350z's pulley to Lightweight pulley, but when I search for it. A lot of them says they are underdrive pulley, but what do they mean by that? And will it damage my car, if I get the underdrive one? Quote Link to comment Share on other sites More sharing options...
Chris`I Posted February 24, 2010 Share Posted February 24, 2010 I am planning to change my 350z's pulley to Lightweight pulley, but when I search for it. A lot of them says they are underdrive pulley, but what do they mean by that? And will it damage my car, if I get the underdrive one? Underdrive pullies mean they will "drive" whatever systems are attached to it less than the current one, ie the pullie will be smaller and each revolution of it will spin the attached pullies less. I think they are used on cars which rev more than stock and thus when they get up the rev range, dont overdrive the attached other bits and bobs (alternator, AC, etc). Thats my take on it, someone more knowledgable will be along to correct me if wrong Basically unless you know you want an underdrive one, you want a standard size. Quote Link to comment Share on other sites More sharing options...
bradleykit Posted February 25, 2010 Author Share Posted February 25, 2010 thx but do i need a special belt to use underdrive pulley? Quote Link to comment Share on other sites More sharing options...
Chris`I Posted February 25, 2010 Share Posted February 25, 2010 That I dont know. I dont know if the normal belt tentioner can take up the slack or if you need a smaller belt. Best as ZMANALEX or Adam@Z1auto, they will know for sure Quote Link to comment Share on other sites More sharing options...
Dblock Posted February 25, 2010 Share Posted February 25, 2010 Dont underdrive pullyies underdrive so there is less drag or parasitic drag on the engine? But if you under drive the alternator then dont run a massive audio system. I could be wrong though. Quote Link to comment Share on other sites More sharing options...
yokomo Posted February 25, 2010 Share Posted February 25, 2010 Dont underdrive pullyies underdrive so there is less drag or parasitic drag on the engine? But if you under drive the alternator then dont run a massive audio system. I could be wrong though. thats about it , wont increase BHP but will show a minuet amount more at the wheels as its not driving the ancilleries as much. Quote Link to comment Share on other sites More sharing options...
bradleykit Posted February 26, 2010 Author Share Posted February 26, 2010 Yeah just got the whole set of Unorthodox Racing pulley kit, and belts (underdrive one), also ask the people in the shop (Top Racing, Hong Kong) They say this will not cause any problem to the car, but will increase 10 hp and will give a much faster respone, coz of the weight. Well will get it installed sometime this week, and see.. Quote Link to comment Share on other sites More sharing options...
sketch Posted March 6, 2010 Share Posted March 6, 2010 lightweight pulleys dont GIVE any power, they reduce drag, you wont gain any power but you may find the car will pick up a little quicker. im not sure if its the same with the 350 as im used to 200sx's, but they have a built in damper in the crank pulley,(cant remember the technical name, resonance dampner???) but when people were swapping out for lightweight pulleys they were finding the main bearings went soon after, but not sure if its the same with the 350, let us know how you get on, and yeah under drive is exactly what people have already said, you may find you need to find differant belts tho as the pulleys are a differant size Quote Link to comment Share on other sites More sharing options...
Valveman Posted March 9, 2010 Share Posted March 9, 2010 but will increase 10 hp and will give a much faster respone, coz of the weight.: 10hp - what a joke! I doubt you will even be able to measure the difference on a Dyno. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.