How to install your underdrive crankshaft pulley

[AveoJoe]

The general rule is that you can expect from 5 to 20 percent power gain, but it is directly proportional to the engine and its output at the time the headers are installed. If a performance exhaust is installed on 100-horsepower, four-cylinder engine, for instance, the gain may only be five to 10 horsepower. Installing a header system on a 1969 hot rod with a big block, however, may net over 50. On top of the power gains, it is very likely that fuel economy will increase because the engine will not have to work as hard to produce horsepower and torque.

[AveoJoe]

While simply installing a good header or headers can definitely increase the power output of most engines, coupling them with a quality exhaust and muffler can further the gains. Adding a well-designed and effective set of headers that flow into a $16 muffler, for instance, probably could be improved upon. Popular quality muffler brands include Flowmaster, Dynomax, Magnaflow and Borla, although several others are on the markets that do the job well.

[petrified.rabbit]

Yea it doesnt do it anymore so i thought it was just since the part is brand new it had to warm up. because it only did it the first night i started running it after i installed the pulley.

i imagine it was the serpentine tensioner then, sometimes when its old, the spring gets corroded and when you use it to take the belt off, or put a new belt on, it is riding on a crusty part of the spring and is noisy until the corrosion either flakes off, or the tensioner breaks.. (corrosion flaking off is much more likely).

the only thing i would check,start the engine, and look at the pulleys to see if anything is wobbling. if no wobble it was most likely your tensioner adjusting back.. but it could have also been a new belt and new pulley making some noise.. o if there is no wobble and the noise is gone, don't worry about it.

[petrified.rabbit]

The general rule is that you can expect from 5 to 20 percent power gain, but it is directly proportional to the engine and its output at the time the headers are installed. If a performance exhaust is installed on 100-horsepower, four-cylinder engine, for instance, the gain may only be five to 10 horsepower. Installing a header system on a 1969 hot rod with a big block, however, may net over 50. On top of the power gains, it is very likely that fuel economy will increase because the engine will not have to work as hard to produce horsepower and torque.

there is no stock engine that will gain over 50 hp from just a header. the 50 hp potential comes from a built crate engine, and purposefully putting a stock restrictive header on (as the only "stock" part) to create a restriction to show that a header will increase the performance that much. Is it trick in advertising? NO because a lot of guys buy crate engines and put all the factory parts on them.. and that is who they are advertising to.

if your crate engine is 572 ci, making 720 hp and you put the stock manifolds on, but with a few minor bolt ons, (compare parts to the parts used to dyno) then you might be able to get 800 hp out of it easily. But it they used headers and you stick on the factory manifolds, you probably wont see the 720 hp advertised.

i do agree however the the MOST restrictive part of the factory aveo exhaust is the muffler.

[dleebold]

how did this thread get hijacked to aveojoes 50 hp header?

[Weirdo_Joe]

Yo, dleebold! I am probably going to go the same route as you... I have never been under a car, and while that may change, this sounds kinda scary for an early learning experience! I may do the CAI myself, but leave this to a mechanic! Good quotes here, both regarding power and price. $30 for an install is VERY reasonable! If I bring in the part(s- including the specified belt) I'm only paying for the tech's time; for a half hour job, this REALLY helps get thing in perspective! Also, about using multiple modifications... A Chrome Intakes CAI, One of these underdrive pulleys, headers, and a better exhaust; any guesses for a total hp increase? Got a stock 08 LS with 103 hp now... 120? Maybe 125? I know the 140 was with more extensive engine work...

[petrified.rabbit]

HP does not work that way. All pieces are rated individually, not as a package.

SO if the CAI adds 5 and the pulley adds 5, they might only produce 7 together, they might make 12 together. The only way to know is to dyno before and after. I would suspect you will break 110.. but you can't guarantee a specific outcome without a dyno.

(plus your car is rated at 103, it could have an actually hp from 95-110)

[Weirdo_Joe]

Right on! Yeah, I am realizing that what it says on a box, what you get, and even what somebody else may get hp-wise from the same mod will vary... and dyno tests are the way to truly read it. Just kinda looking for a guess-timation. But still, I didn't know the variance in stock/factory cars could be so great. I'm gonna be trying to get some 0-60 and 1/4 mile readings (using a passenger and stopwatch for the first few ) and THAT will be what I'll be looking at most, before and after modifications!

[timmytaxi]

Xiogary's car was dyno at 140 with extra mods but his car is a 1.4L engine. Our car should yield more since its a 1.6 right?

Chevrolet Aveo 1.4 specification - Know Chevrolet Aveo 1.4 specs in India | CarDekho.com
94 HP stock

A 1.6
2005 Chevrolet Aveo - Consumer Guide Automotive
103 HP stock

[timmytaxi]

Yea xiaogary's car is a 1.4L:

YouTube - Chevy Aveo 1.4DOHC Lightweight Flywheel RPM

It would not be hard to reach xiaogary's hp with a 1.6 that comes with 9 extra hp stock.