UNDERDRIVE Pully?

BUMP!
i would like to as well being i have a n/a 5 door 3 and would like to get a lil more outta her! could some one shed some light on this for us please? i would get the complete racing set if it worth the money.
 
I haven't read much about pulleys for the ms3, but there are a few points of controversy with them on other cars. One is the tradeoff of having slower-turning alternator and ac pulleys, at lower revs in daily driving your ac won't blow as cold and if you have a mega-stereo it can be harder on the electrical system. The other is that some 4-bangers use the crank pulley to help dampen/balance the crank and a lighter crank pulley that isn't counter-weighted can wear out the bearings faster. Please understand that I don't know this first hand, it's just stuff I've read on other forums over the years. Maybe some of the more experienced gearheads on this forum can add some wisdom to this thread?
 
these engines are internally balanced. the crank pulley does not act as a harmonic balancer on these cars.

we are working on our set of lighter/underdriven pulleys for these cars
 
i dunno they would be nice to have but i dont think that 369$ for a full racing set is even worth 8-11hp gains in my opinion now that i think about it..i can get more hp from a CAI for bout 100 bucks less and this would be a more of a substantial amount than 8-11 horses...
 
but that is at the wheels... its not bad... plus its only 2 bolts... and a pully to install... i wish more companies had them for sale... then the price would be more competitive


Come on AEM.... Unorthodox...make them already! we're waiting!!!!!
 
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most worthless mod ever dont do it. i know some people say that it doesnt matter because the motor is internally ballanced, but it does matter. look at the stock crank pulley it has drill marks for being balanced. the extra 1-2hp isnt worth the possibillity of shaking the piss out of your bottom end eventually tearing up your rod bearings. plus it slows down your assessorys makeing them not work at full potential, your lights will dim at idle ect... just my two cents.
 
Total newb here...

Regarding balancing, would it be possible to balance an aftermarket pulley?

Would it be possible to decrease the size of the alternator pulley as well (to make it turn just as fast)?
 
nig3 said:
most worthless mod ever dont do it. i know some people say that it doesnt matter because the motor is internally ballanced, but it does matter. look at the stock crank pulley it has drill marks for being balanced. the extra 1-2hp isnt worth the possibillity of shaking the piss out of your bottom end eventually tearing up your rod bearings. plus it slows down your assessorys makeing them not work at full potential, your lights will dim at idle ect... just my two cents.
Click to expand...

let me pose this thought to you though - if changing the pulley out were to harm or unbalance the engine, why would not changing out a flywheel for a lighter one do the same? either modification will change the rotating mass applied to the crankshaft. this argument came up back when mazdaspeed proteges and regular proteges were new, and many years hence we've seen little to no evidence correlating engine failure to an underdrive pulley.

funkyman said:
Pulleys are a waist of money,pretty much like CAI`s.
Click to expand...

i thought its been proven time and again by now that CAIs work wonders on these cars?

Hirudin said:
Total newb here...

Regarding balancing, would it be possible to balance an aftermarket pulley?

Would it be possible to decrease the size of the alternator pulley as well (to make it turn just as fast)?
Click to expand...

yes, again as stated above, not needed on this car

and yes it would be
 
Captain KRM P5 said:
let me pose this thought to you though - if changing the pulley out were to harm or unbalance the engine, why would not changing out a flywheel for a lighter one do the same? either modification will change the rotating mass applied to the crankshaft. this argument came up back when mazdaspeed proteges and regular proteges were new, and many years hence we've seen little to no evidence correlating engine failure to an underdrive pulley.
Click to expand...

haha they do **** you motor up the same!! you normally get cels with a flywheel, due to false knock or the engine decelerating too fast. Once again another stupid mod.
 
Car was engineered just fine.If you need power just hurry up and tell these tuning companies to come up with a turbo upgrade and resolve the bloody Cam driven pump and ECU boost controll.The car came out more than a year ago for gos sakes and we`re not getting any younger and the paint job is wearing off,do you know what i mean Heheheh.If you want to reduce weight,the heavy hood is a good start and the wheels and the stock exhaust can go too replaced with a DP and RP and straight one peace pipe no CATS.If you don`t like 12.7 with minor mods and high boost and drag radials then go and buy another car.People spend 10k on their M3`s to get that time,i said M3`s not 330i.Mitsu`s and STI`s 5k to get those times and those cars are a good 8k out the door more than the MS3.
 
I have a set of underdrive pulleys on my '95 VR6 and it honestly made a huge difference! Granted, the low end was a little more sluggish but after you hit about 3000, the tack skyrockets; especially for an engine without valve timing. The hard part was actually getting the crank bolt out of its socket but other than that it didn't throw a CEL or mess up the engine from what I could tell. But as you know, it was a totally different engine being N/A and with 2 extra cylinders (but mysteriously 4 less valves...)

As for these cars, I feel like it already has enough power and I am going to try and stay away from power modifications as long as I can. However, for the MS3, even if the car has been out a year, it will still take quite a bit longer for aftermarket parts to become more "fine-tuned" for our cars. I would recommend waiting and honestly, wait to for someone else who has had them installed for a while and see what they have to say.
 
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nig3 said:
haha they do **** you motor up the same!! you normally get cels with a flywheel, due to false knock or the engine decelerating too fast. Once again another stupid mod.
Click to expand...

i have never gotten a CEL or "****** up" a motor with a lighter flywheel on any vehicle i have ever owned whether it be a domestic v8, import v6 or I4, internally balanced or otherwise. what kind of check engine light would a flywheel cause? there is no trigger or sensor that bases any reading from a flywheel. a flywheel cannot cause false knock and the only thing the engine does from decelerating too fast is stall, which is resolved by the obd2 computer relearning within the first few drives.
 
Captain KRM P5 said:
i have never gotten a CEL or "****** up" a motor with a lighter flywheel on any vehicle i have ever owned whether it be a domestic v8, import v6 or I4, internally balanced or otherwise. what kind of check engine light would a flywheel cause? there is no trigger or sensor that bases any reading from a flywheel. a flywheel cannot cause false knock and the only thing the engine does from decelerating too fast is stall, which is resolved by the obd2 computer relearning within the first few drives.
Click to expand...

ive have seen tons of subys and toyota get missfire codes from using a lighter flywheel. the reason you get get missfire codes and false knock is because the ecu gets confused somtimes when the motor decelerates to fast too often, and the aluminum has less thickness/damepining than a the oem flywheels so the resonate more cause the false knock issues. that and the 1-3 hp you get is not worth the hassel, the money is better spent elseware. im just shareing my experience or opinion is all.
 
I've had underdrive/light-weight pulleys on my Miata, along with an 8lb flywheel and it made a huge difference!!!! My engine never blew up or failed...I traded her in for my 08 MS3 with 204,000 miles and still running strong!!

So yes, if you are looking to squeeze out all the HPs out of an engine then pulleys and flywheels are it...though they are usually on the end of the to do list. The flywheel was one of my favorite mods...most noticeable!!!

Flywheels don't add horsepower...they change engine response. The improvement from a flywheel is way more noticible than a 1-3 HP mod. The ECU does not track/sense engine speed on decel. If your idle speed is set correctly (which is automatically set by ECU) then you have no issues... There were probably other issues with the vehicles you mentioned.

Just my .02 cents...
 
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+1 I would like another company to come out with pulleys as another option.

I have heard that the Shane Racing pulleys have caused some problems....but yet agian that is all forum talk.
 
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