[Don Juan]

I'm not sure if this topic was already discussed or not Sorry in advance.

I have been reading about underdrive pulleys and their claims about 10 to 15HP. Are there any techies, mechanics or anyone that may know anything more about it?

The pages I found was a Mz3 that installed tehm (Arruda MZ3) and a guy in a 330i.

Any info will be apreciated.:tsk:

here is a link of some forum : http://www.bmw-m.net/FAQs/pulleys.htm

 

[Nick325xiT 5spd]

My understanding is that it's like robbing peter to pay paul. Yes, you get a little bit more speed... The cost is that you have a good deal less electricity, perhaps less stable electricity, also. I understand that the pulleys DO affect sound quality, for example. I would also worry about long term electronic damage. :dunno:

 

[Nick325xiT 5spd]

In all seriousness, though, and please don't take this the wrong way, you would be a lot more likely to get an answer at e46fanatics.com. People do a LOT more modifying over there.

 

[bmw325]

Given the complex electronics and sensitve electrical system on our cars, this just seems like a very risky thing to do. I know that lots of performance magazine rave about them-- but I don't know how long they've lived w/ the cars they mdoifed or what the long term effects are. It seems like there are less risky ways of getting 10-15hp.

 

[virtualrain]

I don't think you can save 10-15HP. My understanding is that the alternator, power steering pump, water pump, and air conditioning condenser only consume a few HP each.

If you were to cut the belts and remove them completely, you could save 10-15HP. However, overdrive pulleys only increase the pulley diameter by 10-20% which may net you 2-3HP.

Then you have other complications (mentioned by others) and you will either need longer belts or will be running the tensioners under higher tension which will likely cause premature bearing failure or at least squealing noise (sooner than later).

YMMV.

 

[ed325i]

What about going with the light weight flywheel? Sounds like that's the way to go. Any one know how it sounds at idle?

Ed

 

[nate]

No thanks :thumbdwn:

http://www.dinanbmw.com/html/danger_of_power_pulleys.htm

 

[Rufus330Ci]

I still don't undestand why you would want to mess with your car anyways....I think modifying should be left to muscle cars personally where the vehicle costs 1500 bucks and you can find small block chevy parts for 50-150 bucks....The last couple posts about how it ruins your car might be what is making me post this but I think since the car costs 40 grand and your not happy with the performance of the engine that you should have went out and bought a vette or something....to spend "more money" on something that isn't broken I think is stupid.... (nothing against the original poster) its just a pulley....

 

[Nick325xiT 5spd]

I do have to agree that after a person starts looking at more than a couple thousand dollars of mods, he really should just trade up.

 

[Rufus330Ci]

to what the M3 or a vette?

I tell you I've driven my friends 02 WS6 Transam with the same engine as the corvette and that thing has balls down low (plenty of torque) and then I drove the M3 and I had 4 people in the car you know how you gotta take your 2 friends and the rep always wants to drive along..... and the car was an 01 Laguna Seca Blue it was nice they want 49k which I think is alittle high since they had it a year and it has 4k miles it on it already anyways....I took the car out and stopped in the middle of this straight-away out in the country in carlisle PA and I rev'd the car and dropped it the rep grabbed the sides of his seats and I felt it accelerate and it wasn't like the transam where it had the power down low I had to wait till like 4-5 and sometimes 6-7 to feel it pull (maybe it was the weight in the car i don't know) but I wasn't that happy that day I thought I was going to go out and feel this power monster but it really wasn't there till about 6 grand and then it throws you back in the seat haha which I found out getting up on the highway back to dealership I thought the guy was going to crap his pants he's like "woohooo.." Anyways the M3 is a great car I loved the sound of it and it took corners pretty good, I'm not an professional driver in any sense but I do push cars to their limit on undisclosed back roads :angel: after that day I was set on my 330 I knew i wasn't missing the 13k maybe when I'm 25 or 30 I'll step up just for the looks and minor performance upgrades that I won't use 95% of daily driving...... I won't be keeping up with my friends WS6 or my other friend Johns 350Z he's getting in september but I'm more of a point a to point b kind of guy

Now that I've written a book about my life....I just wanna sum it up. I'm going to be happy with my purchase of a 330 over an M3 it was bothering me for a long time like everyone else but I've settled my concerns

 

[Nick325xiT 5spd]

IMHO, the 'vette is a downgrade. Whatever you want to say about performance, the M3 coupe is cramped enough.... A 'vette would be unusable. I REALLY would like an M3/T. That would be the perfect car for me.

 

[Rufus330Ci]

Are you for or against an V8 M3 in the near future?? Because if it gets some torque in the lower rpm's I'd be happy with its acceleration. I'm not saying the M3 is crap, its a very, very healthy car

 

[Nick325xiT 5spd]

I'm ambivalent to the thought of a V8 3 series. I love the torque of all the V8 cars I've driven regularly (740i, SL500, S55), but they just aren't as smooth as my I6. The 740 is close, but... IMHO, one of BMW's trademarks is the inline six... I wonder how a 4 litre I6 would do instead.

 

[Rufus330Ci]

I definitely know what you mean about "smooth" I couldn't see BMW going with a stock supercharger or turbo in their 3 series line maybe M3 but I'd be happy with they got a good 260-280hp out of the 330. The characteristics of the 3 series puts it ahead of the competition but like EVERYONE says they better get a move on with the power ;o)