flywheel or pulley?!?

[JoeyD]

I know I am a newb to this forum but I just have to chime in on this one. Alot of good information above about the logic behind choosing the proper clutch and flywheel. One other thing to consider is a double or triple plate clutch. This type of clutch allows for greatly increased gipping while maintaining daily civility.

On to the subject of a aftermarket crank pulley. DO NOT USE AN AFTERMARKET CRANK PULLEY. The stock pulley is harmonicly ballanced for your motor. Aftermarket pulleys are made of billet alluminium (usually) they are not as well balanced as the stock units. There have been several write up from well respected tunners on the subject. You will gain an incrimental performance increase but your engine life will be greatly decreased.

 

[rainmen]

I know I am a newb to this forum but I just have to chime in on this one. Alot of good information above about the logic behind choosing the proper clutch and flywheel. One other thing to consider is a double or triple plate clutch. This type of clutch allows for greatly increased gipping while maintaining daily civility.

On to the subject of a aftermarket crank pulley. DO NOT USE AN AFTERMARKET CRANK PULLEY. The stock pulley is harmonicly ballanced for your motor. Aftermarket pulleys are made of billet alluminium (usually) they are not as well balanced as the stock units. There have been several write up from well respected tunners on the subject. You will gain an incrimental performance increase but your engine life will be greatly decreased.

wow! so ur sayin no to the pulley huh? i mean there tryin to say it gives u like 15-20 hp. true? i mean dont get me wrong, i wana have the car for a while, and want the engine to run great, but im lookin to make hp. is the crank pulley gonna do that much damage?

 

[JoeyD]

This is taken from my.is. My old forum. Written by Reg Riemer, a well known and well respected tuner.
http://my.is/forums/showthread.php?t=286507&highlight=crankshaft+pulley

 

[Hughes412]

Ok, before you tell people what they should and should not buy make sure you your self understand what you are talking about. I'm don't want you to think I'm doging on you but I have to step in. If you read the very first paragraph you see it says;

Never remove the factory crank pulley on any engine to replace it with a performance pulley or light weight performance pulley. To replace the factory engineered pulley with something made by a person or company that does not understand the complete engine design will hurt the performance/reliability of your engine not help it.

There should be a comma after PULLEY in the fist sentance not a period.

I am 100% sure MAM understands the engine design. Not only that but there are so many people that use these pulleys and never have any problems.

So if you have questions just call MAM.

 

[JoeyD]

Ok, before you tell people what they should and should not buy make sure you your self understand what you are talking about. I'm don't want you to think I'm doging on you but I have to step in. If you read the very first paragraph you see it says;

Never remove the factory crank pulley on any engine to replace it with a performance pulley or light weight performance pulley. To replace the factory engineered pulley with something made by a person or company that does not understand the complete engine design will hurt the performance/reliability of your engine not help it.

There should be a comma after PULLEY in the fist sentance not a period.

I am 100% sure MAM understands the engine design. Not only that but there are so many people that use these pulleys and never have any problems.

So if you have questions just call MAM.

Well first of all, gramaticly speaking, the sentence is fine. There is no rule anywhere that says he has to use a comma and not a period. Second of all what does gramar have to do with content?

The fact is if you replace your harmonicly balanced and dampened pulley with a solid and inconsistent (study engineering and you will see how hard it is to balance a piece of aluminium) hunk of aluminium you are going to reduce the life of your engine. That is fact and it is undisputable. Yes will you make more power and you can charge 150-300 dollars for a hunk of billet that costs 30 bucks to make. That is why companies make them because it is easy power and a huge profit margin, not because it is safe for your engine.

Think of it like steroids, only for your car. Yeah you get strong fast but in the long run it makes your body weaker and causes unwanted side effects.

Use the money on a boost conroller instead.

 

[gone_fishin]

Although I agree that companies like mental addiction motorsports and unorthadox racing have excellent concept design and CNC machinining, I think your money would be better spent elsewhere. There are many areas of performance inhibition and enhancement on both N/A and turbo motors that should be addressed long before you need to be thinking about lightening pulleys.

As for grammer, the sentence is just fine the way it is. And hughes, although I like you, you're not exactly Strunk and White. Let's just say you wouldn't be the first person I'd consult when I had a question regarding grammatical accuracy.

 

[gone_fishin]

If anything, the author should have omitted the word "To" at the beginning of the second sentence and changed "replace" to "Replacing".

 

[rainmen]

Although I agree that companies like mental addiction motorsports and unorthadox racing have excellent concept design and CNC machinining, I think your money would be better spent elsewhere. There are many areas of performance inhibition and enhancement on both N/A and turbo motors that should be addressed long before you need to be thinking about lightening pulleys.

As for grammer, the sentence is just fine the way it is. And hughes, although I like you, you're not exactly Strunk and White. Let's just say you wouldn't be the first person I'd consult when I had a question regarding grammatical accuracy.

ok then, so what else b4 a pulley then? im lookin for power!!!!

 

[gone_fishin]

ok then, so what else b4 a pulley then? im lookin for power!!!!

Well first of all, I'm guessing you own a mazdaspeed 6? What are your current modifications, and what are your realistic goals for this project?

 

[Hughes412]

I didnt say the first sentence wasnt a complete sentence. But if you read the second sentence by alone it would leave you wondering what the hell the guy is talking about.

To replace the factory engineered pulley with something made by a person or company that does not understand the complete engine design will hurt the performance/reliability of your engine not help it.

Now put to two together and it makes more sense. But if you read them separately it could mislead one into thinking that lightweight pulleys as a whole are bad. And thats just not true.

Our cars do not have harmonic balancers and the pulleys only weigh around 5 pounds. That 5 pounds isnt enough to stop the crank walk if you had any. Plus what little I read from that article it seems hes talking about the Toyota engines anyways.

Im just saying dont say they are bad unless you know for sure you know what youre talking about.


OH and believe me, I dont even trust myself after I spell check!!!

 

[rainmen]

Well first of all, I'm guessing you own a mazdaspeed 6? What are your current modifications, and what are your realistic goals for this project?

ha! man, i wish i has speed6. if u read previous posts, i got 6i. just got magnaflow exhaust, cai. want around 190- 200 hp. stock is 160. so???

 

[gone_fishin]

OH and believe me, I dont even trust myself after I spell check!!!

lol

Hughes is correct though. There's been a lot of discussion on this forum about crank walk being and harmonic discrepancies, yada yada yada. The bottom line is from what I've read, these don't appear to be issues with our engines. Hughes was correct when he said that the stock pulley is not harmonically balanced because it's only about 5-8 lbs. Although an imbalanced pulley would not be great for your crankshaft, it's generally not something you have to worry about. MAM and unorthadox have great CNC machining.

 

[gone_fishin]

ha! man, i wish i has speed6. if u read previous posts, i got 6i. just got magnaflow exhaust, cai. want around 190- 200 hp. stock is 160. so???

I'm assuming that magnaflow is a catback. With a catback exhaust and a cold air intake, you could be putting down an extra 15-25 whp-- I'd say 25 is very generous if it's a catback.

If the magnaflow is a catback, for right now I would focus on eliminating the bottleneck that is your midpipe, and your stock headers. Try to get a hold of an aftermarket midpipe of the same diamter as your magnaflow for your 6i-- preferably one that has one hi-flow cat instead. If you can't find one on the aftermarket, you can always have one made for you. As for the headers, try to find a nice aftermarket set. Stainless steal will discolor over time, ceramic coated will not (and will help to keep ambient temps down). For I4 engines, I've heard there's really no benefit to the 4-2-1 headers over the 4-1... if there is it's negligable. That will get you up there towards your goal. If you're still looking for extra umph, try to locate a more aggressive set of intake and exhaust camshafts. If can't find any for the 6i, you can always have a set ground for you. Hope this helps.

Don't disregard the tranny though-- as that's where a lot of your power is leeched. A lightened flywheel and a stronger clutch is always a good idea, but remember what we talked about.

 

[Raynman]

The bottom line is from what I've read, these don't appear to be issues with our engines. Hughes was correct when he said that the stock pulley is not harmonically balanced because it's only about 5-8 lbs. Although an imbalanced pulley would not be great for your crankshaft, it's generally not something you have to worry about.

While that may be the case for Mazda 4 bangers, I'd caution against changing the pulley for the AJ engine.

http://forum.mazda6club.com/index.php?showtopic=31618&hl=pulley

There's something to be said when the 2.5L Duratec guys want the AJ's DMD. Furthermore, they net more hp with it to boot!

 

[gone_fishin]

Take Raynman's advice, he sounds like he's a lot more familiar with the AJ engines than I am.

 

[gone_fishin]

From what I understood though, the 6i came standard with the I4 or an optional V6. He said he's only netting 160 hp-- be it bhp or whp that's pretty sad for a 6 cylinder so I assumed he had the I4. Still don't know much about the AJ engines though so I could be completely wrong.

 

[JoeyD]

You don't need a harmonic balancer to be harmonicly balanced nor does your pulley need to weigh 15lbs to need to be harmonicly balanced. Also, rotational balance has nothing to do with harmonic balance. This subject is so misunderstood and misconstrued. Put simply harmonic balance means that your crank pulley, crank, and other internal parts must vibrate together at the same frequency. Bottom line is aluminium and steel resonate at different frequencies. Admitidly I don't know nearly as much about this engine as I do a 2JZ but the principles still apply.

 

[Hughes412]

Ok, so far (my self included) there has been a lot of miss information given.
I did some searching both on the internert and talking to the Parts Manager here at Premier Mazda who is a big time SCCA compeditor and found out some good info.

First Ill try to put to rest this idea that a Lightweight pulley is bad, especially on the mazda 2.3.

This engine uses a DUAL SHAFT BALANCER system to balance out the crankshaft. Here is what Mazda has on it.

[The 2.3-liter engine is equipped with a dual-shaft balancer to counter primary secondary vibrational forces from the crankshaft.

This is a cassette-type balancer that holds two small, but precisely weighted counter shafts and is bolted directly under the crankshaft. The crankshaft drive gear directly driver one balance shaft which ten drives the second shaft. The gearing ratio causes the two balance shafts to rotate at precisely twice the speed of the crankshaft countering the latters primary vibrational forces.

The result is an engine with a peak power that means something far more than good numbers on paper, but encourages you to repeatedly explore its full potential of power right up to redline.]

Another words, this engine is made to stay in the higher RPMS!

After talking the guys a Mazda I have found out that the pulley (this is for the 2.3 only) is just a pulley and doesnt do anything balance out the shaft what so ever. So putting on a under drive or a lighten pulley will NOT hurt the engine in any way what so ever UNLESS you dont retime the engine. When ever you remover, replace, or just loosen the pulley you have to re set the timing. That and something about the bolt that holds the pulley on is a one-time use bolt. Once the bolt is loosened you have to replace it.


Now while this info is just for the 2.3 I also asked about the 2.0 Protg too. And basically the same thing applies except the 2.0 dont have the dual balancers. But basically I was right. The 2.0 has a 4bolt main and the pulley isnt heavy enough to do any thing. Now of course if you were to buy a pulley and it was defective (egg shaped or something) then yes it would add vibrations and cause your engine to blow. But I have a feeling that we wont have to worry about that.

Hopefully this will help clear some things up. But like I said before, go with the flywheel and a header and youll be sooooooo happy. Itll be like a new car.

 

[gone_fishin]

hughes, what I think he means by "harmonic imbalance" is just what he said in his previous post-- that aluminum and steel vibrate at different frequencies. I think what he was referring to is the vibrational difference occurring between the two, and consequently causing lateral crank walk over time. I'm not exactly sure why our 2.0 engines don't seem to suffer from crank walk issues relating to this, but I think what he's referring to is not an issue of uniform diameter and thickness and weight, but rather material. I know there are I4 engines out there where this is a real phenomenon, but again like I said earlier I'm not sure why it doesn't seem to effect us.

What you are referring to is rotational imbalance which is caused by the pulley's center of mass not being located at the absolute center of the circle. Irregular diamter and even thickness of any disk does not cause rotational imbalance so long as its axis of rotation is at its center of mass. It would obviously not be able to drive a belt, but it would not be rotationally imbalanced. A rotating disk with a center of mass anywhere else but its axis of rotation would certainly reek havoc on the crankshaft, but this isn't what he's talking about.

He is referring to harmonic imbalance. Harmonic motion is oscillative motion (like a guitar string or a sin curve). Just as when you strike a tuning fork and it vibrates harmonically, impulses given to the pulley by the crankshaft cause vibration as well. Aluminum resonates at a different frequency than steel-- hense the imbalance between the two materials. I suppose over time this could cause lateral walk of the crankshaft.

 

[rainmen]

Ok, so far (my self included) there has been a lot of miss information given.
I did some searching both on the internert and talking to the Parts Manager here at Premier Mazda who is a big time SCCA compeditor and found out some good info.

First Ill try to put to rest this idea that a Lightweight pulley is bad, especially on the mazda 2.3.

This engine uses a DUAL SHAFT BALANCER system to balance out the crankshaft. Here is what Mazda has on it.

[The 2.3-liter engine is equipped with a dual-shaft balancer to counter primary secondary vibrational forces from the crankshaft.

This is a cassette-type balancer that holds two small, but precisely weighted counter shafts and is bolted directly under the crankshaft. The crankshaft drive gear directly driver one balance shaft which ten drives the second shaft. The gearing ratio causes the two balance shafts to rotate at precisely twice the speed of the crankshaft countering the latters primary vibrational forces.

The result is an engine with a peak power that means something far more than good numbers on paper, but encourages you to repeatedly explore its full potential of power right up to redline.]

Another words, this engine is made to stay in the higher RPMS!

After talking the guys a Mazda I have found out that the pulley (this is for the 2.3 only) is just a pulley and doesnt do anything balance out the shaft what so ever. So putting on a under drive or a lighten pulley will NOT hurt the engine in any way what so ever UNLESS you dont retime the engine. When ever you remover, replace, or just loosen the pulley you have to re set the timing. That and something about the bolt that holds the pulley on is a one-time use bolt. Once the bolt is loosened you have to replace it.


Now while this info is just for the 2.3 I also asked about the 2.0 Protg too. And basically the same thing applies except the 2.0 dont have the dual balancers. But basically I was right. The 2.0 has a 4bolt main and the pulley isnt heavy enough to do any thing. Now of course if you were to buy a pulley and it was defective (egg shaped or something) then yes it would add vibrations and cause your engine to blow. But I have a feeling that we wont have to worry about that.

Hopefully this will help clear some things up. But like I said before, go with the flywheel and a header and youll be sooooooo happy. Itll be like a new car.

wow, thank u so much. that helps out tremendously!