RB20/25 Maybe 26 Lightened Crank Pulleys

[Sil240]

Would anyone be interested in Aluminum Lightened Crank pulleys?I have yet to see anyone make them and Unorthodox Racing is not going to make them, because "there is not enough demand for them"

So I figured that I'll make them myself, if you guys were interested.Let me know, because I want one and no one makes them.

[email protected]

[jdmser]

Unless you plan on making them with a damper it won't work. The guys on SDU say your engine will self destruct without it. Thats why the ATI ones are $600.

[Sil240]

Do you know why they say they will blow up?Alot of people say that engines will blow, but i have yet to meet or talk to someone who has blown a motor due to a pulley.

The rubber on the crank pulley is for NOISE dampening. The 300zx pulley is very very similar to the RB pulleys and ton's of guys run the pulley and make alot of power with it.

I've seen these crank pulleys and they do not have harmonic dampeners/balancers on them.The only cars that have legitimate harmonic balancers are the old V8's.They have a huge heavy solid ring that must be PRESSED on to the crank and then you bolt the crank pulley on to it.

Almost all motors from about 1980 are internally balanced. So it does not matter what you put on either side of the crank, it could be a lightened pulley or a lightened flywheel.

[Nameless EJ6]

Your engine will not blow up because of a non dampening (sp?) crank pulley.

However, in the long run.. I guess it's possible that torsional vibration may be accentuated from the use of a solid crank pulley.

I'd advise against it.. considering our engines came with them from the factory.

I wish I could support my argument more, but I really haven't done much research on this subject. :\

My personal choice is the ATI ballancer.

[jdmser]

From everything I read the vibration in the crank reverberates up and down the crankshaft kind of like jumping up and down in a swimming pool. As the waves crash into each other some are canceled out and some multiply in size. The flywheel and transmission dampen at one end while the crankshaft pulley dampens at the other. Without the damper the multiplied vibration exert all their force on the first crank bearing causing premature failure. The reason RBs are more prone to these vibrations is because of the longer crank of the I6 vs the short crank of a V6. This is just what I found while doing research. It could be wrong, but I seem to read the same thing every where I searched.

[Sil240]

Ok well im gonna make one for myselfI'll let you guys know how it comes out

Supposedly you make 2.7hp for every 1LB taken off of the crank. The stock Rb20 pulley is 9 and change lbs. So if i make a 2lb pulley i should see some nice #'s

Also alot of Supra's and BMW's run them as well straight six's.

[skillzilla]

**** ya Ill take one, lemme know how much and Ill ginuea pig the mofo with you

I have a 20 BTW.

[Bluefire]

There are so many other ways to make power reliably, why choose one that will sacrifice reliability for a max of 10-15 hp. Although know one seems to have any personal experience with this. There are a few things that are known for a fact. Your motor will hit its harmonic frequencies. The higher the harmonic frequency the greater the amplitude of the oscillations. The crank pulley and flywheel are there to dampen the oscillations caused by these frequencies. So why take a chance, especially when you don't know the tolerances of any of the components of the RB.

-Bluefire

[Phat_Optimo]

ATI is the only way to go IMO. I wouldn't use a billet pully. Wonder if there is an N1 pully for the rbs. I would use one of thoes.

[dekand]

seriously, whats 10-15hp for the possible danger involved.

you want more hp? upgrade your turbo, injectors and get some kind of fuel management, go to a dyno and get it tuned. least thats what i think

[Cornloaf]

is it just as dangerous if i get a lightweight flywheel. I was planning on getting one, but dont want to risk screwing up my engine.

[Phat_Optimo]

is it just as dangerous if i get a lightweight flywheel. I was planning on getting one, but dont want to risk screwing up my engine.

is it just as dangerous if i get a lightweight flywheel. I was planning on getting one, but dont want to risk screwing up my engine.

I wouldn't worry about the flywheel. I would about a solid billet pully on the other end of the crank though.

[Sil240]

Well I'm going to see, Im having my motor rebuilt right now. It'll be perfect to test it on.Fresh new motor to take some of the variable's out.

Supra's and BMW's do it and I'll find out if RB's can do it too

Its cheapest HP you can get other than turning up the boost.