I bought the rsm pulley and is for the 2.2/2.4 but im having a guy machine it to except the larger belt. I put it on the car to make sure that everthing would still line up afterward and it does. Would anyone be intrested in doing this also?

 

What part is being machined? Do you have pics? My attention has been drawn...

 

what pulley is this the supercharger pulley or the alternator pulley?

i wish they made a light weight one ide rather not have a smaller one my car relies on its electronics

 

Seriously^^^
I think he's talking about the crank pulley, though I'd like to know what was machined in order to use the RSM Pulley. If it's the RKSport pulley, I think that is an underdrive, and any S/C would most likley have to use the Intense supercharger spacer or adjustable tensioner.

 

No its not an underdrive is has the same dimensions, its just lighter. The pulley is from RSM. try this web site is the picture of the pulley.

http://www.z-spec.com/Lrg_Images/rsmcrankpulley.jpg

The 2.2 and 2.4L use a more narrow belt not as wide as the supercharger belt.
So the machineing is done to add a rib for the wider belt.

its the same size as stock. Not an underdrive because that would slow down the supercharger and how wants to do that.

 

The part your showing is a light weight crank pulley. I would not install that on a supercharged application. Consider your going to kill the harmonic balancer.

 

Why not?

 

The motor is built with that specfic crank pulley, by changing it you will throw many internals inside off that relate to the motor, how it's balanced etc. Older motors you could get away with this, putting one on a new one is not necessary. You will cause more damage then good.

 

But we have balance shafts to do that for us, so why would the crank pulley be so importent?

 

someone with a hair more knowledge then myself could answer that better but stating from experience I would not put that pulley on. The change of force on crank pulley is very important, you will in essence put more strain on the motor. Reason being the crank shaft pulley and motor was designed to have the crank shaft work at a certain weight, RPM spin/interia.

I can forsee throwing codes and screwing the shafts up with long term use.

 

So you cant use a lightweight flywheel then either? but i see people running then. Same concept there, right?

 

If the pulley were like the QR25DE in the Sentra Spec-V SE-R, then the crank pulley is accually a harmonic balancer, and it's quite a big piece. The QR25 is also a high vibration motor, but not as bad as the SRT-4 motor. taking balance shafts out of any motor without balancing the rotating assembly will give you those violent vibrations as well as not having a harmonic damper.

If that was the case, then an aluminum flywheel would have the same effect if not balanced. Besides, we have balance shafts for a good reason.

 

^^^correct sir. It's AKA harmonic dampener/balancer. Because it does just that. Don't mess with crank pulley's. Not enough "free power" given the risk your taking. Lightened flywheel's are much safer, but will change your torque curve a bit, which you might not want for a street car. You need a heavier flywheel for high torque motors because you need momentum from the flywheel for the torque to effectively travel to the wheels. There are better ways to make horsepower safely than to swap pulley's IMO. The only other effective way to make power with pulley's is to remove pulleys from the underdrive. Otherwise don't expect anything more than 3-5% gains atmost.

 

So why even sell the pulley in the first place if there going to damage motors?

 

To make a quick buck off you. Why do you think they make fake BOV for ricers & big wings for cars? Advertisement and to look cool.

That Crank pulley will kick you in the face if you install it.

 

^^To make money

 

im till going to put it on after i get it machined and then i guess well know? althought i wont be dynoing.

 

Well, alot of these parts are truly meant for race cars. The market however, has manipulated many consumers into thinking that these parts are ideal for street power while showing no reduction in reliability. The market vouches for these unworthy upgrades with only a handful of individuals that sucessfully used the parts while increasing performance. This market will never consider reliability, and will never show the CONS to products. So it's up to the consumer to make a decision about the pro's and con's.

With that said..you can buy an ultralight crank pulley, an ultralight flywheel, and an ultra knife-edged and lightened crankshaft and have them all balanced together, including the clutch. This would net a much greater gain than to just install one at a time, while not balancing the system. Reliability will not be an issue, as you are only trying to make peak torque gains. I wouldn't suggest anyone trying this with a street car since reliability will fly out the window, not to mention the low-end torque sacrifice. (I'm referring to the crankshaft mods)

 

I guess I'll just have to wait 'till they make one for the LSJ.

 

I looked in to geting one of these but after talking with an enginer from a company that makes the stock dampaners for alot of the cars on the road I decided that I want my motor to last more then 30K befor it smoked its main baerings.

Later

 

balance shafts only change engine vibration as in vibration that will be transmitted through motor mounts if I'm not mistaken. The harmonic balancer changes the vibrations of the crank shaft.

My Dad's 94 Silverado with the 5.0 had the balancer for a 5.7 from the factory. After about 8,000 miles the rear main seal started to leak oil like crazy. The dealer determined that the harmonic balancer was the cause and fixed it under waranty.

Also the balance of a 4 cylinder is much worse than a V8 because of the time seperation of strokes. I was reading that boosted 4 cylinder engines are very bad with high boost at rpms lower than 1,500.