xCxHxRxIxSx

as all sc tc owners know there are oversized sc pulleys out there for the tc that are made to up the boost on the sc . other cars have achieved this very same thing by adding oversized crank pulleys. so why is there no lightweight oversized crank pulley made for the tc yet? plus this would help out with the tamper proof bolt situation .

GammaTNT

iTrader: (8)

dude, crank pulley doesn't make higher boost.
If you think about it , bigger pulley will spin slower. There is no way bigger crank pully will maker higher boost.
If you did your research, smaller sc pulley makes higher boost,
Sc tc people use lighter crank pulley that is same size as stock. , it is to free up few ponies.

Nick06tC

Actually a bigger crank pulley will make more boost. And like you said, smaller sc pulley will make more boost as well.


Its all about gearing. In any gearing situation, if you make the input pulley (crank) larger it will make the output pulley (sc) spin faster. Smaller input, slower output. And so forth and so on. But there are also issues of torque in gearing as well. You cant just go insane about it.

Only issue is, with a larger crank puley it would put the belt in a position that it would hit other components, thats the reason it hasnt been done yet.

xCxHxRxIxSx

thanks nick for the good answer. i was just wondering why they never went that route to get the higher boost .

engifineer

Incorrect. It is all gearing. Making the SC pulley smaller is the same as making the crank pulley larger. No different than changing sprocket sizes on a bike. A larger crank pulley will change the ratio to the sc pulley, hence spinning it faster.

You would want to probably be sure you are not over-spinning the other components though in the process. Best bet would be a larger crank pulley and slightly smaller accessory pulleys for everything but the SC so everything else is spinning at the right rpm. And you should actually want a crank pulley with the elastomer damper like the stock one.. not a super light one. But I wont get into that whole argument any further than that.

05-RS1

Nick's right, there's actually something that will get in the way if the crank is made to be bigger.

ScionGT35R

Wise words!!!! Completely rigth!!!!

draxcaliber

yup, all about the ratio's, but unfortunately, increaseing the crank pulley seems to run into clearance issues.

another option i would like to see explorered would be a cog style gear pulley for the supercharger so that you could run a smaller pulley without fear of belt slippage.

GammaTNT

iTrader: (8)

thanks for the info,
learn something new today.

xCxHxRxIxSx

drax is cog the kind of pulleys that have like teeth in them ? because the would be cool to change out our pulleys for the would help so much with slipping . and would be able to create an even better pulley for the sc

BLUEMEANIE

^ they're multiple gears that drive each other.

Thats not a bad idea and while that might eliminate the slippage, I would think clearance issues would arise since at some point you'd have to have a pulley cog stack so one could drive the other.

xCxHxRxIxSx

thinking about this whole pulley thing makes me go cross eyed lol

Garage1217

iTrader: (5)

A larger crank pulley was the first thing NST and I looked into when NST was making a proto of the sc pulley, you would have to take off your timing cover and cut off the timing markings that are cast into it. It is very possible but more than most people would do work wise. Also you would be overdriving your ac, alt, ps, wp and so forth unless custom pulleys were made for all those parts to compensate.

Also from memory "been two years" The crank pulley would hit another pulley if enlarged more than a few mm.

xCxHxRxIxSx

thanks for all the info . i was wondering why no one did it . now i know!