which got better response?? lighten crank pulley or adjustable cam pulley?

Izso

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I read some article from Dinan BMW that said, undersized pulleys would affect the accesories (water pump, air con, wtv is attached to the crank pulley) at idling speeds.
Well, some of the Mythelogy pulleys are 5% undersized. It's not enough to affect the accessories but it's small enough to make the accelerator lighter (in terms of feel).


i agree that there's not much effect on SOHC....

but on DOHC car....they made a whole lot of different...

its like u have 2-3sets of stock camshaft from different engine spec. to play....

especially when u change the overlapping duration of both camshaft... :adore:


p/s:however stock setting still the best balance between fc and performance.... :driver:

Really? Ok. I'm a DOHC newbie so I didn't know you could mess with stock cams like that for DOHC.
 

pwhyze

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Had no idea about the difference of adjustable cam pulley tuning on DOHC and SOHC engines..care to share more?
 

^pomen_GTR^

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Had no idea about the difference of adjustable cam pulley tuning on DOHC and SOHC engines..care to share more?
SOHC engine u got only 1 camshaft that control intake and exhaust valve together....


while DOHC engine got 2 camshaft 1 for controlling each intake and exhaust valve....

in term of engine performance, not only valve opening duration and valve lift amount matters....


intake and exhaust valve overlapping duration also as important as the other 2factor mentioned earlier.....

thus with adjustable cam pulley on DOHC engine can be utilized to adjust this overlapping factor to make change of engine character and driver's preference...(because some like high rev power buildup,some like meatier low-mid range torque) so with adjustable cam pulley one can adjust to suits the need.... :adore:
 

N/A secret

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actually correct me if im wrong but lighten crank pulley does free a bit of horsies, throttle response will be light and smooth. Wherease for adj cam pulley will/does the work in retarding/advancing the powerband. You can only make the power comes early rpms or high rpms.

P/S: unless there is addition highcam would be a different story.:driver:
 

Izso

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I personally don't think you can do much with stock camshaft. Retard a bit or advance a bit for that pathetic little bit of gain, no point la. Get a mild cam together with that pulley and then play around with the settings la.
 

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