Need Advice for Adjustable Cam Pulley (DOHC Engine)

szeeonn

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Jun 6, 2007
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to all pro zth member

usually u all Set how much Cam pulley timing for adjustable Cam Pulley (DOHC) Engine ..?

how much Degree u all advance ?

Intake ..?
Exhaust ..?

need sincere advice for GSR and EVO Engine

tq ^^
 

Veloc

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May 19, 2010
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Erm... For me, I think adjustable pulley is not v good for everyday car la... Because by just advancing/retarding the timing, there is little power gain. Got la.. But not so much... The obvious effect is the shifting of the powerband. This is because earlier opening or valves also result in earlier closing. The lift, duration and overlap is unchanged. Thus power gain is minimal and the main function is shifting the powerband, either higher up the rpm range or lower. Why not save up and get camshaft?

Just my opinion la... Anyways, mudah got sell a lot. Some claim to be HKS lightweight ones but don't know ori or not. Works engineering got also. That one most probably ori la... :biggrin:
 

0382

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Erm... For me, I think adjustable pulley is not v good for everyday car la... Because by just advancing/retarding the timing, there is little power gain. Got la.. But not so much... The obvious effect is the shifting of the powerband. This is because earlier opening or valves also result in earlier closing. The lift, duration and overlap is unchanged. Thus power gain is minimal and the main function is shifting the powerband, either higher up the rpm range or lower. Why not save up and get camshaft?
i agree...
 

szeeonn

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good one . usually which cam profile better ?
272/272 or 270/260

heard 270/260 timing idle better , any comment ?
 

Veloc

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good one . usually which cam profile better ?
272/272 or 270/260

heard 270/260 timing idle better , any comment ?
For intake... Nothing more than 272 is best. 260 is fine too. More low end torque. 272 is minimum for good idle and low torque. About exhaust, I don't know. any sifu can advise on this? :hmmmm:
 

szeeonn

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hmm now i am confusing for Exhaust Cam..
dont know whether should choose 272 , or 260 ...?

pro fren say exhaust 260 would stable for idle for air cond
another racer fren say choose 272 for exhaust , FOR Turbo engine ..

need more advice from pro ^^
 

Veloc

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hmm now i am confusing for Exhaust Cam..
dont know whether should choose 272 , or 260 ...?

pro fren say exhaust 260 would stable for idle for air cond
another racer fren say choose 272 for exhaust , FOR Turbo engine ..

need more advice from pro ^^
Bro... first, you plan to go NA or turbo? If youplan to go turbo, don't go for too much valve overlap. If you plan to go NA all the way, chose max overlap. But still depends on how much low-end torque, FC and city drivability you willing to sacrifice la...
 

szeeonn

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mine is 4g93 gsr turbo ..
u mean dont go too much valve overlap .. means i should choose 260 or 270 for exhaust ?
haha , thank u
 

D7zul

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mine is 4g93 gsr turbo ..
u mean dont go too much valve overlap .. means i should choose 260 or 270 for exhaust ?
haha , thank u
interesting question.. cuba citer.. cuba citer.. :biggrin:
 

Veloc

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mine is 4g93 gsr turbo ..
u mean dont go too much valve overlap .. means i should choose 260 or 270 for exhaust ?
haha , thank u
All I heard before is that if want to play turbo, there should be minimal valve overlap. The intake should stay open longer but exhaust should be should be shut earlier to prevent boost leak. That is for turbo. However, I can't advise on the exact duration and lift as I have no experience on this before. Hope other sifus with experience can give input.

But if you plan to play NA, go ahead and get the max overlap as far as you can stand the decrease in low-end torque. But I heard anything above 272 will be costly as you also have to upgrade the valve springs, higher compression and port and polish, and piggyback to get the best performance.
 

szeeonn

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ooo.. finally i understand you
u suggest me take 270/260 .. ?

tq
 

Veloc

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ooo.. finally i understand you
u suggest me take 270/260 .. ?

tq
No bro... I suggest get opinions form sifus who got experience... :burnout:
 

szeeonn

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sifu sure say higher better lol .. but i only scare the timing nia
well u know .. daily car scare timing issue
 

93na

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for 93t or 93na...

turbo 272 is the best wan la any lower u dont really feel the diff...

Na 300 and above la(he he he)...

matspeed 272 is good enough for daily drive for 93 engine.. I have used it before..
 

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