[blownsvt]

When a cam gear is tuned for all out top hp, is that hurting gas mileage or anything else for a daily driver? What exactly is happening when you either retard or advance the cam gear? It seems weird that one would tune the cam gear on a daily driver for the most hp, when in fact you are not at wot all the time with a daily driver. See what I am saying? Just want to know exactly what is happening when advancing or retarding the cam gear, as well as the pluses and minuses of doing so on a daily driver.
2002 SVT Focus

 

[zx3 focus racer]

moving the cam gear realy just moves the hp band. so i dont realy think you mpg changes.

 

[blownsvt]

Ok, understood. But, what is happening when you adjust the cam gear?

 

[blownsvt]

Thank you.^^^^^^ That is exactly what I wanted to know. I figured that, but it was just a hunch. 140hp and 132trq? Thats more trq than my svt when it was stock, and pretty close to the hp! Very nice.

 

[smoke3006]

I think that as along as you stay with the stock shafts and just tune with new gears it shouldn't hurt the MPG.
You are just changing the timing of the intake and exhuast cycles to make it more efficient.
Going to a 'hot' cam shaft would affect the MPG I assume.

Of course I'm probably wrong anyway

 

[UltegraSTI]

my stage 1s (which were tuned to match the cam's tendencies, ie. good balance of power increase, boost in low/mid tq) saw no decrease in mpg.

great cam for a power boost across the board...when tuned they do even better across board. how's 140whp/132tq grab ya? thru stock head and header...she still has some left in there as well, need more time and money.

-Ult

 

[Andy Smith]

Ok, understood. But, what is happening when you adjust the cam gear?

Well you shift the power up and down the band with cam gears by retarding or advancing cam timing. This means you're rotating the cam a little bit, so that the valves open and close at more optimal times during the combustion cycle. By changing a cam you change how much the valves open and close and how long they stay open. Neither of which directly effects your injectors or fuel system, but you may notice a slight increase or decrease just from power being in different areas.