High angle cam's function is increase the duration of open and close valve to make more air in&out to produce more power. Is it right?

Many people said: When you use Toda C cam, you need to change your piston to increase the compression. Why?

If I change high compression piston (12.5) and still using Toda A cam or stock cam, what will it effect?

Any opinions ??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Edward &raquo;</TD></TR><TR><TD CLASS="quote">High angle cam's function is increase the duration of open and close valve to make more air in&out to produce more power. Is it right?
</TD></TR></TABLE>
Right. Although from what I've seen, cams just move the power more often than not. In other words you kill some low end and add it to the topend.
I dont know specifically about Toda cams.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Edward &raquo;</TD></TR><TR><TD CLASS="quote">If I change high compression piston (12.5) and still using Toda A cam or stock cam, what will it effect?</TD></TR></TABLE>
More power. Regardless of cams, more compression = more power.
Assuming you run the right gas and timing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Edward &raquo;</TD></TR><TR><TD CLASS="quote">High angle cam's function is increase the duration of open and close valve ...</TD></TR></TABLE>

Your notion of "high angle" seems a bit off. Cames can have the same ramp portion but still have longer "duration".
Also, many performance cams have added duration as well as added "lift".

Higher compression motors make more power N/A, and also need more air through them to do so, hence the "bigger" cams. HTH

 

http://www.team-integra.net/se...D=472
They can be a bit pompous and condescending there, but there are some useful tidbits of information.

 

Any side-effect with high compression motor?

Moreover, if i use 12.5 compression motor, what's the different between Toda A cam and Toda C cam with this motor?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Edward &raquo;</TD></TR><TR><TD CLASS="quote">Any side-effect with high compression motor?

Moreover, if i use 12.5 compression motor, what's the different between Toda A cam and Toda C cam with this motor?</TD></TR></TABLE>

Toda C = More lift and duration as I understand it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Slick GS-R &raquo;</TD></TR><TR><TD CLASS="quote">Toda C = More lift and duration as I understand it.</TD></TR></TABLE>

And a crappy idle

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Edward &raquo;</TD></TR><TR><TD CLASS="quote">Any side-effect with high compression motor?

Moreover, if i use 12.5 compression motor, what's the different between Toda A cam and Toda C cam with this motor?</TD></TR></TABLE>

For starters, higher compression requires higher precision of tuning.

If you are running a static compression ratio around 12.5:1, your dynamic compression will be lower running the C's than if you ran the A's. Reason being is that the compression has more time to "bleed off" with the longer duration, but this also means you are using more air, and with the correct tuning, more air = more power. With the C's, you would be able to run more ignition timing because you will have a lower dynamic compression, which will also gain more power compared to the A's.

For a very basic response, the A's are more ideal for a mild compression motor, ie: 11:1, whereas the C's need compression to make optimum power, so they would be more ideal for a static CR of 12.5:1, or more.