I noticed the static cr's are going up nowadays. Not too sure what other tech they have to achieve this on pump gas. My guess would be the works on the combustion chamber etc.

So maybe I made a good decision to run my static cr to around 12.7? Despite lower timing, car still feels much better.

 

its all in the tune and supporting mods. and just hope you dont get a shitty tank of gas.

 

big cams like the jun3's you have will bleed off some of the static compression making it a little safer. you still need a good tune regardless.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by camlob &raquo;</TD></TR><TR><TD CLASS="quote">I noticed the static cr's are going up nowadays. Not too sure what other tech they have to achieve this on pump gas. My guess would be the works on the combustion chamber etc.

So maybe I made a good decision to run my static cr to around 12.7? Despite lower timing, car still feels much better. </TD></TR></TABLE>

They pull that off on pump gas with FSI (direct injection) by spraying atomized fuel directly into the combustion chamber instead of the end of the intake runner.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by H-PIMP &raquo;</TD></TR><TR><TD CLASS="quote">

They pull that off on pump gas with FSI (direct injection) by spraying atomized fuel directly into the combustion chamber instead of the end of the intake runner.</TD></TR></TABLE>

Thats probably it. FSI is the best explanation.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by doood &raquo;</TD></TR><TR><TD CLASS="quote">big cams like the jun3's you have will bleed off some of the static compression making it a little safer. you still need a good tune regardless.</TD></TR></TABLE>

Yes. Based on my computation for the loss in dynamic cr using the Jun 3's, my static cr is where it should be. But the primaries of the Jun 3's are like stock so static cr does'nt get bled off in daily driving.

 

So far, K-series engines are the best Honda engines when it comes to the ability to run a higher than "normal" static CR.

With VTC control, you can tune the intake cam gear to bleed off compression in the higher load/low RPM region, and then close the overlap as the RPM's increase to build dynmamic CR and make more power.

With Big cams and Kpro, you can easily run 13:1 static on 92 octane. A few have even faired well with 13.5:1

As for the RS4 V8, it is running a direct injection system similar to that on the new GTi. Exhaust temps are usually cooler at the same air-fuel-ratio on a direct injection engine, allowing manufacturers to push the boundries further. Don't forget, a hotter combustion is a cleaner combustion, and more efficient.

What surprises you more, BMW running 15:1 AFR's at 12psi on the 335i, or Audi running 12.5:1 static CR on the RS4?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 92TypeR &raquo;</TD></TR><TR><TD CLASS="quote">So far, K-series engines are the best Honda engines when it comes to the ability to run a higher than "normal" static CR.

With VTC control, you can tune the intake cam gear to bleed off compression.

What surprises you more, BMW running 15:1 AFR's at 12psi on the 335i, or Audi running 12.5:1 static CR on the RS4?</TD></TR></TABLE>

Tuners here dont have that much knowledge with the K engine. When we tuned my brothers DC5 the tuner did'nt know about that(well I too). That seems to be a brilliant idea to bleed off cr at the low rpm region.

Can't even imagine the BMW running AFR's at 15 coupled with boost! Times are a changing.....