this info came from a article from teamintegra.com

"A suggested starting point for the length of a tube with peak torque at 6000 rpm is 13 in.

You add 1.7 in. for every 1000 rpm that you want to move the peak torque below 6000.

Or subtract 1.7 in. for every 1000 rpm you want to move the peak torque above 6000."

based on this information, if using cams with vtec set at 6100 and peak power at 8800, how would you adjust the length accordingly to maximize power gains.



based on the info above, what do you guys think the length used was?


Modified by CXtypeR at 11:01 AM 12/8/2006

 

bump

 

What is the set-up? There are too many variables to consider that would determine the proper intake length. ex intake manifold, headwork, headers, etc. Maybe that length works best on that motor. I would say try that length on a motor similar to yours and see if the results are the same

 

12.15 inches???? just a quick guess

 

actually i change my guess to 13.85 i did my first one backwards

 

According to their BS:

Your max torque is 600 RPM below 6000, so according to them, your length of air intake tubing would be 13 + (.6)(1.7) = 14.02 inches. But I call BS.

 

Just FYI those Graphs are identical to the Thread BearsEK Created. The Intake was custom tuned for the engine on the dyno. The link below is the original thread on this topic and has the full engine specs.
https://honda-tech.com/zerothread?id=1812935


Modified by PURE Tuning at 11:47 AM 12/13/2006

 

i wonder if the same tuned length can work on the same displacement engine

somebody find out the perfect lengths for 1.6, 1.8. 2.0 engines and manufacture the intakes with the vstack!!! id buy it

 

I was always under the impression that added length moved the powerband up? This is news to me. What about air inertia?

 

got it backwards phil. longer length increases airspeed and inertia, therefore cylinder filling overcomes rising piston as intake valve is about to close sooner in the rpm range.

torque usually peaks sooner, whether from additional boundary layer adding fluid friction, or from going over the velocity threshold of sonic choke sooner.. i couldnt tell you. once airspeed gets too high though, flow takes a dive. as does cylinder filling and tq.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mike_belben@yahoo.com &raquo;</TD></TR><TR><TD CLASS="quote">....longer length increases airspeed and inertia, therefore cylinder filling overcomes rising piston as intake valve is about to close sooner in the rpm range.

torque usually peaks sooner, whether from additional boundary layer adding fluid friction, or from going over the velocity threshold of sonic choke sooner.. i couldnt tell you. once airspeed gets too high though, flow takes a dive. as does cylinder filling and tq. </TD></TR></TABLE>


wtf ? Did this make sense to anyone else ?

The longer tubing does increase low end since the velocity increases and the air moves easier once you get moving.... but where did team integra get their info from to base the theory ? just dynos ?

 

your intake valve closes well after bottom dead center while the piston is rising and chamber volume is shrinking. if the intake is open, what keeps the charge from getting spit out? what happens inside the engine to create the torque peak?

-edit- i was addressing phil in the quote so it was a patchy explanation because i know hes on the same page as me. if you remember that longer tubes make more charge inertia, and therefore make peak torque sooner, then taper off sooner relative to shorter tubes, youll have the gist of it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CXtypeR &raquo;</TD></TR><TR><TD CLASS="quote">this info came from a article from teamintegra.com

"A suggested starting point for the length of a tube with peak torque at 6000 rpm is 13 in.

You add 1.7 in. for every 1000 rpm that you want to move the peak torque below 6000.

Or subtract 1.7 in. for every 1000 rpm you want to move the peak torque above 6000."

based on this information, if using cams with vtec set at 6100 and peak power at 8800, how would you adjust the length accordingly to maximize power gains.



based on the info above, what do you guys think the length used was?


Modified by CXtypeR at 11:01 AM 12/8/2006</TD></TR></TABLE>
The calculations that were posted aren't even close to what it ends up being, The graphs that I tuned which u posted yourself are lengths that were dynoed with a specific goal in mind. From what i have learned what mathmatically works doesn't always work on every different setup the ONLY way to find what works is to acutually pay to dyno your setup changing the lengths to your specific needs. If you need info on this setup check my original thread.
https://honda-tech.com/zerothread?id=1812935