Webra 1.45 tuning length?

[Rcmaster199 at aol.com]

Dave, what pipe is the 1100/260? Whose mfg?
 
MattK
 
In a message dated 1/7/2005 12:29:01 AM Eastern Standard Time,  
DaveL322 at comcast.net writes:

Ryan,
 
The Asano setup is designed for the OS140 which has different port timing  
than the 145 - the stock setup is about 24" (610 mm) exhaust flange to tuning  
baffle.
 
The recommended tune length from Webra for the 145 using the tuned  muffler 
(Horizon part # 1100/260, I believe also sold by Piedmont) is 780mm  (30.75"), 
from the exhaust flange to the flat end of the pipe before the  exhaust 
stinger.  800m for the 160 - which is interesting because the 160  is a lower timed 
engine which typically will utilize a shorter tune  length.  I believe Webra 
is specifying these tune lengths for approx 8100  RPM.
 
I am running the 160s and find that the 1100/260 at 31" ( 787 mm) to  the 
flat end (24" to the tuning baffle) and the Asano at 23.785" run  similarly at 
about 7700 RPM.
 
More RPM = shorter pipe.  If the pipe is too short, the main needle  will be 
sensitive and the midrange will be less linear.
 
Less RPM = longer pipe.  If the pipe is too long, the boost of the  pipe will 
be limited, and the engine will be very "friendly".
 
Anywhere between 25-27" should work, best length will depend on prop and  
flying style.

Regards,
 
Dave
 
----- Original Message ----- 

From:  _Rcmaster199 at aol.com_ (mailto:Rcmaster199 at aol.com)  
To: _discussion at nsrca.org_ (mailto:discussion at nsrca.org)  
Sent: Thursday, January 06, 2005 10:48  PM
Subject: Re: Webra 1.45 tuning  length?



I am still flying the 145 blackhead  too. I use the Hatori/os140  pipe with 
the macs header. The first reflector is set at 24inches from  the plug, 
straight line. I don't know how the Asano is setup inside so use  the first reflector 
distance as a good place to start.
 
MattK
 
In a message dated 1/6/2005 10:06:30 PM Eastern Standard Time,  
Acroman300 at aol.com writes:

Hello guys,
 
I would like to know the tuning lengths that you all are running with  the 
Webra 1.45. I have the blackhead version and am running an Asano pipe.  I was 
running the flex header combo with it, but it broke and really  didn't seem that 
it was tuned as well as it could be, as it was a pretuned  system. Any input 
is greatly appreciated.
 
Ryan  Smith






 
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