Backpressure - Page 8 - Harley Davidson Forums: Harley Davidson Motorcycle Forum
Reply
 
LinkBack Thread Tools Display Modes
post #71 of 76 (permalink) Old 11-25-2012, 12:29 PM
Junior Member
 
Dave Harryman's Avatar
 
Join Date: Sep 2012
Location: so cal
Posts: 28
I know Im new here so let me tell you guys that Im not new to building engines for more power , I am a engine builder / machinist / fabricator , here are a couple pics of some VW engines I built back in the 80's ,you cant buy these parts , they are hand made , not trying to brag ,just trying to let you guys know I have a lot of experience when it comes to hot rodding stuff this one had Porsche Hemi heads and overhead cams fitted

Dave Harryman mrd-racing

91 Heritage ST
80 cid
ported / 5 angle
EV 46
edelbrock 40mm
Dyna S / Nology
MRD exhaust 1 3/4" x 1 7/8" x 2" 2 into 1

Last edited by Dave Harryman; 11-25-2012 at 08:32 PM.
Dave Harryman is offline  
Sponsored Links
Advertisement
 
post #72 of 76 (permalink) Old 11-25-2012, 01:05 PM
Luke 22:36
 
Kainam's Avatar
 
Join Date: Oct 2006
Location: Kansas City
Posts: 19,968
Images: 149
Garage
Nice!

'05 Carbed Night Train
111 rwhp, 112 rwtq
Best 1/4 ET 12.557s
Best 1/4 MPH 108.59
Kainam is online now  
post #73 of 76 (permalink) Old 11-26-2012, 08:23 AM
Banned
 
Join Date: Sep 2009
Location: Hamilton, Canada
Posts: 5,336
Images: 4
Quote:
Originally Posted by Dave Harryman View Post
does the thunderheader antireversion cone have a baffle ? and by baffle I mean a component that restricts flow, because that is what I designed and it drastically reduces noise with virtualy no power loss

Yes, see for yourself here:
Thunderheader X-series Exhaust
chris_lacey is offline  
post #74 of 76 (permalink) Old 11-26-2012, 10:35 AM
Senior Member
 
Join Date: Sep 2008
Location: Munnsville, N.Y.
Posts: 1,627
It is not about "backpressure", but rather the ability to CORRECTLY control the reversion.
Scott

"....3 dueces and a 4 speed..........and a 389"..........
Goodson H-D Cylinder Head Tooling Manufacturer
Celebrating 30 Years of HD Engine Building
Hillsidecycleco is offline  
post #75 of 76 (permalink) Old 11-26-2012, 10:47 AM
Junior Member
 
Dave Harryman's Avatar
 
Join Date: Sep 2012
Location: so cal
Posts: 28
Quote:
Originally Posted by chris_lacey View Post
Yes, see for yourself here:
Thunderheader X-series Exhaust

thanks for the info , looks like that is how it can be done on a meg ,has anyone dynoed it back to back against a empty one and do they say how many DB it lowers the noise output ? ....anyway my design is for glasspack type mufflers not megs , and it lowers full throttle noise output drasticly with only a .5 peak HP loss , it makes an overly loud open system pass the FIM/AMA sound test on the dirtbikes we run them on

Dave Harryman mrd-racing

91 Heritage ST
80 cid
ported / 5 angle
EV 46
edelbrock 40mm
Dyna S / Nology
MRD exhaust 1 3/4" x 1 7/8" x 2" 2 into 1
Dave Harryman is offline  
post #76 of 76 (permalink) Old 11-26-2012, 11:20 AM
Junior Member
 
Dave Harryman's Avatar
 
Join Date: Sep 2012
Location: so cal
Posts: 28
Quote:
Originally Posted by Hillsidecycleco View Post
It is not about "backpressure", but rather the ability to CORRECTLY control the reversion.
Scott
that is what I was trying to say

Dave Harryman mrd-racing

91 Heritage ST
80 cid
ported / 5 angle
EV 46
edelbrock 40mm
Dyna S / Nology
MRD exhaust 1 3/4" x 1 7/8" x 2" 2 into 1
Dave Harryman is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Harley Davidson Forums: Harley Davidson Motorcycle Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome