MBH Tri-Y scavenging effect video
#1
Former Vendor of MBWorld
Thread Starter
MBH Tri-Y scavenging effect video
Ever since I developed headers for 55s I was always fielding questions about exhaust scavenging effect on headers. I've never been the best at explaining it in a typed out reply or post. So Today at the shop we had one of your 63 long tube headers just about finished up. Just before we welded on the third Y collector we shot this video to demonstrate how our header scavenging works.
For all of us car nuts out there, we've hear about scavenging alot, but have you ever seen it? So we shot a quick video to share with you guys.
http://www.youtube.com/watch?v=pDQXsfeZGwk
For all of us car nuts out there, we've hear about scavenging alot, but have you ever seen it? So we shot a quick video to share with you guys.
http://www.youtube.com/watch?v=pDQXsfeZGwk
#3
headers looks very nice but I fail to see anything to do with scavenging effect, what I see is vacuum being created
can you make another video showing the inside of the header, I want to see how clean the welds are where the flange meets the tubing
can you make another video showing the inside of the header, I want to see how clean the welds are where the flange meets the tubing
#4
Former Vendor of MBWorld
Thread Starter
Does this pic help? I might have something more close up for ya. I'll check and see what I got. My brother takes most of the photos so better ones could be on his computer.
#5
MBWorld Fanatic!
I really like the welds and the cleaned up tube-to-flange area on MBH's headers. At first I was wondering what the heck you are trying to demonstrate until I saw the guy using the blower into one of the tubes creating the scavenging effect on the other tubes. Great work!
Cant't wait to see and hear them on bhamg's car this Thurs.
Cant't wait to see and hear them on bhamg's car this Thurs.
Trending Topics
#8
MBWorld Fanatic!
Join Date: Aug 2006
Location: S.D Cali
Posts: 1,885
Likes: 0
Received 0 Likes
on
0 Posts
CLS63
I really like the welds and the cleaned up tube-to-flange area on MBH's headers. At first I was wondering what the heck you are trying to demonstrate until I saw the guy using the blower into one of the tubes creating the scavenging effect on the other tubes. Great work!
Cant't wait to see and hear them on bhamg's car this Thurs.
Cant't wait to see and hear them on bhamg's car this Thurs.
#12
that pics help, but very little. I would like to see a light or flash onto the flange-tubing conncetion to see the welds. And then another shot on the merger side after the collector looking in, thanks.
#13
MBWorld Fanatic!
Join Date: Jun 2007
Location: Philadelphia, PA
Posts: 2,949
Likes: 0
Received 0 Likes
on
0 Posts
2008 A8L, 2002 996TT X50, 2009 X5
#14
Former Vendor of MBWorld
Thread Starter
Stock runs
Stock ECU, headers, test pipes, with secondary cats intact
ECU,headers, test pipe, secondary cats intact
ECU, headers, Primary cats and secondary cats intact.
With that said I'll wait for bhamg to post if he so chooses.
#17
MBWorld Fanatic!
Join Date: Jun 2007
Location: Philadelphia, PA
Posts: 2,949
Likes: 0
Received 0 Likes
on
0 Posts
2008 A8L, 2002 996TT X50, 2009 X5
Very cool; hope he posts - sounds like valuable data (especially A/B'ing the first two).
#19
Senior Member
No offense but I think the video and it's relationship to "exhaust scavenging effect" is a bit misleading. My understanding is that header primary tube diameter, and more important, primary length are tuned to a specific RPM. Pulses are created in the primary tube by the opening and closing of the exhaust valve. A negative pressure wave naturally develops after an exhaust charge leaves the primary. The science and art of header engineering is to adjust header length so that the negative pressure wave reaches the exhaust valve at the optimum working rpm. That is what creates "exhaust scavenging effect". It does no good to tune headers for 7000 rpm if the engine spends most of it's working life well below. "Long tube" headers work so well on the street because the maximum "exhaust scavenging effect" takes place in the middle of the engine working RPM. This creates a much better torque curve, which is very desirable in a street application, verses a race engine requirement of maximum horsepower with little regard for mid-range torque. Simply blowing air in a tube does create vacuum, known as the venturi effect. Every carburetor and perfume sprayer uses that principle. Tuning negative pressure waves in the exhaust primary tube is what creates exhaust scavenging. Hopefully your long tube headers were designed using the scientific formulas available and then fine tuned on the dyno for a specific torque range. If so, I'm sure they are winners!
#20
Senior Member
here is a good read.
http://www.ssheaders.com/header.htm
http://www.ssheaders.com/header.htm
#21
Former Vendor of MBWorld
Thread Starter
Dyno-Comp installed aftermarket cats. So the primary cats used are not stock, but the secondary cats are stock.
#22
Former Vendor of MBWorld
Thread Starter
Last edited by MBH motorsports; 06-16-2010 at 11:13 PM.
#23
No followup until the weekend but lots more power and an unreal exhaust note...OE quiet on the highway but unleashing a wild guttural howl on full throttle. I have more of everything engine/exhaust-related but with absolutely no loss of civility. Great, great crew at Dyno-Comp...Hooley's headers are a work of art!
Last edited by bhamg; 06-17-2010 at 01:56 AM. Reason: sp typo
#24
Super Moderator Alumni
Join Date: Dec 2009
Location: USA
Posts: 2,189
Likes: 0
Received 6 Likes
on
4 Posts
2011 GLK 350, 2013 GT-R, & 2013 RAM 1500
No followup until the weekend but lots more power and an unreal exhaust note...OE quiet on the highway but unleashing a wild guttural howl on full throttle. I have more of everything engine/exhaust-related but with absolutely no loss of civilty. Great, great crew at Dyno-Comp...Hooley's headers are a work of art!