Merge collectors. Do they really help?
#2007506
02/07/16 06:50 PM
02/07/16 06:50 PM
|
Joined: Jan 2005
Posts: 4,243 Charlotte, North Carolina
sgcuda
OP
master
|
OP
master
Joined: Jan 2005
Posts: 4,243
Charlotte, North Carolina
|
Since I'm still in the rebuilding stages, I have been doing a lot of reading. I am currently running 2 1/8" primary tubes into 3 1/2" collectors. I am going to build up another set of 4" collectors for testing, since the new motor is 500". I have been thinking about trying out some merge collectors. Maybe narrow down to 3" and come back up to 4" or 4 1/2"? Has anyone seen any real improvements over a standard type collector? From what I have read, bottom end torque really increases without sacrificing top end hp.
[image][/image]
|
|
|
Re: Merge collectors. Do they really help?
[Re: sgcuda]
#2007537
02/07/16 07:44 PM
02/07/16 07:44 PM
|
Joined: Jan 2003
Posts: 14,479 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,479
So. Burlington, Vt.
|
Ive tested them on a few motors. They don't always work....... And they aren't all created equal.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: Merge collectors. Do they really help?
[Re: AndyF]
#2007544
02/07/16 07:59 PM
02/07/16 07:59 PM
|
Joined: Jan 2005
Posts: 4,243 Charlotte, North Carolina
sgcuda
OP
master
|
OP
master
Joined: Jan 2005
Posts: 4,243
Charlotte, North Carolina
|
How far are you from Elston Exhaust? Calvin can answer your question. I'm pretty sure he'll tell you that it isn't as simple as changing the collector. Never heard of them, but I will find out. Thanks.
[image][/image]
|
|
|
Re: Merge collectors. Do they really help?
[Re: fast68plymouth]
#2007548
02/07/16 08:05 PM
02/07/16 08:05 PM
|
Joined: Jan 2005
Posts: 4,243 Charlotte, North Carolina
sgcuda
OP
master
|
OP
master
Joined: Jan 2005
Posts: 4,243
Charlotte, North Carolina
|
Ive tested them on a few motors. They don't always work....... And they aren't all created equal. I have noticed that price varies, along with construction, which I am sure reflects function. The old saying "You get what you pay for" still applies. The cheaper ones have very short tapers back to a straight tube, while the more expensive ones will have a much more gradual, longer cone.
[image][/image]
|
|
|
Re: Merge collectors. Do they really help?
[Re: ozymaxwedge]
#2007645
02/07/16 11:40 PM
02/07/16 11:40 PM
|
Joined: Feb 2005
Posts: 20,116 PA.
pittsburghracer
"Little"John
|
"Little"John
Joined: Feb 2005
Posts: 20,116
PA.
|
Thanks. I can't wait to give them a try.
1970 Duster Edelbrock headed 408 5.984@112.52 422 Indy headed small block 5.982@112.56 mph 9.42@138.27
Livin and lovin life one day at a time
|
|
|
Re: Merge collectors. Do they really help?
[Re: sgcuda]
#2007806
02/08/16 05:45 AM
02/08/16 05:45 AM
|
Joined: Jan 2003
Posts: 2,902 A shed in England
Tig
master
|
master
Joined: Jan 2003
Posts: 2,902
A shed in England
|
We went from a set of horrible, home hash up 2 1/4 x 4 straight collector to a beautifully made custom set of stainless 2 1/4 with merge collectors and picked up nothing, there was no other changes. Sure looks a lot better under the hood though.
'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials. 9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge. RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
|
|
|
Re: Merge collectors. Do they really help?
[Re: Tig]
#2007807
02/08/16 05:52 AM
02/08/16 05:52 AM
|
Joined: Aug 2003
Posts: 43,007 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
|
I think the key to merged collectors working well or not is the pipe timing in relation to the firing order and the placing of the pipes from each other based on the firing order. What little I remember about the theory is you do not want two pipes blowing into each other that are 90 degrees crankshaft firing order away from each, you shold have them side by side so the pulse from the first one helps suck the other out the collector, not blow against each other Maybe not I'll try and ask my Son tomorrow about what they did and the rules they followed when he made them for Rob Muzzy racing.
Last edited by Cab_Burge; 02/08/16 02:15 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
Re: Merge collectors. Do they really help?
[Re: sgcuda]
#2007851
02/08/16 11:45 AM
02/08/16 11:45 AM
|
Joined: Jan 2003
Posts: 13,319 Marion, South Carolina [><]
an8sec70cuda
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 13,319
Marion, South Carolina [><]
|
If you had a lot of time, plenty of money, and your own dyno...I'm sure you could eventually find a header primary and collector combo that would make a few more horsepower over an off the shelf set.
CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 18 spline 4 speed, Dana 60 '71 Demon, 340, low gear 904, 8.75 '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax
|
|
|
Re: Merge collectors. Do they really help?
[Re: sgcuda]
#2007886
02/08/16 12:57 PM
02/08/16 12:57 PM
|
Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
|
Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
|
Merge collectors have to be built to YOUR engine.. they are designed for a certain rpm and if you move too far from that rpm they dont add anything.. so if you feel you can buy a off the shelf merge and expect to to add performance your kidding yourself... a straight collector will do more if you make the collector 16"-18" long... I made a few merge collectors at work to test on the dyno... each one hurt power at most points(until it crossed the RPM where it worked).. think a expansion chamber on a 2 stroke.. they work on a certain engine for a certain rpm range... I built a set of chambers for my snowmobile.. it KILLED the top end but it turned it into a tree puller on low end.. because I didnt have the inlet cone and exit cone the right diameter and length
Last edited by MR_P_BODY; 02/08/16 12:59 PM.
|
|
|
Re: Merge collectors. Do they really help?
[Re: sgcuda]
#2007899
02/08/16 01:22 PM
02/08/16 01:22 PM
|
Joined: Jan 2003
Posts: 14,479 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,479
So. Burlington, Vt.
|
There are very few "silver bullets" in the power building hobby.
The biggies are nitrous and boost of course.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: Merge collectors. Do they really help?
[Re: sgcuda]
#2007953
02/08/16 03:26 PM
02/08/16 03:26 PM
|
Joined: Jan 2003
Posts: 20,149 Park Forest, IL
slantzilla
Too Many Posts
|
Too Many Posts
Joined: Jan 2003
Posts: 20,149
Park Forest, IL
|
My buddy put some merge collectors on his stocker. He said it seemed to pick up .01 or so in the 60', but he said the change was so small he could not prove it one way or the other.
"Everybody funny, now you funny too."
|
|
|
Re: Merge collectors. Do they really help?
[Re: fast68plymouth]
#2007964
02/08/16 03:44 PM
02/08/16 03:44 PM
|
Joined: Jan 2003
Posts: 30,947 Oregon
AndyF
I Win
|
I Win
Joined: Jan 2003
Posts: 30,947
Oregon
|
There are very few "silver bullets" in the power building hobby.
The biggies are nitrous and boost of course. I've read most of what Calvin has posted on 4-2-1 headers and merger collectors and I think it boils down to building an effective extractor type header system which then allows the engine builder to use a smaller exhaust valve which in turn allows a larger intake valve. So not a silver bullet at all! But the NASCAR guys have used it to pick up some power and I'm pretty sure those engines are tuned now to a point where a standard off the shelf type of header would kill off a bunch of power. The big trick seems to be cutting the primary length way down to improve high speed performance. Then the merge and choke are used to make it work on the bottom end. This is why just welding a merge collector onto a standard set of pipes doesn't do much. It doesn't start to work until the pipe length is correct which takes some math to figure out.
|
|
|
Re: Merge collectors. Do they really help?
[Re: sgcuda]
#2007972
02/08/16 04:10 PM
02/08/16 04:10 PM
|
Joined: Nov 2015
Posts: 870 Missouri
jwb123
super stock
|
super stock
Joined: Nov 2015
Posts: 870
Missouri
|
For my Dodge these make the most power Flowmaster’s retrofit-style 4-2-1 Scavenger Series. I built several sets of headers for the car, used standard 4 into one and merge type collectors. 512 wedge NSS type car. There is a program called pipemax that allows you to size your headers correctly, and give you lengths for step headers as well. http://www.maxracesoftware.com/It also has a pretty good engine output estimator in the program as well.
|
|
|
Re: Merge collectors. Do they really help?
[Re: jwb123]
#2007976
02/08/16 04:14 PM
02/08/16 04:14 PM
|
Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
|
Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
|
For my Dodge these make the most power Flowmaster’s retrofit-style 4-2-1 Scavenger Series. I built several sets of headers for the car, used standard 4 into one and merge type collectors. 512 wedge NSS type car. There is a program called pipemax that allows you to size your headers correctly, and give you lengths for step headers as well. http://www.maxracesoftware.com/It also has a pretty good engine output estimator in the program as well. I've used that program for YEARS
|
|
|
|
|