evo916

As most of you know the Merge Collector in an All Motor setup is a very important key piece in making Naturaly Aspirated horsepower...Here's a look into the steps it takes to make one...

First select a merge bend ranging from 12 to 25 degrees..

Then expand the entry to the designated tube size...

Make the necessary cuts to form an internal pyramid..

Fit all 4 together and weld inside and out..

Cut and expand outlet to desired size, clean and polish the inside and there you have it!

SL0WEGG

Looks to be a quality piece. Nice work

J35monster

Do you sell collectors built to desired specs?

evo916

yes I do..

coryb13ser

How much. Stainless and mild steel?

unusual71

how do you size the choke?
how does either end of the merge angle range compare?
does it make a difference which position you put each cylinder in?

evo916

Both..pm me

evo916

-Motor size, head flow etc....
-merge angles are based on collector volume, space and exhaust pressure..
-without giving out info.. yes!

evo916

Thanks!

unusual71

you forgot a couple of other generic answers like fuel, for a turbo or na, n2o usage, material, primary size, spark plug gap lol jk

NAH2B

why is everyone worried about giving out answers lol

primary pairing in the collector should always be your firing order 1342 in rotation. this helps w/ scavenging, basicaly the exhaust from the firing cylinder pulling the exhaust from the next firing cylinder and so on in a rotation.

a longer convergent angle on the collector will almost always make more hp than a shorter angle which is mainly used for tighter spaces.

inlet and throat sizing is determined by displacement among many other things as stated. i can tell you anything larger than a 2.5" choke has been proven by others to kill power on engines ranging in size from 2500 to 2700 cc

however i will be doing my own testing next week including choke size, convergent angle, different brand collcetors, w/ and w/o megaphone, also w/ and w/o rev cone.

theres alot more that goes into echaust design such as pre and post collector setup but i will give the other guy a chance to post some info afterall this is h-t and threads w/o much tech could easily be assumed sales threads and locked or deleted (ask me how i know). so there ya go, plenty of tech in the thread now

unusual71

This is honda-tech man there are literally HUNDREDs of dollars to be made.

this forums has always confused me because you can go to a lot of other forums where this type of thread will actually spawn some real discussions but here everyone tries to look like they know their **** and like the info they have is something that only they have been able to figure out. honestly when people make posts like "without giving out too much" or "can't afford to share the details" it really make me believe they dont understand themselves, but admitting that would be bad for business i suppose.

the throat size is a function of primary size, rpm, power, and desired collector volume, in that order. displacement doesnt really tell you very much by the time you have made it to the collector, the volume of flow is what were interested in which is more closely related to power level.... ok and fuel, timing, afr, header material etc...

A relationship could be developed so that you could go Choke = Primary * (some flow factor / some powerband factor) which gives something like Choke = Primary * (1.158).

the factors would be weighted and it would obviously only be good for a ball park, but it would get us close. obviously 2.5" isn't some magic number but I would say its by far the most commonly used. I have only really done one good test comparing two equal headers with only the collector differing between them. Of course i can't share the results or my children might be impotent, but it would be nice to be able develop some of the ideas further.

I'd be interested in seeing good comparisons between megaphone, reverse cone, and nothing, because i dont really feel like there are any actual gains to be had, and any time someone does find a gain its because there is some flaw that is characteristically changed in the flow inside the collector. I would like to be proved wrong because that would mean there really is power to be gained after the collector.

evo916

ok...

SP GARAGE

iTrader: (1)

Merge collectors look great.. My header is at the shop getting coated.. I can't wait till it's out

NAH2B

well id be more than happy to share the results of my upcoming testing, however id like to hear your results as well. feel free to pm me if your worried about your kids being unable to make their own kids

N/A

Anatomy: the study, description, structure, and classification of a body

unusual71

most people won't think much of it because there was no back to back dyno the only comparison i have is the fuel maps, data logging and an accelerometer. It was nothing much though really i just went from 2" primary to a step from 2 to 2 1/8th right at the collector. Moved the power band up by about 6-700 rpm but the actual increase in tq was mostly negligible. obviously nothing break through but I was just sort of curious how much variation you would see between 1 step in tubing size.

lol i just assumed he had his own meaning for the word

NAH2B

so you must have changed out the 2" inlet collector for one w/ a 2 1/8th inlet correct?

what size were the throats on each collector?

N/A

Are there any sites/threads showing the anatomy of a header and its parts?

unusual71

it was a home made merge in both cases. made by cutting both ends of a short length of tubing at 15* putting the piece in the band saw and taking cuts out of the side. just the method that works easiest for me. first header used 2" tubing for collector pieces, second 2 1/8". otherwise the collectors were as equal as i could get them and both headers had the same length primaries. two sources of error include the fact that a step existed right right before the collector of header two which which influence the flow in some way at that point, second source of error was my welds. I took a bit more time to make sure there was no contamination the second time around and also just had a little less slag inside in general.

evo916

Guys I just wanted to share how my collectors are made...That was it! I thought it would be interesting. I don't claim to know everything...(Obviously) I tell my kids you learn something new everyday and the exhaust business is no different. Innovation and trial and error are key things in development and everyone has thier own ways of doing things but I have spent alot of my own time and money developing what I know... to just give it away. Not that I won't share anything in the futue it's just not what I intended to do with this thread!

Thanks,
Jack

N/A

Then why mislead people with the title, I thought advertising was banned in this part of the forum

unusual71

the problem with your original post is that you say things like "make the necessary cuts" well making the cut is the difficult part. maybe if you shared your method of how to actually make the cut or how to better weld the pieces inside it would be a different story.

mvm

evo916.. Thanks for sharing. Your craftsmanship is undeniable !

vteczone

no wonder HT is now known as Hater-tech.com..

ok, i dont care what or how mislead the OP start the thread... all i care is someone else (knowledgeable) to chime in and make this thread useful so i could subscribe it and can be useful for me in the future.