I am seeking guidance on what to look for and do to port the exhaust headers, and the y-pipe? I think the headers are pretty self explanitory, but the y-pipe I have no idea...
Picures please?
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03:47 PM
PFF
System Bot
Carrolles Member
Posts: 2799 From: Alabaster, AL USA Registered: Apr 99
The most important thing is to open up the throat ,but leave material so as not to weaken valve seat,each throat must be equal make a guide template..
Read all you can ,read it again port port match port exhaust manifold or use headers smooth flow pipes & bends to the muffler use turbo or free flow muffler of your choice mount muffler in original muffler location ( not easy) avoid glasspacks, they hurt performance you can get 30 to 40 horse power
I know you said you already figured out the exhaust manifolds, but for the sake of anyone doing a future search here's a couple pictures of what needs to be done:
You have to cut the Y pipe below the Y. Port it and weld back. I marked the pipe so I could re-align it after getting done. You also want to weld the Y in the valley to prevent leaks from removing the joint of the Y inside. I did a gross cut with a torch and then clean up with a grinder.
[This message has been edited by Dodgerunner (edited 05-13-2011).]
Custom2m4 30 to 40 shetland ponies can be had by porting & proper exhaust system ,most exhaust manifold ports are not properly done. the weld on my manifolds entrance at the flat of the flange is beveled ,the inner pipes are sannded smooth where the entrance tubes blend into the manifold collector, there is not a lot of performance equipment for the 60o V6 there are porting masters like dutwieler or branch that can get 30 to 35 ponies from just porting,but most of us are to cheap to have a head ported on a V6 Just my ported manifolds,Y pipe & mandrel bend exhaust with a neck down ,& a proper mounted turbo muffler will add 15 hp easy. "The horsepower is in the heads",of course I get this info from 15 or 20 nationally known tuners I have just purchase Truelo headers,but these are for increase gas milage & will add a midget pony or 4 & one seventh..I want a 2.8 that goes from 0 to 60 in 7 seconds & gets 22 to 24 mpg around town.do not care if gas goes to $10.00 a gallon , the day will come,when you can not buy gas easily,, there will be long lines,just like there were in the 70s,,Price that mo ped again ??
[This message has been edited by uhlanstan (edited 05-13-2011).]
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08:14 PM
AL87 Member
Posts: 2578 From: Bradenton, Florida, United States Registered: Mar 2010
I know you said you already figured out the exhaust manifolds, but for the sake of anyone doing a future search here's a couple pictures of what needs to be done:
QUOTE]
Thank you very much, the header porting you have pictured isnt as extreme as what I saw from last night in another thread, but it was more along the lines of what I was thinking it was...
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10:38 PM
AL87 Member
Posts: 2578 From: Bradenton, Florida, United States Registered: Mar 2010
Originally posted by Dodgerunner: You have to cut the Y pipe below the Y. Port it and weld back. I marked the pipe so I could re-align it after getting done. You also want to weld the Y in the valley to prevent leaks from removing the joint of the Y inside. I did a gross cut with a torch and then clean up with a grinder.
Your pics are a good enough example of the y-pipe, but messy lol, I hope you didnt just weld it back up all messy like that... It would get under my skin if you didnt clean out all that little stuff, and smooth out and sharpen up on the insides. ugh... perfectionism is a b-otch, lol.
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10:48 PM
AL87 Member
Posts: 2578 From: Bradenton, Florida, United States Registered: Mar 2010
The most important thing is to open up the throat ,but leave material so as not to weaken valve seat,each throat must be equal make a guide template..
Read all you can ,read it again port port match port exhaust manifold or use headers smooth flow pipes & bends to the muffler use turbo or free flow muffler of your choice mount muffler in original muffler location ( not easy) avoid glasspacks, they hurt performance you can get 30 to 40 horse power
I highly doubt you can achieve 30-40 hp just on what you have described.
1st of all, the best exhaust is "no exhaust" any muffler is a detriment to horsepower. If mufflers increased horsepower, then tell me why they arent used on high performance race vehicles?
There is alot of math involved like measuring the total intake of an air/fuel mixture into a combustion chamber, how it enters the combustion chamber, the compression ratio of the combustion chamber, how thuroughly the mixture is then burnt during combustion, how many bends, how sharp the bends are in the header, and then how equal in length the exhaust header pipes are and how large thier diameter is to either increase or decrease (or even negate or reverse) the exhaust's scavenging effect when it finally reaches the header collector (depending on style of header), and it should be measured from a baseline of no exhaust scavenge (vacume) at all. you have to match the exhaust's efficientcy to the intake's efficientcy... if you leave the intake alone, you will not make as big a gain if you just installed headers, as you would if you matched the intake and the exhaust (and that includes everything in between too)
So in essence, you do need backpressure, to make exhaust scavenging happen (so 3-inch piping isnt a good idea). And a glass-pack is best (in the case that you actually need a "mufler") and it shouldnt hurt if its internal diameter is larger than the exhaust pipe's diameter.
you are so wrong, the glasspacks hurt performance ,I use to be a strong advocate of the cherry bomb,but the small inlet holes required kill performance . there was a dynomax turbo glasspack in the early 90s but people did not buy it.IT WAS GREAT many turbo mufflers produce more horse power than a straight pipe!! 40 horsepower is a LOW conservative astimate. glasspacks hurt performance, they suck,hurt performance most people want cheap price flowbench, & cheap they get. with proper ported ex manifolds ,Y pipe & smooth flow to Turbo muffler with a neckdown will give 15 horse power easy,,the turbo muffler MUST be mounted in the stock muffler location,,mounting where the cat went hurts performance ,,mounting in the stock location is difficult,but can be done "Google" the following for muffler dyno test Titantalk.com,flowchart for a few mufflers Carcraft magazine muffler test hotrodmagazine muffler test
this was a longer in depth post but the computer ate it I am an advocate of the jennings exhaust systems and the bell measurements ,but the math is totally wrong on a Fiero V6 you have to ""trial & error"" which I have been doing on the cheap , there are about 14 components in my exhaust system,Im going to truelo,but the stock manifolds ported work great Installing a later model duke head on an 87,88 fiero duke makes a great performance increase,an example of what can be done
[This message has been edited by uhlanstan (edited 05-14-2011).]
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12:02 AM
G_Reaper Member
Posts: 171 From: Nanaimo, BC, Canada Registered: May 2011
best exhaust is no exhaust are you joking? You obviously need to start doing some research before you go making statements like that in the future. Exhaust is everything and if you can tune it to match the motor it won't get you 30-40 hp increase but a good 20 that's for sure. Before I go and write a page on the importance of exhaust (trust me I was researching exhaust for 3 months) do some more research. But if your one of the ones that like a certain sound to your exhaust that's cool too. We're all different. But don't go saying stuff like that. seriously.
-Cody
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12:13 AM
AL87 Member
Posts: 2578 From: Bradenton, Florida, United States Registered: Mar 2010
if an exhaust with a muffler makes more horsepower than one without, then tell me why race cars dont have mufflers?
Believe me, I hate straight pipes... I would prefer to have my 2.8 droning like a V8 at idle, but an exhaust like that will yeild no performance gains, Its true that doing work to the stock setup can free up some horses, but if you want to make power there then go with a tuned exhaust, like the ones from truleo (which I keep reading are and have been the best exhaust headers made to date for our Fieros) and as for an actual muffler, a turbo muffler is supposed to be a step up from a stock muffler, but then a glass-pack is supposed to be better... and then no muffler at all is supposed to be best, but like I said its all in the math... I bet I can make more horsepower with custom headers and a straight pipe setup than someone can with a turbo muffler or glass-pack...
