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Posted: Fri Nov 07, 2008 1:00 am 
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tickford_6 wrote:
as for the pipes, if anyone has the time and money, build a set with 2inch primary pipes 40inches long into a pair of 3into1 merge collectors
with 2 1/4 inch secondaries 12inches long into a single 3inch system.


interesting idea, one hurdle being legality on emisions, as we all know the further you move the cat down the line, the less effect they have cleaning up the emisions. long series headers like 4480's and JMM race series are borderline on emisions.

sweet looking pipes though, have you ever tried a straight through muffler, like a hooker instead of an offset? Im thinking of using a hotdog too, but up front, want to keep as much flow speed as possible meaning one straight thru muffler just before the diff bend.

 

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Posted: Fri Nov 07, 2008 8:01 am 
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tickford_6 wrote:
as for the pipes, if anyone has the time and money, build a set with 2inch primary pipes 40inches long into a pair of 3into1 merge collectors
with 2 1/4 inch secondaries 12inches long into a single 3inch system.


IT WONT WORK!... sorry couldn't help it :roll: What's the most you have managed to increase torque/hp on engine analyzer just from exhaust?

Grimketel wrote:
interesting idea, one hurdle being legality on emisions, as we all know the further you move the cat down the line, the less effect they have cleaning up the emisions. long series headers like 4480's and JMM race series are borderline on emisions.

sweet looking pipes though, have you ever tried a straight through muffler, like a hooker instead of an offset? Im thinking of using a hotdog too, but up front, want to keep as much flow speed as possible meaning one straight thru muffler just before the diff bend.


How many cops check to see how far back your cat is/what muffler's your using? Apart from when I have been driving like a d**k once I haven't ever had my car checked for defectable stuff.

I used a hooker on my mates car and it picked up average 0.2 down the strip. His old one was quite old though (probably had more of an effect than its design) plus his driving is difficult to use as a comparison (erradic might be a nice way to put it)

 

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Cramping in the hand from having it on your Wang for an excessive period of time is a definate con.
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Posted: Fri Nov 07, 2008 10:28 am 
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on my el at the moment i got 4480s' a steel cat, 2 1/2in the whole way single muffler, its not what i would call loud, proberly just legal or a little over but but i cant help feeling that if i took out the single muffler and added 2 straight through mufflers like a hooker or something of the equivilent than it would flow more (being straight through) than the single muffler thats on it now. when it had the stock exhaust it felt like it was really really choked up, when the exhaust went on it reved much free'er and more cleanly but i didn't really feel it in the seat of my pants where i should feel the torque. i understand that one single mod wont make it rev like a doorslammer but it still feels a little choked and i thought i should at least feel a tiny bit quicker i noticed heaps more torque and hp when i replaced my fuel filter,

 

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Posted: Fri Nov 07, 2008 8:15 pm 
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skidder wrote:
tickford_6 wrote:
as for the pipes, if anyone has the time and money, build a set with 2inch primary pipes 40inches long into a pair of 3into1 merge collectors
with 2 1/4 inch secondaries 12inches long into a single 3inch system.


IT WONT WORK!... sorry couldn't help it :roll: What's the most you have managed to increase torque/hp on engine analyzer just from exhaust?



It was a few years ago know, but there was about 10hp peak over 'traditional' headers. with no loss under 3000rpm compared to the same headers

 

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Posted: Fri Nov 07, 2008 10:12 pm 
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Grimketel wrote:
gogetta wrote:
and i also by implication it does not destroy your bottom end torque

have a look at a set of pacmakers they have 3" flange on them...aftermarket cats are easy to get in 3" so why then downsize the rest of the system....u might as well run 3" all the way....


just remember that a 3 inch cat might only have the flow of a piece of 2.25 inch straight pipe.

Pacemaker 4480
Primary Pipe:
1 ⅝"
(41mm)
Secondary Pipe:
1 ¾"
(44mm)
Outlet (flanged):
2 ½"
(63mm)

Pacies do not have a 3 inch flange if you team them up with a 3 inch cat you need to cut them back a few inches and weld on a new flange at the 3 inch diameter mark.

the idea is to keep flow rates up. a fast flowing cat, and straight through single chamber mufflers would be a better port of call than increasing the size of your pipe that far. Its not a v8, its only 4 litres, and only revs to ~5500 rpm. the ricers only use 3 inch pipe to get better spool up, due to a hi pressure on one side of the vanes, and low pressure on the other. having 3 inch pipe after a 3 inch cat would see low rpm air speed drop after the cat, as it is restricted and slowed, and then fed into a low pressure chamber.

just to put it into context about mass and velocity, a 6 litre V8 revving to 6500 rpm will need the exhaust capacity to move 39,000 litres of air a minute (on paper, reality differs slightly with gass expansion, sacavenging, and residual deposits). a 4 litre 6 revving to 5500rpm needs to move 22,000 litres of air a minute. which is almost half!

Im not saying 3 inch is bad, just size the pipe for where you want it to be most efficient, and thus make its power. size it to your mods. Biggest is not always best.

I garauntee you, get a stock falcon on a dyno, then put on a 3 inch and dyno it again. there will be a small hole in the torque on the graph early on.


ive got a set of pacemakers here....I measured them myself and they are 3".....I also have a set of genies and they are 3" also...

enough of the theory.....3" outlet -> 3" cat -> pipes...people here have done this with good results (proven)

yes it may not be that fantasitic on a stock motor but I dont care as im gunna put a mild cam it at the same time that i actually get around to doing some mods

 

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Posted: Fri Nov 07, 2008 11:44 pm 
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well that data is from pacemaker themselves so i trust they arnt s**t. somehow you have gotten modified sets. dont know about the genies, the ones i had were 2.5 though.

Hope it all works out for ya gogetta, i know the hardest part for me is getting the money together coz some thing usually pops up to snatch it away! lol

 

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Posted: Sat Nov 08, 2008 10:41 pm 
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tickford_6 wrote:
skidder wrote:
tickford_6 wrote:
as for the pipes, if anyone has the time and money, build a set with 2inch primary pipes 40inches long into a pair of 3into1 merge collectors
with 2 1/4 inch secondaries 12inches long into a single 3inch system.


IT WONT WORK!... sorry couldn't help it :roll: What's the most you have managed to increase torque/hp on engine analyzer just from exhaust?



It was a few years ago know, but there was about 10hp peak over 'traditional' headers. with no loss under 3000rpm compared to the same headers


here is the results of a quick few tests.
the engine is a stock EB with 9.3:1 comp and a wade cam. it also runs a BBM manifold locked in the short runner position, so ignor results under 3800rpm.

DO NOT take the actual numbers for gospel. this is a SIMULATOR. the difference in power though is generaly trust worthy and i know the input info good. all of the numbers are repeatable.

i also ran one with the 40 inch headers and a 3inch pipe it picked up a few HP above 4000rpm

The JMM headers are based on the average lengths of the race header and use 1.5inch primary and 2inch secondary sizes. all of these test are run through and exhaust system capable of about 550CFM

 

 

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Posted: Sun Nov 09, 2008 9:21 pm 
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do you the specs of a stock cam? or is that why you used a wade cam?
Also what engine did you start with?

I have only been playing with a 302 able to flow 400cfm through the exhaust and managed to get 10-12hp out of it through exhaust

 

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EVL098 wrote:
Cramping in the hand from having it on your Wang for an excessive period of time is a definate con.
Seriously do people google "f**k up modifications for Fords owned by Jews" and get linked straight to this site nowadays?

AU,factory fitted tickford kit/IRS, t5,Sports ryder/KYB: gone.

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Posted: Sun Nov 09, 2008 10:02 pm 
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skidder wrote:
do you the specs of a stock cam? or is that why you used a wade cam?
Also what engine did you start with?

I have only been playing with a 302 able to flow 400cfm through the exhaust and managed to get 10-12hp out of it through exhaust



i've got the specs for the EF cams, but most people buy a a bigger cam, so i used one of wades mid sized cams.

the spec for the short block are based on messuring an actual EF engine, (same as EB aside from the counter wieghts on the crank) and entering the needed info. head specs are for and EB because i had the flow data and had access to a head at one stage to take measurements from.
i also have the data to do an AU head.

when playing with the exhaust for an inline engine it is important to remember the program assumes a V configuration for engine with more then 4cyls. you can't test the pacie comps, The collector length is the secondary pipe length and you need to use a detailed collector to set the specs. If you use a simple collector the program will use a very large sized pipe.. (over 3inch for the secondary pipe).

 

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Posted: Wed Nov 12, 2008 9:58 am 
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My impression is a bigger muffler is better than a smaller muffler in terms of reducing noise without increasing drag. But they are usually heavier. It would be interesting to compare the noise and drag of one of them versus two or even three hotdogs or similar.

Another point to consider is 3" piping is heavy, maybe around 50% or more heavier than 2.5". This is because the circumference increases as a square of the diameter, and to prevent crushing the wall needs to be thicker too.

 

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Posted: Wed Nov 12, 2008 10:15 am 
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Grimketel wrote:
the idea is to keep flow rates up. a fast flowing cat, and straight through single chamber mufflers would be a better port of call than increasing the size of your pipe that far. Its not a v8, its only 4 litres, and only revs to ~5500 rpm. the ricers only use 3 inch pipe to get better spool up, due to a hi pressure on one side of the vanes, and low pressure on the other. having 3 inch pipe after a 3 inch cat would see low rpm air speed drop after the cat, as it is restricted and slowed, and then fed into a low pressure chamber.

just to put it into context about mass and velocity, a 6 litre V8 revving to 6500 rpm will need the exhaust capacity to move 39,000 litres of air a minute (on paper, reality differs slightly with gass expansion, sacavenging, and residual deposits). a 4 litre 6 revving to 5500rpm needs to move 22,000 litres of air a minute. which is almost half!

Im not saying 3 inch is bad, just size the pipe for where you want it to be most efficient, and thus make its power. size it to your mods. Biggest is not always best.

I garauntee you, get a stock falcon on a dyno, then put on a 3 inch and dyno it again. there will be a small hole in the torque on the graph early on.

I wonder if the hole in the torque curve (assuming it exists) is not because of low air velocities falling to scavenge the exhaust gases. Less restriction in the latter part of the exhaust will only increase air velocities in the exhaust ports and manifold.

I wonder if the hole is because of too much scavenging drawing the mixture out of the exhaust ports before full combustion has taken place?

Or is it the other way around, is the excess scavenging drawing a small amount of unburnt intake fuel through and out the exhaust before the exhaust valve is closing (prior to compression stroke)?

I know i've read something, sometime, about this.

 

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Posted: Fri Nov 14, 2008 5:08 pm 
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err . . . edited previous post, refer above

 

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Posted: Fri Nov 14, 2008 11:31 pm 
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to help the context also, please dont assume full throttle at all times. part throttle produces low exhaust velocity, for instance driving up hill at 1600 rpm. when I say hole i mean a half dozen newtons, it is only an exhaust. not a magic wand.

 

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 Post subject: Re:
Posted: Fri Jan 30, 2009 1:15 am 
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relaxed_diplomacy wrote:

I wonder if the hole is because of too much scavenging drawing the mixture out of the exhaust ports before full combustion has taken place?

Or is it the other way around, is the excess scavenging drawing a small amount of unburnt intake fuel through and out the exhaust before the exhaust valve is closing (prior to compression stroke)?

I know i've read something, sometime, about this.


The latter would be closer to correct. The first statement isn't possible, as both valves are closed for the duration of the combustion.

 

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Posted: Fri Jan 30, 2009 4:22 pm 
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relaxed_diplomacy wrote:
My impression is a bigger muffler is better than a smaller muffler in terms of reducing noise without increasing drag. But they are usually heavier. It would be interesting to compare the noise and drag of one of them versus two or even three hotdogs or similar.


What do you mean by bigger? I'm assuming you mean bigger sized not bigger diameter entry/exit?

Its completely dependant on what mufflers are used, you will find there can be quite a difference between muffler brands and types. I posted a link off a magazine I found that ran consecutive dyno tests with different mufflers (multiple times for each muffler). I think the Borla muffler performed the best, Hooker Maxflow and Aerochambers were within the top 5 for power, however the Borla was also the quiestest, the Maxflow was about 4th and the Aerochamber was about 8th. This was out of 11 mufflers.

Note also there was only a 3bhp difference between #1 and #5, but I think about 7-8bhp between #1 and #11.

 

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EVL098 wrote:
Cramping in the hand from having it on your Wang for an excessive period of time is a definate con.
Seriously do people google "f**k up modifications for Fords owned by Jews" and get linked straight to this site nowadays?

AU,factory fitted tickford kit/IRS, t5,Sports ryder/KYB: gone.

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