Best exhaust for going all NA?
06-16-2004, 08:23 AM
#21
Originally posted by bwzabodyn
the thing with an N/A setup is that if you go with a too free-flowing exhaust (ie large diameter single outlet) - you might gain the most power up top, but you're also going to lose the most torque down low - a race car spends most of its time in the upper-range of the RPM band (that's why peak HP gain is most relevant to them) whereas street cars spend most of their time in the lower-to-mid range of the RPM band - some restriction/backpressure needs to be there on an N/A car in order to keep from losing the low-end torque these cars are known for - unless you're going to be tracking your vehicle constantly, I would first suggest a true-dual setup (Stillen, GReddy, Injen) then either a good y-pipe (JIC) paired with a good y-pipe back exhaust...
the thing with an N/A setup is that if you go with a too free-flowing exhaust (ie large diameter single outlet) - you might gain the most power up top, but you're also going to lose the most torque down low - a race car spends most of its time in the upper-range of the RPM band (that's why peak HP gain is most relevant to them) whereas street cars spend most of their time in the lower-to-mid range of the RPM band - some restriction/backpressure needs to be there on an N/A car in order to keep from losing the low-end torque these cars are known for - unless you're going to be tracking your vehicle constantly, I would first suggest a true-dual setup (Stillen, GReddy, Injen) then either a good y-pipe (JIC) paired with a good y-pipe back exhaust...
06-16-2004, 09:42 AM
#22
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Originally posted by bwzabodyn
the thing with an N/A setup is that if you go with a too free-flowing exhaust (ie large diameter single outlet) - you might gain the most power up top, but you're also going to lose the most torque down low - a race car spends most of its time in the upper-range of the RPM band (that's why peak HP gain is most relevant to them) whereas street cars spend most of their time in the lower-to-mid range of the RPM band - some restriction/backpressure needs to be there on an N/A car in order to keep from losing the low-end torque these cars are known for - unless you're going to be tracking your vehicle constantly, I would first suggest a true-dual setup (Stillen, GReddy, Injen) then either a good y-pipe (JIC) paired with a good y-pipe back exhaust...
the thing with an N/A setup is that if you go with a too free-flowing exhaust (ie large diameter single outlet) - you might gain the most power up top, but you're also going to lose the most torque down low - a race car spends most of its time in the upper-range of the RPM band (that's why peak HP gain is most relevant to them) whereas street cars spend most of their time in the lower-to-mid range of the RPM band - some restriction/backpressure needs to be there on an N/A car in order to keep from losing the low-end torque these cars are known for - unless you're going to be tracking your vehicle constantly, I would first suggest a true-dual setup (Stillen, GReddy, Injen) then either a good y-pipe (JIC) paired with a good y-pipe back exhaust...
Yes....but whether you have one larger pipe, or two smaller ones, with the same combined cross-sectional area, it doesn't make a difference. Don't fool yourself into thinking it does. At the lower rpms, the gas/pipe surface dynamic resistance will not be as much of a factor, and at high rpm, where it does matter, the single pipe performance will be better.
Last edited by Speedracer; 06-16-2004 at 10:26 AM.
06-16-2004, 10:51 AM
#24
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Originally posted by PoWeRtRiP
dont ever trust a manufacturers dyno sheet. they often take the lowest dyno they ever get stock then compare it to the highest one with their mods. at most i could see you gaining 15whp with header back exhaust on an na.
dont ever trust a manufacturers dyno sheet. they often take the lowest dyno they ever get stock then compare it to the highest one with their mods. at most i could see you gaining 15whp with header back exhaust on an na.
so i'll just assume what u said is not the case for Amuse.
+ ppl on the bored had dynoed the amuse Ti exhaust only for 11~12 whp.(could'nt remember exatctly).
with a y-pipe and test pipe, i belive it can bump up at least another 6~8 whp without the headers u mentioned.
Last edited by GY-Z; 06-16-2004 at 11:04 AM.
06-16-2004, 01:33 PM
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APS's exhaust is also a dual exhaust - and regardless of who says what about the numbers that their exhaust can put out (remember they're trying to sell this product) it has been PROVEN with numerous dyno's that no combination of test pipes/high-flow cats and cat-back exhaust on an N/A car can produce over 15 HP... period. But I promise you that I will be pretty close to that number after I bolt my Greddy EVO II up to my test pipes... but maybe I'm wrong - either way I really don't care b/c 1-2 HP more or less really doesn't matter as long as YOU are happy with what you have - and that's probably my #1 reason for choosing the GREddy - liked the exhaust's designed and loved the sound it makes w/ test pipes....
06-17-2004, 04:48 AM
#27
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Originally posted by GY-Z
i dont know, the # Amuse cliamed for the s2k Ti exhaust wasn't off too much from ppl went to dyno their car.
so i'll just assume what u said is not the case for Amuse.
+ ppl on the bored had dynoed the amuse Ti exhaust only for 11~12 whp.(could'nt remember exatctly).
with a y-pipe and test pipe, i belive it can bump up at least another 6~8 whp without the headers u mentioned.
i dont know, the # Amuse cliamed for the s2k Ti exhaust wasn't off too much from ppl went to dyno their car.
so i'll just assume what u said is not the case for Amuse.
+ ppl on the bored had dynoed the amuse Ti exhaust only for 11~12 whp.(could'nt remember exatctly).
with a y-pipe and test pipe, i belive it can bump up at least another 6~8 whp without the headers u mentioned.
06-17-2004, 10:54 AM
#28
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Originally posted by PoWeRtRiP
headers back means test pipes, y pipe, exh. not including headers gains.
headers back means test pipes, y pipe, exh. not including headers gains.
then i belive ur # is somehow correct, i have double check the # amuse claimed. they claimed 22 whp with test pipe, ti ypipe and exhaust.
which i bevlive wont be too much off.mabye somewhere saround 18~20 whp seems reasonable with test pipe and y-pipe.
as i said, the claimed 12 whp for just the exhaust. and some member on my350 with onlt the ti exhaust had dynoed with 11~12 whp already.so another 6~8 whp from test pipe and ypipe sounds reasonable?
06-17-2004, 11:11 AM
#29
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A Japanese magaizne called HyperREV, they did the test on Amuse's exhaust, down pipe, Y- pipe, and Amuse ECU. The results are near 40hp gained.
Most of the powers acutally coming from test pipe, exhaust and ECU. The Y-pipe only increased around 2 hp.
And since Amuse unit are light weight unit, so overall performance gain regarding from power/weight ratio is very impressive.
You guys should buy a copy of that Magazine to check it out.
Most of the powers acutally coming from test pipe, exhaust and ECU. The Y-pipe only increased around 2 hp.
And since Amuse unit are light weight unit, so overall performance gain regarding from power/weight ratio is very impressive.
You guys should buy a copy of that Magazine to check it out.
06-17-2004, 11:20 AM
#30
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the j-spec cars have less power than ours due to a more restrictive exhaust (i believe around 7-10hp less) you really cant compare gains on the z's from anywhere else in the world to ours.
the australian z's get 15-20 hp from exhausts alone for the same reason.
the australian z's get 15-20 hp from exhausts alone for the same reason.
06-17-2004, 11:32 AM
#31
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Originally posted by PoWeRtRiP
the j-spec cars have less power than ours due to a more restrictive exhaust (i believe around 7-10hp less) you really cant compare gains on the z's from anywhere else in the world to ours.
the australian z's get 15-20 hp from exhausts alone for the same reason.
the j-spec cars have less power than ours due to a more restrictive exhaust (i believe around 7-10hp less) you really cant compare gains on the z's from anywhere else in the world to ours.
the australian z's get 15-20 hp from exhausts alone for the same reason.
06-17-2004, 11:43 AM
#32
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they have exact same engine but are able to tune them different due to the availability of better gas. i believe they have the equivalent of 95 oct. they have diff exhaust due to emissions. there is definitely room to improve the stock exhaust, its the y pipe and cats that choke it not the muffler section.
06-17-2004, 12:32 PM
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ok, here's the deal - we're talking about N/A cars, but if you bring up the word "downpipe" that automatically signals **TT** in my head - which would definitely justify the increases you see - just an observation...
06-17-2004, 06:21 PM
#34
Originally posted by bwzabodyn
the thing with an N/A setup is that if you go with a too free-flowing exhaust (ie large diameter single outlet) - you might gain the most power up top, but you're also going to lose the most torque down low - some restriction/backpressure needs to be there on an N/A car in order to keep from losing the low-end torque these cars are known for
the thing with an N/A setup is that if you go with a too free-flowing exhaust (ie large diameter single outlet) - you might gain the most power up top, but you're also going to lose the most torque down low - some restriction/backpressure needs to be there on an N/A car in order to keep from losing the low-end torque these cars are known for
There is no such thing as a "too free-flowing exhaust." And backpressure is NEVER necessary to make power or torque at any range, just the opposite in fact.
06-18-2004, 06:15 AM
#35
clarification
Originally posted by PoWeRtRiP
they have exact same engine but are able to tune them different due to the availability of better gas. i believe they have the equivalent of 95 oct. they have diff exhaust due to emissions. there is definitely room to improve the stock exhaust, its the y pipe and cats that choke it not the muffler section.
they have exact same engine but are able to tune them different due to the availability of better gas. i believe they have the equivalent of 95 oct. they have diff exhaust due to emissions. there is definitely room to improve the stock exhaust, its the y pipe and cats that choke it not the muffler section.
How do you like your Injen exhaust? Is it the one with the exhaust tips exiting the undercarriage at an angle? I really like that style. Just wish they had it in titanium.
06-18-2004, 06:52 AM
#37
Originally posted by kzshin
A Japanese magaizne called HyperREV, they did the test on Amuse's exhaust, down pipe, Y- pipe, and Amuse ECU. The results are near 40hp gained.
Most of the powers acutally coming from test pipe, exhaust and ECU. The Y-pipe only increased around 2 hp.
And since Amuse unit are light weight unit, so overall performance gain regarding from power/weight ratio is very impressive.
You guys should buy a copy of that Magazine to check it out.
A Japanese magaizne called HyperREV, they did the test on Amuse's exhaust, down pipe, Y- pipe, and Amuse ECU. The results are near 40hp gained.
Most of the powers acutally coming from test pipe, exhaust and ECU. The Y-pipe only increased around 2 hp.
And since Amuse unit are light weight unit, so overall performance gain regarding from power/weight ratio is very impressive.
You guys should buy a copy of that Magazine to check it out.
06-18-2004, 07:05 AM
#38
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Originally posted by mrgwski
What do you guys think of the Injen dyno test done at this website: http://www.hopupracing.com/insesex3512w1.html ???
What do you guys think of the Injen dyno test done at this website: http://www.hopupracing.com/insesex3512w1.html ???
06-18-2004, 07:09 AM
#39
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Re: clarification
Originally posted by mrgwski
So you're saying that on the stock exhaust system, the biggest flow restriction is found in the y-pipe and the cats, and that the stock muffler is no more restrictive than aftermarket mufflers? What evidence do you have to support this statement?
How do you like your Injen exhaust? Is it the one with the exhaust tips exiting the undercarriage at an angle? I really like that style. Just wish they had it in titanium.
So you're saying that on the stock exhaust system, the biggest flow restriction is found in the y-pipe and the cats, and that the stock muffler is no more restrictive than aftermarket mufflers? What evidence do you have to support this statement?
How do you like your Injen exhaust? Is it the one with the exhaust tips exiting the undercarriage at an angle? I really like that style. Just wish they had it in titanium.
yes thats why ppl gain 5-9whp from test pipes. and another 5whp from a ypipe on stock. the only ypipe back exh i can think of with proven gains is the nismo (3.16" pipe) which will only give gains of 5-6 whp.or the true dual exhausts only gain 8-9whp bc they have a ypipe replacement. do the math and youll notice that the muffler section difference is not significant compared to the other components.
its the angled tips, very loud. its also much lighter than stock i believe its the lightest true dual non-ti exhaust. dont quote me on this but i think it weighs like 45lbs? whats a true dual ti weigh 25lbs? is 20 lbs worth $1000 to you?
Last edited by PoWeRtRiP; 06-18-2004 at 07:13 AM.
06-18-2004, 07:09 AM
#40
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If you check the Australian regional forums in my350z you'll find the sticky we've posted for local dynos.
You'll find we gain between 15-20 rwkw with a full exhaust swap. Since we have pretty much the same car as Japan i'd say those figures can be reproduced anywhere except in the US. You guys already are 10-15hp over us.
The dyno thread is informative anyway.
You'll find we gain between 15-20 rwkw with a full exhaust swap. Since we have pretty much the same car as Japan i'd say those figures can be reproduced anywhere except in the US. You guys already are 10-15hp over us.
The dyno thread is informative anyway.