Question about 3" exhaust on stock KA24DE - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Silvia240sxxx · 06-16-2005, 10:49 PM

I just bought the Megan Racing 3" Turbo Spec exhaust for S13 application. I currently do not have a turbo on my ka24de. It is completely bone stock. My question is if I put this 3" exhaust on my stock S13, is it going to lose power?? or will it still improve horsepower? I was going to install it this weekend, but didn't want to lose any power. Thanks in advance

mjjstang · 06-16-2005, 10:55 PM

why 3" do you at least plan on upgrade to turbo or something later.

***S14DB*** · 06-16-2005, 11:12 PM

To beat a dead horse....

You will not lose hp or tq. you will only gain.

slivia-junkie · 06-16-2005, 11:19 PM

you wont loose any hp, according to all the dyno charts i have seen, but all you will gain is a lot of noise

vinhisbored · 06-16-2005, 11:51 PM

Quote:

Originally Posted by slivia-junkie

you wont loose any hp, according to all the dyno charts i have seen, but all you will gain is a lot of noise

That is not true. First, I used to have stock piping with some exhaust tip. I could see a difference. Now, I have an HKS cf/ti tip, with 3" straight piping, and I have somewhat of a power lose, though not that much. Secondly, it will NOT be louder. After I installed my exhaust, it's not as loud as it used to be as before, because the piping is so big. Me and my friend have the same exhaust, but I have 3" straight piping, and he has 2.5" straight piping. His car is alot louder than mine. (The tips are the same too.) I personally like how it's not that loud, BUT the downside is that I back-fire like a bitch.. like if you rev it up to 3+ rpms, you'll back-fire a bit, and if you downshift, it'll be loud. Possibly not for yours? But I have 3" piping on a stock KA24DE, and that's what I see. Then again, it's straight piping..

kandyflip445 · 06-16-2005, 11:57 PM

I don't backfire that much at all. It's not that loud. And show me your dynograph from your "butt dyno" vinh.....

speedjay · 06-17-2005, 12:06 AM

I've got a 3" blitz with highflow cat and hotshot header....i lost a little of low end power but the high end gains more than make up for it. It is very loud.

vinhisbored · 06-17-2005, 12:10 AM

I don't know, maybe it's because you have headers.. or it's something with your exhaust.. my hks tip w/ 3" piping is pretty quiet.. (it's not even as loud as those honda's running around.) Also.. it's no where near what the N1 Style exhausts sound like either. So I guess it depends on the factory that made the exhaust..

Silvia240sxxx · 06-17-2005, 12:10 AM

mjjstang: yeah i'm planning on turboing the engine...

S14DB: That's what i'd like to hear and have heard it from otheres also...

vinhisbored: And this is what I am afraid of...losing power. (which i don't exactly understand how I would lose power...it just seems to me like it would be able to push the unwanted exhaust out easier which frees up power for the engine. I guess I just dont understand back pressure.)
and backfiring...i'll have to research why that happens.

vinhisbored · 06-17-2005, 12:19 AM

Quote:

Originally Posted by Silvia240sxxx

mjjstang: yeah i'm planning on turboing the engine...

S14DB: That's what i'd like to hear and have heard it from otheres also...

vinhisbored: And this is what I am afraid of...losing power. (which i don't exactly understand how I would lose power...it just seems to me like it would be able to push the unwanted exhaust out easier which frees up power for the engine. I guess I just dont understand back pressure.)
and backfiring...i'll have to research why that happens.

Well, you won't be losing that much power, but I could see a small difference. From what friend's have told me.. Yeah, I don't quite understand it, but it is the back pressure. If you purchased a complete cat-back, and it comes with a resonator, you shouldn't backfire as much as I do. I'm running straight-pipe, keep that in mind. Back-firing isn't really a big problem for regular driving unless you're downshifting though. Lately, I've just been putting it in neutral and braking.. (because I just got new pads).

Silvia240sxxx · 06-17-2005, 12:28 AM

Hmmmm...we'll I'll have to see this weekend. I just hope that I gain some power from the exhaust so it's not a total waste before I put my turbo in. They call this megan racing cat-back straight piping so if it does happen to backfire I might have to upgrade my ignition.

Flybert · 06-17-2005, 12:46 AM

3" piping is great for KA whether it be turboed or NA. 2.4L is a large displacement for a 4 banger and it pushes a lot of gases out. Do a search for Alex Chang's 5zigen exhaust dyno.

***S14DB*** · 06-17-2005, 12:55 AM

yeah, I lost so much power....

I went from an N1 to a Can and the sound went down.

vinhisbored · 06-17-2005, 12:56 AM

Yeah the only reason I got it (3" piping) was because I plan going turbo, and my friend regrets getting 2.5" piping because it's not enough when going turbo, and I didn't want to go out and buy piping for a second time.. I just put the money out first..

Silvia240sxxx · 06-17-2005, 08:51 AM

Yeah, I plan on going turbo for sure. And that's why I was hesitant to at least buy the exhaust now. But from what I hear I don't think I will lose power on the 240 slapping this 3"er on. Thanks for the info.

lilredstiffy · 06-17-2005, 09:20 AM

Put as big of an exhaust as you want, you won't lose power, anyone who says otherwise is an idiot because there are dyno-proven results (years old also) on many 240 boards. It may change the characteristics of your powerband slightly...but more power.

24Dee · 06-17-2005, 09:33 AM

Quote:

Originally Posted by S14DB

I went from an N1 to a Can and the sound went down.
[/IMG]

I don't see or understand how just a change in canisters can reduce db levels of the exhaust?

I've been in love with the sound of and have pleased with the gains of the HKS Hi-Power exhaust 60mm. But if I can gain more power while most importantly keeping the noise down just from a different design, then I will do it. My main concern here is that exhaust noise.

what's the difference in piping / resonator designs from the two exhausts you've had?

vinhisbored · 06-17-2005, 10:26 AM

Quote:

Originally Posted by lilredstiffy

Put as big of an exhaust as you want, you won't lose power, anyone who says otherwise is an idiot because there are dyno-proven results (years old also) on many 240 boards. It may change the characteristics of your powerband slightly...but more power.

There is a dyno sheet up there that shows at some points, he did lose power dude, so what are you talking about?

24Dee · 06-17-2005, 10:29 AM

Quote:

Originally Posted by vinhisbored

There is a dyno sheet up there that shows at some points, he did lose power dude, so what are you talking about?

The larger piping just shifted his power band so to speak.

420sx · 06-17-2005, 10:55 AM

damn it! stop spreading bullshit! you will gain tq/hp. you will gain sound level. the bigger the more u gain. although 4 inch will be too big for n/a. 3 max. 2.5 is ok too but quiter.

you gain either way. now go and read this, (its being posted a lil while back nad prety helpful with stuff like this)
Exhaust theory

***S14DB*** · 06-17-2005, 10:58 AM

Quote:

Originally Posted by 24Dee

I don't see or understand how just a change in canisters can reduce db levels of the exhaust?

I've been in love with the sound of and have pleased with the gains of the HKS Hi-Power exhaust 60mm. But if I can gain more power while most importantly keeping the noise down just from a different design, then I will do it. My main concern here is that exhaust noise.

what's the difference in piping / resonator designs from the two exhausts you've had?

Mufflers work by sound pressure absobtion/dissapation. N1 cans are thin and can't absorb/manage alot of pressure. A larger can will absorb/manage alot more pressure. Also, the 80mm has 33% more surface area in the core to absorb more pressure, which makes the 80mm quieter than the 60mm. The reason people say the 80mm is louder is that the bigger can makes the tone lower than the 60mm and the ear perceives lower tones at the same dBL as louder than the higher tone.

420sx · 06-17-2005, 11:07 AM

Quote:

Originally Posted by S14DB

Mufflers work by sound pressure absobtion/dissapation. N1 cans are thin and can't absorb/manage alot of pressure. A larger can will absorb/manage alot more pressure. Also, the 80mm has 33% more surface area in the core to absorb more pressure, which makes the 80mm quieter than the 60mm. The reason people say the 80mm is louder is that the bigger can makes the tone lower than the 60mm and the ear perceives lower tones at the same dBL as louder than the higher tone.

loudness depends on lack of restriction.

muffler-sound suppressor. do is resonator.

2 types.
1) chamber (cherry glass pack, flowmaster etc) stock uses it, but to make one that actually is not as restictive is expensive. it restricts the gasses, slowing them down, thus making it quiter.
2) can type (n1 etc) its REFLECTION suppression, sound reflects thus getting delayed, thus being quiter but sound good (n1, my rsr, etc)

also u got resonators which is a REFLECTOR.
so its not only the size of piping its the availability of muffler and/or resonators. exhaust is about velocity on ka. you dont need backpressure, muffler does that job fully for you at 3 inches. anything bigger than 3 is too much

24Dee · 06-17-2005, 11:09 AM

Quote:

Originally Posted by S14DB

Mufflers work by sound pressure absobtion/dissapation. N1 cans are thin and can't absorb/manage alot of pressure. A larger can will absorb/manage alot more pressure. Also, the 80mm has 33% more surface area in the core to absorb more pressure, which makes the 80mm quieter than the 60mm. The reason people say the 80mm is louder is that the bigger can makes the tone lower than the 60mm and the ear perceives lower tones at the same dBL as louder than the higher tone.

Ahhh I see says the blind man.

Good shit.

I was searching around for regular canister exhausts that I like and found the Blitz Realize and the ex-mag. I couldn't find any clips of the Realize but I found one of the ex-mag on an n/a KA and honestly, it sounds pretty close to the Hi-power 65mm exhaust that i've planned on buying. I like it. Might be too loud for some at higher RPMs but I really don't get on my car unless on the highway so I really don't care.

The only concern of mine so far is that i've read that overtime the ex-mag gets louder on a n/a engine. Any validity to this?

vinhisbored · 06-17-2005, 11:09 AM

Quote:

Originally Posted by 420sx

the bigger the more u gain. although 4 inch will be too big for n/a. 3 max. 2.5 is ok too but quiter.

Not true. As stated, me and my friend both have the same exhaust. HKS CF/Ti Tip. I have 3" straight piping, and he has 2.5" straight piping. His exhaust is louder than mine, and we both are running stock ka24de's with no modifications. Also.. one of my friends have an Apexi GT Spec exhaust.. (3.74" piping) and he has no back pressure..

420sx · 06-17-2005, 11:11 AM

^ and where is the part that you didnt bother to read that i said bigger than 3 is too big? or you would like me to quote myself for you?

vinhisbored · 06-17-2005, 11:12 AM

Quote:

Originally Posted by 420sx

^ and where is the part that you didnt bother to read that i said bigger than 3 is too big?

I read it. I'm just saying, and throwing out a fact.

420sx · 06-17-2005, 11:14 AM

your friends 2.5 cant be louder than yours. he has an exhaust leak. 3 will always be louder on n/a with n1 design. thats counting you both drive s13/s13 or s14/s14.

Apexi 3.74 inch isd made for 400+ turbo where ur chocking due to the becoming restrictive 3 inch piping. you dont need a 4 inch exhaust for under 400 hp

24Dee · 06-17-2005, 11:15 AM

Quote:

Originally Posted by vinhisbored

Not true. As stated, me and my friend both have the same exhaust. HKS CF/Ti Tip. I have 3" straight piping, and he has 2.5" straight piping. His exhaust is louder than mine, and we both are running stock ka24de's with no modifications. Also.. one of my friends have an Apexi GT Spec exhaust.. (3.74" piping) and he has no back pressure..

Interesting, but to share another story..

At the shop I go to, there were/are two s13's with the HKS Hi-Power exhaust. 65mm and the other 80mm. The 80mm is deeper and louder then the 65mm. Both cars just have intakes as well.

vinhisbored · 06-17-2005, 11:17 AM

Yeah, it actually is louder. When I got my car back from the muffler shop, I was amazed because I expcected for it to be louder than his car, but it's not. That's what happened, and I researched some places, asked a couple of people, and that's what they told me. Also, no, he has no exhaust leak. Oh yeah.. the exhaust is the HKS 'Hi-Power' tip I believe.. not N1 style.

Oh yeah.. and for the post before.. I don't know. At the moment, I'm guessing that it's the restrictions on my car, being that it is OBDII. My car still not as loud as my friend's with the 2.5" piping though.. Yeah, I'm sorta tired of 'arguing' but this is only in my situation.. and I'm sharing..

420sx · 06-17-2005, 11:18 AM

of course nobody even bothered to look at the link i posted....

06-16-2005, 10:49 PM	#1
Silvia240sxxx Zilvia Member Join Date: May 2005 Location: USA Age: 38 Posts: 161 Trader Rating: (5) Feedback Score: 5 reviews	Question about 3" exhaust on stock KA24DE I just bought the Megan Racing 3" Turbo Spec exhaust for S13 application. I currently do not have a turbo on my ka24de. It is completely bone stock. My question is if I put this 3" exhaust on my stock S13, is it going to lose power?? or will it still improve horsepower? I was going to install it this weekend, but didn't want to lose any power. Thanks in advance

06-16-2005, 11:57 PM	#6
kandyflip445 Post Whore! Join Date: Sep 2002 Location: Arden, NC Age: 40 Posts: 4,460 Trader Rating: (1) Rides Gallery: kandyflip445 Feedback Score: 1 reviews	I don't backfire that much at all. It's not that loud. And show me your dynograph from your "butt dyno" vinh..... __________________ My 240 vBgarage

06-17-2005, 12:06 AM	#7
speedjay Join Date: Jan 2004 Location: Bellevue, WA Posts: 22 Trader Rating: (0) Feedback Score: 0 reviews	I've got a 3" blitz with highflow cat and hotshot header....i lost a little of low end power but the high end gains more than make up for it. It is very loud. __________________ Team Deception

06-17-2005, 10:55 AM	#20
420sx Post Whore! Join Date: Jun 2004 Location: Texas Age: 42 Posts: 3,960 Trader Rating: (0) Rides Gallery: 420sx Feedback Score: 0 reviews	damn it! stop spreading bullshit! you will gain tq/hp. you will gain sound level. the bigger the more u gain. although 4 inch will be too big for n/a. 3 max. 2.5 is ok too but quiter. you gain either way. now go and read this, (its being posted a lil while back nad prety helpful with stuff like this) Exhaust theory __________________ hydropgrahics! ls1......

06-17-2005, 11:11 AM	#25
420sx Post Whore! Join Date: Jun 2004 Location: Texas Age: 42 Posts: 3,960 Trader Rating: (0) Rides Gallery: 420sx Feedback Score: 0 reviews	^ and where is the part that you didnt bother to read that i said bigger than 3 is too big? or you would like me to quote myself for you? __________________ hydropgrahics! ls1......

06-16-2005, 10:55 PM	#2
mjjstang Post Whore! Join Date: Apr 2003 Location: Michigan Posts: 2,654 Trader Rating: (5) Feedback Score: 5 reviews	why 3" do you at least plan on upgrade to turbo or something later.

06-16-2005, 11:12 PM	#3
*S14DB* AFC #1 Join Date: Oct 2003 Location: 昨晩あなたのお母さんの家 Posts: 20,181 Trader Rating: (3) Feedback Score: 3 reviews	To beat a dead horse.... You will not lose hp or tq. you will only gain.

06-16-2005, 11:19 PM	#4
slivia-junkie Leaky Injector Join Date: Jan 2005 Location: if you could tell me i would be most greatfull Posts: 87 Trader Rating: (0) Feedback Score: 0 reviews	you wont loose any hp, according to all the dyno charts i have seen, but all you will gain is a lot of noise

06-17-2005, 12:10 AM	#8
vinhisbored Zilvia FREAK! Join Date: Apr 2005 Location: socal Posts: 1,359 Trader Rating: (15) Feedback Score: 15 reviews	I don't know, maybe it's because you have headers.. or it's something with your exhaust.. my hks tip w/ 3" piping is pretty quiet.. (it's not even as loud as those honda's running around.) Also.. it's no where near what the N1 Style exhausts sound like either. So I guess it depends on the factory that made the exhaust..

06-17-2005, 12:28 AM	#11
Silvia240sxxx Zilvia Member Join Date: May 2005 Location: USA Age: 38 Posts: 161 Trader Rating: (5) Feedback Score: 5 reviews	Hmmmm...we'll I'll have to see this weekend. I just hope that I gain some power from the exhaust so it's not a total waste before I put my turbo in. They call this megan racing cat-back straight piping so if it does happen to backfire I might have to upgrade my ignition.

06-17-2005, 12:46 AM	#12
Flybert Post Whore! Join Date: Mar 2003 Location: none Posts: 3,862 Trader Rating: (7) Feedback Score: 7 reviews	3" piping is great for KA whether it be turboed or NA. 2.4L is a large displacement for a 4 banger and it pushes a lot of gases out. Do a search for Alex Chang's 5zigen exhaust dyno.

06-17-2005, 12:55 AM	#13
*S14DB* AFC #1 Join Date: Oct 2003 Location: 昨晩あなたのお母さんの家 Posts: 20,181 Trader Rating: (3) Feedback Score: 3 reviews	yeah, I lost so much power.... I went from an N1 to a Can and the sound went down.

06-17-2005, 12:56 AM	#14
vinhisbored Zilvia FREAK! Join Date: Apr 2005 Location: socal Posts: 1,359 Trader Rating: (15) Feedback Score: 15 reviews	Yeah the only reason I got it (3" piping) was because I plan going turbo, and my friend regrets getting 2.5" piping because it's not enough when going turbo, and I didn't want to go out and buy piping for a second time.. I just put the money out first..

06-17-2005, 08:51 AM	#15
Silvia240sxxx Zilvia Member Join Date: May 2005 Location: USA Age: 38 Posts: 161 Trader Rating: (5) Feedback Score: 5 reviews	Yeah, I plan on going turbo for sure. And that's why I was hesitant to at least buy the exhaust now. But from what I hear I don't think I will lose power on the 240 slapping this 3"er on. Thanks for the info.

06-17-2005, 09:20 AM	#16
lilredstiffy Zilvia Addict Join Date: Nov 2001 Location: louisiana Posts: 618 Trader Rating: (0) Feedback Score: 0 reviews	Put as big of an exhaust as you want, you won't lose power, anyone who says otherwise is an idiot because there are dyno-proven results (years old also) on many 240 boards. It may change the characteristics of your powerband slightly...but more power.

06-17-2005, 11:14 AM	#27
420sx Post Whore! Join Date: Jun 2004 Location: Texas Age: 42 Posts: 3,960 Trader Rating: (0) Rides Gallery: 420sx Feedback Score: 0 reviews	your friends 2.5 cant be louder than yours. he has an exhaust leak. 3 will always be louder on n/a with n1 design. thats counting you both drive s13/s13 or s14/s14. Apexi 3.74 inch isd made for 400+ turbo where ur chocking due to the becoming restrictive 3 inch piping. you dont need a 4 inch exhaust for under 400 hp __________________ hydropgrahics! ls1......

06-17-2005, 11:17 AM	#29
vinhisbored Zilvia FREAK! Join Date: Apr 2005 Location: socal Posts: 1,359 Trader Rating: (15) Feedback Score: 15 reviews	Yeah, it actually is louder. When I got my car back from the muffler shop, I was amazed because I expcected for it to be louder than his car, but it's not. That's what happened, and I researched some places, asked a couple of people, and that's what they told me. Also, no, he has no exhaust leak. Oh yeah.. the exhaust is the HKS 'Hi-Power' tip I believe.. not N1 style. Oh yeah.. and for the post before.. I don't know. At the moment, I'm guessing that it's the restrictions on my car, being that it is OBDII. My car still not as loud as my friend's with the 2.5" piping though.. Yeah, I'm sorta tired of 'arguing' but this is only in my situation.. and I'm sharing..

06-17-2005, 11:18 AM	#30
420sx Post Whore! Join Date: Jun 2004 Location: Texas Age: 42 Posts: 3,960 Trader Rating: (0) Rides Gallery: 420sx Feedback Score: 0 reviews	of course nobody even bothered to look at the link i posted.... __________________ hydropgrahics! ls1......