exhausts

[ken81590]

whats the best catback exhaust system for any 240sx i figured either the blitz nur-spec r or the APEXi gt spec cuz it has 3.7 inch piping

wut do u guys think

[Nismochick240]

I wouldn't go any bigger than 2.5 on a na ka if you are turbo i would go 3-3.5.. no bigger though. you dont want it to be TOO loud

[dickie]

maybe he does...

what kind of applicatin are you looking for? full race, part of a package? n/a or planning for turbo upgrade? how loud do you want to be? this is a really poor question to ask. if youre only buying for looks just go to ebay and shop around. buy whatever you feel looks the best.

[onosqv]

exhausts will all perform about the same - the differences lie mainly in sound & quality/price.

It's all broken down into how you like your exhaust to look & sound. And like everyone else would say, anything about 2.5" (maaayybbee 3") will be overkill for an N/A car.

If you stick w/ a good brand name, the quality of your exhaust will be fine.

[A34D4ME]

Find a local guy to custom bend a 2.5" - Put an inexpensive performance muffler, or two in place of the resonator and you should be good. You can always add a can in the rear if you like. Just don't go can alone or you'll get tickets.

As for size, 2.5 or 3" is good, but loud. Any bigger than a 3" and you'll lose gas velocity and end up with a plug of cool, dense gases in the pipe that will cause back pressure.

[dickie]

oh crap. not another backpressure argument thread.

[InsanityInc]

3" Is ideal as far as I've seen. It's definitely superior to 2.5". 3.7" would most likely be inferior to 3".

[InsanityInc]

Also, who the heck keeps removing the freshalloy link from my signature?

http://forums.freshalloy.com/u...&vc=1

[Skidmark]

Just got done putting a GT-Spec on my friends kouki about 10 minutes ago. He was running a borrowed one for about a year, and just got his own. He's N/A for now, but going turbo soon, so you guys don't lay an egg over his sizing choice. He says he lost some bottom end torque with it, but gained on the top end, so I guess it all depends on what's more important to you. And the bigger is louder philosophy is garbage. It's all in the resonator, and the GT-Spec has a fairly large one. It's actually very mild, but it's all BASS baby. One of the best sounding exhausts out there, IMO.

[sileighty85]

i got the blitz nur spec-r exhaust system, which it sounds nice and it's not that loud even though my motor is still an n/a.

[A34D4ME]

Just got done putting a GT-Spec on my friends kouki about 10 minutes ago. He was running a borrowed one for about a year, and just got his own. He's N/A for now, but going turbo soon, so you guys don't lay an egg over his sizing choice. He says he lost some bottom end torque with it, but gained on the top end, so I guess it all depends on what's more important to you. And the bigger is louder philosophy is garbage. It's all in the resonator, and the GT-Spec has a fairly large one. It's actually very mild, but it's all BASS baby. One of the best sounding exhausts out there, IMO.

If you leave in the resonator your probably right about size not effecting sound. Personally, I wouldn't want anything in my system that doesn't go straight threw on account of turbulance.

I suspect that the biggest problem with aftermarket exhaust systems is that they are designed for appearance before performance. Most use the "cool looking" can type mufflers which don't quiet all that much.

I live in a no test state so I can put up to 2 thrush type mufflers up front and just use whatever tip looks good it back - all straight threw.

[InsanityInc]

Just got done putting a GT-Spec on my friends kouki about 10 minutes ago. He was running a borrowed one for about a year, and just got his own. He's N/A for now, but going turbo soon, so you guys don't lay an egg over his sizing choice. He says he lost some bottom end torque with it, but gained on the top end, so I guess it all depends on what's more important to you. And the bigger is louder philosophy is garbage. It's all in the resonator, and the GT-Spec has a fairly large one. It's actually very mild, but it's all BASS baby. One of the best sounding exhausts out there, IMO.

You cant lose torque compared to stock with any size exhaust. You could take off your exhaust manifold and you'd gain torque over stock. The only discussion relevent with aftermarket exhausts is comparing them against eachother, because pretty much anything beats stock.

[Skidmark]

You might gain peak torque, yes, but it's going to shift it higher in the band because of the extra flow capacity. His car doesn't quite have the same snap down low as it did before. Top end is a little improved, though. Overall not a huge difference, but he's more into the look/sound anyways.

[A34D4ME]

You cant lose torque compared to stock with any size exhaust. You could take off your exhaust manifold and you'd gain torque over stock. The only discussion relevent with aftermarket exhausts is comparing them against eachother, because pretty much anything beats stock.

Yes, you can. The reason this can happen is because too large of a pipe will allow the gases to slow down and cool in the pipe. This causes a mass of dense gas that causes backpressure. When RPMs pick up the gases speed up and this doesn't happen.

The trick is to use the largest possible diameter that will evacuate the gases before they cool.

[InsanityInc]

Yes, you can. The reason this can happen is because too large of a pipe will allow the gases to slow down and cool in the pipe. This causes a mass of dense gas that causes backpressure. When RPMs pick up the gases speed up and this doesn't happen.

The trick is to use the largest possible diameter that will evacuate the gases before they cool.

Hey, looks like you failed fluid dynamics as well. Probably never took it from the steaming heap of misinformation going on here.

The stock system has more than 0 backpressure. Even at ideal operating conditions (maximum velocity), the backpressure adjusted for the bernoulli principle is STILL greater than 0. Open exhaust ports obviously have 0 backpressure.

Conclusion: The stock system always has more backpressure, and thus less ability to evacuate the cylinder than running without any exhaust piping at all.

Not to mention the reason why a larger pipe can be worse than a smaller pipe has nothing to do with the larger pipe creating more backpressure due to lost velocity. If your exhaust pulses are moving out the pipe you have 0 backpressure, regardless of how slowly they're moving out. Thing is, you can actually have SUCTION in your exhaust pipe due to the bernoulli effect.

Since I'm betting you haven't got a ****in clue what the bernoulli principle is, here's a link:

http://en.wikipedia.org/wiki/Bernoulli_ ... uri_effect

[A34D4ME]

Dude, stop talking out your arss. That's the best you know is an online encyclopedia?

Stop pretending to know stuff you don't.

[InsanityInc]

You're pretending again.

Is wikipedia pretending?

http://en.wikipedia.org/wiki/Venturi_effect

How do you think a carburetor works? Oh wait, you haven't got a ****ing clue do you?

[InsanityInc]

You have a problem with wikipedia? Alright, here's a google search for venturi effect, read up moron:

http://www.google.com/search?h...earch

As for the validity of wikipedia:

http://www.npr.org/templates/s...55388

Quote »a survey by the science journal Naturefinds that science entries in the volunteer-driven, online encyclopedia Wikipedia are "not markedly less accurate" than those found in Encyclopaedia Britannica. Nature reporter Mark Peplow discusses the survey.[/quote]Specifically.

You have been owned. Suck it up and have a read. You might learn something.

[A34D4ME]

^^^^^ LMAO again. What's a guy to say? LOL! ^^^^^^^^^

Anyone want to wast some time?

[Skidmark]

Sorry, don't mean to interrupt egofest '05 here, but I'm curious as to why we don't see any small displacement N/A race cars running god-aweful huge exhaust systems. Most of the sport compact race cars I remember seeing down here at Road Atlanta are running somewhere in the ballpark of a 2" straight pipe, and that's on ported & cam'd motors that rev to high heaven. Just wondering if anyone has any input as to why that is so.

[InsanityInc]

Sorry, don't mean to interrupt egofest '05 here, but I'm curious as to why we don't see any small displacement N/A race cars running god-aweful huge exhaust systems. Most of the sport compact race cars I remember seeing down here at Road Atlanta are running somewhere in the ballpark of a 2" straight pipe, and that's on ported & cam'd motors that rev to high heaven. Just wondering if anyone has any input as to why that is so.

Is it professional racing, or club racing? Non-professional racing has noise limits. Also, you'll never get THAT huge of a pipe, since the area of a circle is pi*r^2, your cross-sectional area (and flow characteristics) increase exponentially with the radius.

[A34D4ME]

Sorry, don't mean to interrupt egofest '05 here, but I'm curious as to why we don't see any small displacement N/A race cars running god-aweful huge exhaust systems. Most of the sport compact race cars I remember seeing down here at Road Atlanta are running somewhere in the ballpark of a 2" straight pipe, and that's on ported & cam'd motors that rev to high heaven. Just wondering if anyone has any input as to why that is so.

Skidmark - as I was attempting to explain. When you increase the diameter of your exhaust, you allow the hot gases to flow out with less restriction. However, this also allows the gases to flow more slowly. When you go overboard with the pipe size, gases slow so much that they begin to cool while still in the pipe. When gases cool they become more dense and require more force to push out. Basically, you get a dense "plug" of gas in your exhaust pipe that causes backpressure.

I gleaned this from a website from some professional race car builders - I wish I didn't lose the link.

Anyway, they were probably more like 2.5" than 2" that you saw but that is the basic idea according to the experts.

And now, I leave you with idiot boy who will no doubt offer his own made up theory. Just ignore him and perhaps he'll go away.

[InsanityInc]

Skidmark - as I was attempting to explain. When you increase the diameter of your exhaust, you allow the hot gases to flow out with less restriction. However, this also allows the gases to flow more slowly. When you go overboard with the pipe size, gases slow so much that they begin to cool while still in the pipe. When gases cool they become more dense and require more force to push out. Basically, you get a dense "plug" of gas in your exhaust pipe that causes backpressure.

I gleaned this from a website from some professional race car builders - I wish I didn't lose the link.

Anyway, they were probably more like 2.5" than 2" that you saw but that is the basic idea according to the experts.

And now, I leave you with idiot boy who will no doubt offer his own made up theory. Just ignore him and perhaps he'll go away.

http://en.wikipedia.org/wiki/Venturi_effect

Read it. Learn it. Love it.

Carburetors wouldn't work without it, and neither would tuned exhaust systems.

Oh, and I like how you just "conveniently" lost the link. Man, you're a riot.

[naed240sx]

Wow, insanity, for once I agree with you man. Not sure what A34 is smoking, but whatever, leave him be.

[ken81590]

so the blitz is only 3" right, im guessing that would be fine, and the blitz has no resonators either, right?

and is the gt spec or the blitz sideways?

[mkory]

How about this...

I have a 3" BRM system, with dual tips and a 22" resonator. I love the way it sounds, and wouldn't change a thing. I also love how I support Greg and all of us on NICO by buying it. You should most definately look into these.

Was that the kind of answer you were looking for?

[sunnys14]

so the blitz is only 3" right, im guessing that would be fine, and the blitz has no resonators either, right?

and is the gt spec or the blitz sideways?

dude, go with the BLITZ. i put on the blitz nur spec when i was NA. the gains were phenomenal! gains all across the powerband, you wont regret it. all i can say is f*** any exhaust smaller than 3".

[ken81590]

does the blitz have good top and bottom end gains?

[hondahater240]

i have a european custom exhaust on my 240 it is 8in. in diameter man it sounds so good!! but i think i lost a little bit of torque and when i hit a small bump it scrapes but that is ok

[Tulsa_S-13]

LOL!!! ^Hilarious^

Maybe you mean 8 inch tip? But anyway, I have 2.5" BRM dual tip exhaust and its great. The exhaust looks fairly close to stock and the customer service is amazing. Currently though I'm running stock exhaust, it sounds great with my intake setup. You should check it out at http://www.brmexhaust.com

HKS Hi-power exhaust is fairly popular and looks great too, not to mention the piping size that allows for the addition of boost down the line