3" Exhaust on N/A Cars

[driftk2000]

Though you will lose low end torque. Will it be worth it to ride around with a Blitz Nur Spec cat back on a N/A car?

What would you guys recommend?

What about the Apex GT spec?

[TheTimanator]

It seems that the N1 dual works great on NA cars and Turbo cars. Its not loud either compared to a 3" on an NA. A lot of people on these boards have the N1 dual...NA or turbo.

I wish I would have gotten one :rolleyes:

[SilviaDriver]

blitz nur spec is an axle back..blitz nur spec R is the catback. theres a difference

[robinlow88]

N1 Duals look good and sound cool, and I think it should work as well on NA car.

If you slammed your car (like rims are under the fenders, etc) they would last you 6 months before you they totally wear out buy daily driving in Boston.

[Yoshi]

FWIW, every study I've read says that backpressure helps the power (low end) and fuel efficiency of N/A cars with smaller engines (ie 4bangers). Putting a turbo on creates an opposite effect where it's more important to get the air out as fast as possible.

Having the nur spec(R) will make you slower under around 50mph and have a higher top end as the rpms are able to wind out, which means it'll only help you on the highway/freeway. Pretty pointless. As an annoying side effect, your car will be annoyingly loud. Not like mild irritation loud. Like, "don't-hear-the-siren-from-the-cop-behind-you-pulling-yo-arse-over-cuz-you're-too-loud" loud. Especially on the Nur spec, which tends to have a buzzy tone to it.

Cliff Notes:
3" pipe on a small N/A engine, bad idea.

edit: the N1 is available in turbo and N/A sizes. Apex is a good company, they do their homework with R&D, if they have a size specifically for N/A, use that as a guideline, they have 2 version for a reason.

[andrave]

import tuner dynoed an apexi GT spec exhaust on a ka24de, and that is like what, 3.6 inch pipe?
anyway it lost a teeny bit of torque down low but made a few hp and ft lbs up top.

[Zenki_S14]

i have a N/A ka24de, and i bought my 3 inch apex N1 3 years ago. i didn't put too much research into it cause i was 19 and i was excited about my first mod. if i could go back and change my decision, i'd go with 2 1/2 inch piping. on the other hand, with just an intake and my apex N1, i've easily pulled away from civics but kept up with modified b18's on the freeway. in a way, i'm glad i got my N1. it looks baddass, dude!!!

[Jsquared]

FWIW, every study I've read says that backpressure helps the power (low end) and fuel efficiency of N/A cars with smaller engines (ie 4bangers). Putting a turbo on creates an opposite effect where it's more important to get the air out as fast as possible.

NO. NO NO NO NO NO. :mad: read a book about fluid flow... backpressure is ALWAYS bad. the whole backpressure myth is from redneck muscle car boys and undereducated clear-taillight-lovin' riceboys who don't have the mental capacity to explain how flow velocity affects flow volume. the reason to not go to a big-*** pipe on NA is because the exhaust flow will slow considerably and the flow volume will be low. if you have too small a pipe, the cross-sectional area won't be enough to flow the correct amount of air. that's why you want a bigger, but not huge, pipe on an NA car. for turbo cars, well they flow so much freaking air on boost that you basically need a huge-*** pipe to get all that exhaust out...

[misnomer]

Bad Yoshi, I thought you knew better. Increased backpressure is often mistaken as a good thing because it is a bad side effect of scavenging. I just want to expand a bit on what Dousan said.

There are a few reasons to have a not huge exhaust on a naturally aspirated car beyond scavenging (something to do with gasses at the back of the pipe helping suck the gasses off the cylinder heads). Smaller pipes have less volume. Less volume has less mass. Less mass takes less energy to push around, hence less parasitic loss.

Just remember, corellation is not casation :P

[Black 97SE]

I'm about to get a CAI, Headers, and a Blitz Nur Spec R exhaust, will it seriously be that loud?? How loud is loud....I'll probably end up putting on the silencer if it's too loud.

[Chernobyl]

The tuned section of your exhaust closer to the engine (headers to cat) is far more important as far as scavenging and backpressure and all those fun exhaust terms are concerned. By the time your exhaust pulses reach past the cat, the pipe diameter has very very little effect on all this. IMO, at this point, you just want the exhaust to dump out, so a larger pipe so far down your exhuast will really not harm performance.

[Grant]

FYI Apex doesnt make a N/A exhaust for a 240sx.

N1 is 3". n-1 dual is 3" and split (both designed for turbo cars).

Originally posted by Yoshi
FWIW, every study I've read says that backpressure helps the power (low end) and fuel efficiency of N/A cars with smaller engines (ie 4bangers). Putting a turbo on creates an opposite effect where it's more important to get the air out as fast as possible.

Having the nur spec(R) will make you slower under around 50mph and have a higher top end as the rpms are able to wind out, which means it'll only help you on the highway/freeway. Pretty pointless. As an annoying side effect, your car will be annoyingly loud. Not like mild irritation loud. Like, "don't-hear-the-siren-from-the-cop-behind-you-pulling-yo-arse-over-cuz-you're-too-loud" loud. Especially on the Nur spec, which tends to have a buzzy tone to it.

Cliff Notes:
3" pipe on a small N/A engine, bad idea.

edit: the N1 is available in turbo and N/A sizes. Apex is a good company, they do their homework with R&D, if they have a size specifically for N/A, use that as a guideline, they have 2 version for a reason.

[Yoshi]

Originally posted by Grant
FYI Apex doesnt make a N/A exhaust for a 240sx.

N1 is 3". n-1 dual is 3" and split (both designed for turbo cars).

I agree Grant, but I've also seen both 60mm and 80mm N1's

as for the backpressure thing, I guess my face is pretty red.... in my defense, I DID say that's what I've read (looking back now tho, it WAS a domestic based book/articles). I never worried too much about the details as I'm turbo and bigger is better there ;)

Now I know, and knowing is half the battle!

[JEDubzII]

Originally posted by Black 97SE
I'll probably end up putting on the silencer if it's too loud.

Noooooo! Just get the right exhaust the first way aroun. If your car is going to be moderately NA tuned without extreme work on Internals etc. With mods liek CAI, Headers, Exhaust, etc then don't go with a pipe that big. Especially don't get an exhaust in which you are going to need to use the silencer. Not only are they ugly but they are bad for your car and reduce power. Get the right exhaust the first time around. DRFT!!!! (do it right the first time)