This one's more of a technical question...

So please only people with answers, answer....
[I need fact not opinion]

Here we go....

Intro:
Every engine needs Exhaust Flow... As Well as the often over looked 'backpressure' - With this combination... tuning hp out of stock to custom exhaust can give you more gains than just bolt'n on some kit... [although most kits are designed specifically for a car, most people mix/match - headers/downpipes/cats/mufflers]

My Goal: is to have an efficiant flow of exhaust through low and high rpms with a mild/low tone exhaust note.

My Idea: If... [These numbers are way off it's just an example to express the idea]... you have an SR20det that needs a certain amount of flow... like "SR20DET28 uses a 3.5 exhaust"... And you have the piping... On say a 6" exhaust [obviously not real, but it helps for the demonstration] - Would you be able to run a splitter/Y-Pipe from the cat [or would it be better to run 2 cats] - And Split the 6" Exhaust into a Dual Exhaust with 3" Pipes... then run two Mufflers with Silencers.....

On paper, sounds good....
6" of flow.... 1 Muffler... Loud
6" of flow [3"+3"]... 2 Mufflers [Silencers installed to recreate backpressure] .... Low Tone/Quiet[er] even in High RPMS

One of the reasons is because I'm getting a body kit that's gunna require a Dual Exhaust to look good...

And Mainly.... I hate the Dirt Bike Whine when trying to leave a redlight at a decent speed... YES - IM AWARE MOST EXHAUSTS SELL SILENCERS - BUT THEY DONT SILENCE AND THEY RESTRICT HP... WHY WOULD I SPEND QUALITY CASH ON AN EXHAUST THEN PLUG IT?.... PLEASE DONT TALK TO ME ABOUT SILENCERS>> THEY SUCK << I've Done the research [Even the Active Exhaust Silencer from Apex... because it still opens on high RPM creating that sound]

When I'm flying down the road I dont want a cop to have that audible invite to pull me over and notice my illegal engine.

I was even thinking of possible running two Stock Mufflers... because most after market ones ADD the sound... and the 240's have good flow...

[Side Note... off Topic]
I was trying to see if anyone has a powered moonroof/sunroof on their 240... I searched "Powered/Power moonroof/sunroof" and didn't see anything pertaining to the upgrade/replacement of the stock pop-up - if it is somewhere on here, can you link me?

THANKS A GRIP GUYS... Love the passion and knowledge we share for these great machines.

 

Ummm....no. Just get a normal exhaust you dont need duals to get power.

NEXT

 

umm... I'm confused. but um yeah ^what Fast1One said. oh, and I have a power moonroof~ it doesn't work, but it should once I fix it... lol.

 

So I am assuming that you are going sr20det, but you still didn't say that you will have an sr20det..... Next question......

6" exhaust on paper even as trying to represent exhaust size and flow is rediculous. Sr power cars even exceeding over 500hp at the wheels don't need anything over 3.25". Exhaust is matched to RPM rev, and fuel dumping. Then fine tuning the exhaust is used to control scavaging, and back pressure, to allow your hp/torque ratio through the power band. This means researching and developing weither or not you would even want 3.25", most go with the typical 3", and being that it is turbo charged, it will be quieter than an NA car, only because the sound of detonation, and explosion is held back before the turbo using heat for power. Thats why 3" exhaust is loud as hell on an NA ka24de rather than a turbo powered SR20det or KA24det. I wouldn't even think of using silencers.

Nope no chance that you will get a dual exhaust that will be effecient. The 240sx/silvia were designed to use a single exhaust. In all it's nature it only has one header. The rear sway bar won't allow you to use a dual exhaust for the fact that there is only one huge bend in the bar to only allow for the use of one exhaust.... Plus once you slam the suspension you won't have room to add a second exhaust that can move past the drive shaft.
Example: look at my bar and tell me igf you can see what tthe problem is.....


Worst idea ever, those stock mufflers have herendous flow numbers, your exhaust will back up more shiat than it can force out, if anything a Magna flow is what you want........


You should work on your own car before asking these kinds of questions. With all seriousness these questions didn't take any serious thought. They were derived of your own imagination, and not derived from any type of "REAL" car building experience.
Body kits that have the dual exhaust look suck on 4bangers IMO....
If I sound like Simon Cowell from American Idol understand I am not here to hurt your feelings, I'm just here to tell it how it is.....

 

now about them side-exhausts...

 

Big Vinnie did it. Thanks for taking the time to answer my question, and the whole 6" thing, was just so I could say 3" instead of 2.85" [split from a 3.5] - That's why I emphasized the 'ignore the numbers' - But everything else was dead on and I appreciate it, Yeah I can see from the pic what you mean... I'll have to do some cutting and custom fiberglass to ditch the extra hole I guess, haha...

FASTONE.. SLOW DOWN, the question stated "I want fact, not opinion - please only answer the question if you have an <u>answer</u>" Don't tell me what kind of exhaust I want/need - the question was relative to dampening the sound, not extracting performance... NEXT....

CowBoyTurbo: Is the power moon roof stock? Cuz' mines a flip up and I was thinking of having it changed, that's why I was wondering.. post some pics I wanna see it inside/out if you can.

I've been toying with the engine swap Idea a lot, right now more of a research phase... gathering information on what will suit me best. I was thinking RB26 but I'll probably end up with an SR T28...

I do work on my own car, and prefer to do it myself. Only way to learn... but before I make any moves I like to ask questions, sorry if it was completely from 'my imagination' - and I have no experience, but... isn't that what this forums for? heh... Thanks again Vinnie I really appreciate your insight and advice. - Phaded J

 

Oh and another emphasis on thanking you for the detailed information about the turbo and how it prevents the louder sound... I never knew that.

I hate silencers too

 

The turbo T** rating works best for engine displacement.
A T25 works best on an sr, good spool time and power to displacement.
A T28 works best on a KA24 and RB25, again displacement size is the main factor.
Building something new and fresh is better (hint the KA is bad *** turbo charged)...........

 

Building something new and fresh is better (hint the KA is bad *** turbo charged)........... [/B][/QUOTE]

BigVinnie get's the idea........now lets see if we can get more people to go ka-t insted of everyone going SR..........

Oh and as for the T25 just being for the SR......well i'm going to have to say thats about right.......i hit my max boost at 2300 RPM's with my t25.......i would have went with the T28, but........$500.00 for a used t28 is really crazy......but i guess thats what i'm going to have to save up...... .....oh well......its all in good fun........

 

I'd post pics if you really want them, but I have a S14 so I dunno what good it would do you. Sry, wuz just being a wiseass.

 

WOW someone needs to not get buthurt about a response...

FACT: If you want a quiet exhaust get a good flowing muffler (I.e. Magnaflow, etc) or two if it makes you feel special, and add a RESONATOR to it...the bigger resonator...the quieter....unless your running a 6 inch exhaust

NEXT

 

you have a hatchback and those only came with popups im pretty sure there isnt a way to got the power moonroof like in the s14s or the coupe s13s

 

Thats what im talking about, im saving up for my KA turbo right now!!!

 

you can do it, it'd just have to be custom fab'd.

 

BigVinnie get's the idea........now lets see if we can get more people to go ka-t insted of everyone going SR..........

Oh and as for the T25 just being for the SR......well i'm going to have to say thats about right.......i hit my max boost at 2300 RPM's with my t25.......i would have went with the T28, but........$500.00 for a used t28 is really crazy......but i guess thats what i'm going to have to save up...... .....oh well......its all in good fun........ [/B][/QUOTE]

yo how much did u spend in total to turbo ur KA.cuz I got a **** load of money from insurance some went to fix the car and now everybody said go sr cuz less money and wit ka u have to built it right u know the pistons and head jobs all that crap.but how long did u have ur turbo on the ka and how much did u spend.thanks