Delphince

I hope that was a joke; even if so, it's so far off it's not even funny. Stripping your car down to an improbable 500 lbs would do a little more than take off 1/4 of a second from your quarter mile time.

Gain from effect on a % for % scale, no modification is more effective than weight reduction. Cutting your weight in half is far more effective overall than doubling your horsepower. But arguing over 20 or 30 lbs when your car is still well over a ton is like a heated debate about the effects of putting on a cold-air intake on an otherwise stock engine.

...Especially when many drivers aren't exactly the trim athlete themselves. The driver is part of the car, after all.

tandolla

iTrader: (1)

every 100lbs is a tenth of a second.. for 40 pounds wont do much.. basicly its up to you.. i wanted dual really bad.. but i onyl have money for a single so i went single havnt recieved my exhaust yet but everyone that has the exhaut that i got loves it.. go to www.ssautochrome.com $385.00 shippeed to my house.. cheap and great..

*EDIT*

It turbo back..

Rxseven7

waht dose everyone thing of the dual hks system and pictures if anyone has any

NZConvertible

Do you realise how much your car weighs? A dual-muffler system adds ~20lb compared to a similarly built single-muffler system. Do you understand what a tiny percentage difference that makes to the car's total weight? Even on the lightest FC it's well under 1%. Do you honestly think you can tell the difference? You add 80-100lb to the car just from filling up with gas. Or do you add fuel in 1gal lots (~6lb each)?

sleeepyhead

I had a stock rx7 and raced my friend's rx7 and we were even, strong engines and bone stock. I started to lighten my car gradually over the year and didnt notice a difference. Spare and jack, rear interior, aluminum hood, battery, seat, all done at seperate times. I thought i was gonna beat my buddy by 1/2 a car or so cause i didnt really feel a change. When we raced again, i easily won, i pulled almost 2 cars on him by the end of second gear. I had a corksport single too and didnt feel a thing other than the ringing in my ears, I currently have a stock catback after i welded a extra muffler on the corksport which rubbed the ground and eventually broke off....

My friend did a little experiment and stripped his car bare bones, not even a dash, he zip tied his guages to the firewall. He has a streetport(ghetto 1st time try with no runner work at all) and true dual exhaust for power mods, stock intake. He destroys 350zs and s2ks and lost to an evo by about a car length. He is now addicted to lightening

Bottom line is if you want to go faster, single is obviously better even if you might not notice the difference

Rxseven7

or if you want the dual just get it and if the 15lb makes that much of a diffrence to you then jsut take the weight off somewere else.

drft_180sx

Ummm....i do agree with the general consensus that 15-30 lbs won't make a difference especially for a car that probably wont see any further weight reductions.

BUT...you can't possibly tell me that a full tank to a 1/4 tank-fueled car doesnt make a difference? I only fill up to 1/4 tank (cause i got no moneys) and if i ever fill the tank the car feels like a pig.

FCKing1995

iTrader: (3)

I dont see the deal here.

Single:
Slightly lighter
Slightly less restriction

Duel:
Slightly more restrictive
Slightly heavier

But Duel looks much nicer and cleaner to me. Its all up to personal taste cause performance and weight isnt enough of an issue to bitch about, when we are speaking in such small amounts (1-2hp and 10-20 pounds)

SirCygnus

iTrader: (1)

driving around in my corksport it wasnt too loud cus you got used to it. after i stopped and drove my new fc, and finally starting my old one back up i must say, its loud as ****. really really fucken loud. of course i must say that i had a completly uncorked exhaust. anyways. a true dual setup from mazda trix is a nice investment. its quiet, and it will be pretty quiet. its much quieter than the uncorked corksport, yet it will still produce AROUND the same hp that mine did. plus weight should not be a factor for a daily driven car. unless you compete heavilly in competitions, weight isnt an issue. now if you have a friend in your car and hes 300 lbs, kick that ****** out.

FCKing1995

iTrader: (3)

Something that pisses me off a bit is people that talk about weight savings and make a big deal of it... then you look in the back of their car and they have a bunch of subs and amps and whatnot... WHAT THE HELL IS THE POINT of saving weight when you have 75-100 pounds of audio equip. in the back of your damn car Just an observation

Valkyrie

It's so you still weight slightly less than you started out with, I would imagine :p

Personally I like single-exit exhausts (as long as they aren't too ginourmous), but that's just me. I like the asymmetry.

What I find more amuzing is when people spend 500 bucks on a carbon fiber hood when they haven't even so much as bought new tires, suspension, or rims... especially when they have hood pins (and almost certainly the stock latch as well).

papiogxl

iTrader: (6)

Disclaimer: This post contains liberal amounts of sarcasm.

If you are THAT obsessed with weight redux, cut a hole in your fender and route a custom exhaust. It'll weigh less than the stock mani, not to mention all the massive amounts of sheet metal removed by cutting the hole.

Rotary Noob

Yes, 5 pounds can make a difference, but only if youve already got it gutted, tuned, proper suspension, and remember, you still have to be at the proper weight, you might even have to add balast for races!

Tool.

staticguitar313

iTrader: (2)

I like my borla duals, **** single tips, no good reason to even bother, most aftermarket duals are featherweight compared to the stock system anyways, and if you wanna remove exhaust weight, ditch everything stock, RB or corksport header, presilencer, stainless dual catback, deep and free flowing without sounding like a folgers can. Dual mufflers give you the option of being mellow when you need your hearing or wanna actually use your bling stereo to pick up chicks since your single, as MadRX7Racer has successfully concluded through deductive reasoning.

EJayCe996

Proof please.

NZConvertible

Like I already said, there are many other more important variables other than single or dual that determine how well an exhaust flows. You simply can't make blanket statements like that.

Cosmo_TT

iTrader: (11)

so you are telling me that if you had a car that could fit four of your friends who weigh about 200lbs each you would not run slower than .1 difference than if you ran a 1/4 mile by yourself with the car empty hahahahahhahahahahahhahahahahahahahhahahahha dude please dont post on here if you have no clue as to what the hell you are talking about i am so sick of people who type stuff on here and have no clue or experience with cars/racing/or anything that has to do with this forum
wow i think i have a headache now

stevenx788

i have duals and nothing beats the sound also i havent owned single exuast because why leave the other exaust slot empty...lol

Madrx7racer

it really looks weird...........I know there are several rear skirts that have the inserts to cover up the other opening but still not worth it unless you've already gutted and race-prepped your car and are looking to decrease the most amount of weight possible.

FCKing1995

iTrader: (3)

yeah i should have been more clear. i was speaking on the terms of having a 3'' stright through exhuast with single muffler (Corksport) vs something like RB kit with presilencers and y pipe, then 2 mufflers. The ehxuast gas has to split and move around a bit more. In general they are about the same, but again Im speaking such low numbers you wouldnt hardly be able to see them on a dyno

13BT_RX3

If you were to compare a single 3.5"with a magna flow and a dual 2.5" system with two magna flows. These sizes would have nearly the same flow area.

The dual system would cost more, be quieter, fit better, look more balanced and have better ground clearance.

The single system would have less internal turbulance and friction, but I don't know if you would see much of a gain in power.

Which one is better? That is up to the individual. I like dual. Single gives a second gen the looks of a v6 mustang. An empty spot on one side.

86TwinTurbo

The racing beat true dual outperforms the "Dual exhaust" which I believe is less restrictive than a single exhaust...I have compared the true dual and i think an hks version and the true dual gave more power. Also if you do go single....please..i repeat get a rear bumper that is made for a single....I laugh at 7's racing around with one muffler and a gaping hole on the otherside

Valkyrie

For the record, a 30-pound loss (if you took off one of my mufflers it would probably be closer to 40 pounds... for a Magnaflow and some bottlenecked piping) makes a much bigger difference on a car with a stock-ish engine versus one with say, 400 HP...

Sort of how a golf car with no one on it would be pretty damn fast, reasonably fast with one, and slow as hell with 4. Or why even a racing go cart will be different with a 130 pound driver versus one that weighs 180 (that's why they're in different classes)... or why someone who weighs 200 pounds wouldn't be very satisfied on a 250 CC motorcycle, but someone who weighs maybe 170 would have the time of their life (...well, maybe not on a 250).

Obviously the difference between any of these things an a car is a bit different, but if you were compare a 160-HP torqueless NA to a turbo with 300 ft-lbs of torque, those 20-30 pounds (combined with say, 20 pounds from taking off the A/C, 18 or so from the PS, etc) have very different meanings to different people.

SASSER

Agreed, like maybe loosing the extra pounds. Oprah's Weight Loss Plan!

NZConvertible

So you're actually comparing two completely different systems. Like I've already said twice, there are many other variables to consider and the many differences between your two examples prove that. I also don't think you realize that two mufflers in parallel aren't necessarily more restrictive than a single. It depends entirely on the size of the pipes. My dual system has 70mm rear pipes and mufflers. Two 70mm pipes will flow ~35% more than a single 80mm pipe at the same pressure. That's a huge reduction in restriction. A well-built Y will only have a minor effect on flow in comparison.

There is no reason a dual system can't be built as a mirror image of a single system, so there's no need forany more "moving around". The only difference would be the Y, which isn't an issue if the pipes are sized correctly.

For starters, if you’re comparing similarly constructed systems it's not 40lb, it's only about 20. You're not just taking off one muffler; you're replacing two mufflers with one bigger one. Unless you plan to strangle your engine with an undersized single system, some of the weight lost from not having two mufflers is offset by the increased size of the single muffler. As for power difference, we're still talking about such a tiny percentage of the car's total weight that this is largely irrelevant.