IP RACING

Ive been wanting to get a good sounding exhaust for a while but haven't felt capable of buying a 500 exhaust system to much money for my car. My 96 coupe has a new magnaflow cat and the rest is crappy old oem starting to go out. I want to hear your opinion on how loud the cat hooked up to about 3ft of pipe to a 24in magnaflow straight muffler would be . Basically just a straight through exhaust ending right before the first curve under the car. If this was all done in 2in piping i would think it wouldnt have a lot of rasp or noise it would be a pretty deep tone. any opinions on this set up I want. and if u say its riceycry me a river. im asking for an opinion

joelmatt89

I would think that would be really loud but you mine as well give it a try it doesn't seem like there is anything to lose

90Rexx

3 inches is too big you will lose too much backpressure. use 2.25 inch piping if your not planning on making alot of power. as long as u use a resonator and a stock exhaust manifold it will not be raspy. get a knock off apexi world sport muffler to keep it quieter...

joelmatt89

he never said 3 inches and how would he fit an actual muffler where he wants to put it i would think there isn't enough room there

IP RACING

yea I said 2in all the way through. my magnaflow cat is 2in and the piping would be 2in to a 24in 2in straight thru magna flow. The magnaflow would fit perfect in the muffler area nice and tight fit because its only 4in total height. So i thought keeping everything magnaflow with a thick walled pipe would give me a clean deep tone with out an echoish sound and some back pressure . not much but more than nothing sicne it will all be 2in

jay2020

first of all what motor do you have? Im rockin the d-series and i have a 2.25 in exhaust no res and a bypass for my cat ending with a flowmaster 40-series muffler. I have a nice deep tone down low, higher rpm's has a little rasp to it but nothing terrible.

IP RACING

its the stock motor nothing really done to it. just intake and always tuned up right. I just miss having a a tone to my car my ef had a nice deep tone to it but rasped in high rpms. so i thought this would be a cool exhaust. Ill prob be trying this in the next month. I need to do brakes first.

newtron63h

what makes you people think that backpressure is good?

accrdwgnguy

All the stuff I've read about tuning exhaust systems never mentioned backpressure.

about ending the exhaust under the car like that, its gonna be loud as **** inside the car, the sound gets trapped under the car. Build or have a full system built for the car that has a resonator in the midpipe and a nice muffler at the back, make sure the tip extends beyond the bumper a little. Magnaflow is good stuff, you should get a nice deep throaty tone with that setup, and interior noise that won't kill your hearing

newtron63h

you havent seen it, cuz its not there.

what you will find is stuff that talks about velocity and volume, all these idiots with 3" exhaust on their stock D15 have wasted their money. a D15 doesnt flow anywhere near enough air to need that much exhaust AND since the volume isnt there, then the velocity isnt there. velocity is what keeps the exhaust moving out, so with out velocity its kinda like having a traffic jam of exhaust gases in the system. not exactly back pressure but if nothing else thats ALOT of extra metal being wasted and weighing down the car for NO reason

R666_EK

YOU WILL LOSE POWER WITH A 3inch EXHAUST! Your engine NEEDS the appropriate amount of back pressure. Bigger isn't always better. Especially on our little engines. Large diameter exhaust are only necessary for turbo charged and high horse power N/A apps. Now to the O/P 2 inch will be just fine for the d series especially with only some light mods. As said before as long as you are running the resonator and factory ex. manifold WITH a decent muffler you should be relatively quiet and the rasp won't be as prominent. But i really wouldn't bypass the resonator and have the exhaust "dump" right there. Just my opinion.

IP RACING

well i was thinking it might be loud under the car so I was gonna put some sound mat under the carpet around the ending area that way it would be ok. I think it will be loud but I dont think to loud. well see

newtron63h

how does backpressure help? how is ANY backpressure appropriate?

i explained why too much exhaust is bad. and its not because of backpressure. its about volume and velocity.

IP RACING

well if its all 2in then that should be a good amount of velocity volume and velocity right?

R666_EK

They go hand in hand. I didn't say adding back pressure would help but the fact is on a stock engine when you decrease the backpressure by a large amount you will end up losing power as opposed to gaining. The engine forces such a small amount of exhaust as it is. Honda designed the exhaust the way it is for a reason. If most aftermarket companies sell 2 - 2.25 in exhaust don't you think there's probably a reason behind that? I'm gonna go put a 4 inch exhaust on my GEO i'll be be right back.

mormonboy

buddyclub spec II.

/thread.

boostatic

proper backpressure is nice for drivability..and the proper backpressure will give you more torque..everyone thinks that an aftermarket exhaust on a car that is very mildly modified makes a huge amount of power..its very funny because an exhaust is one of the worst mods you can make for the money(depending on your setup)...an exhaust doesnt add much power on hondas...hondas dont flow much air as compared to bigger motors which can see bigber power #'s from an upgraded exhaust..its designed to support mods..turbos do not like backpressure..they like the exhaust to be as freeflowing as possible..thats y i run the 3" exhaust on my car but if i was NA i'd proly keep it at 2" or less..

R666_EK

Thank You.

newtron63h

hmmm ok, well lets think about this.

"proper backpressure will give you more torque"

well lets start with what backpressure is. back in this case is defined as reverse. pressure is something thats created when there is a RESTRICTION to flow. so reverse restriction is what we are talking about.

whats the purpose of an exhaust system, to get the exhaust gases out of the engine.

ok so you are saying that restriction is GOOD when trying to get exhaust gases out of the engine? doesnt make much sense to me.

now ill give you a few examples.

1) stock exhaust on a D series is very small diameter. this is because the D series was a very economical engine family, even the Z6 is still capale of amazing mileage. so since the exhaust is small diameter, the gases flowing through it have to move at high velocity. velocity is the type of airflow that is generally good for torque. thats why some aftermarket systems can hurt torque.

2) 3" system, not much good because the engine doesnt flow enough air without big mods to need an exhaust capable of that much volume.

3) fully built N/A D16, revs to 9,000rpm. bored, stroked, custom tuned intake manifold....etc. it has a header that was designed for the airflow of the engine, likewise the exhaust was designed for the airflow.........what this means is that it keeps velocity up by being as small as possible while keeping flow as high as it needs to be at maximum rpm. the key to a good exhaut is finding the middle ground between flow and velocity. once you find the point where velocity starts to drop off, you stop decreasing the diameter. keeping velocity up is a key ingredient for scavenging. headers are designed to improve scavenging.

newtron63h

so the point is make sure you dont go too big with your exhaust. 2-2.5" is plenty for D series.

alphalanos

Straight through mufflers are fairly loud. Id go with the Apexi WS2 on some 2-2.25 piping. Wouldnt really need a resonator, but it would smooth and quiet it more. I have just a generic baffled muffler on 2.25 piping on a stock d16 and its a little deep but mostly quiet. Prob gain a few HP over stock.

Backpressure reduces HP. newtron63h is correct. search exhasut backpressure on Google.

R666_EK

No. Backpressure goes hand in hand with velocity. The FASTER the exhaust travels the better. If you have a larger diameter exhaust you will DECREASE the back pressure while AT THE SAME TIME decrease velocity. More air will be able to be removed from the engine through any given part of the exhaust but the SPEED at which it is exhausted is slowed. I never argued the fact that velocity plays a key role in the way the exhaust performs but you guys make it seem like you will make gains by just slapping the biggest exhaust you can on a little engine. That's just stupid. The ONLY thing I'm trying to argue is the fact that you think that no backpressure is a good thing. If that were the case then the factory would put bigger exhausts on than they do from the factory.

IP RACING

alphalanos: I would get an apex but the reason for this whole thread was Im not going to spend $600 on an exhaust. I made this thread for some feedback on how loud my possible set up would be. I wouldnt spend $600 on an exhaust , for that price id rather get all new suspension.

newtron63h

wrong again, backpressure is a restriction, PERIOD.

the best way to describe exhaust tuning is to start with pipes that are too big. go a lil smaller, and a lil smaller until you find the point where flow starts to drop. that is the point where both velocity AND flow will be at their peak, which is best for power. its about both, not just flow, but finding the point where both are at their peak.

you can most definitely put too big an exhaut on a car. absolutely, in fact its WAY too common.

i want you to explain to me how a restriction in the exhaut is good EVER.

car companies put restrictive exhausts on cars because of mileage and emissions restrictions. its much easier and cheaper to make one engine, then restrict it to meet the requirements of a car or country. as opposed to making 3 different engines.

R666_EK

Yes I know its a restriction. I know its a resistance to flow. I never said you are wrong about velocity. And about the exhaust tuning, its the opposite. You start small and go bigger until you lose velocity. How is what I just said contradicting the point you're trying to make? This is a pointless argument.