big bore on 20v

[loganh]

Does anyone no wat brand or size big bore tip i should put on my 1992 trueno ive already got extractors and 2 1/2 inch right threw but a crapy muffler at the end so wat would sound the best ????

[1598cc]

You shouldnt. Its not going to give any more gains, unless your car is heavily modded.

Think of it as wankfactor

[Silent Knight]

if you don't like your muffler then just change to a different one. as for any other mods on your exhaust leave it like it is at the moment. since it's only a 20V and non turbo you are going to need a bit of backpressure as all NA cars do. If you go much higher than 2 and a half inch pipe you'll start loosing power.

Just get a muffler with the right sound that you want and put that on.

[Sanxta]

Definatley - in fact your pipe may be too big already. But apart from that your system sounds good.

Put on a ricey/blingy 2.5 straight-thru if your worried about aesthetics, and if it's too loud or sounds raspy, then slap a resonator or two on there.

But if it aint broke - I wouldn't try to fix it . . .

[AXNGRL]

I have a muffler for sale, stainless steel... it will fit on a 2 1/2" exhaust...

[Levin111]

i had a 2 1/2 from cat back with 1 resonator straight through mandrell bent with a 3" barrel at the end, gave me heaps of power and still had tones of back pressure, mean back fires too hehe.

[Dr-X]

Backpressure is a myth. Do some research. There's no point spending the cash on a 3" exhaust, for example, because it's not worth it...but you wouldnt lose any power.

[strap-on]

this has been posted ALOT of times before

and again i keep saying......

best size exhaust for a 20v is the FACTORY 2 an 1/4 inch pipe, i think this DOES have something to do with backpressure,it is to ensure a consistent flow of gases out of teh engine, and stops them swirling.

keep the factory extractors...

get a couple of goo resonators ( cobys or the like) and a good well packed muffler in the rear to keep it quiet,

my exhaust is two 16 inch cobys and an rps 5 inch cannon and it is WAY too loud as im sure people on here will tell you.

mod's you should lock this now.

[Dr-X]

best size exhaust for a 20v is the FACTORY 2 an 1/4 inch pipe, i think this DOES have something to do with backpressure,it is to ensure a consistent flow of gases out of teh engine, and stops them swirling.

Jesus go read a book.

[strap-on]

i did. then again the swirling bit i heard from someone on here,

then again i do grapple to understand it, you are right.... its not really back pressure its all to do with tuning, and timing, and intake tuning etc etc etc etc etc etc etc etc etc etc and ETC.

but the point i its too complicated to talk about so from my understanding everything is refered to as backpressure, but as far as i understand the myth of adding in resonators or mufflers for backpressue is indeed just that a myth like you say, however there is a lot to be gained by having the rite sized pipe

[Dr-X]

but the point i its too complicated to talk about so from my understanding everything is refered to as backpressure, but as far as i understand the myth of adding in resonators or mufflers for backpressue is indeed just that a myth like you say, however there is a lot to be gained by having the rite sized pipe

Aaaah, you were so close to being right, then you had to add that little piece of bullshit at the end.

Lets put it this way: In absolutely no situation (that i can think of) would a 2.5 inch exhaust give you more performance than a 3 inch exhaust. Backpressure has no positive benifits. If you want the best possible exhaust performance, just run off the headers. You dont see drag cars with complex exhausts, do you? The only reason race cars use exhaust and muffler systems is for noise restrictions.

There's no advantage in a smaller pipe. period.

[strap-on]

yeah we are talking about street systems here, you are rite, running straught of the headers is a mint way of getting the best power, but, for a street system, im pretty sure the exit on the 20v's extractors is 2 and a 1/4 so i dont se eth point in going to a 2.5, i heard a snippet from redmist ( im not quoting him tho incase i heard wrong) that having too big a pipe ( ie a 2.25 going into a 2.5, will disrupt flow, which will fuk up the awesome job that the headers are doing, then again what he said was in reference to the cannon type muffler that i have so yeah i dunno, it makes sense tho

[Dr-X]

OK, seriously, im trying not to insult you here, but you clearly know nothing about exhaust systems. I dont think you are pretending you do know much, but trust me here, there's a lot you dont understand.

im pretty sure the exit on the 20v's extractors is 2 and a 1/4 so i dont se eth point in going to a 2.5

Increasing pipe size after extractors, or after restrictions, can still give increased air flow. For example, in the U.S. where cat's are required, most people only do cat-back exhausts, where the exhaust is only modified after the catalytic converter. It still results in increased power.

a 2.25 going into a 2.5, will disrupt flow, which will fu*k up the awesome job that the headers are doing

increasing pipe size doesnt $&#$% up flow. Otherwise, wouldnt it 'disrupt your flow' when your exhaust ends?

Backpressure is a myth put together by people who like to think they know about exhaust flow. The fact of the matter is, that you want your exhaust gasses to flow as freely as possible, without exception. That's why people spend thousands on good extractors, because they are well tuned to give the best possible flow, using many complex methods. As far as your exhaust system goes, however, backpressure is a no-no. Big pipes = big flow. Increasing backpressure may give you a nicer sound, but it will not help performance.

As far as small engines like this go, your factory pipes would probably do just fine (2.25", right?). But the point I'm making is, that bigger pipes dont hurt.

[celica_tommo]

Bigger doesnt always equal bigger flow. You want an appropriate size exhaust so that you maximise the high temp of the gases (lighter gases are easier to push out) and the timing of exhaust pulses (from what I remeber after each exhaust pulse there is a vacuum created and this helps pull later exhaust gases out of the cylinders and down the exhaust system). So larger pipes might cause the exhaust gases to cool down and also not make use of the pulses energy to pull the gases out and thereby harm performance.

[celica_tommo]

http://www.nsxprime.com/FAQ/Miscellaneo ... theory.htm

[trueno]

The whole 'backpressure' thing is about maintaining gas velocity so that you get some scavenging effect at the end of the exhaust stroke.

If you can empty a little more of the cylinder then it probably would be worth some pumping losses (backpressure) but if you just slap on a pipe you dont know what it's doing. To develop an engine you need to experiment and spend hours on the dyno, everything else is just guesswork and hearsay.

[Sanxta]

The whole 'backpressure' thing is about maintaining gas velocity so that you get some scavenging effect at the end of the exhaust stroke.

If you can empty a little more of the cylinder then it probably would be worth some pumping losses (backpressure) but if you just slap on a pipe you dont know what it's doing. To develop an engine you need to experiment and spend hours on the dyno, everything else is just guesswork and hearsay.

^This guy knows what he's on about

[shaggz]

i had 2.5 inch mild steel with mandrel bends straight from the extractors (trd issue) no reasonater then had a tornado(uk brand) muffler with a 4 inch tip......it was farkn loud and backfired like a bitch not to mention the odd flame....that was cool,and the car charged hard but perhapes a reasonater and a smaller muffler on the end it will be quiter but still go like a little bad thing