i just put a new exhaust on my 90 240sx and its backfiring. alittle bakefire is ok but mine sounds like im shootin somebody, and i cant figure out why. any suggestions

there was a thread not too long ago, talked about fuel filters and the fuel pump, try changing that. The fuel filter is cheapest, get the z32 one. And what is your engine setup? Maybe you need a new exhaust system. Anyway i dunno if this could help you or not. Welcome to the forums.

uhhh u have a cat converter?
any leaks?

there was a thread not too long ago, talked about fuel filters and the fuel pump, try changing that. The fuel filter is cheapest, get the z32 one. And what is your engine setup? Maybe you need a new exhaust system. Anyway i dunno if this could help you or not. Welcome to the forums.

YA I DO HAVE A CAT AND IT HAS A SMALL LEAK. I AM EVENTUALLY GOING STRAIGHT PIPE NO CAT NO NOTHING JUST A MUFFLER

^ lolz... whoa there.

YA I DO HAVE A CAT AND IT HAS A SMALL LEAK. I AM EVENTUALLY GOING STRAIGHT PIPE NO CAT NO NOTHING JUST A MUFFLER

WHY DO YOU SAY THAT I WILL HAVE NO RESTRICTION

What's with the caps?

you realize that once you get your straight pipe the backfiring will get worse dont you...?

what other mods do you have?
backfiring is usually a result of running over rich and the unspent gas is hitting the superhot exhaust manifold and detonating out the exhaust pipe

The reason why it doesnt back fire inside the exhaust is because the gas is heated to temperature past combustion and has no oxygen to cause the chemical reaction and when it exits..bam lots of oxygen

I'm also having a problem like this... I put a 80mm exhaust on my N/A KA24 and it got louder! a little throatier would have been ok but louder???? PLZ HELP ME!!!







:gay: OMG OMG BACKFIRES!!!!111!!1 :hyper:

I'm also having a problem like this... I put a 80mm exhaust on my N/A KA24 and it got louder! a little throatier would have been ok but louder???? PLZ HELP ME!!!







:gay: OMG OMG BACKFIRES!!!!111!!1 :hyper:
if you run a turbo exhaust on a n/a car it's going to "backfire". just go turbo.

So i should expect...Loud and backfires form my exhaust not good sounding...but the performance should still be there correct? just like 5-8 HP?

You won't rly get any flaming since you have a cat (right?) but you will hear the backfiring.

if you use a turbo exhaust on the ka without a silencer you will lose hp/tq on the lowend.

Modified cars backfire. No two ways about it. Going turbo is only gonna make it worse.

But look at the plugs. If they are black, then try cleaning them. Typically obnoxious backfires on a mostly stock car are linked to ignition. At least mine was. Turned out to be a bad coil. Then after replacing coil, wires, plugs and cap/rotor, car ran super smooth with minimal backfires.

Modified cars backfire. No two ways about it. Going turbo is only gonna make it worse.
thats not true. going turbo will not make it worse in some cases it makes it quieter. it's just the exhaust size it was not meant for n/a use.

It will make it more quiet with a turbo, but it'll prolly backfire still. You do know that a stock SRT-4 backfires rite?

I'm also having a problem like this... I put a 80mm exhaust on my N/A KA24 and it got louder! a little throatier would have been ok but louder???? PLZ HELP ME!!!



i dont mean to flame you but you didnt know putting ANY higher flowing exhaust on a car makes it louder?

the reason a stock exhaust is so quiet is because of the super-small diameter piping and all the bends and stuff in the pipes AND in the muffler(take a stock muffler apart sometime. you can see how restrictive the path is with the exhaust bouncing off walls and changing directions all over the place)

basically adding restriction quiets exhaust(this is why turbo motors are quieter than N/A motors, the turbo is essentially a big restriction)

there are some of the more expensive exhaust makers out there who are able to quiet the exhaust note somewhat without restriction(like RS-R exmag 1). they use more exotic materials in the silencer walls that help a little more.

backfiring is an issue that involves the engine, not the exhaust. if you noticed it just when you changed to a 3", it was happening before but the stock muffler, ect. was hiding it.

Before I turboed, my car woudln't really backfire at all when I downshifted. Now it pops like crazy and occasionaly I'll get a little fire. Its not so bad recirculated, but VTA like I am now, I can get some pretty good ones.

Going turbo will make the exhaust note quieter.

He's completely aware of all of what you said.

big deal (back fire)..so what??

the only time back fireing will be a BAD thing is when a COP is next to you..

is it illegal to backfire?

I think shootin flames is...poor RX-7s....but anyways, putting a turbo exhaust on a KA won't make it lose power, they gain power, even with a big ass GT-Spec, it might shift the power band, but you won't notice a loss, only a little top end gain.

SARCASM > THIS THREAD


Adding a Turbo will generally equal more backfires because more fuel is being run though the motor. lots of fuel plus no air (caused by closing the throttle while shifting, ect.) is a sure fire way to get a backfire. however some backfires are caused by being too lean - where the mixture is too lean to ignite in the cylinder so it burns in the exhaust where it has more time to light off.

The reason turbos are quieter than N/As is that the Turbo uses some of the acoustic energy to spin the turbine... Turbos dont just use exhaust flow they use whatever energy is around them (heat, sound, pressure) and "recycle" it. even a 1.00 A/R turbine will be quiter than an uncorked N/A but not nearly as quiet as the pinhole sized T25.

Theres really nothing you can do to get rid of back fires short of tuning the motor for less power. if your plugs are fouled or your ignition is 15yrs old (bingo!) its not helping the situation but fixing it will only lessen the occurance.

s13bitch i cant believe you actually responded to R.W.'s post that is hilarious

The lean backfires usually occur around 17:1AF. By then, you're screwed if you're putting down decent power.

The lean backfires usually occur around 17:1AF. By then, you're screwed if you're putting down decent power.


Its an off throttle thing too... if I was going to try and hit 17:1 on the gas I'd make sure there were at least 4 camera angles and then pray for something spectacular.

What vidos would you guys want from exhaust samples out of the following?
Slow Rev, Fast Rev, BackFire, Hard Launch, Full Throttle Drive By, Normal Driving Drive By, Inside, Normal Drviing Launch.
Which ones if not all?

all.. :)

lol R.W., me too.haha maybe see a piston shoot out or something.

then...send a nice 5 easy payments of $250 to the PO Box of.....
Ok ill do all of them then