Hey guys i was wondering Why my S4 Na dosn't backfire.. im not saying backfire is good but I'm just saying. I have no cat, and stock exhaust with a RB header.
I'm just wondering so please don't hate or bash, just thinking why it isn't happening.

Thank you

Regards
Pat

 

You probably have an amazing tune, OR you're running leaner than most FCs on the road.

Do you WANT to backfire?

 

hmmm the thing is My Fc was never tunned lol stock ECU.. And yes it is kinda worrying me because if its running leaner the motor has a better chance of diein, so yes i would like the make the car's mixture alittle more rich but how!

 

My s4 has like once, and when it happened I was at the gas station and some old guy said "Get the hell outta here before you blow us up with your flamethrower exhaust" Im not sure why it has only done it once. I have a RB header and resonator back to some mufflers that the previous owner had put on. Ive got about 20k on a rebuild though..

 

Exhaust leak?
I see that you also have the stock exhaust, it might be a little too restrictive.
You will normally backfire with a more free flowing exhaust

And theres the antiburn plunger on the tb thst lets more air in when the throttle is closed

 

^this

 

I was alarmed when my car has yet to backfire at all. (Unless it is extremely quiet and I have yet to notice)

3inch dp to a 2.5 and out dual borlas on a 87 t2

I'm a little worried about running lean but I haven't had any other signs. Guess when the wideband goes on I'll know.

 

hmm so what do you think i should do guys? how can i make "backfire" if possible please help
how can i make the "antiburn plunger" less used haha XD i want some flame i am making my own straight piped exhaust 3.5 RB header, rest will be a 2.75 pipe with a (unknown muffler please help picking) at the end will that help.

Im still thinking on what muffler i should pick.. do you guys wana help me out?

MazdaTrix Rotorshaped
Tanabe
HKS
Apexi Noir
5 zigen

i will custom fit the mufflers so their isnt an issue but please help thank you

 

I advanced the timing a bit, which in turn has leaned the car out, but not in any way dangerously. My car no longer backfires, and has a **** load more power. It was a night and day difference.

 

hmm do you have coils? or do you have the distributor? and how can you do the timing on the coils? thanks

 

If you want to make your car run richer there is a little **** above the airfilter, 1 direction is labeled L for lean and the other R for Rich. Try that out, i personally wouldn't **** with it though.

 

Thats the variable resistor and only affects idle.

 

Thats going to be some loud exhaust. Why do you want it to backfire/shoot flames?

 

Wait what? Thats not the AFM?

How does it affect idle?

 

You have to turn the CAS. Now, WARNING: If you don't know what the hell you are doing, or do not have a timing light to safely turn the base timing up, don't **** with it. Just slightly too high and poof goes the motor.

No, it is idle fuel mixture and does not have any effect at any other time besides idle. Btw, this screw does not exist on the S5.

 

you can retard the timing a little bit (though you lose some power)
you can unhook the vacuum off the antiburn, and cap them so more air wont enter after tb plate are closed.

Though the best way is to just get a more non restrictive exhaust, though the more free flowing, the louder the car will become.
If you are making a custom exhaust...I do hope you plan on using a presilencer also. With just mufflers, it will be extremely loud.

You wont be shooting flamesthrowers on a n/a if thats what you are trying to do. Unless you increase fuel, even then, stock FCs already run rich.

 

The Exhaust piping i am using is Titanium. and when i had the pipe just hooked on going to the back, for some reason it wasnt That loud i don't know why but this car wasnt that loud.. can it be the metal?. The only thing what was annoying was the rasp so i'm thinking really hard but ill just put a muffler on and it will be good if not ill install the pre silencer after no biggy. The car is a track car tho so im not worried at all but i also dont want the car to be annoying as **** lol to the other people!
i dont want the car to be a huge flame thrower but i dont i also dont want it to never backfire.

do you have a thread on how to I want it to backfire or shoot flames because im worried that it is running lean as hell it isn't shooting flames at all.. i cant even hear the car backfire in the mid range of the exhaust so that is kinda not good.

One more Thing is their a way i can control the fuel mixture with my Apexi SAFC to make it run alittle more richer with out hurting the car?

Thanks guys!

 

Yep, you can sir. Do you have a wide band?

 

dam no lol i cant find a low cost one! im running out of money haha!

 

Without a wideband system, I would recommend much tuning. There's no real way to tell if the car is running lean without one either.

 

yea i know, dam im looking of getting one but im broke right now and prob will be for a while XD LOOL! all well i guess i have to wait and see what happens! thanks guys!

 

I popped flame when I ran with the stock exhaust, my CAS was advanced by 5 degrees RB Header and resignator, a Air filter and would pop after 7200 Rpm. If you have a cat on it just forget it I never popped flames with the cat on... Now I running with my CAS 2 degree Retarded RB header a 2 foot Toyota truck resignator and a 3 inch 5Zigan catback, A Fujita Air filter and now depending on if I'm WOT between 5500 to 7500 contributes the size of the flame in 1st,2nd or 3rd. Now my car is ****** LOAD at WOT Im about to put it back to stock after 7 Stock.

 

When my car still NA it would only backfire when I was revving it really high and then letting off the gas. Now TII with a bov and open exhaust it does it fairly randomly, usually after it's been driven far enough to get the exhaust really hot, and then let off the gas.

 

are the air pump and ACV still installed?

 

nope on the air pump and i dont recall ACV <<what is that again.