backfire

[HJLamont]

Hi guys,

i was doing a bit of drag racing a few days ago and noticed a guy sitting at the line making his car backfire repeatedly while stationary before he pulled away.

any ideas how he did it?

thanks

 

[HuskyGT]

1. Your car needs a modified exhaust. (It can be done with turbo engines with alot of power, as well as higly powered N/A engines)
2. Gently press the gas until you get around 2000 or 2500Rpms.
3. Put the pedal to the metal.
4. Enjoy the fireworks.

 

[GTguy88]

Hi guys,

i was doing a bit of drag racing a few days ago and noticed a guy sitting at the line making his car backfire repeatedly while stationary before he pulled away.

any ideas how he did it?

thanks

Just rev

 

[HJLamont]

ive been trying to do it but the results are very inconsistent. im trying in a 800hp corvette and it does it about 1 in 10 times.

im really trying to get pictures of it.

 

[HuskyGT]

ive been trying to do it but the results are very inconsistent. im trying in a 800hp corvette and it does it about 1 in 10 times.

im really trying to get pictures of it.

I´ve noticed that when it is a fast reving car, its more difficult to do. When its a slow reving car, like a turbocharged car, it is easier. I dropped a stage three turbo on a Samba bus, and it does it everytime I push the right analog, not even reaching half the max revs.

Or you can do like GTguy88 says: Just rev. Like crazy, let me add...

 

[zedextreme8177]

Full revs don't work actually. I tried it in my modded Tuscan, which only backfires at 75% of it's max revs.

 

[CivicInLake]

just keep blipping the throttle and it will backfire over and over

 

[Mysterious R]

Gear changes people.

 

[AliasJR]

Gear changes people.

while standing?

 

[HJLamont]

i was racing online last night in my ford focus with 345hp. it was backfiring constantly as i changed down gear. do you think the engine needs to get warm before it backfires? it wasnt doing it much at all for the first lap or so.

 

[Mysterious R]

while standing?

Yeah, you press the up button, it goes up, press the down button and guess what...👍

 

[928autobahn]

What this is doing is simulating what happens in real life. When you are on the throttle, there is increased fuel in the system. If you suddenly lift, there is excess fuel dumped into the system that is not fully combusted. This exits the exhaust and ignites.

So, it is on the lift off of the throttle that this happens.

 

[HJLamont]

so im guessing that the exhaust has to be hot before this will happen. so do a few laps and then try generating some backfires?

 

[HJLamont]

got some finaly!!

thanks for all the help guys, it seems you do indeed need to do a lap first to get the exhaust hot. im frankly amazed that they went to this level of detail on backfire and not on a lot of other things.

 

[HuskyGT]

I don´t think the warmup thing did it, or that it exists in the game, but... Well, I´m happy you got it.

(BTW any exhaust, rather than the stock one, make the focus sound like a 4 cylinder... yuck... Leave the stock one if you want the correct 5 Cylinder sound)

 

[JvM]

I noticed a weird bug with the backfire, when I was shifting with the paddles, there was backfire on almost every downshift, but when shifting with the stick (g27) without clutch, no backfire at all..

Car was an Esprit, not stock.. Haven't looked with other cars yet.

Can someone confirm this maybe on another car?

 

[notveryhappyjac]

Gear changes people.

qft, this is the way it is done, shift up and down while sitting still

 

[notveryhappyjac]

What this is doing is simulating what happens in real life. When you are on the throttle, there is increased fuel in the system. If you suddenly lift, there is excess fuel dumped into the system that is not fully combusted. This exits the exhaust and ignites.

So, it is on the lift off of the throttle that this happens.

6 years of driving RX-7's tells me this is almost all false, maybe 3 words are true, maybe

irl, if you are driving in gear and you take your foot off the gas NO GAS PASSES through the injectors, your engine just spins and passes air through it as you are effectivly telling the engine management to give the injectors 0% duty cycle. Try taking your foot off the gas in 1st gear going 1mph, the car would turn off not get a 'dump of fuel', if excess fuel was dumping after the throttle goes to 0% the car would not shut down, aka stall

flames out the exhaust pipe are caused by a combination of these things, maybe more but these are the basics

-unused fuel in a gasses vapor which has passed through the engine and now is trapped in the exhaust
-high exhaust material temps
-sudden pressure drop allowing 'clean' air to sneak up through the exit of the exhaust, air+fuel+temp=ignition
-gutted cats/mufflers or straight pipes

low pressure exhaust+unburned fuel+high temperatures+sudden drop in exhaust backpressure=flame out the exhaust

 

[Dennisch]

An add-on to that ^^^^

Turn your distributor so that your timing is late, go drive, rev it up, then let go of the gas, voila : Flames out of your (or mine) exhaust.

Or, even more fun, in a car with a carburator, go drive, and while driving, turn off the ignition, step on the gas pedal for a few seconds, turn the ignition back, and watch your exhaust explode from under your car! Did it once with an old Fiat, Awesome!

 

[BroncosXR8]

The SLS will do it just by changing gears, even at a standstill. Stock.

 

[SkylineObsession]

Backfires are awesome. Love doing it in GT and Grand Theft Auto IV. And of course in real life - my Skyline GTS (red coupe in my avatar) has done some real nice backfires before (just the sound and no flame i'd expect, its got a dump pipe type exhaust tip instead of a big bore like my turbo Skyline) and have been in and driven a 600hp R33 GT-R that was shooting flames out the exhaust.

 

[Yev]

Rev to the max, let go.
Works in real life too (I've done it).