n00b question... plz answer.. then laugh

BeEfCaKe · #1 06-03-2002, 05:42 PM

Ok. I was wondering what causes "fire" to come out of the exhaust pipe on fast cars.. what causes this? and is there a special term for this?

454Casull · #2 06-03-2002, 06:30 PM

1 of 2 things:

1. The A/F mixture hasn't completely burned yet, and is doing so down the exhaust passage. This happens often with methanol cars, where because it burns slower. (Or is it nitromethane? Not sure.)

2. There's a separate kit for the explosions.

TrvlynAlec · #3 06-16-2002, 02:29 AM

hahahahahahaha

CAptynCrunch · #4 06-19-2002, 09:15 AM

Theres actually another explanation for this.

Some high power, turbo charged cars(like in the WRC) are equiped with a system that lets a little bit of unexploded fuel into the exhaust system. Now why the hell would you want to do that you may ask? well simple, it makes you faster.

What it does is that as you shift up to another gear you'd normally have to wait a second or so for your turbo to spool up before it starts creating boost. With this system the small bit of fuel thats in the exhaust system is ignited when you shift. The expansion of the gases causes the turbo to spool while your shifting, so as soon as you put it back into gear you have instant boost.

However, this isn't something you put on your own car, at least not unless you have a fortune to spend on new turbos. As you would expect, causing an explosion in the turbo isn't a good thing. This system has a tendency to ruin a turbo after one race.

Other then that, like 454 said, it could just be a ricer with a spark plug bolted to his exhaust.

454Casull · #5 06-19-2002, 10:45 AM

That sounds pretty bad... Is that the misfiring exhaust of Kyouichi Evo III GSR?

SaabJohan · #6 06-20-2002, 09:35 PM

Quote:

Originally posted by CAptynCrunch
Theres actually another explanation for this.

Some high power, turbo charged cars(like in the WRC) are equiped with a system that lets a little bit of unexploded fuel into the exhaust system. Now why the hell would you want to do that you may ask? well simple, it makes you faster.

What it does is that as you shift up to another gear you'd normally have to wait a second or so for your turbo to spool up before it starts creating boost. With this system the small bit of fuel thats in the exhaust system is ignited when you shift. The expansion of the gases causes the turbo to spool while your shifting, so as soon as you put it back into gear you have instant boost.

However, this isn't something you put on your own car, at least not unless you have a fortune to spend on new turbos. As you would expect, causing an explosion in the turbo isn't a good thing. This system has a tendency to ruin a turbo after one race.

Other then that, like 454 said, it could just be a ricer with a spark plug bolted to his exhaust.

What you have described is ALS, Anti Lag System (also known as bang-bang system). This is a function in the engines management system, it can also be found in aftermarket systems like Autronic and Motec. It can be used with diffrent aggressitivities. The use of ALS increase stresses in exhaust manifold, turbo and exhaustpipe, how much depends on the aggressitivity of the system.

Fuel can also be injected to cool down the combustion chamber, this also causes flames but these are compared with the ones created with ALS much more quiet and burns slow with long flames.

454Casull · #7 06-20-2002, 10:36 PM

Some info about ALS
And I was right about Kyouichi's car.

BeEfCaKe · #8 06-21-2002, 11:39 PM

Um... how would those explosions in the tail pipe help a turbo?? i don't get it... i thought turbo sucked in air from the front?? how does exhaust affect turbo? wouldn't that be a supercharger instead??

Rich · #9 06-21-2002, 11:53 PM

Quote:

Originally posted by BeEfCaKe
Um... how would those explosions in the tail pipe help a turbo?? i don't get it... i thought turbo sucked in air from the front?? how does exhaust affect turbo? wouldn't that be a supercharger instead??

Turbo's use exhaust gases. Check out this link and read more about turbos

Bryan8412 · #10 06-22-2002, 12:54 AM

Quote:

Originally posted by BeEfCaKe
Um... how would those explosions in the tail pipe help a turbo?? i don't get it... i thought turbo sucked in air from the front?? how does exhaust affect turbo? wouldn't that be a supercharger instead??

yeah, like he said turbos use the wasted energy that flows through the exhaust. It's hooked up to the piping so the airflow turns the blades and it compresses the air. supercharger uses engine power, and sometimes the pully, thus turbos are more efficient in they help reduce the amount of wasted power.

454Casull · #11 06-22-2002, 09:33 AM

Yup, a lot of energy gained by using a supercharger is put back into spinning it. A turbo operates almost for free, once you get past the lag.

hermunn123 · #12 06-23-2002, 12:43 AM

from a book i have, Technology of the F1 Car, it says a little something something about the flames shooting out. it shows a picture of an F1 car shooting flames and says this:
"Entering a corner, the driver has lifted his foot off the throttle pedal. The engine is now on the 'over-run' - retarding the car rather than accelerating it - and the flames belching from its exhaust are the result of unburnt combustion products being ignited by the intensely hot pipes."

help?

454Casull · #13 06-23-2002, 09:52 AM

That's a pretty old book.

Pennzoil GT-R · #14 06-23-2002, 02:07 PM

A friend of my dads is a racing driver and has an F40. the F40 does it all the time and i asked my dad (who used to be a mechanic) and him why it does it.

When the throttle is lifted, for a split second it takes a while for the fuel intake system to catch up with the drop in revs. as there is now an excess of fuel in the the cylinder, some of it escapes into the exhaust system next time the exhaust valve opens. this then explodes on the red hot exhaust pipe, causing the fireball to come out of the end of the tail pipe

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