Instead of screwing up your engine why not just inject a flamable fuel into the tail pipe directly(kind of dangerous). It seems like i have seen this done with propane somewhere before.

Posted at 11:16 am on Mar 3rd, 2006 by rmiller021

Yeah, a friend did this using a 510cc injector off the fuel return line i beleive, he controled the injector and sparkplug with some switched in the car. He controlled the pulse width to the injector with something… I’m no good at that stuff so I’m not sure…

Posted at 11:24 am on Mar 3rd, 2006 by mike

The article states that the hack/mod does not work for fuel-injected or electronic fuel-injected (same smell right?) vehicles. But on the contrary… with a catless exhaust system and a richer air/fuel mix, the exhaust gasses can be reignited. Granted of course the flames are more like quick bursts of smoke most of the time (with an occasional flame here and there), but nonetheless… an exhaust “popping” sound. This mod seams to be a little more high-tech as compared to just purchasing a blast coil and a spark plug and some wires. Great mod!

Posted at 11:25 am on Mar 3rd, 2006 by BLUE-ZERO

yeah miller, I’ve seen it with propane too
Usually those kickass ones at car shows

best looking one I’ve gotten to look at closely used a slick little side by side exhaust setup, piped exhaust out one and would fill the other with propane from a tank in the trunk, then vent exhaust through the propane filled one while sparking the igniter, it was fairly ingenious, albiet a little complex comparatively, but the effect looked outstanding, nice solid flame, almost like a welding torch in shape

simplest was a brass nipple through the pipe, connected to a solenoid off a propane generator, connected to a highflow regulator on a standard tank, shorter flame, but it was cheap to make, cheap to upkeep, and with the concept of “what isn’t there can’t break” should last as long as the solenoid and/or coil

Posted at 11:50 am on Mar 3rd, 2006 by Munky

you don’t need to cut the spark to the engine to make it work. If the engine is left just a touch on the rich side the exhaust gases can be reignited. This goes for carbed engines. Also an engine always goes to the rich end during acceleration and deceleration. mash the throttle and let off. During both the uptake and downside the engine is rich by design thus giving the flames. the only time you wouldn’t have any is when it is just idling or while you are just cruisin down the road.

Posted at 12:21 pm on Mar 3rd, 2006 by chevyman

Propane has been done, And as far as I can tell it is safe since you will be pushing the propane out with the force from the exhaust.

Posted at 12:36 pm on Mar 3rd, 2006 by John

yeah I have done a few things like this
even with a efi system you can tune you
idle to run rich you just need a multi meter to watch your O2 sensor then adjust your idle fuel
or if you have a Mega squirt or any other
standalone EFI computer can be programmed witha rich fuel map for just such fun things maybe I’ll
when the new side dumps on my mud truck are done I’ll make a slightly rich map on my Mega Squirt and light it up get some nice side lighting not really for use while 4×4ing I wouldn’t want to light the forest on fire

Posted at 1:35 pm on Mar 3rd, 2006 by Rob

What’s with the alleged polarity of the resistors (red end vs. gold end)? Where did that come from? Resistors have no polarity.

Posted at 1:43 pm on Mar 3rd, 2006 by Lou

I love how he points out that it matters which direction you install the resistors. Is there such a thing as polarized resistors? Ha. I guess you learn something new every day…

Posted at 1:59 pm on Mar 3rd, 2006 by levi

I did something similar, quite by accident, with my car. It seemed that one of the plugs wasn’t firing. So all that unspent fuel got dumped into the catalytic converter as I was driving. Which is where it ignited and caught fire.

I was driving around town with a RED GLOWING HOT catalytic converter. When I parked it and discovered a strange smell, I was sure the car was going to blow.

But nope. The red hot metal eventually cooled and everything was back to normal again. No explosion. No long term damage that I was aware of. (Except, perhaps, for less treatment of my exhaust.)

Posted at 4:15 pm on Mar 3rd, 2006 by Mantari Damacy

VW bug exhaust hack:

While going down the freeway, put in the clutch and turn off the ignition. Pump the gas pedal several times to make the accelerator pump in the carb pump in a bunch of extra gas- which flows through to the exhaust uncombusted. Turn the key back on and let the clutch out. Boom!

Just make sure you budget for a new muffler.

Posted at 4:28 pm on Mar 3rd, 2006 by paul h

last time i checked flame throwing exhaust pipes arent street legal.

Posted at 5:08 pm on Mar 3rd, 2006 by Cyrix

this mod is somewhat legal, provided that it does not produce excessive noise.

the legal problems actually come when you add fuels to your exhaust pipes, probly wy he just didn’t take the easy route and use propane

Posted at 5:34 pm on Mar 3rd, 2006 by pretorious

That depends on the state pretorious, a few have wording so vague even a backfire could get you tagged if it produces a visible flame.

Posted at 6:48 pm on Mar 3rd, 2006 by Munky

I’m pretty sure this isn’t street legal in any state

Posted at 11:00 pm on Mar 3rd, 2006 by matticus66

I should do this on my other car, a Triumph Spitfire. Make the car truly live up to its name.

Posted at 12:47 am on Mar 4th, 2006 by BigTeebo

And it will be perfect add somthing like this
http://www.shoplaser.com/PRODUCTS%20-%20Exhaust%20Tip%20Spinners%20-%20ShopLaser.com.htm#TURBINE
for artificial day.

Posted at 3:32 am on Mar 4th, 2006 by choral

Couldn’t you connect a switch to the spark plug in the exhaust so it doesn do it all the time? My father-in-law did this back in the day, think he just ran a spark plug in the exhaust line for acc/deaccelaration lighting.

Posted at 9:19 am on Mar 4th, 2006 by jstem

This will also work in an EFI car. If the catalytic converter has been removed (replaced with a straight pipe or the like) and you place a spark plug in the exhaust tip or before it should ignite the unburned fuel…assuming you aren’t running too lean. Also, I have only seen this work on a turbocharged car, not that it should matter.

Posted at 8:52 am on Mar 5th, 2006 by Aaron

anyone got any idea of how much more environmental damage
this mod will inflict over using an un modded car ?
How does this work with catylitic convertors ?

Posted at 9:54 am on Mar 5th, 2006 by amias channer

I made one of these for diesel trucks. I used a propane system and a taser for ingnition (spark plugs foul with diesel smoke). I got 10 foot flames with the flow set on high. I will post pics when I get to my other computer.

Posted at 6:39 pm on Mar 5th, 2006 by Mark Umpirowicz

This mod actually CAN be done on a fuel injected car, but one would require a specially made kit (yes, they exist, and in quite large numbers, too!), or a bit of know-how and time to do it themselves. Either that, or a Mazda RX-7, a car which normally runs quite rich and has been known to spit flames from the exhaust regularly all by itself.

Posted at 3:20 pm on Mar 6th, 2006 by tennisd

This was shown using propane the very first build for the monster garage on discovery channel (the Lawn mower car)

Posted at 9:06 pm on Mar 6th, 2006 by Jonathan

i’m not sure… where are supoze to be connected the spark plugs??? help me pls because i’m a beginner (15 years old). thnx a lot

Posted at 6:31 am on May 26th, 2006 by Radu

i need to know where can i get step by step plans & what parts i need to install ppropane flame throwers on my 95 mark viii.

Posted at 9:13 pm on Jun 28th, 2006 by the blk knight

Does this little unit that you make continuously spark (like spark, wait a second, spark again, ….) or do you have to hook a wire up to the main engine coil so it tells this little unit when to spark?

answers- papawheelie@charter.net

Posted at 1:21 am on Jun 30th, 2006 by John fischer

i just built one and it seems that the power transmiters get hot and dont work again is this a common problem ive changed them but it keeps doing it ?
but its getting good flames though when it works
cheeers dave

Posted at 11:51 am on Jul 8th, 2006 by dave

I haven’t done any mods to my car as of yet, but I am planning on using the ‘un-burned fuel’ type of flamethrower to get some results. If you wire a secondary ignition coil into your car somewhere (preferebly close to the tailpipe, I’ll explain why in a bit) and wire one terminal on that to the battery. Wire the other terminal to a switch, and wire the switch to a ground somewhere on your car (slip the wire under a bolt that touches the chassis, or something metal would usually work.) What this will do is produce a spark every time you throw the switch on, then off again. It works this way due to the nature of the coil. The spark comes out of the HV (High-Voltage) output on the coil, and arcs to the ground on the car (i.e., almost any metal on the car, tailpipe, chassis, engine, ya know). The coil ought to be close to the spark-plug because pulses of HV electricity don’t travel as far as 12 volt battery-style stuff. Any more questions, just post.

Posted at 5:21 pm on Aug 19th, 2006 by Gravy Train

i am going to install an electronic cold start fuel injector into my exhaust that is supplied right from my fuel rail. anybody know if this is a good idea? also where should the injector and spark plug be installed into the exhaust?

Posted at 7:01 pm on Mar 19th, 2007 by dave

Hello Mate!! first thanks for the DIY information!!!
I built some and it seems that the power return to the transmiters and then don’t work again is this a common problem so I’ve changed them and include a diode but keeps doing it ? Could you please help me…
Cheers Mate!!

Posted at 5:19 pm on May 29th, 2007 by Oliver

Hello Mate!! first thanks for the DIY information!!!
I built some and it seems that the power return to the transmiters and then don’t work again is this a common problem so I’ve changed them and include a diode but keeps doing it ? Could you please help me…
Cheers Mate!!

Posted at 5:24 pm on May 29th, 2007 by Oliver

You can create a fuel injected system using a nitros injector. Depending on your app. Its a simple design. You don’t have to run your engine rich and can be used as either gas or propane. I built and designed mulitple systems and all work great. I designed a modified tailpipe to allow for expansion ( flame ) instead of having the common torch flame. Anyone looking for info is free to e-mail me for plans. If I get enough responses I’ll create a link to the info. I even added nitros to the mix but I found out it was a ” little ” too much for how I had it installed. Blew the exhaust right off the headers! Still working on that. I was told the wire schematic didn’t work by some people. They said it got too hot but I have never had any problems. Take a look at it and redesign it if you feel its needed. Let me know. Drop me a line at aryan900@yahoo.com. Put flame under subject so I know its not spam. Laterz

Posted at 7:55 pm on Nov 29th, 2007 by Ron

Hey, just hooked up an ignition coil and bolted it under my boot, connected that 2 the battery and earthd it, connected it to a spark plug in the exhaust tip and a switch in the dash. that works sweet. also put it switch in the dash which turns off all spark plugs in the engine, which should mean id pump raw fuel through my exhaust? spent a lot of time on this but cant seem to get any flames :S please help?

Posted at 7:32 am on May 1st, 2008 by James Manning

Idea is right, circuit description has some mistakes though. This circuit could be improved upon a little bit. A rubber grommet is a MUST when running wires through a metal chassis. This mod as built does not interrupt the spark from the engine therefore the only fuel in the exhaust is what did not burn during combustion. If you wanted to interrupt the engine spark its easy with an MSD AL6, or AL6-2 select a low value for the 2step rev limit hit the rev limit swtic and rev the engine and it will randomly drop the spark from 1 cyl. The same cyl will never be dropped twice in row to prevent the washing of oil from the cyl walls. “raw unburnt fuel” (Sounds scary dont it?) is in you engine for 2 out of the 4 cycles anyway…

Oh and to the guy who put a switch to the ignition coil and the battery, and rigged another switch to cut all the spark plugs. If your still alive… There is an infinite to list the reasons why you should put this project down.

Posted at 4:59 pm on Feb 9th, 2009 by Tom