Make exhaust shoot flames
 

Ok for the theme we are going for in the miata lemons car i'm putting to togther one of the ideas needs the exhaust to be able to throw flames. I know the computer in stock form with the cat can't do this and it can really only be done well on carburated cars. Is there a way to richen up things enough to where they don't effect how the engine runs but would make me be able to shoot flames? Maybe some 305cc injectors? I would be removing the cat.

install a spark plug in the exhaust....

Not just a spark plug, but an injector upstream of the spark plug.

If you do that you won't have to worry about screwing up your engine's tuning at all.

Why scare the competition when you can burn them to a crisp?

Install a spark cut rev limiter (like Bee*R racing, MSD) and set it below the factory fuel cut limiter. Then drive around bouncing off the limiter, you'll make flames and scary loud pops.

At stock form just installing a spark plug in the exhaust with the cat removed will not make it really shoot flames. I was thinking something like an injector or a nozzle like in water injection and have a seperate small gas tank just for this.

Wow, for a first post, I get to relatively inform! For reference, my Miata with a JR/Sebring supercharger, full exhaust with no cats, MSD boost cut/retard box, and a voodoo box on 93 will shoot flames. But I also have it tuned rather conservatively which is what makes this happen. The idea behind flames is that there is leftover, unburnt fuel in the exhaust, coming from off-throttle or part-throttle tuning. Ideally, there would never be any unburnt fuel, but thats nearly impossible. When you again go to full throttle or part-throttle in some cases, the flaming exhaust reignites these fuels and causes a fire ball. Leaner mixtures, 13:1+ typically won't do this simply because there isn't enough fuel to start with. Turbo cars with lower compression and lower AFR's do much more often. Thats not the reason though per say. Timing is the critical key to shooting flames. Stock timing is optimized to burn as much fuel as possible resulting in better MPG. Turbo timing is typically retarded quite a bit from NA tune, which as a result leaves much more unburnt fuel. Touring cars with NA engines are the same, as they retard timing to conserve power and longevity of the engine, considering the fragile state they are in to begin with.

So there are a variety of solutions. Assuming its on 24 heures du lemons car, you probably won't have any forced induction. So typically you make up the power of retarding the timing by increasing boost (kind of a net nothing trade off). Also assuming you don't have an aftermarket EMS that allows specific fuel trims and timing, you're kind of crap out of luck. The factory ECU isn't spitting enough fuel for there to be much leftover to burn. I'd try bumping the factory timing (I think you have +/- 10 degrees) all the way to full retard and see how crappy she performs. If you can't feel a noticable difference in power, run a really short side pipe of some sort, and throw a flame kit on it for craps and giggles. Maybe buy a voodoo box or some equivalent and throw as much fuel in as possible, retard it out, and hope for the best.

all the cylinder wash wont be good for a 24 race, fwiw.

and a propane feed.

Get a rotary.

My srt would shoot flames with 682 injectors and a 3" catless exhaust. Most turbo cars with a 3" catless exhaust will shoot flames.

now there is an idea.........that would be constant pressure and make the flame uniform. Now i need to rig something relatively small, say a 33 lb bottle where the passanger seat goes and we will have exactly what i am looking for. lol.

But seriously, is there any chance to be able to shoot a flame with nothing other than removing the cat?

it sounds like mine shoots a fireball sometimes, but i have never had anyone watch for one at night to know if it actually does. i can shoot flames on my bike, and the miata will make the same exact sound.

Before i fitted the SC i just removed me CAT and me car flamed on throttle close pretty much every time when the exhaust was hot.

Attachment 209687

Now me cars tuned correctly no flames.

If the cars stock then just remove the CAT and O2 sensor.
Car i'll run pig rich and once the exhaust is not it'll ignite on overrun/closed throttle.

Just a1 word of caution though i eventually busted me weld seams.


Cheers
Mark

No.

Its usually done with propane or gasoline. Mostly propane though because you can get it in tanks that come in a variety of sizes and a variety of nozzles.

Going to be honest........thought you were joking about the propane. Makes sense, but thought you were joking.

+1

easy if u have an ecu u can tune on my evo i setup a type of anti lag and it shot flames everytime i let off the throttle and if i was really beating on it it would shoot long blue flames from the methanol. even idling sometimes after driving hard the anti lag and meth would have a afterburn lol and a flame would just chill there for a few seconds after i stopped and the turbo timer was on haha. basically on throttle lift if u go by load values vs rpm tables in the spark maps just retard the timing by like -10 or more and u will get loud pops and flames since it'll will be sparking on the exhaust stroke lol thats BASIC antilag. not very good for anything in its way headers, turbo, welds, bolts etc. haha but its pretty damn cool.

I'm going to say lemons would have a rule against this for saftey...

what year is said miata?

I take it you didnt get the memo. The internet is serious business ;)