Flames on decel
 

Excuse the rice question. And yea I know this could be bad for the engine/turbo/rear bumper blah blah, I'm just curious.

I've seen clips and stuff of cars where when they lift off the throttle, there's a fireball/flame that comes out the exhaust. But it's not like those gunshot BMW -10 ignition retard BS or 2-step. It's just a quiet and subtle flame that comes out of the exhaust. What causes this? Super rich overrun? I've gotten my car to just burble and pop here and there but as far as I know, there's no flame. Is it just that the exhaust is so hot, the fuel that gets passed through ignites in the exhaust system during overrun?

Here's a couple of clips of the flames:

https://www.youtube.com/watch?v=gsMP...outu.be&t=1047 - quiet and subtle, maybe cause its a rotary TIME; 17:37

https://www.youtube.com/watch?v=eEvj...outu.be&t=2180 - quiet? Music drowns out TIME: 36:20

probably depends a lot on your exhaust setup too -- I see 3" but do you have a cat or resonator and what muffler are you running -- or str8 pip3. I would imagine you are on the right track with overrun, but timing retard could definitely make it help too, not necessarily -10 but

tell us more about your setup. Youll get flames either way, either flamed here on the forum, or flames out your tail pipe...... time will tell

Straight through muffler, dynomax race bullet. Yah I figured timing retard helps make flames but I was under the assumption that retard makes more of bangs and real loud noises. I guess maybe if you retard it just a little it won't be so abnoxious.

Thread is too retarded ;)

:rofl: Yeah, I know. Was just on the mind wondering how it works

NOS injection in exhaust with an ignition system should work.

Sounds like cheating to me :jerkit:

I like pops and bangs, so sue me. I built my car to be cool. Pops and bangs are cool.

spark cut launch/flat shift
spark cut revlimiter

I only turn on overrun under like 2% throttle. So I can de accelerate, give it just a touch of throttle and pop pop balm blam blam.

this combined with natural rumble of big cams sounds badass.

if you want to be an arse, set up a switch to enable spark cut rev limit at like 2k. Rev up and flaaaame ooon.

Ya I've got some pops and bangs on decel. No big flames as far as I can tell. Spark cut sounds nice but I don't think my stock block and turbo like it very much...

You missed the big one, and it's air.

Hook up one of those old electric emissions pumps to your exhaust and set it to switch on below so much MAP, then fatten the fuck out of the low MAP cells. It will flame, pop and bang. Like a SV650 without a marble shoved in the pear....

Or keep your foot on like earlier, or try and tune the MS3 idle valve so it's not retarded.

Wouldn't leaning out the VE cells in the overrun areas have a similar effect?

Not if you want flames out the back, it does make a popping noise though

Yah I've gotten the burbles and stuff with leaning it out. Maybe I'll mess with richening the hella out of it and see what happens.

Start at 39 seconds in:

Classic. I'll make sure I end my exhaust inside the rear bumper area so I can get mad internet views.

https://cimg0.ibsrv.net/gimg/www.mia...56ae62a7db.jpg

--Ian

Can't let my dreams just be dreams

Karma's a bitch.

I wish I could find the post... It was from several years ago. Someone here did an exhaust system that dumped right around the differential. Melted the whole bumper cover.

https://forum.miata.net/vb/showthread.php?t=233272 I found this on miata.net :giggle:

I'm glad I fabbed up my 3" system. My exhaust was dumped right at the diff for serval months...