Shooting flames..all in the tune?
 

With all the rave of guys getting launch control/2 step units.Some just plug n play and go..others are highly modded cars with a tune. I see lots of guys shooting large flames and banging popping effects.Which ofcourse always gives the wow cool factor but how safe is that on the internals? I assume that with the unburnt fuel and having it ignite can eventually shorten life somewhere on some components. My setup with using an msd 2 step and now a lingenfelter box never shoots flames no matter what rpm its set too. My tuner has mentioned that he tunes boosted cars to be cleaner/safer on decel to prevent lean pops etc. My car hits 2 step and cleaner builds boost without all the loud bangs or flameage. Id love to see my car do it but not if its risking failure of my motor.

Whats all involved in the tune that gives this dramatic effect while on the launch control?

Retarding the timing (and or partially cutting spark) and richening the mixture during the "2 step event" is what makes fire.

Here is the info I found on the topic, but my application is a cammed NA LS3 in a C5

https://ls1tech.com/forums/pcm-diagn...t-2000-c5.html

Think about combustion, piston comes up, mixture gets compressed, spark, out the exhaust. What if you make the spark really late, and add extra fuel, yep you're allowing the combustion bang to go out the exhaust valve/pipe before the process completes. Not sure how this effects engines internals but having a raw combustion process taking place in the pipes and turbo can't be good for them, but is exactly why it makes the turbo spool. Double edged sword.

True,in my head..doing it that way can lead to burnt exhaust valves and build up carbon faster. The launch control isnt adding more fuel and my tuner has assured me its not tuned to act in this fashion. i got build almost 6psi with the lingenfelter box and it leaves hard. Doesnt crack the theactrics everyone assumes should happen when i get on the 2 step

probably won't hurt it as long as you dont sit on it for a solid minute straight like the damn subaru vape-heads around here do

Yeah, Im all for common sense. There is way too many people on a two step, if it hurt shit nobody would be doing it. Use with discretion, get on it when needed to stage and that's it. Only in short bursts makes sense as heat takes time to build right? Really no different then loading a converter at the line. Wanna piss off an old school guy? Let him stage and get up on the converter and then something happen where the tree doesn't fall. Trans overheats real quick. They have to back off at some point or burn the trans up. I figure a two step is the same thing.

flames on deceleration is excessive fuel still being injected with almost no timing, in most cases negative timing on the coast down. the fuel is compressed by the piston but the spark ignites it so late that the burning mixture is pushed out the exhaust. with too much fuel and it being ignites post TDC the combustion process is lengthened in time allowing it to still be in progress as the piston pushes the cylinder contents out the exhaust. bigger flames..... more timing retard and more fuel.

flames on 2 step.... 2 step is typically to build boost on the line for a turbo car. excessively rich AFR, whilst hurting power and torque cause the turbo to spool faster. simply because more fuel being combusted, the greater the volume of air created when the cylinder mixture is combusted and heated. the cylinder mixture expands from the heat and is consequently a greater volume that now needs to pushed out the turbine while, the more gas volume pushing on the wheel the faster it will spin. add to this retarded timing.... again allowing the cylinder mixture to be combusting and in turn rapidly expanding as its entering the exhaust system. the combination of those two things make the turbo spool much faster than normal. its not uncommon to see a 2 step of 4200rpm, 10.5:1 AFR and -6 degrees spark. that will make it blow huge flames. the addition of alcohol based fuels make the flames bigger and different colours.

its terrible for the pistons, rods and bearings.... but given its limited use in a race application its not all bad.

use it all the time on a street car and you can crack ring lands, bend rods and bruise big end bearings

nah the only thing 2 steps used as an anti lag can hurt is exhaust valves and you gotta be really trying

Please spend your time learning how to make your car better, instead of learning to waste time keeping up with posers who have a need to be noticed. I promise the extra knowledge you gain will make your car faster/better handling/ easier to live with. People who cannot do that shoot flames out their ass to make up for it.

It's about the GO, not the SHOW.....

I like a nice anti lag flame now and again. Nothing wrong with doing mods for strictly aesthetic reasons...we all do this for fun anyways

I wasnt asking for the sake of trying to achieve it.just understanding the events in the tune that cause it to happen because i know my tune was setup not to produce such events as best as possible. I wasnt sure that to guys who do make such large flames and 2 step battle their cars all the time..if its worth the show for the damage it can create.

I only use the 2 step at the track for the most part. Ive had my car 11yrs with many different setups,I got the 2 step for launch control..not for the show scene.Dont mistake that Im trying to keep up with posers to make up for not having a quick car.i get more ppl asking if something is wrong with my car since it doesnt shoot flames on a 2 step for the power it makes..youtube has people twisted for rev battles..popping.flames these days.

Apparently I misunderstood your reason for asking the question. Shooting flames out of the exhaust is wasted energy that should have been absorbed by the turbo. With a 2 step or an antilag setup the fueling is increased while decreasing the timing in order to burn fuel in the exhaust. This pressurizes the turbo more than would otherwise happen. The easy hack way of doing this is just to cram in fuel and kill timing in bulk amounts. This leads to shooting flames out your ass. Flaming exhaust pipes are a sure sign someone did not spend enough time optimizing your tune.