WTF Is Rolling Coal?
Originally only found in truck-based motorsport, rolling coal has become a modification found in many road-going trucks in a stand against any form of eco-friendly motoring. These systems have now also made their way into the modified car scene, so here’s a quick explanation of what is going on behind the scenes of these smoke-billowing crowd-pleasers.
Rolling coal is the combination of throwing a large amount of fuel into the engine’s cylinders along with the bypassing or removal of the emission control devices further downstream. By flicking a switch rigged up on-board to the ECU, the air/fuel mixture can be made extremely rich, pushing it past the optimum combustion condition called the Stoichiometric ratio. This richer mixture (below 14.6:1) subsequently creates more particulates within the exhaust gases, otherwise known as soot.
The EGR (exhaust gas recirculation) valve controls the amount of exhaust gases that are recycled back to the combustion chamber to help absorb unwanted emissions from the post-combustion gases. However, in rolling coal setups, the EGR valve can be bypassed using aftermarket kits. Couple that with the removal of the catalytic converters within the exhaust system and you have virtually no control over the emissions coming from the engine, thus resulting in huge billows of soot emanating from the tail pipes.
To finish off potentially the most-obnoxious modification known to man, straight-piped ‘smoke stacks’ can be fabricated directly behind the truck’s cabin or even as straight-up chimneys protruding from the bonnet, making sure there is no dilution of the exhaust gases immediately after combustion.
Originating from the sport of truck pulls – where large trucks compete to see who can drag the heaviest load – rolling coal was designed as a grand show of horsepower and torque in these most American of gladiatorial battles. But the trend has swiftly made its way into road trucks.
Unfortunately, the US Government deems any form of emission-control tampering illegal under the Clean Air Act. If all the videos on YouTube are to be believed, it seems most rolling coal systems are normally only used in rare Prius-scaring situations, therefore switching off any bypass valves should see a truck successfully complete an emissions test. So just don’t get caught smoking out some poor hybrid driver by the local law enforcement and you’ll be just fine!
Comments
Taking overcompensation to a whole new level
How to diagnose Micropenis
like lowering the car installing anti lag or shooting flames,stupid kills the cat but some people think it’s “cool” right
Anti lag isn’t just for flames, you get a flame kit for that
This thing rolls coal straight outta the dealership
In finland we call it voimasavu = powersmoke :D #oldturbodiesels
The problem is when the assholes do this right next to you when you have your window down.
cumstang. nice.
stil better than ibiza’s in portugal
The majority of your write up is accurate, but you are wrong on a few major portions of it.
1) With regards to pulling trucks, the smoke is not a grand show of power. It is the byproduct in the quest to find torque. It is the result of maxing out the fuel pump and dumping as much fuel into the engine as possible in order gain every single bit of power you can to beat the next guy. This is also true of drag trucks.
2) Most of the diesel heads remove the EGR, it’s not for the purpose of rolling coal but simply because it robs power. While my truck is too old to have a EGR, if it had been on the engine it would have been deleted.
3) As with the EGR, most of us are not deleting our cats to roll coal. Rather when we upgrade our exhaust systems, cats are an added unnecessary cost. You think replacing the cat is expensive on your daily driver? Trying finding one for a 7.3L PowerStroke that is 4” in diameter. I am lucky enough that my truck’s previous owner saw the value in it and had them install it when the 4” turbo back exhaust was installed.
4) Not every truck that is spewing black smoke is rolling coal. My 2000 Ford F250 will pour out some serious smoke if I want, with only the addition of a 100 horsepower tuner (Your right foot does have to be buried pretty far in her). Still have all the emission controls, still have a cat and I can still pass the bi-yearly CA smog test.
The take away from this is please don’t let a few bad apples speak for the group as a whole, just like we don’t judge you on your unnecessarily cambered wheels. We are not all wanabe redneck tools. Most of us are in the pursuit of power same as you.
It is a $4000 ticket in the State of North Carolina if you roll coal.