Question about exhaust popping!

[timmygogdon]

So I raced my Supra for the first time today and I noticed that the engine started popping when I started braking, is this normal? I put a full tank of gas before so could it be I had too much fuel?

The popping wasn’t like bad or anything and I couldn’t test it further but it only happened when I braked. Just wondering if this is normal!

I had nothing done to the car all stock 2021 3.0 premium. I know that the exhaust can pop but I thought that was only with a tune?

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[zrk]

The car was in auto mode? It will definitely pop out of the exhaust quite aggressive while downshifting.

 

[timmygogdon]

The car was in auto mode? It will definitely pop out of the exhaust quite aggressive while downshifting.

Yeah I wasn’t using the paddle shifters and it wasn’t like a drag race or anything pretty sure i only went like 100. just never went that fast or heard it pop before haha and also i was in sport mode

 

[Loco38SUP]

That sounds like normal A90 music, enjoy it.

-RJM

 

[timmygogdon]

That sounds like normal A90 music, enjoy it.

-RJM

ty! just wanted to make sure it was normal

 

[XtremeMaC]

Almost sounds like you were not even in Sport mode???

 

[timmygogdon]

Almost sounds like you were not even in Sport mode???

I was in sport mode! Also watched some youtube videos of the exhaust sound and the popping happens in all of them. just wasn’t used to hearing it at all since i’ve never really accelerated in the car like i did tonight

 

[timmygogdon]

so just to clarify other people get the popping noises too right? i overthink a lot and wanna make sure i didn’t break anything lmao.

i was in sport mode, accelerated to about 100, didn’t use the paddle shifters and then slowing down is when the popping of the exhaust happened so i’m assuming it’s normal?

 

[YellowJacket]

so just to clarify other people get the popping noises too right? i overthink a lot and wanna make sure i didn’t break anything lmao.

i was in sport mode, accelerated to about 100, didn’t use the paddle shifters and then slowing down is when the popping of the exhaust happened so i’m assuming it’s normal?

Yes this is normal. You can rest easy and enjoy it!

 

[puzzled]

Supra is singing you a tune with burps and farts and pops..

Hummm... that does not sound very elegant..

 

[_Sp1ral0ut]

The sweet songs of the Supra sirens are indeed enchanting. I smile every time it happens.

 

[zrk]

is this normal? I put a full tank of gas before so could it be I had too much fuel?

The popping wasn’t like bad or anything and I couldn’t test it further but it only happened when I braked. Just wondering if this is normal!

I had nothing done to the car all stock 2021 3.0 premium. I know that the exhaust can pop but I thought that was only with a tune?

Yes - very normal. Nothing to see here.

Fuel is fine. you can't fill it up too much

You can make the pops louder and more prominent with a tune, but please don't - that shit is obnoxious as fuck.

 

[SupraDC]

Ohhhh yes...... wait til he gets the fart...


BRRRRRT.......BRRRT......BRRRT!!!!

 

[timmygogdon]

LOL thanks for all the replies! i heard a tuned supra with lots of pops and i doubt i’ll ever do that, too obnoxious for me

 

[Thraxbert]

The pops and bangs are generally normal for high-performance vehicles, but there are factors that can moderate or exacerbate their presence.

First and foremost, let's talk about the origin of a pop:

The engine's computer is constantly blending an optimal mixture of air and fuel to achieve the right ratio for however hard you're pushing the engine. For example, idle and cruising is often 14.7 parts air to 1 part fuel, also known as a 14.7:1 ratio. Cars going to full throttle usually like to be between 11.5:1 to 12.2:1. The higher the first number, air volume is increasing relative to fuel volume. The lower the first number, fuel volume is increasing relative to air volume. You'll notice that the car moving into full throttle increases fuel relative to air intake (the ratio gets smaller), because a heavier supply of fuel is required to move the engine (naturally) but also because fuel has cooling properties that can keep the engine block cooler under heavy load.

So, now we know the engine increases fuel by a lot under hard throttle. We also know the computer is constantly seeking the best ratio for what's happening with the gas pedal.

Free Range, Organic, Non-GMO Pops: When you suddenly cut throttle on decel, it's easy to encounter a scenario where the car was dumping fuel for high engine load and was gulping down air from the intake to mix and burn that fuel... but that's not what the combustion chambers need anymore. Now there's way too much fuel relative to the air coming in. In such cases, the excess fuel escapes the cylinders through the engine block exhaust ports and detonates somewhere in the exhaust system because the exhaust is hot enough to ignite the fuel. Is this damaging? No. Not really. There's a very small quantity of fuel producing this combustion, and your exhaust is nothing if not a big echo chamber. We'll call this the "natural" way of producing pops and bangs, and their quantity+decibels can increase with wider exhaust diameters and fewer restrictions like resonators and catalytic converters.

The Splenda of Pops: The _other_ source of pop is an artificial one, sometimes called "fuel dump and timing retard." Engines operate in four strokes: suck, squeeze, bang, blow. Suction takes in air + fuel to the cylinder, squeeze compressed the air/fuel mix at the top of the cylinder under incredible pressures, bang is the spark plug detonating the compressed air/fuel mixture, and blow is the engine opening valves to evict the gases from compression into your exhaust. In fuel dump and timing retard, the car's computer is deliberately programmed to add extra fuel during suck and to delay ("retard") the timing of the sparkplug during bang so the blow stroke deliberately has unburned fuel and/or the air-fuel mix is still combusting as it leaves the valves. It's the same effect as the natural pops and bangs: unburnt fuel is detonating in the exhaust system. But this time, the engine has been deliberately programmed to trigger this condition when the user lifts off the throttle. The strength of the bang just depends on how aggressively this function was tuned, and how much throttle you're coming off of. Since the user is already coming off the throttle, the performance loss of firing the sparkplug late doesn't really matter.

The Supra has both of these. A high-flowing 3.5-4.0" catless exhaust will absolutely have its own pops and bangs. But the burble you hear on an OEM car is almost entirely artificial. That's neither bad or good, it just is and everyone has their own opinion on it.

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