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Discussion Starter #1
Recently I noticed a lack of throttle response at or below 2000 rpm in my M6 AT. The vehicle has just done 40,000 miles. What could be wrong?
 

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Got the AC running? That'll instantly wipe about 20% off the car's power.
 

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Discussion Starter #3
Phew!!!....20% at what rpm?
 

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Discussion Starter #5
Across the board. You're just going to feel it more where power is already low.
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Makes sense...it ruins zoom zoom feel below 2000 rpm 😭
 

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Let's be honest, there isn't much zoom zoom under 2k RPMs in the 3rd gens anyways lol.
 

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Discussion Starter #7
Let's be honest, there isn't much zoom zoom under 2k RPMs in the 3rd gens anyways lol.
85% of peak torque available at 2000 rpm...should be good enough to weave through traffic in 3rd gear 😁
 

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Head pressure goes 'way up when it's hot... and as such a/c hp draw goes 'way up. Happens with any and all cars...
 

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Discussion Starter #11
Also, the ECM pulling timing on hot days will make the car feel lethargic. Using Premium fuel helps with that.
Sounds interesting...Can u explain please ?
 

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Discussion Starter #12

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2016 Mazda 6 Touring AT, coilovers 1.2" drop, OVTuned, Injen CAI, Thrush Exhaust
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If it's hotter higher octane can help as it may be reducing timing to prevent knock (you can monitor with OBD reader 'knock retard timing'), try putting some higher octane and see if that makes a difference for you...
 

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85% of peak torque available at 2000 rpm
Engine torque isn't what moves you, engine power is what moves you. That's why an engine with a completely flat torque curve accelerates the car faster at higher rpm; same torque, but much higher power output. If you're looking at the drive axle (or the tire), then go ahead and look at torque. When looking at the engine, power is what's relevant. The transmission exchanges between speed and torque for you.

So, to make sure this stays on-topic: The A/C system robs a certain amount of power (probably about 5 - 10 hp for the 6) from the engine. Like DrFeelGood said, when the engine is only making 25 hp, that's a big chunk! The A/C shuts off when you're at WOT, but pretty much anything less than that and it's a noticeable draw particularly at low rpm.
 

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Discussion Starter #15
Engine torque isn't what moves you, engine power is what moves you. That's why an engine with a completely flat torque curve accelerates the car faster at higher rpm; same torque, but much higher power output. If you're looking at the drive axle (or the tire), then go ahead and look at torque. When looking at the engine, power is what's relevant. The transmission exchanges between speed and torque for you.

So, to make sure this stays on-topic: The A/C system robs a certain amount of power (probably about 5 - 10 hp for the 6) from the engine. Like DrFeelGood said, when the engine is only making 25 hp, that's a big chunk! The A/C shuts off when you're at WOT, but pretty much anything less than that and it's a noticeable draw particularly at low rpm.
But please note...at any rpm, the accelaration is proportinal to the torque (read force=mass * acceleration)...and kinetic energy is proportional to power. The kinetic energy increases exponentially with velocity , thats why you need immense power to accelerate a vehicle which is already going fast.

For eg , the energy needed to accelerate a body from 60 mph to 90 mph is roughly double the energy needed to accelerate it from 30 to 60 eventhough the difference in speed is 30 mph in either cases.

Cheers...👍
 

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You're still conflating engine power and wheel torque.
Moreover, you might be forgetting that power is a way to express how much time it takes to accomplish work.

That is why, in terms of the engine, only power matters. Keep that separate from what is needed at the wheels. The engine's job is to supply power (including to the A/C compressor). The transmission's job is to make an essentially free exchange between speed and torque at the wheel, in order to deliver the power in the most appropriate way.
 

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Discussion Starter #17
Please realize that power is proportional to the product of Engine torque and engine rpm. Power is also propotional to the product of wheel torque and wheel rpm.

From torque and rpm you calculate power. Hence torque is more fundamental than power.

Cheers..👍
 

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Power is how long it takes to do work. It is the only relevant thing to acceleration or the accomplishment of any other task.

If you lose sight of the ball, it’s very easy to get confused.
 

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In racing parlance, horsepower is how fast you're going when you hit the wall while torque is how far the wall moves after you hit it.

Sent from my SM-G960U using Tapatalk
 

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In racing parlance, horsepower is how fast you're going when you hit the wall while torque is how far the wall moves after you hit it.
I've heard that before and it's such a good analogy.
 
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