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Turbo exhaust brake on gasoline motor?

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Old Oct 1, 2007 | 04:12 PM
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hooohaa2's Avatar
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Default Turbo exhaust brake on gasoline motor?

I'm actually thinking of doing this, not just wondering for the sake of wondering.

Diesel motors use either a jake brake or an exhaust brake to basically turn the motor into an air compressor when engine braking. Gasoline motors use a throttle plate to block air when the accelerator is let off, causing the motor to expend energy in the opposite way.

I'm wondering if adding an exhaust brake to a turbo on a gasoline motor would help with engine braking, or if it wouldn't make a difference since the throttle plate is already restricting air under engine braking conditions.

Another thought is that the exhaust brake might help spool the turbo back up when going from the brake to the accelerator pedal, since those compressed exhaust gases would pass through the turbine as soon as the exhaust brake was opened. If I were going for this effect it might be better to create an exhaust manifold with more volume.

Old Oct 1, 2007 | 04:50 PM
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Default Re: Turbo exhaust brake on gasoline motor?

good thought and all but why not just brake boost if your tryn to build boost better ?
Old Oct 1, 2007 | 05:18 PM
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Default Re: Turbo exhaust brake on gasoline motor?

I want engine braking more than I want to build boost. That was just a secondary benefit.
Old Oct 2, 2007 | 03:12 PM
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Default Re: Turbo exhaust brake on gasoline motor?

I've '07 yamaha R6's have exhaust brakes.

@least thats what the look like in the exhaust system
Old Oct 2, 2007 | 04:13 PM
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Default Re: Turbo exhaust brake on gasoline motor?

Thought this topic would have provoked a little more discussion than this here.
Old Oct 3, 2007 | 04:31 PM
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Default Re: Turbo exhaust brake on gasoline motor?

Why the ---- would you want to "increase engine braking"

On a gasoline engine powered street car whose 'wheel' brakes are adequate, what need do you have for this? Not to mention the fact that most gas-powered engines dont have the rotational mass of a diesel.

Honestly, do you drive down alot of hills all the time with your *** end loaded up with lead bricks

BTW engine braking is not exactly a good thing for your engine. Disk brakes and pads are cheaper than motors.
Old Oct 3, 2007 | 05:11 PM
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Default Re: Turbo exhaust brake on gasoline motor?


I don't think you guys have any idea how complex it would be to add an engine braking system.

You are talking about adding some sort of actuating system usually driven by oil pressure to open the exhaust valves. This is usually placed between the head and the valve cover.

Engine braking is where on the compression stroke, the exhaust valve is opened, thus preventing the rebounding effect on the compression stroke and making the engine do more work.



Originally Posted by Hitchhikkr
BTW engine braking is not exactly a good thing for your engine. Disk brakes and pads are cheaper than motors.
Engine braking is not harmful to an engine.

Old Oct 3, 2007 | 06:28 PM
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Default Re: Turbo exhaust brake on gasoline motor?

Originally Posted by Hitchhikkr
Why the ---- would you want to "increase engine braking"

On a gasoline engine powered street car whose 'wheel' brakes are adequate, what need do you have for this? Not to mention the fact that most gas-powered engines dont have the rotational mass of a diesel.
Nor anywhere NEAR the compression....
Old Oct 3, 2007 | 06:55 PM
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Default Re: Turbo exhaust brake on gasoline motor?

Originally Posted by MADMAX
I don't think you guys have any idea how complex it would be to add an engine braking system.

You are talking about adding some sort of actuating system usually driven by oil pressure to open the exhaust valves. This is usually placed between the head and the valve cover.

Engine braking is where on the compression stroke, the exhaust valve is opened, thus preventing the rebounding effect on the compression stroke and making the engine do more work.



Engine braking is not harmful to an engine.

I'm pretty sure he didn't want a jake brake, more like an exhaust brake. A flapper of some sort that increases backpressure by a ton put in the exhaust.
Old Oct 3, 2007 | 07:28 PM
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Default Re: Turbo exhaust brake on gasoline motor?

Originally Posted by Hitchhikkr
Why the ---- would you want to "increase engine braking"

On a gasoline engine powered street car whose 'wheel' brakes are adequate, what need do you have for this? Not to mention the fact that most gas-powered engines dont have the rotational mass of a diesel.

Honestly, do you drive down alot of hills all the time with your *** end loaded up with lead bricks

BTW engine braking is not exactly a good thing for your engine. Disk brakes and pads are cheaper than motors.
You are a moron. I have plenty of good reasons to want more engine braking. And please go tell a trucker that engine braking is bad for a motor. See how he responds.

You have nothing to add to this discussion, besides misinformation.



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