2017 BRZ Performance Package Impressions

[JSube]

Originally Posted by Tcoat

Yep. The design is similar but that is more due to the nature of the engine than Porshe being involved. There is a really good write up on the development of the Subaru engine that they put out a few years back. They specifically speak to the fact people frequently say Porsche was involved. I will see if I can dig it up.

Just found this, don't know if it's the same article you're thinking of. Subaru's made over 11 million boxer engines, starting in the 1960s!

http://www.revvedmag.com/engine-tech...boxer-engines/

This is written more info-heavy, less of an advertisement-

http://www.superstreetonline.com/how...-engines-work/

[Tcoat]

Originally Posted by JSube

Just found this, don't know if it's the same article you're thinking of. Subaru's made over 11 million boxer engines, starting in the 1960s!

http://www.revvedmag.com/engine-tech...boxer-engines/

This is written more info-heavy, less of an advertisement-

http://www.superstreetonline.com/how...-engines-work/

Well that is not the article I was speaking of but it does quot it and some sections are pretty much word for word.
It fails to mention that GM also developed their own boxer back in the 60s but dropped it partially because the North American buyers did not understand how it worked and didn't trust it.

[Gforce]

Originally Posted by Tcoat

Can get the same noise reduction from plugging it. I hate that noise.

I discovered not. I plugged mine but after the Supercharger install, which eliminates the noise maker, the noise reduction is quite obvious. The improvement also answers all those journalists who routinely complain about the FA20 uninspiring orveven annoying engine sound. Remove the juvenile noise maker completely and the characteristic Subaru engine note is revealed, which I rather like, sort of a refined old Porsche 4 cylinder roar.

The latest Eaton Superchargers are very quiet and I was surprised at how quiet the Subaru engine actually is. The best way to eliminate the noise from the intake noise generator is to take it off completely. There are kits, or were, to plug the big hole in the intake bellows.

[Gforce]

Originally Posted by Tcoat

Yep. The design is similar but that is more due to the nature of the engine than Porshe being involved. There is a really good write up on the development of the Subaru engine that they put out a few years back. They specifically speak to the fact people frequently say Porsche was involved. I will see if I can dig it up.

A few years back I read a technical paper published by Subaru in which they explained the involvement of Porsche in adapting Variocam to the Subaru engine. ACVS is pretty much identical to variocam. I didn't bookmark the page and now cannot find it again.

Here's a contemporaneous pr reference:

http://australiancar.reviews/Subaru_EZ30R_Engine.php

[Gforce]

Originally Posted by nikitopo

Superchargers still require to be at a certain rotational speed until they are able to produce maximum boost.

Technically, at idle, the Eaton type Supercharger can pump its full capacity of air into the engine. They do not compress the air and so, technically, do not create boost pressure. They supercharge by pumping more air into the intake than the engine could draw in. Turbochargers are centrifugal compressors which actually compress the air inside the turbo compressor housing.

Twin lobe Superchargers deliver linear intake pressures. Turbos produce pressures that curve higher as rpm rises.

To a point in both cases.

[Tcoat]

Originally Posted by Gforce

A few years back I read a technical paper published by Subaru in which they explained the involvement of Porsche in adapting Variocam to the Subaru engine. ACVS is pretty much identical to variocam. I didn't bookmark the page and now cannot find it again.

Here's a contemporaneous pr reference:

http://australiancar.reviews/Subaru_EZ30R_Engine.php

That link says nothing about Porsche. In fact it clearly says "Subaru's ACVS" They are capable of engineering without help.

Originally Posted by Gforce

Technicall, at idle, the Eaton type Supercharger can pump its full capacity of air into the engine. They do not compress the air and so, technically, do not create boost pressure. They supercharge by pumping more air into the intake than the engine could draw in. Turbochargers are centrifugal compressors which actually compress the air inside the turbo compressor housing.

Twin lobe Superchargers deliver linear intake pressures. Turbos produce pressures that curve higher as rpm rises.

To a point in both cases.

What? Wow. Just WOW. Full capacity at idle? Do not compress? Do not create boost? Do you know how superchargers work at all?

[Gforce]

Here's link describing the spring rate changes:

10% increase front, 15% decrease rear.

Other sources confirm that the rear roll bar is up 1 mm to 15 mm.

The description of the new rate dampers is picturesque and suggests higher rates in both directions.

https://www.motormag.com.au/reviews/...yota-86-review

[Gforce]

Originally Posted by Tcoat

That link says nothing about Porsche. In fact it clearly says "Subaru's ACVS" They are capable of engineering without help.

What? Wow. Just WOW. Full capacity at idle? Do not compress? Do not create boost? Do you know how superchargers work at all?

You did not read the sentence:

"Subaru's AVCS+ system was developed by Porsche and based on their own Vario Cam plus".

Subaru's system is practically identical to Vario Cam and produces remarkably similar torque curves. If Porsche did not develop Subaru's system they would have sued for patent infringement. Vario Cam is ten years older than AVCS so, yes, Subaru not only needed help from Porsche they asked for it.

As for understanding how positive displacement Superchargers work, yes I do. I have two. Your questions imply that you do not. Read up a bit and get back to me if you discover something new. Hint, PD "Superchargers" have been around since the 19 th century. Back then they were just air pumps used to ventilate coal mines. Engine builders in the early 20th century quickly discovered they worked well to pump air into engines. They don't compress. Boost pressure develops only in the intake manifold. Turbosuperchargers were first applied to engines in the Aero business and they compress the intake air, which is why they have a compressor. The air entering the intake manifold is therefore already compressed. The difference in how these two types of Supercharger work is obvious to the reasonably alert driver. Turbocharging variable rpm engines was unsatisfactory until SAAB developed computerized feedback boost control which everybody now uses. Even Superchargers have computer controlled bypass valves nowadays, instead of just dump valves.

You know my shoes are still dry....

[nikitopo]

[Tcoat]

Originally Posted by Gforce

You did not read the sentence:

"Subaru's AVCS+ system was developed by Porsche and based on their own Vario Cam plus".

Subaru's system is practically identical to Vario Cam and produces remarkably similar torque curves. If Porsche did not develop Subaru's system they would have sued for patent infringement. Vario Cam is ten years older than AVCS so, yes, Subaru not only needed help from Porsche they asked for it.

As for understanding how positive displacement Superchargers work, yes I do. I have two. Your questions imply that you do not. Read up a bit and get back to me if you discover something new. Hint, PD "Superchargers" have been around since the 19 th century. Back then they were just air pumps used to ventilate coal mines. Engine builders in the early 20th century quickly discovered they worked well to pump air into engines. They don't compress. Boost pressure develops only in the intake manifold. Turbosuperchargers were first applied to engines in the Aero business and they compress the intake air, which is why they have a compressor. The air entering the intake manifold is therefore already compressed. The difference in how these two types of Supercharger work is obvious to the reasonably alert driver. Turbocharging variable rpm engines was unsatisfactory until SAAB developed computerized feedback boost control which everybody now uses. Even Superchargers have computer controlled bypass valves nowadays, instead of just dump valves.

You know my shoes are still dry....

Yep imissed that statement. Not sure I believe it's accuracy though.

Not sure where you cut and pasted the SC stuff from but boost is boost. The history lesson is worthless

[Gforce]

Originally Posted by Tcoat

Yep imissed that statement. Not sure I believe it's accuracy though.

Not sure where you cut and pasted the SC stuff from but boost is boost. The history lesson is worthless

Your belief or disbelief in facts is irrelevant. If you paid a bit more attention to history lessons, and lessons in general, you might know more and write less.

Boost most definitely is not boost as you would know had you driven turbo and supercharged engines back to back, as I do on a daily basis. I've owned and driven turbo cars since 1984, my favourite drive ( though not owned!) was a 6.75 litre Bentley Turbo R. The most recent turbo engine I've driven (though not owned) is the Mclaren 12C twin turbo V8. I've also driven essentially the same engine in turbo and supercharged forms and the same turbo engine in both LPT (which is quite like a supercharged engine) and HOT tunes.

Shoes still dry, how're yours holding up under the downpour?

[thomasmryan]

I have the first version of the porsche Vario-cam and the first stateside version of Subarus ACVS parked in the driveway. The B9 has to think about what it's doing sometimes but both have a nice torque curve.

[Tcoat]

Originally Posted by Gforce

The beauty of adding the Eaton type Supercharger option is the engine isn't altered in character. Because it's just an air pump the supercharged engine behaves more or less like a 3.0 litre version.

Frankly, just deleting the intake noise generator from the stock engine reveals the true personality of this Subaru boxer. It is just as characterful and capable as any Porsche boxer engine.

Originally Posted by Gforce

Technically, at idle, the Eaton type Supercharger can pump its full capacity of air into the engine. They do not compress the air and so, technically, do not create boost pressure. They supercharge by pumping more air into the intake than the engine could draw in. Turbochargers are centrifugal compressors which actually compress the air inside the turbo compressor housing.

Twin lobe Superchargers deliver linear intake pressures. Turbos produce pressures that curve higher as rpm rises.

To a point in both cases.

Originally Posted by Gforce

Your belief or disbelief in facts is irrelevant. If you paid a bit more attention to history lessons, and lessons in general, you might know more and write less.

Boost most definitely is not boost as you would know had you driven turbo and supercharged engines back to back, as I do on a daily basis. I've owned and driven turbo cars since 1984, my favourite drive ( though not owned!) was a 6.75 litre Bentley Turbo R. The most recent turbo engine I've driven (though not owned) is the Mclaren 12C twin turbo V8. I've also driven essentially the same engine in turbo and supercharged forms and the same turbo engine in both LPT (which is quite like a supercharged engine) and HOT tunes.

Shoes still dry, how're yours holding up under the downpour?

The debate is not that turbos produce different boost but your assertion that superchargers don't produce boost at all.
My feet are not wet and yours can't possibly because they are buried in bullshit in everything you say.

I give up. You are a waste of time and energy.

[Scrappydoo]

I always thought that superchargers and turbochargers were both compressors. Both driven by the engine, one mechanically, one by waste gasses. The drive type gives them different characteristics.

Simples.