Who is happy the engine will be Naturally Aspirated?

[Random_Art]

Because I feel like it. And because from what I've researched Rotrex units are supposed to be more efficient than the traditional roots type.

[madfast]

Originally Posted by Random_Art

Because I feel like it. And because from what I've researched Rotrex units are supposed to be more efficient than the traditional roots type.

so you want power sapping forced induction AND lag... got it

[Random_Art]

I'll take my chances. all of my research has said that they don't really suffer from lag problems. Are you speaking from personal experience?

[tranzformer]

On the tC TRD SC kit, TRD went with a centrifugal kit right? While the roots has better potential for higher boost and less lag, it is not as thermally efficient from a centrifugal sc from what I have read online. I have also read that for an engine not built/designed for boost, a roots system can be pretty hard on the car/parts as well as having a violent throttle response? So for a stock N/A engine I would also pick the centrifugal sc over a roots. If you are doing a built motor, that is a different story. But for a lightweight RWD, I would personally prefer a turbo over any sc.

[madfast]

Just did some reading and the rotrex units sound pretty cool. its sounds like a good compromise between roots sc and turbo... unlike the traditional centrifugal sc.

[Exage]

Originally Posted by tranzformer

On the tC TRD SC kit, TRD went with a centrifugal kit right?

Yes it was a centrifugal supercharger (vortec).

http://www.toyotaracing.com/trd/part...ugal_type.html

Originally Posted by tranzformer

I have also read that for an engine not built/designed for boost, a roots system can be pretty hard on the car/parts as well as having a violent throttle response?

Any forced induction system that is implemented on an engine not optimized for the increased pressure will damage it regardless of the type of induction. Theoretically if all forced induction systems (Roots, Centrifugal, Turbo) produce 7psi maximum to damage the engine then they will all provide equal damage as an effect.

[82mm 4g63]

Originally Posted by madfast

if you want more power go turbo...

Originally Posted by tranzformer

I would personally prefer a turbo over any sc.

Amen x2.

Originally Posted by Exage

Any forced induction system that is implemented on an engine not optimized for the increased pressure will damage it regardless of the type of induction. Theoretically if all forced induction systems (Roots, Centrifugal, Turbo) produce 7psi maximum to damage the engine then they will all provide equal damage as an effect.

Exactly why I want a car with a factory turbocharger, even if it's a teeny tiny Garrett T25.

[bigbcraig]

Originally Posted by Exage

Any forced induction system that is implemented on an engine not optimized for the increased pressure will damage it regardless of the type of induction. Theoretically if all forced induction systems (Roots, Centrifugal, Turbo) produce 7psi maximum to damage the engine then they will all provide equal damage as an effect.

This is simply false. It depends a LOT on compressor efficiency and flow.

It is true that adding power, with forced induction or not, increases cylinder pressures and may damage internals. But you absolutely cannot say that that any amount of forced induction will automatically result in catastrophic failure of the engine; and you cannot say that 7psi from one compressor is equal to 7psi from another.

[tranzformer]

Originally Posted by bigbcraig

This is simply false. It depends a LOT on compressor efficiency and flow.

It is true that adding power, with forced induction or not, increases cylinder pressures and may damage internals. But you absolutely cannot say that that any amount of forced induction will automatically result in catastrophic failure of the engine; and you cannot say that 7psi from one compressor is equal to 7psi from another.

+1, it's all about the efficiency and flow.

[Dimman]

Originally Posted by bigbcraig

This is simply false. It depends a LOT on compressor efficiency and flow.

It is true that adding power, with forced induction or not, increases cylinder pressures and may damage internals. But you absolutely cannot say that that any amount of forced induction will automatically result in catastrophic failure of the engine; and you cannot say that 7psi from one compressor is equal to 7psi from another.

Yeah, different efficiencies will mean different intake temps to go with the boost.

[Exage]

Originally Posted by bigbcraig

This is simply false. It depends a LOT on compressor efficiency and flow.

It is true that adding power, with forced induction or not, increases cylinder pressures and may damage internals. But you absolutely cannot say that that any amount of forced induction will automatically result in catastrophic failure of the engine; and you cannot say that 7psi from one compressor is equal to 7psi from another.

I can see what you're arguing.

I was basing it on theoretics to illustrate a basic point without getting into fluid dynamics as a whole.

As a basic principle: If you put an excessive flow rate in the intake circuit of a engine and said flow rate has a damaging effect on the engine, then it doesn't matter where said flow rate comes from (this was my point).

Now granted I didn't say that in the original post subsequently using pressure. Theoretically assuming that the maximum intake restriction after the throttle body (being the intake manifold, port, head) was left unaltered with similar intake tempatures. Obviously not real world case.

Is it absolutely correct... no. I was trying to keep it simple for the common man.

[dominican]

I'm in for the NA crowd. I prefer less components in my engine bay, less vacuum tubes, less oil lines, etc... I just hope it revs to more than 7k, gets more than 30+ MPG, and has 200HP+.

[ichitaka05]

Originally Posted by Driftster

I for one wish the engine was not naturally aspirated, as i'd prefer to not only be able to tune the car without pouring thousands of dollars into it for menial gains, i'd also like everything as a result of the turbocharger to be slightly over engineered instead of being just enough to cope with the excess factory power production..

On top of that, there's nothing worse than a car that requires the top shelf of everything at the local autoparts store to run correctly which is usually the case with a performance oriented moderate/high compression n/a engine..As in spark plugs wires and fluids..

Not to mention the inevitable need for 91 octane or higher gasoline or you'll burn through plugs in half the time and quickly get buildup in various locations of the fuel system..

Let's not exclude the direct injection woes this car will face in terms of both upgrades and longevity...

I love how everyone is talking about the complexity the turbo plant would bring to the fray...Yet they're forgetting the thousands of PSI of fuel and all the accompanying electronics to go along with the D4-S....

As much as i bad mouth subaru and their unwillingness to progress as a company in terms of engine dynamics or design..this is one situation i wish they would have stuck to their guns and gone with a platform they knew in and out and weren't experimenting with...Either that or go with a hum-drum boring as p*ss toyota engine

This is funny post.

First of all, if you're complaining bout minimal gain of NA engine vs high gain of turbo engine, there's no end argument.

NA require top shelf parts are pure BS. Turbo require more top shelf parts plus some more than NA parts.

91 octane is most average requirement for most sports car. If you gonna complain bout filling 91 octane then don't buy sports car to begin w.

"Subaru and their unwillingness to progress as a company in terms of engine dynamics or design"

WTF is that mean? If that was the case, WTF is wrong w Ford? It sure taking ridiculous amount of time to get that 5.0 engine to where they are now. How long they took em? What's up w Stang's chassis design? Why are they still using old design? How bout those Viper engine? WTF w that?

Again, if you got time flaming this car or Toyota/Subaru buy GC turbo or Stang and don't waste our time.

[chulooz]

Yeah jeeze. I hope that I dont have to pay the extra $3.00 for sparkplugs or buy legitimate brakefluid for $10 more than the generic stuff.

I cant stand people complaining about petty costs relative to that of a new car.

Im predicting that boost is going to make this car famous.