Damnit! I better give my wife control of the finances now...

AMCRambler

Diamond Member
Jan 23, 2001
7,715
31
91
So damn temping:

El Es Juan GTO .com
/forums/showthread.php?t=525609

... told myself the clutch and brake lines were the last dollars I'd throw at the goat for now. $4,250 is starting to get seriously within budget range for a supercharger.

And then Exdeath posts up that vid with his Kenne Bell screaming and I just want it even more.

Edit: WTF I can't hyperlink to the GTO forum?
Ohh because its got /forums/ in the link ha. Meh whatever.
 
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Zivic

Diamond Member
Nov 25, 2002
3,505
38
91
f^ck a supercharger.
twin turbos
gto_3_4_rear.jpg


not up to date on APS stuff, but it used to be top quality in some applications I was familiar with. There may be better out there, but it it sure does look good
 

phucheneh

Diamond Member
Jun 30, 2012
7,306
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And they're more efficient.

They're also a heck of a lot harder to do right on a V-engine.

What's the cooler for? I mean, with a roots (or screw) supercharger, there's no way to cool the intake charge after it's compressed, right? It's getting jammed right down the intake ports in any application I've ever looked at.
 

KentState

Diamond Member
Oct 19, 2001
8,397
393
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And they're more efficient.

They're also a heck of a lot harder to do right on a V-engine.

What's the cooler for? I mean, with a roots (or screw) supercharger, there's no way to cool the intake charge after it's compressed, right? It's getting jammed right down the intake ports in any application I've ever looked at.

Supercharges are cooled using an external heat exchanger, but use liquid for transferring the heat.
 

phucheneh

Diamond Member
Jun 30, 2012
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Supercharges are cooled using an external heat exchanger, but use liquid for transferring the heat.

Well that feels like a big 'derp' on my end...

Googled it and saw the removable cooler that goes inside the intake. Neat. So much easier than even just a oil-cooled turbo with an air/air cooler.
 

AdamK47

Lifer
Oct 9, 1999
15,698
3,545
136
Get a forged rotating assembly first if you want big gains. That's what I plan on doing. Forged 402 with heads and intake. I'd also upgrade some of the driveline components (especially the rear diff). Possibly get the T56 built and a twin disk clutch. Wouldn't want any weak parts potentially breaking.
 

Zivic

Diamond Member
Nov 25, 2002
3,505
38
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Well that feels like a big 'derp' on my end...

Googled it and saw the removable cooler that goes inside the intake. Neat. So much easier than even just a oil-cooled turbo with an air/air cooler.


turbos are much easier to adjust power levels. just turn a knob. superchargers are always being driven. there is some complexity to adding an air to water setup, more so than an air/air with turbo setup.

I still favor going turbos
 

Vic Vega

Diamond Member
Sep 24, 2010
4,535
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turbos are much easier to adjust power levels. just turn a knob. superchargers are always being driven. there is some complexity to adding an air to water setup, more so than an air/air with turbo setup.

I still favor going turbos

This is why I prefer them.
 

Zivic

Diamond Member
Nov 25, 2002
3,505
38
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This is why I prefer them.

You perfer them constantly being a parasitic drain on your motor?

or that they are RPM dependent on boost?

you think that equates to instant boost? it generally means you don't reach peak boost till redline. where as with a turbo you can reach peak boost much earlier in a lot of cases.
 

_Rick_

Diamond Member
Apr 20, 2012
3,963
71
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Why are there still no hybrid antilag systems, that use a cap/battery/flywheel to store energy short term, electric motors to spool up the turbos to kill lag, and a beefy alternator to charge the battery back up.

Basically an electric version of that horrid leafblower forced induction kit from the other thread, only engineered for more static pressure.

Maybe F1's new turbo era will allow for such developments. I suppose the extra weight won't help in quali, but the lower fuel consumption of running anti-lag not off the engine, but electrically on demand (and you already have KERS on board anyway) might reduce the starting fuel load sufficiently to make up for an advantage over a race distance.
 

KentState

Diamond Member
Oct 19, 2001
8,397
393
126
You perfer them constantly being a parasitic drain on your motor?

or that they are RPM dependent on boost?

you think that equates to instant boost? it generally means you don't reach peak boost till redline. where as with a turbo you can reach peak boost much earlier in a lot of cases.

A positive displacement SC will give the same level of boost at any RPM. Yes, it's instant boost.
 

exdeath

Lifer
Jan 29, 2004
13,679
10
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Why are there still no hybrid antilag systems, that use a cap/battery/flywheel to store energy short term, electric motors to spool up the turbos to kill lag, and a beefy alternator to charge the battery back up.

Basically an electric version of that horrid leafblower forced induction kit from the other thread, only engineered for more static pressure.

Maybe F1's new turbo era will allow for such developments. I suppose the extra weight won't help in quali, but the lower fuel consumption of running anti-lag not off the engine, but electrically on demand (and you already have KERS on board anyway) might reduce the starting fuel load sufficiently to make up for an advantage over a race distance.

Because its not worth it.
 

Phanuel

Platinum Member
Apr 25, 2008
2,304
2
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How are turbos also not a parasitic drain on the engine? You have to shove the exhaust gases out through the turbo, that takes more energy as well.

Dat supercharger whine :awe:
 

phucheneh

Diamond Member
Jun 30, 2012
7,306
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How are turbos also not a parasitic drain on the engine? You have to shove the exhaust gases out through the turbo, that takes more energy as well.

Dat supercharger whine :awe:

Turbos are essentially recapturing heat lost through the exhaust. It's as close to 'free' energy as you're going to get. Exhaust gases are already being 'shoved' through the exhaust; it doesn't change a whole lot move them through a turbine on their way out (assuming proper exhaust design).

Both forms of FI contribute to an overall increase in engine efficiency, though.
 

Phanuel

Platinum Member
Apr 25, 2008
2,304
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Heat has nothing to do with how a turbo is spun. Gas expansion has already happened in the cylinder. You're moving a hot gas through the housing, sure, but all of the energy being used to spin the compressor is just the engine forcing the exhaust gas through the turbine housing.

You're using other detonation cycles to increase the power of the exhaust cycle due to the additional resistance of the compressor. It still has a loss, it's just easier to turn a turbo 'off' by waste gating around it at low engine loads to reduce this drag on the engine.
 

exdeath

Lifer
Jan 29, 2004
13,679
10
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Turbos are ALL about heat. The working fluid (the combustion gases) is still burning and expanding as it leaves the cylinder. The hot expanding gases perform work on the turbine blades as they expand from the hot side to the cooler side and reach thermal equilibrium.

Its all heat and expansion, not just "pushing stuff through".

Piston/rotor type engines are inefficient at capturing all expansion energy because the volume of the chamber increases too rapidly. But turbines are able to incrementally capture and integrate expansions at a smaller and continuous scale (Eg the amount needed to rotate the turbine position by x degrees) making them much more efficient heat engines.
 
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JCH13

Diamond Member
Sep 14, 2010
4,981
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Heat has nothing to do with how a turbo is spun. Gas expansion has already happened in the cylinder. You're moving a hot gas through the housing, sure, but all of the energy being used to spin the compressor is just the engine forcing the exhaust gas through the turbine housing.

You're using other detonation cycles to increase the power of the exhaust cycle due to the additional resistance of the compressor. It still has a loss, it's just easier to turn a turbo 'off' by waste gating around it at low engine loads to reduce this drag on the engine.

Wut...

You just said, essentially, that a thermodynamic element has nothing to do with thermodynamics.

phucheneh is spot-on when he says they recover wasted heat from the exhaust stream. Turbos also remove kinetic energy (velocity) and potential energy (pressure) from the exhaust stream. Funny enough, all of these energies are interrelated.
 

Phanuel

Platinum Member
Apr 25, 2008
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Fine, you're correct. It's still nowhere near free power. You still have all of that pressure pressing back against any cylinders with their exhaust valves open. That's still a parasitic loss on the engine that you've got to pay to generate the compressed intake air on the other end of the turbo. In addition to additional cooling requirements for any FI systems.
 

phucheneh

Diamond Member
Jun 30, 2012
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As I said, force induction still increases engine efficiency. I know it can seem like a bit of 'perpetual motion' shenanigans on the surface, especially when you're talking about power from the rotation of the engine...to rotate the engine. But there's science there.

Remember that internal combustion engines are only 30-40% thermally efficient. The higher end of that is for diesels. 60% or more of your fuel is wasted as nothing but heat. Hence a turbo makes sense in applications of all sizes (i.e. small 4cyls to diesel truck engine in excess of ten liters of displacement).

You should probably listen to JCH. Even I giggled at your heat/turbo comment...and he knows a hell of a lot more about all the thermodynamic and other physics-related principles than I do.

Even exhaust design, on both NA and turbo cars, has a LOT of intricacies to it. And yeah, they're different; which is why they use different designs. Turbos are about increasing velocity before the turbine, which means smaller header primaries, and a lack of exhaust backpressure, which means as much flow as you can get after the turbine.

NA exhausts favor bigger primaries, which might seem like a big 'duh, because the turbo is not robbing power'...but then it is advantageous to add [some] restriction AFTER the primaries to increase velocity and promote scavenging. Making the engine 'breath' doesn't mean just having giant valves, giant exhaust ports, and giant exhaust pipes.
 

phucheneh

Diamond Member
Jun 30, 2012
7,306
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Oh, and also, if you wanna totally blow your mind, go read about how firearms suppressors work...hint:




heat.

(or, 'why you can't suppress your sniper rifle with a plastic bottle'...it's worthless as a heat exhanger)