Turbo or Supercharger poll

[djvaly]

[ATCharming]

sounds good. thanks guys, its not like i even have the money for any of it right now, or even an fbody yet... i was just wondering for future plans

[djvaly]

get a mazda miata

[djvaly]

[ATCharming]

get a mazda miata

yea... ummmm...

[secondgearscratch]

this poll has me getting anxious....ive got the fabrication itch today. may have to hit up a junk yard....

[djvaly]

you have an itch for the pole?

[secondgearscratch]

you have an itch for the pole?

sick bastard....i have an itch for the boobies!!!!

newly single!

[djvaly]

so ahem. back on track, turbo or s/c ?

[97Trans_AM]

so if s/c and and turbos both help the same and produce the boost that makes them the same thing

[djvaly]

turbo vs s/c
pros vs cons

both turbo and superchargers force more air to burn more fuel.
the turbo is exhaust gas driven forced induction, the supercharger uses an air compressor to get more air into the combustion chamber.

superchargers can eat away as much as a third of the total crankshaft power of the engine. in many applications they are less efficient than turbochargers. on the flip side turbo setup have the turbo lag in which initial acceleration from low RPMs is limited by the lack of sufficient exhaust gas pressure.

turbo setup can be damaged by dirty or ineffective oil, and most manufacturers recommend more frequent oil changes for turbocharged engines, and use synthetic oil.

the downside to supercharging is that compressing the air increases its temperature which causes pre-ignition and detonation (bad air fuel mix can damage an engine)

now talking about altitudes, the amount of power in the gas is the difference between the exhaust pressure (turbo) and air pressure induction (s/c) which increases with altitude, so turbos generally have much better altitude performance.

[ATCharming]

turbo vs s/c
pros vs cons

both turbo and superchargers force more air to burn more fuel.
the turbo is exhaust gas driven forced induction, the supercharger uses an air compressor to get more air into the combustion chamber.

superchargers can eat away as much as a third of the total crankshaft power of the engine. in many applications they are less efficient than turbochargers. on the flip side turbo setup have the turbo lag in which initial acceleration from low RPMs is limited by the lack of sufficient exhaust gas pressure.

turbo setup can be damaged by dirty or ineffective oil, and most manufacturers recommend more frequent oil changes for turbocharged engines, and use synthetic oil.

the downside to supercharging is that compressing the air increases its temperature which causes pre-ignition and detonation (bad air fuel mix can damage an engine)

now talking about altitudes, the amount of power in the gas is the difference between the exhaust pressure (turbo) and air pressure induction (s/c) which increases with altitude, so turbos generally have much better altitude performance.

what do u mean by the supercharger eating away crankshaft power? that doesnt make sense to me, if they create power...

[djvaly]

they create power but eat away crankshaft power in the process. it take power to spin the blower, but the net result is gain in power.

[ATCharming]

they create power but eat away crankshaft power in the process. it take power to spin the blower, but the net result is gain in power.

ohh.. do certain s/cs take up lesspower than others?

so when superchargers say they add (for example purposes only. random number) 120hp, really they are first eating up a certain amount, then making enough power to make up for what its eating up PLUS another 120?

[djvaly]

, it depends on what your boost level is and the setup, I like Procharger better than Vortec but that's my 2 cents. also get an intercooler with it, the cooler the air the more hp...

[superchargedblackgto]

, it depends on what your boost level is and the setup, I like Procharger better than Vortec but that's my 2 cents. also get an intercooler with it, the cooler the air the more hp...

OK DJ...I got to say the new S/C are way more efficient than the ones of yesteryear....@ 60mph my maggie scavanges 1/2 Crank HP to run it....now it is blowing out the bypass not making boost....but when you kick it down makes serious HP and roots blowers make better torque throught the rpm range....but you can make way more power with turbos...because you can crank up the boost...unlike s/c you have to change pulleys, port it ect....my .02 worth....lol..I know
http://i149.photobucket.com/albums/s...gto/img001.jpg look @ that TQ curve

[djvaly]

love the dyno

[RJWZ28]

I'll be getting a turbo, if you have fuel injection the turbo is the way to go. If your old school with the carb, put a blower on it and go, turbos with carbs are peaky, temperamental, and harder to tune, due to the lack of linear power gain. A guy out here by me supercharged his LT1 and it sounds great and rips like mad, but a turbo is my preference when electronic fuel injection is involved.

[ericwilloughby]

whichone hurts gas mileage more?

The sc is the only one that hurts MPG. Because it's using crank power and compressing all the time at all RPM and throttle positions. The roots type like the Maggie have a bypass valve that helps but still. The centri has no bypass but since it is nothing more than a turbo driven by a belt instead of exhaust it makes little boost at < 3,000 rpm so doesn't hurt MPG much.

The turbo on the other hand increases MPG slightly. There is no lose in power at the crank to turn it. The backpressure it puts on the exhaust causes some of the exhaust to stay the cylinder after the exhaust stroke and that has the same effect as a EGR valve.

Both increase pressure in the cyl and that makes for higher dynamic compression ratio with increases efficiency. It's just that there is much less lose in power to turn a turbo.

[ericwilloughby]

turbo vs s/c
pros vs cons

both turbo and superchargers force more air to burn more fuel.
the turbo is exhaust gas driven forced induction, the supercharger uses an air compressor to get more air into the combustion chamber.

superchargers can eat away as much as a third of the total crankshaft power of the engine. in many applications they are less efficient than turbochargers. on the flip side turbo setup have the turbo lag in which initial acceleration from low RPMs is limited by the lack of sufficient exhaust gas pressure.

turbo setup can be damaged by dirty or ineffective oil, and most manufacturers recommend more frequent oil changes for turbocharged engines, and use synthetic oil.

the downside to supercharging is that compressing the air increases its temperature which causes pre-ignition and detonation (bad air fuel mix can damage an engine)

now talking about altitudes, the amount of power in the gas is the difference between the exhaust pressure (turbo) and air pressure induction (s/c) which increases with altitude, so turbos generally have much better altitude performance.

Not busting on you here, would just like to clear up a few things.

All turbo's and all super chargers are nothing but air compressors. As a matter of fact the Procharger, Vortex, centri type, actually use a turbo's impeller wheel to force the air. The only dif is the sc is driven by taking power from the crank to turn a pulley, and the turbo gets its push from the exhaust gasses still burning in the pipes.

I think a third is on the very high side for the amount of power robbed. I've been involved in some testing and for the normal street car centi making about 500 RWHP about 75 HP extra was used to turn the sc. In other words the car was making about 575 but that much was taken off of the front of the crank to turn the sc. That's about a 13% lose.

You might think that the turbo on the same car, same boost, would make 575 but not quite. 555ish. The turbo, in blocking the exhaust to make it spin robs the engine of about 20 hp because the exhaust has a much harder time getting out of the engine so a full,fresh air charge, can't quite get in. Again, this is also why turbos make slightly better MPG than N/A.

Turbo lag is nothing compared to the boost a centri, procharger, vortex, can not make at low RPM's. Lag is gone by about 2,200 rpm on a turbo. Boost doesn't hit it's peak on a centi until red line. Because being belt driven, it's speed is always dependant on the rpm of the engine. The only type that makes more low end boost, below 2,200 rpm than a turbo is a roots, Maggie, type supercharger. But these roots type kill you on the top end where it matters most. The only time you miss that 2,200 rpm or less power is on the launch and you better have some drag slicks. Anyway, what's the point, if your looking for power down that low get a high stall converter and just move the launch rpm up to 3,000 or higher.

As for the oil. All of them have to be changed. Change it every 3,000 and it wont matter. On the down side for the Procharger, you have to change it's oil in a separate job because it has a self contained system. A little more work.

Compressing the air, no matter what system you use, increases it's temp. And if you are looking for more than 6 psi you need an intercooler no matter what system you use. All kits I can think of come with an intercooler anyway. Except for the entry level STS turbo kit, which runs at 6 psi.

The altitude part made little since to me but I think I know what you are getting at. The sc, being belt and gear driven, compresses the air by a factor of x. Lets say that at sea level you are making 14.7 psi of boost. That is double atmosphere. If you were to drive up a very tall mountain and the atmo pressure at the top was only 8 psi. You would only be making 8 psi of boost up there.

A turbo on the other hand actually controls the boost pressure via the wastegate. Where there is NO pressure control on a sc, just controlled shaft speed based on RPM. The turbo will make whatever psi you have it set to make no matter the atmospheric pressure.