Super chargers

[m1lky]

Questions I've had for a while just for my knowledge rather than any actual application.

Do super chargers have a lag like a turbo?

Is it worth cooling the air out of a supercharger? Obviously compressing the air will generate heat but surely a large amount of a turbos heat comes from conduction through the metal from the hot exhaust gases?

[Sabbath']

No lag as such, get an after cooler and put it under the supercharger.

[walesy]

if you go with a top mount charger its almost full boost as soon as you hit the accelerator

[AirStrike]

No lag as such, get an after cooler and put it under the supercharger.

Depends on what type of charger and if it is correctly sized for the application.
As for a turbo getting hot from conducted heat, the air isn't in the housing long enough for that.
Not all turbo's have lag, in fact there shouldn't be any if it is sized correctly. Normally only high horsepower applications will have a decent amount of lag which can be rectified by other means (nitrous, 2 step setup, etc).

[Sabbath']

Depends on what type of charger and if it is correctly sized for the application.
As for a turbo getting hot from conducted heat, the air isn't in the housing long enough for that.
Not all turbo's have lag, in fact there shouldn't be any if it is sized correctly. Normally only high horsepower applications will have a decent amount of lag which can be rectified by other means (nitrous, 2 step setup, etc).

Yeah sorry, i was a bit non-specific with my advice.

[PaRaDoX]

Depends on what type of charger and if it is correctly sized for the application.
As for a turbo getting hot from conducted heat, the air isn't in the housing long enough for that.
Not all turbo's have lag, in fact there shouldn't be any if it is sized correctly. Normally only high horsepower applications will have a decent amount of lag which can be rectified by other means (nitrous, 2 step setup, etc).

Heat is a byproduct of compressing air, a smaller turbocharger or supercharger operating outside its efficiency range will superheat the air sometimes in excess of 100deg C.

My turbo is cool enough to touch after operation as most turbo's are water cooled removing most of the heat from the 'core', the oil also cools the housing.
the best way to determine if a intercooler is needed is to monitor the intake tempratures.

My supra for example makes over 300rwkw @ 15psi of boost on a T61 turbo, I've plotted out the turbo map for my engine and determined it is in the %90 efficiency range well into 30psi, I have very little lag as a result of the tune, diff gears, gearbox ratio's and driving style.

Ive done plenty of logging and at full boost my intake temperates only raise by 3deg at full boost, even when running 20psi.


As for superchargers, they increase boost on a linear scale which is in direct relation to RPM. Where it may be possible to achieve full boost at 3000rpm on a turbo car it is impossible on a supercharged car. the trade off is when you apply the throttle you get instant boost, this may only be 2-3 psi but it's there.

[AirStrike]

Heat is a byproduct of compressing air, a smaller turbocharger or supercharger operating outside its efficiency range will superheat the air sometimes in excess of 100deg C.

My turbo is cool enough to touch after operation as most turbo's are water cooled removing most of the heat from the 'core', the oil also cools the housing.
the best way to determine if a intercooler is needed is to monitor the intake tempratures.

My supra for example makes over 300rwkw @ 15psi of boost on a T61 turbo, I've plotted out the turbo map for my engine and determined it is in the %90 efficiency range well into 30psi, I have very little lag as a result of the tune, diff gears, gearbox ratio's and driving style.

Ive done plenty of logging and at full boost my intake temperates only raise by 3deg at full boost, even when running 20psi.


As for superchargers, they increase boost on a linear scale which is in direct relation to RPM. Where it may be possible to achieve full boost at 3000rpm on a turbo car it is impossible on a supercharged car. the trade off is when you apply the throttle you get instant boost, this may only be 2-3 psi but it's there.

Not all chargers are linear. A centrifugal-type supercharger will see boost rise with rpm, a positive-displacement will provide a fixed volume of air no matter the rpm.
What part of the turbo are you touching? Turbine housing

[PaRaDoX]

Not all chargers are linear. A centrifugal-type supercharger will see boost rise with rpm, a positive-displacement will provide a fixed volume of air no matter the rpm.
What part of the turbo are you touching? Turbine housing

Very valid point, i stand corrected, i was talking about a roots charger.

Compressor housing as thats where the charge air goes through :P

[one_and_only2004]

My turbo is cool enough to touch after operation as most turbo's are water cooled removing most of the heat from the 'core', the oil also cools the housing.
the best way to determine if a intercooler is needed is to monitor the intake tempratures.

I can say without a doubt that I could cook my lunch on my turbo - even the front gets very warm.

[AirStrike]

I can say without a doubt that I could cook my lunch on my turbo - even the front gets very warm.

Really? I can easily touch the comp housing no problems at all.

[one_and_only2004]

Really? I can easily touch the comp housing no problems at all.

The whole exhaust including the exhaust housing is ceramic coated along with a turbo beanie - I think this helps it hold the heat inside the charger itself a lot more.

[Drawnnite]

superchargers run off the crank (you know what i mean... =P)
turbos run off the exhaust.

dont quote me on this, but top mount S/C's drain power from the motor. however they give more then that % back with what they produce.

but listen to air and para and so forth.
their info is much better then what most can provide =P

[m1lky]

superchargers run off the crank (you know what i mean... =P)
turbos run off the exhaust.

dont quote me on this, but top mount S/C's drain power from the motor. however they give more then that % back with what they produce.

but listen to air and para and so forth.
their info is much better then what most can provide =P

Yeah fundamentally I know how they work. Id just wondered about what the performance is like.

[one_and_only2004]

My centrifugal raptor on my VY had what i'd class as a bit of lag, it only started to make boost at about 3000rpm very similar to my turbo setup.
I like the lag though, it helps when it's wet.

[PaRaDoX]

Yeah fundamentally I know how they work. Id just wondered about what the performance is like.

For arguments sake i will compare my supra when stock to my VT

VT 171kw - 3.8L v6 - 1600kg aproximately 6psi
Supra 172kw - 3.0L I6 - 1550kg aproximately 6psi

N/A the Supra makes 142kw and the VT makes 147kw so they are pretty much on par with each other

After having driven both it is clear.

The VT has a bulk amount of torque availiable off the line but looses it in the top end. where as the supra has the bulk of the torque in the top end.
Turbo's are more efficient as they recycle exhaust gases but my supercharger is as easy as a alternator to turn over.

Everyone always complains about lag, but if you drive in the right gear lag is not an issue, ie instead of starting off at 2500rpm in 3rd you can use second at 3500rpm and cut down the spool time by a significant amount, Once the turbo is spooled aswell you no longer have to suffer lag into the next gear, so from a standing start lag is only a problem in first gear which if the turbo was spooled anyway wouldn't yeild much power anyway.

I prefer driving a turbo because its fun to get the power at high RPM, however I the supercharger is a beast for towing.

[detox_nath83]

i like lag as well..,,,

coz u know its coming and then Bam ur off like grannies knickers. ahh good times

[AirStrike]

i like lag as well..,,,

coz u know its coming and then Bam ur off like grannies knickers. ahh good times

Your running a hicomp RB with a T04E...........what lag?