jrsc for the ep

[JruSi02]

Hmm... my b-day is in april... wonder if I should get it for myself or go with turbo... oh well I've got a month to decide.

[rhs29]

CSMsi311...i don't agree with you, because the boosts are NOT the same.... a turbo system relys on exhaust gases to turn the turbine wheel, then air from the atmosphere is induced into the compressor...then the air is moved into the intercooler to be charged, then it is crammed into the intake ( throttle body)... a roots type supercharger ( like the jrsc ) relys on the engine belt system to increase airflow into the intake ports...and most root type of superchargers is not intercooled because there is no reason to charge the air or cool the air if the air is not hot.... but, there is a supercharger that is more like both turbo and roots type.... the centerfugial supercharger ( vortech supercharger) , has the compressor side of the turbo housing, but not the turbine housing...on the centerfugial system, the turbine housing has been replaced with a belt driven system...and the system does have its own version of an intercooler however a front mount intercooler can be installed...
SO, its not the same because the source of the power is different...

[CSMsi311]

Boost for an engine is loosely defined to be an increased AIR FLOW beyond the amount of air an engine can normally intake. When the supercharger/turbo forces more air into the engine than it can take it builds up the pressure (boost) in the intake manifold. Therefore, in my definition boost is the same whether it comes from a supercharger or turbocharger. As you stated above very nicely for newbies, the means by which the boost is created is different this explains the differences in power bands (compressor efficiency, parasitic drag...)

The way you make boost is different, but both the supercharger and turbo will force more air into the engine than it would have gotten normally aspirated.

Two excellent books for reading up on turbos and s/c are "Maximum Boost" (for turbos) and "Supercharged!" by Corky Bell. They are written like you are having a conversation with the author. I've only read Superchargers and I highly recommend it. After reading the book, I felt very disappointed with my jrsc in terms of its compressor efficiency compared to a turbocharger.

I hope this clears up some earlier confusion
Jason

[ssvr6]

It's also common knowledge that a roots based blower is less efficient than a centrifigal unitl. That's why Vortech makes WAY more power with their '00 Si kit compared to JRSC.


Steve

[CSMsi311]

Originally posted by ssvr6
It's also common knowledge that a roots based blower is less efficient than a centrifigal unitl. That's why Vortech makes WAY more power with their '00 Si kit compared to JRSC.


Steve

yes, that is (or should be) common knowledge. Why would you want a Vortech. It's just a turbo on a stick. You still have the drag associated with a supercharger. If I remember right, a vortech NOT "aftercooled" at 6 psi was making only a minimal amount more than a jrsc at 6. The big difference comes when you crank up the boost and but on the "aftercooler" for the vortech.

I see where I think I miss interrepted you earlier. You said you like boost. I took that as you like turbos b/c they make boost. But I now see that I think you meant that turbos make more boost, more efficiently.

Jason

[Djmamayek]

Originally posted by CSMsi311


I don't know where you got the idea that a turbo can turn off at a given rpm. Unless you mean when the throttle is shut the wastegate is opened the boost level "by-passes" the engine. A supercharger is always spinning, but the air it is compressing is not always going to the engine.

DONT GIVE PEOPLE MISINFORMATION!!!!

A turbocharger does not shut off at a set RPM, HOWEVER, the wastegate opens at a certain boost level, and allows some exhaust gasses to bypass the turbo altogether. Keeping the maximum boost level constant, so in effect the turbocharger is "shut off" in a very abstract sense. When you close the throttle, the air that has already been compressed by the turbo is released from the intake manifold, ic, and piping by the blow off valve, or compressor bypass valve. The wastegate stays closed when you chop the throttle.

Also an intercooler has nothing to do with "charging" the air, all it does is take the air charge after leaving the turbo and cool it down, because when you compress air it gets warm (obviously).

[CSMsi311]

Originally posted by Djmamayek


DONT GIVE PEOPLE MISINFORMATION!!!!

i didn't realize I was misinforming people. If you read what I wrote I said that I did not understand what the other guy meant by a turbo could "turn off" What you said was what I was trying to get across