[paul]

Hey!!

well this might sound like a crazy question....
if you have a 400hp turboed car and the same one with 400hp supercharged, is there going to be a performance difference since they both have the same amount of total HP ??? thanks!!!

:thumbsup:

 

[hazade]

one difference i can think of is the turbo lag but you also must consider the numbers across the power band

edit: sorry wasnt thinking right this morning

 

[toykilla]

the turbo car should be faster, as it will achieve greater power throught the RPM range.. Peak #'s do not always tell the whole story.

 

[Got Rpm]

Judging potential performance by only looking at peak horsepower is an amateur mistake. In a 3500# car, which will get to the end of the track sooner, a 300hp 2.0 or a 300hp 4.6? Answer, the 4.6 because it has more area under the hp curve.

The turbo has more potential because it can develp boost sooner than a centrifugal SC, but a roots-type blower may out-perform both. Looking at the entire rpm range is what professionals do - newbies benchrace with peak power numbers. Guess who wins the most races? wned:

 

[Dissident]

Yeah, I keep thinking about this question. I mean, the real useable power has to do with, like RPm said, the area under the curve, but how to you quantity that into a useable quantity? Integrate and use that number?

I think the other difference would have to do with heat, and which setup makes more heat and experiences more heat soak sooner...

Wouldn't torque make more difference than HP, too? which setup typically to make more?

 

[Lo Fi Ched]

To start, you can't really compair turbos and SCs without talking about torque. If HP is the same for both, for the most part, whichever has more torque, or more correctly, has the higher average torque, should get down the track faster.

However, if you assume they both have equal torque (which would never happen) then the SC should be faster, because of the nature of the HP/torque curves. The SC's HP/torque curve is more linear, therefor would spend more time at optimum HP/torque. The turbo is a slope curve and takes longer to get to its max, and spends less time there.

At least that's how I understand it.

 

[smoothz]

I've always thought that if you have very little torque, it really doesn't matter how much HP you have. HP #'s sound great, but I also like to read about torque ratings.

 

[paul]

Hey Got Rpm.. what makes you say that roots blowers might out perform both??? i have always heard much better things about the cent SC's ?? i would really like to do the Vortech setup but im still tryin to get as many opinions as possible. but still not too sure!!! LOL

 

[aps]

Originally posted by toykilla@Oct 27 2004, 10:45 PM
the turbo car should be faster, as it will achieve greater power throught the RPM range.. Peak #'s do not always tell the whole story.

Absolutely spot on..............the car with the best power across the entire rpm range (the best avereged horsepower from idle to redline ) will be quicker car more often than not. :thumbsup:

Peter

APS

 

[aps]

Originally posted by Got Rpm@Oct 28 2004, 02:00 AM
Judging potential performance by only looking at peak horsepower is an amateur mistake.  In a 3500# car, which will get to the end of the track sooner, a 300hp 2.0 or a 300hp 4.6?  Answer, the 4.6 because it has more area under the hp curve. 

Absolutely spot on........a smart engine tuner will always look at the power/torque under the curve........peak power figures can be very misleading as the engine in question may produce much less power in the low to mid rpm range. :thumbsup:

Peter

APS

 

[aps]

Originally posted by Dissident@Oct 28 2004, 03:27 AM


I think the other difference would have to do with heat, and which setup makes more heat and experiences more heat soak sooner...

I belive you will find that the Intercooled Twin Turbos will have the lowest charge air temperature..............hence more consistent power in day to day on road driving conditions.

In many cases superchargers (positive displacement and centrifugals) produce much higher charge air temperature than efficient ball bearing turbos at the same presure ratio (boost level) though ultimately high power comes down to the mass air flow delivered (in weight) and cooler charge air temperature. :smiley69:

Peter

APS

 

[aps]

Originally posted by Lo Fi Ched@Oct 28 2004, 04:04 AM
To start, you can't really compair turbos and SCs without talking about torque.  If HP is the same for both, for the most part, whichever has more torque, or more correctly, has the higher average torque, should get down the track faster.

However, if you assume they both have equal torque (which would never happen) then the SC should be faster, because of the nature of the HP/torque curves.  The SC's HP/torque curve is more linear, therefor would spend more time at optimum HP/torque.  The turbo is a slope curve and takes longer to get to its max, and spends less time there.

At least that's how I understand it.

Just to clarify one point, power is proportional to torque.............it's just a mathematical equation.

Bottom line it does not matter whether you look at the power or torque graph, the real issue is how much do you have (horsepower or ft lb) and at what point in the rpm range do you have it.

I beg to differ with you on your assessment that the turbo takes longer to get to it's maximum torque as this will depend on the type of supercharger you're comparing it to.

I believe that on the Z engine a well designed Intercooled Twin Turbo system will produce a superior torque curve across the entire rpm range than either a large centrifugal or postive displacement Supercharger.

This is the reason why I believe you will soon see that the fastest/Quickest Z cars around will be Twin Turbo.............not supercharged.

Peter

APS

 

[paul]

Hey APS... I agree about what you have said after doin some more research on my end ) LOL but as far as either goin with a "Stillen" roots type blower or a vortech which one would you say is goin to perform better ????

 

[aps]

Originally posted by paul@Oct 30 2004, 12:40 AM
but as far as either goin with a "Stillen" roots type blower or a vortech which one would you say is goin to perform better ????

It all depends on the type of power delivery you like as to which type of SC best suits your need.

In my own experience the centrifugal SC (Vortech and ATI) produce good power in the high rpm range though low to mid rpm power is disappointing at this type of SC can't produce much positive pressure at low rpm.

I believe that the whipple type of SC has the better power delivery across the entire rpm range (better for day to day driving) though may not have the power in the high rpm that the bigger Vortech units have.

In some cases it's more difficult to package the whipple due to available space in the engine bay.............as you can see it's no easy decision either way you look at it...............good luck with either way you choose to proceed. :thumbsup: Peter

APS

 

[paul]

thanks aps.... yeah its gonna be tough... LOL
but well see huh ?