[jj89fox]

I have a 2.2 kenne bell and love it. I made 359rwhp & 419rwt with stock heads cam & block

 

[indy2000]

centri is more efficient..mmmmmmmmm:bs:

From Whipple's site (they make twin screws): "The Whipple twin screw compressor is 75% to 85% adiabatic and volumetric efficient while the roots is commonly 40% to 55%. Common centrifugal superchargers have a peak of 65% to 80% but do just that, peak. Over an entire rpm range, a screw compressor has an average efficiency far greater than the roots or centrifugal."

From Colorado Cobra's site: "The Roots blower has the lowest adiabatic efficiency of all the forced induction designs (including the turbocharger, which has to start off with hot exhaust gases to deal with) - generally around 50 percent. The roots type is so inefficient because it doesn't compress the air directly, but delivers uncompressed air which wells into the intake manifold, becoming more compressed, but with additional heat gain from the turbulence and reverse flows of air mixing. Centrifugal superchargers can vary from 60% up to perhaps approaching 80% efficiency, as can turbochargers; both are more efficient at higher rpm, which is another way of calling them more inefficient at lower rpm. The twin screw supercharger normally delivers lower output temperatures, for adiabatic efficiencies of 70-80% across the whole rpm range."

The KBs - boost-for-boost produce LESS heat than a centrifugal. That is with both blowers at 10#, the KB would produce cooler air. The KB DOES heat the air longer,because the blower is delivering full boost for the entire 1/4 mile run - and the centrifugal will only be at full boost a part of the time. Plus the blower case gets more heat soak from the engine because it sits on top of it.

The 2200 can support over 700 RWHP - so it won't run out of breath for most people...

 

[gnvair]

centri is more efficient..mmmmmmmmm:bs:

From Whipple's site (they make twin screws): "The Whipple twin screw compressor is 75% to 85% adiabatic and volumetric efficient while the roots is commonly 40% to 55%. Common centrifugal superchargers have a peak of 65% to 80% but do just that, peak. Over an entire rpm range, a screw compressor has an average efficiency far greater than the roots or centrifugal."

From Colorado Cobra's site: "The Roots blower has the lowest adiabatic efficiency of all the forced induction designs (including the turbocharger, which has to start off with hot exhaust gases to deal with) - generally around 50 percent. The roots type is so inefficient because it doesn't compress the air directly, but delivers uncompressed air which wells into the intake manifold, becoming more compressed, but with additional heat gain from the turbulence and reverse flows of air mixing. Centrifugal superchargers can vary from 60% up to perhaps approaching 80% efficiency, as can turbochargers; both are more efficient at higher rpm, which is another way of calling them more inefficient at lower rpm. The twin screw supercharger normally delivers lower output temperatures, for adiabatic efficiencies of 70-80% across the whole rpm range."

The KBs - boost-for-boost produce LESS heat than a centrifugal. That is with both blowers at 10#, the KB would produce cooler air. The KB DOES heat the air longer,because the blower is delivering full boost for the entire 1/4 mile run - and the centrifugal will only be at full boost a part of the time. Plus the blower case gets more heat soak from the engine because it sits on top of it.

The 2200 can support over 700 RWHP - so it won't run out of breath for most people...

The KB's do not produce less heat. They most certainly produce more. You should see the temps on the Lightnings and Cobras when the intercooler pump craps out. We had one Lightning that was over 500°!
Show us a Whipple in a sub 9 second car. Actually show us lots of Whipples on sub 9 second cars.

 

[OneFastEclipse]

centri is more efficient..mmmmmmmmm:bs:

From Whipple's site (they make twin screws): "The Whipple twin screw compressor is 75% to 85% adiabatic and volumetric efficient while the roots is commonly 40% to 55%. Common centrifugal superchargers have a peak of 65% to 80% but do just that, peak. Over an entire rpm range, a screw compressor has an average efficiency far greater than the roots or centrifugal."

From Colorado Cobra's site: "The Roots blower has the lowest adiabatic efficiency of all the forced induction designs (including the turbocharger, which has to start off with hot exhaust gases to deal with) - generally around 50 percent. The roots type is so inefficient because it doesn't compress the air directly, but delivers uncompressed air which wells into the intake manifold, becoming more compressed, but with additional heat gain from the turbulence and reverse flows of air mixing. Centrifugal superchargers can vary from 60% up to perhaps approaching 80% efficiency, as can turbochargers; both are more efficient at higher rpm, which is another way of calling them more inefficient at lower rpm. The twin screw supercharger normally delivers lower output temperatures, for adiabatic efficiencies of 70-80% across the whole rpm range."

The KBs - boost-for-boost produce LESS heat than a centrifugal. That is with both blowers at 10#, the KB would produce cooler air. The KB DOES heat the air longer,because the blower is delivering full boost for the entire 1/4 mile run - and the centrifugal will only be at full boost a part of the time. Plus the blower case gets more heat soak from the engine because it sits on top of it.

The 2200 can support over 700 RWHP - so it won't run out of breath for most people...

We can all quote from other sources.

superchargersonline.com

"The centrifugal supercharger enjoys several advantageous characteristics that make it the most popular supercharger design in the aftermarket world. First, it is simple and reliable because it has very few moving parts - just a few gears and the impeller. Second, the centrifugal supercharger produces very little heat because of its internal compression ratio. It is also small in size and very versatile because it can "free-wheel" and allow the engine to suck air through it or even flow air backwards. For this reason it can be placed anywhere in the intake tract - it can even "blow through" the throttle body, meaning it can be mounted nearly anywhere. It is also the most thermally efficient supercharger, meaning that it produces the lowest discharge temperature."

There is no denying that pound for pound a Centrifugal will make more topend power then a twinscrew.

 

[indy2000]

The KB's do not produce less heat. They most certainly produce more. You should see the temps on the Lightnings and Cobras when the intercooler pump craps out. We had one Lightning that was over 500°!
Show us a Whipple in a sub 9 second car. Actually show us lots of Whipples on sub 9 second cars.

its says very clearly 'boost for boost' meaining when they are both producing the same boost.

The KB produces more heat overall because it is producing MORE BOOST overall........I know you can see this point.

FACT: The twin screw has a HIGHER ADIABATIC EFFICIENCY across the rpm range, period....that is just the nature of positive and non-positive compression.

 

[indy2000]

We can all quote from other sources.

superchargersonline.com

"The centrifugal supercharger enjoys several advantageous characteristics that make it the most popular supercharger design in the aftermarket world. First, it is simple and reliable because it has very few moving parts - just a few gears and the impeller. Second, the centrifugal supercharger produces very little heat because of its internal compression ratio. It is also small in size and very versatile because it can "free-wheel" and allow the engine to suck air through it or even flow air backwards. For this reason it can be placed anywhere in the intake tract - it can even "blow through" the throttle body, meaning it can be mounted nearly anywhere. It is also the most thermally efficient supercharger, meaning that it produces the lowest discharge temperature."


There is no denying that pound for pound a Centrifugal will make more topend power then a twinscrew.

Its the most thermally efficient, lowest discharge temp, because it produces the LEAST amount of boost.......but in ain't the best adiabatically......

Top end power means everything

 

[gnvair]

Its the most thermally efficient, lowest discharge temp, because it produces the LEAST amount of boost.......but in ain't the best adiabatically......

Top end power means everything

It does and its proven over and over again at the track. Look at the Outlaw classes if you dont believe me. Actually, look at the NMCA classes as well. There are no twin screws. They dont have units that are competitive or move air like the centrifugals.
I am sure you are proud that you own a twin screw, but they arent the end all be all. On the street Modo and I will both tell you that centrifugals have no problem kickin butt. By the way, if you ever come out to New Jersey I can arrange a demo on a dyno with temperature probes to show you that the centrifugals when comparing similarly sized blower produce cooler boost. I run about 19lbs of boost on my T trim on 93 octane pump gas with NO methanol and no intercooler.
Try running that much boost with any twin screw and no intercooler and methanol and see what happens.
I am not sure where you are getting your info from, but its not accurate.

 

[Chipperdavis2305]

:lol:

Well at least we all drive Mustangs ain:


I just seen a 950hp TwinScrew Vette,

Why cant we do that.

2.8 on a 408,,,hmmmm

Kenne Belles aren't the all to be all, but they are badass. For the money, by the hairdryer, hands down. I still aint trading in my Kenne Bell, I will sit here with my small ass 331, and overheated Blower, and well I still feel cool.

Now how many are as cool as the guys across the street from my house,

All Aluminum 427 with an F3 gear driven Procharger, something about the first to hit 2200HP with that setup. , dunno Ati is local to me here in KC, guess we will see. ,,,:king: I like all BOOST regardless of its delivery.

 

[indy2000]

You ignore every point I made about your critique on the quote I made from whipple.

Explain the heat issue....boost=heat.?

Which has more heat 5psi or 10psi in the same volume?

Now compare the boost of a WOT run between twin screw and centri.

Picture in your head since you are ignoring the data, a run between 2000-6000rpm.

centri makes boost from 0-10psi(the end point we are comparing) as a function of rpm, its linear progression. ie 1-2-3-4-5-6-7-8-9-10psi as rpm increases.

twin screw boost from 0-10psi is instant 1-10psi in less than a second....

Why do you think the twin screw generates more heat? cause its generating max boost for more time.

Has nothing to do about my pride, its your incorrect statement that propagates thru forums......".KB make too much heat and is inefficient".

 

[OneFastEclipse]

You ignore every point I made about your critique on the quote I made from whipple.

Explain the heat issue....boost=heat.?

Which has more heat 5psi or 10psi in the same volume?

Now compare the boost of a WOT run between twin screw and centri.

Picture in your head since you are ignoring the data, a run between 2000-6000rpm.

centri makes boost from 0-10psi(the end point we are comparing) as a function of rpm, its linear progression. ie 1-2-3-4-5-6-7-8-9-10psi as rpm increases.

twin screw boost from 0-10psi is instant 1-10psi in less than a second....

Why do you think the twin screw generates more heat? cause its generating max boost for more time.

Has nothing to do about my pride, its your incorrect statement that propagates thru forums......".KB make too much heat and is inefficient".

You're forgetting what platform we are arguing here. Twinscrews for the 5.0 have a serious dissadvantage simply because they can't go much more then 10psi without too much excessive heat. Intercoolers aren't available for them and it's not easy to implement one yourself. This is where the centrifugals will shine. You may make your boost early in the game but from 4k on up the centrifugal is going to make more power. Power where it counts in a drag race. Again I ask, how much time do you spend at less then 4k rpm in a race?

 

[buddha]

It does and its proven over and over again at the track. Look at the Outlaw classes if you dont believe me. Actually, look at the NMCA classes as well. There are no twin screws. They dont have units that are competitive or move air like the centrifugals.
I am sure you are proud that you own a twin screw, but they arent the end all be all. On the street Modo and I will both tell you that centrifugals have no problem kickin butt. By the way, if you ever come out to New Jersey I can arrange a demo on a dyno with temperature probes to show you that the centrifugals when comparing similarly sized blower produce cooler boost. I run about 19lbs of boost on my T trim on 93 octane pump gas with NO methanol and no intercooler.
Try running that much boost with any twin screw and no intercooler and methanol and see what happens.
I am not sure where you are getting your info from, but its not accurate.

X2

I'm glad you guys are taking time to type what I'm thinking. Saving me time.....lol!


The bottom line is they both work great on the street which is where the majority of us spend out time. It all depends on what you like, how you drive, the setup of the car, etc.

 

[modo]

My datalogs from my ysi on a pass show consistant boost on shifts and my iat holds steady at roughly 200 degrees. I highly doubt a non intercooled kb or whipple would show the same. Put both blowers on a flow bench for a hour at max boost and I'd still bet the cent would have lower temps.

 

[fmyth]

centri is more efficient..mmmmmmmmm:bs:

From Whipple's site (they make twin screws): "The Whipple twin screw compressor is 75% to 85% adiabatic and volumetric efficient while the roots is commonly 40% to 55%. Common centrifugal superchargers have a peak of 65% to 80% but do just that, peak. Over an entire rpm range, a screw compressor has an average efficiency far greater than the roots or centrifugal."

From Colorado Cobra's site: "The Roots blower has the lowest adiabatic efficiency of all the forced induction designs (including the turbocharger, which has to start off with hot exhaust gases to deal with) - generally around 50 percent. The roots type is so inefficient because it doesn't compress the air directly, but delivers uncompressed air which wells into the intake manifold, becoming more compressed, but with additional heat gain from the turbulence and reverse flows of air mixing. Centrifugal superchargers can vary from 60% up to perhaps approaching 80% efficiency, as can turbochargers; both are more efficient at higher rpm, which is another way of calling them more inefficient at lower rpm. The twin screw supercharger normally delivers lower output temperatures, for adiabatic efficiencies of 70-80% across the whole rpm range."

The KBs - boost-for-boost produce LESS heat than a centrifugal. That is with both blowers at 10#, the KB would produce cooler air. The KB DOES heat the air longer,because the blower is delivering full boost for the entire 1/4 mile run - and the centrifugal will only be at full boost a part of the time. Plus the blower case gets more heat soak from the engine because it sits on top of it.

The 2200 can support over 700 RWHP - so it won't run out of breath for most people...

This is a big problem: "Plus the blower case gets more heat soak from the engine because it sits on top of it." Its a problem with all 5.0's and putting a KB on it only exacerbates the problem.

Mine was fine when I was running 5-6 lb pulley, when I installed the 9lb pulley the AIT soared to 280+ on the first dyno run and just kept increasing. We moved the AIT sensor from the intake to the supercharger discharge to make sure we were getting an accurate reading. AIT temps were so high we had to pull a ton of timing to keep from detonating.

The KB melted down the coupler after fewer than 100 street miles. According to big Jim at KB its because the SC gets hotter when running on the street than it does on the track or dyno because it is building boost at such a low rpm it is always heating the air.

I added the best dual nozzle AIS kit available and retuned. AIT temps dropped to 257+ on the first pull and continued to climb. Popped a HG on the way home and torched a new AFR 165 head. This SC/combo would not take more than 5-6lbs of boost wo pulling so much timing it was a dog. After watching the KB eating over $2,500 of my hard earned money in tuning, head replacement, Meth injection, etc. I took it off and sold it.

I think the KB is great for a low boost street car but I'd never own another one.

 

[craigaria]

I'd quit arguing about which blower is more efficient, and slap on a turbo


If I was rich...

I'd have one of each...

 

[jj89fox]

just make your own intercooler. I did there is diy thread on how to do it by 92rohcp

 

[Chipperdavis2305]

what KB did you have Fmyth? The 1.5L?

 

[fmyth]

what KB did you have Fmyth? The 1.5L?

1.5l

 

[92rohcp]

A 1.5 KB maxed out with no bypass is a bad idea on the street for sure. But a properly setup 2.1 with bypass can run for years on the street with the proper tune up to around 12 psi. With meth you can run up to 15 and, I'm talking pushrod setup. I run a 2.1 with bypass and custom A2A 17.5 psi on the street and 22 degrees max timing. My AIT's are 15 degrees above ambient and at WOT maybe 30/40 above.

 

[Chipperdavis2305]

I just made my mind up, Im doing an A2A, I believe with lower Air temps it is a much more Hot lap able......92rohcp, I will be in touch, LOL

 

[blown 91 gt]

I run 9lbs 0n my D&D motorsports Comp Hawk 342 all built & cam specs arround the 2.2 kennebell. It only makes 410 whp 490 wtq. But when you go through the gears to 5500 to 6000 rpm, it feels like a 550 whp set-up.
My HP stays the same peak from 4200 rpm to 6200 rpm. Thats 2000 rpm of full whp. Not just at the end of rpm range for 300 rpm. The feeling of the TQ is just crazy. You ad a 50 shot NOS and be shredding BFG D/R @ 60 mph.
I think if you looking for a 550 whp cent car? Go by a engine block that can handle it first, then enjoy. I like um both, just enjoy the KB much much more.
Plus everyone has a cent on a fox.
Man we all hy jacked this thread.:rofl: