Finally....KB dyno numbers

Discussion in 'SN95 4.6L Mustang Tech' started by Ibeyorsuperman, Nov 29, 2003.


  1. hedstrosity

    hedstrosity Founding Member

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    then you always have the thread $hitters :nonono: .....
    great numbers.....
    ill have mine soon enough.. i got crappy 91 octane gas, and i wonder what kind of numbers ill make with the maf, longtubes 75mm t-body, and other goods :nice:
    #41
  2. kirkyg

    kirkyg Founding Member

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    holy crap BC you ran 12.3 with all that weight? get everything out of your inside and trunk next time, and get your spare and jack too while your at it. Heat those nittos up we want to see some 11's!!!!!! :D

    kirkyg
    #42
  3. DeadLurker

    DeadLurker Daily Driven

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    B C,

    After looking at the picture it looks like you could have been hurt really bad but luckly you weren't. Did you get an estimate on how much damage there is to repair to the driverside? And has the camaro agreed to help you at all? I'm sure your car is a 11 second car...it's just a matter of time. :)
    #43
  4. Michael Johnson

    Michael Johnson Founding Member

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    The Saleen kit must have a very restrictive intake and/or intercooler. I think KB learned allot from the 5.0L guys grass roots R&D. That is open up everything from the filter on back and an intercooler is as useful on a twin screw as it is on a centrifugal or turbos. Many people don't understand how a twin screw functions or know just how efficient they can be. I've run 16 psi on my car without boost dropping off or the belt slipping. Considering the KB's use the stock accessory drive system with the stock tensioner says allot about their efficiency. Add to this their volumetric and thermal efficiency and they're one of the most, if not the most, efficient superchargers you can put on a car.



    Sorry to hear about your car. Where did he hit you?
    #44
  5. Primo

    Primo New Member

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    Last time I was on a mustang dyno, I was seing 7lbs of boost at 6K RPM. I have recently changed my pulley from the stock 3.5" to a 3.3". I don't know how much boost I saw in the FFW, but I think I was at the same since I was getting a lot of belt slippage. I had a crap load of belt dust after the 1st run with the RR pulley. I swapped belts the night before and When I was measuring the stock gates and the new Napa gates belt, the Napa was about an inch longer. I was ****ed since they stated that it was the same as a gates with the same Part number. Any way, to make a long story short, I was not running through the traps at full throttle since my 4.10's were bouncing me of the limiter at a good 100' before the traps.
    #45
  6. Primo

    Primo New Member

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    BTW, the KB rocks :nice:
    #46
  7. B C

    B C New Member

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    The Camaro hit me in my door and pushed the door and my arm into my upper rib/chest area.
    Actually I am a little banged up. Bruised ribs and sore muscles still.

    Tod the Camaro driver turned it into his insurance. The claim review board has yet to go over it. Tod has been real good at keeping me informed. I am hopeful but I understand it is a longshot. I haven't got an estimate yet. I think the frame is ok, I crawled around under the car and can not see any damage. It drives straight. I have a little wrinkle in the roof I am concerned about. Door, window, quarter panel, rocker, bumper cover (hit rail on passenger side) and then whatever else that is damaged behind those pieces.

    I guess I helped this thread go all over the place. Sorry about that.
    #47
  8. kirkyg

    kirkyg Founding Member

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    sorry to hear about your collision :( :(

    Just glad your ok. The cars can be fixed but your life is invaluable!

    kirkyg
    #48
  9. VETKILR

    VETKILR Founding Member

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    BC do you a auto or 5sp?

    I also think the stock 327s are the best for a roots/KB setup.When I went from 327s to 373s I lost 2mph and .15 at the track.
    #49
  10. z28killer

    z28killer New Member

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    I am not argueing that you guys are wrong but I have seen the effeciency ratings on all the blowers and the cintrificul blowers had higher effeciency ratings than the roots style. Those figures are based on amount of power going in to make the blower work compared to amount of power that comes out. The graphs I saw showed the roots style blowers producing max power at a much lower rpm but the peak pwr numbers werent as high and they fell off much more dramaticly when the rpms got close to redline. Whats the most boost you guys have seen a roots blower produce ? Why dont the really fast cars use roots blowers ? Keep in mind if money was no issue I would have the KB. This is just for the sake of conversation
    #50
  11. JM01

    JM01 Founding Member

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    A centrifugal blower will outperform a roots style blower....but KB uses a twin screw blower wich is way more efficient than the roots.

    Michael Johnson: As I told you... people keep thinking that KB is a roots style blower...thats why they think that they do poor at the track like the saleen blowers.
    #51
  12. forpit2000gt

    forpit2000gt Founding Member

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    great times..........
    now to go another direction, if you are going to dip into the 11's and those speeds, make sure you have the saftey eq. , correct cage and helmet at least. Driveshaft loop s great and c clip elims. hope I am not raining on a parade.
    glad you are all right. :nice:
    #52
  13. kirkyg

    kirkyg Founding Member

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    efficiency "ratings" bah...There is alot more that comes into play than hp output. You have to consider inlet temperatures will affect power which of course is in the twin screws favor and moreover this will help you get higher boost levels safely without detonation and without additional power loss from high temperatures.

    Id also like to throw in you should not compare the saleen blower to the true twin screws...i dont know how they screwed up but they are nothing like autorotor's KB and lyshoms whipple supercharger. The power levels speak for themselves and they boost odd idle to redline speaks for itself too.

    kirkyg
    #53
  14. kirkyg

    kirkyg Founding Member

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    he'll probably just get one run at the track next time ;) :D

    kirkyg
    #54
  15. JM01

    JM01 Founding Member

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    Why I cant find hard to believe that you are again talking without knowing a thing... :nonono:
    Efficiency is the KEY word that kenne Bell himself uses to market his blower . Sure you have to give credit to the design of the intake but the efficiency of the twin screw is the real reason of the high HP numbers.

    So to what type of blowers should we compare them ? electrical blowers? :shrug:

    JM
    #55
  16. Dan_Soprano

    Dan_Soprano Mustang Master

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    just a quick note, everyone is calling the Kenne Bell a "Roots" style blower. This is incorrect. The KB is a Positive Displacement Blower, which although a "Roots" is also a Positive Displacement type, is very different to a "Twin Screw" type. Go to the Kenne Bell Website and look at the tech tips and F.A.Q.'s. (www.kennebell.net). You can read for yourself the difference. Sorry guys, not trying to flame, but you got to read it for yourself. I was DEAD SET on an ATI Procharger until I did some SERIOUS research on Twin Screws and the Kenne Bell kit. With that said, I know some others here have also said that you need to get the correct blower for your needs and budget. Any blower is going to make your car a whole lot more fun, so lets forget the :bs: and go kick some ricer and GM A$$ together!!!!!!!
    ~DAN~

    P.S. B C sorry to hear about your wreak, I'm glad to hear you weren't hurt.
    #56
  17. VETKILR

    VETKILR Founding Member

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    I dont think you can compare a sallen blower to any blower on the market Period......they just plain suck.
    The Saleen intake is the worst design available and the intercooler is a POS also.

    If you can compare the KB to anything compare it to a Roush Stage 3.My car makes 9psi and puts down 399rwhp/404rwtq.
    The designs of the little things like intake/intercooler are what makes a good positive displacment combo.
    I dont really think the KB is all that much better than a Roots blown car until you up the boost past 10psi.
    Simply put a Roots just cant keep makin boost past 10psi (m90) it starts making heat while a KB can still provide usable boost.
    #57
  18. kirkyg

    kirkyg Founding Member

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    Sometimes i wonder about people...you just proved my point... I'm saying you can play with efficiency ratings all day but the real efficiency of the twin screw proves to be the best period.

    ratings are crap but lower intake temps and higher hp prove efficiency.

    kirkyg
    #58
  19. Michael Johnson

    Michael Johnson Founding Member

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    I've had a KB blower on my car for years and have had to point out the difference between twin screws and Root's over and over. I call the remarks the "twin screw myths" and there's about half a dozen of them that I don't want to take the time to mention.

    IMO, this is statement is right on the money. KB has finally put together a kit that lets the twin screws abilities show. It seems that twin screws are much more sensative to inlet and outlet restrictions. Maybe the centrifugals have a built-in advantage in that they pressurize the entire intake tract. It's easier force air through under pressure than to draw it through by vacuum. Under vacuum you can only have atmosheric pressure to move the air so its more critical to make the inlet tract larger to supply a sufficient volume of air to feed the blower.

    Technically the twin screw isn't a positive displacement type blower. It's similarities with a Root's supercharger pretty much ends with how boost is delivered (i.e. full boost at low rpm to redline). In function it is actually closer to a centrifugal because the are both compressors. This means that the air is pressurized inside the blower case.

    The Root's move a packet of air at basically atmospheric pressure to the discharge manifold. The actual compression occurs in the discharge manifold. While this sounds like a small difference it is actually quite a big one when efficiency is considered. The Root's gets a quick surge of air INTO the blower because the discharge manifold has higher pressure than the packet of air the blower is moving. The quick in and out movement of the air causes it to heat up quite a bit. Also, the Root's design requires that the rotors fit tighter to prevent pressurized air leaking back through the blower. This increases the amount of power needed to turn the blower and further reduces efficiency.

    Since the twin screw compresses the air inside the blower case it doesn't get the in and out motion and the air doesn't receive the additional heat. This is why the discharge temperatures are lower. Personally I don't think the difference in discharge temperatures between a twin screw and a centrifugal are really worth much consideration. One area that twin screws accell is in how much power it takes to turn the blower. The rotors are manufactured to very tight tollerances but they do not touch each other. This reduces friction a good amount which also helps lower temps but more importantly reduces its power consumption. A clear indicator of how little power a twin screw takes is to look at the drive belts needed to turn a twin screw and centrifugal at 15-20 psi. Some of the charts I seen over the years show a twin screw takes anywhere from 30%-40% less power to turn than a centrifugal. This could easily add another 20-30 rwhp by itself over a centrifugal at similar boost levels (probably double digit levels).
    #59
  20. TJM01

    TJM01 Patience is a GD virtue Founding Member

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    And you know who really got it right? Ford (with a little help from Roush). IMHO it's all about the intake and intercooler. Notice the ports are big and up top.

    [​IMG]
    #60

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