PSI Screw Blowers

Discussion in 'PSI Superchargers Tech Questions' started by WIZBANG, Jun 30, 2017.

  1. WIZBANG

    WIZBANG Member

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    What is the difference between the models ?
    200H
    B
    C
    D

    Do they all look the same on the outside ?

    Are the rotors all the same ?

    Case bottom opening different ?

    Front bearing plate different ?

    Thanks
     
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  2. ta455

    ta455 Member

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    the difference between a "D" and a "C" measure the female or driven rotor lobe thickness, there are small variation based on application and date of manufacture or customers specific needs but on average a "C" will measure .483-.485 a "D" will measure .594-.596 both blowers have a open port in the housing between the front shaft/bearing supports.
     
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  3. WIZBANG

    WIZBANG Member

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    Thank You, I have seen the "open port " between the bearing hubs. Do you know if the "B" model has that open area ?
     
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  4. nitrowannabe

    nitrowannabe Member

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    B rotor is for gas. Used on boats. There are old threads here that answer these questions.
     
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  5. Mike Canter

    Mike Canter Top Dragster
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    See if this helps. I found this in my old notes. it also compares the Whipple to a PSI C and D
    PSI "D" is 422 cu.in.per/rev or 6.752 liters per/rev

    PSI "C" is 476 cu.in. per/rev or 7.616 liters per/rev

    Whipple R980 & A980 is 612.5 cu.in. per/rev or 9.8 liters per/rev

    So if you look at SFI max overdrive based on safety and then parity based on swept volume per/rev in 1996 this is how NHRA wrote there rules,

    Top Alcohol Dragster,

    PSI "D" 422 cu.in. x 2.15 or 115% = 907.3

    Whipple 601 cu.in. x 1.52 or 52% = 913 (.6% advantage in swept volume as it was wrote however based on the math 9.8 liters per/rev it should have read 612.5 cu.in. x 1.52 or 52% = 931 (2.6% advantage in swept volume)

    Top Alcohol F/C,

    PSI "D" 422 cu.in. x 2.25 or 125% = 949.6

    Whipple 601 cu.in x 1.60 or 60% = 961.6 (1.2% advantage in swept volume however just as before based on the math 9.8 liters or 612.5 x 1.60 = 980 (3.2% advantage in swept volume)

    Considering the fact that the swept volume per/rev is the only legitimate way to establish a fair and level playing field it is then up to the manufacture to design a supercharger that best meets the applications requirements for safe operation at a required operating overdrive limit per SFI regulations after that has been established the supercharger with the highest adiabatic and volumetric efficiency and the least parasitic loss at high pressure with a linear airflow curve will then allow the engine to create the highest net torque/horsepower curve based on superior air delivery.

    There has been a few questions about how a PSI "C" and "D" compare so here it is in overdrive a "D" at 125% would be approximately the same as a "C" at 104% so just over 10% 2.25/2.04 = 1.102 - 1 = 10.2%

    The last question that comes to mind is how to tell the difference between a "D" and a "C" measure the female or driven rotor lobe thickness, there are small variation based on application and date of manufacture or customers specific needs but on average a "C" will measure .483-.485 a "D" will measure .594-.596 both blowers have a open port in the housing between the front shaft/bearing supports.
    I hope this sheds some light on the questions that have been asked.
     
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  6. Blown5402

    Blown5402 Member

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    Mike, do you have the same figures for the B PSI screw? Thanks in advance--
     
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  7. Mike Canter

    Mike Canter Top Dragster
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    Nope, sorry I don't. Call PSI and talk to Norm Drazy or Andy. Norm built it. 480.820.6511
     
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  8. WIZBANG

    WIZBANG Member

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    Thank You very much for the help !
     
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  9. Dale H.

    Dale H. Member

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    The B blower has the same rotors as the D but the case is shorter and the opening in front of the rotors does not extend down past the
    rotor shafts.The 200 has smaller dia. rotors I believe,and no vertical braces beside the mounting holes at the base.
    -Dale
     
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  10. 1320metalman

    1320metalman Member

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    We have 3 model's, & will offer up assistance if we can.

    We have a C rotor, aka 210
    Also a 206B , billet rotors, yes, as stated, for gasoline/ hence offshore boat racing on race gas, as its common knowledge i hear that the laminated rotors dont like gas,

    but alcohol, prop, & nitro, although (slightly debated, as use of say 90% nitro) a screw, sense it truely compresses its air/fuel mixture, but norm says amato tested the screw on nitro, amongst others, & its no problem @ any amount of dynomite juice im told.
    Some, or at least 1 Engineer who wrked on developement w norm & Niver, on the other hand, didnt like the idea of compressing the juice between the rotors.

    (btw, the 206b, or aka, boat D rotor, will NOT HAVE a burst panel built into rear cover,
    like full tilt buggie 200H, D & C, all built w/ laminated rotors.

    We have a 200H model as well,
    & it does in fact have does have a laminated rotor in it,
    (hence the H for high speed) & the 200H also has the burst panel in rrar cover.

    I thk norm built a 200B, which again is billet rotor, small disp, like 38x cu in, for gasoline.

    That lil 200H kicks butt, btw, for its size. Its combo of being a screw, laminated lite rotor, & decreased hp to rotate, really makes her a banger for her size.

    I guess we are saying that, besides askin Norm, which is best, , we may be able to answer some simple ??s about them
    But we dont have a mag case tad D to provide u any insites w.

    The 206B(D size billlet rotor & the 200H are both, as stated earlier, are like 1.5" Shorter, by mrmory, not fact @ moment, and both use Alum Cases vs
    magnesium cases like a D NHRA version, & the C, which is also Mag case obviously.

    Im far far from being any kinda knowledge base on these, just saying we hav a few models if u got a ?? that, visually, we can verify an answer.

    If u need specific details design,
    & can refer to a model ur wanting to work w/, if thats a possibility?
    Vs every model, that helps us as some are bolted on intakes.

    or yes, smart thing is to call norm if u can get him or Andy
    Regards

    Oh, my understanding , & im sure i will be corrected on this if wrong, and all other accounts as well , w politeness of coarse,
    is that the #s are a referance to diam. In millimeters for largest spec on rotor diameter...??
    Hence 200 = 200mm in a B or an H
    D=206 mm ,
    206 models were made in a B, & now only a D to my knowing as the true D's are (laminated & longer by 1.5" & burst panel in tear cover, are most of the basic diff ive seen.

    & lastly, the "980 Knocker", the C rotor, largest psi to date.
    C= 210mm , no B model C rotor im aware of, not yet.

    I thk i might have some really early drawings, 80s, somewhere of the early rotors.
    Folk art now, and no real value but covering up holes in drywall.
    Good hunting
     
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  11. Mike Canter

    Mike Canter Top Dragster
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    Thanks Norm
     
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  12. 1320metalman

    1320metalman Member

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    If anyone has a billet cover D rotor, can be the first gen , block letter "PSI" LOGO version , or later,( may consider a nice mag frt cover thou,)
    The billet frt blk letter logo's were buult/sold from about '06 to '09, we are looking to add 1 more to the ' museum' to pay hommage to Norm, ofcoarse.

    Snouts, & hats included or not are ok, but not a necessary.

    Thx to Lil Jerry as well as Norm, as he built nearly all the tooling, by Norms designs, for decades,
    He even cut tip strip grooves on manual bridgeport.
    him & Norm were one Awesome team together.
     
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