Want to slow car down...

Discussion in 'PSI Superchargers Tech Questions' started by alkyholic, Oct 31, 2012.

  1. alkyholic

    alkyholic Jr. Dragster

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    OK Here goes....

    i converted my funny car to an altered.

    Current set up -
    542ci Hemi, brad fuel heads, littlefield 14/71 HH delta older style.
    Crane R-296/500-16
    Enderle 1100 pump
    11.3 to 1 compression ratio.
    Hays steel 3 disk
    Lenco 3sp 1.92 low
    4:30 gear.

    Car runs 6.40 - 6.50's. (although the motor has gone as quick as 6.07)

    I want to run 7.0's or so (7.0 pro, top dragster).
    Any thoughts on what the car would run if I ditched the blower and went FI only.

    Also, considering swapping the lenco for a powerglide.

    What other changes would need to be made? Compression ratio? cam? to make this run good (reliable) and be relatively low maintenance?
    Am i barking up the wrong tree entirely?
    Honestly i dont know if this is dumb idea or if anyone has done this (seemingly going backwards).

    If there are many changes to the motor to get this setup working i may look in a different direction but i'd like some opinions.

    Thanks
     
    #1
  2. vega funny

    vega funny New Member

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    Hemi for chevy

    I'll trade ya a blown and injected sbc and you can go 7:O'S ALL DAY LONG;);););)
     
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  3. M Tigges

    M Tigges TAFC

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    slow down

    less compression, less fuel, less boost = less power. my 2 cents, that would slow it right down.

    Mark
     
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    Last edited: Oct 31, 2012
  4. alkyholic

    alkyholic Jr. Dragster

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    Hey ive been thinking of selling the car and building an injected bbc or sbc fed :cool:
    But, before i go that route, i want to read about how dumb i am :D
     
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  5. Dave Koehler

    Dave Koehler Member

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    I don't think it's so dumb but I would look at continuing with what you are familiar with.
    Seems the better course than following the Chevy crowd and starting over from scratch.
    I will start.
    Keep the Lenco unless rules say a 2 speed but even then I would keep the lenco.

    Dave Koehler
    http://www.koehlerinjection.com
     
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  6. Ken Sitko

    Ken Sitko Super Comp

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    I dont think you want injected, then you might have a hard time hitting the number. Slow the blower down to about 20 percent, install a pump loop or get a smaller pump so you are at about 10 gallons per minute (to start, might need to go down to 9 gpm), put as little timing in as possible (about 30 with a Mallory, 23 with an MSD 44), and put a little thicker head gasket in to get down to about 11 to 1. You should be close.
     
    #6
  7. M Tigges

    M Tigges TAFC

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    I would say Ken is correct! maybe 10 to 1 with 9 or 10 gallons then it wont pollute the oil at all.
     
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  8. alkyholic

    alkyholic Jr. Dragster

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    Thanks for all the advice guys. So if i change the pump, comp ratio and blower overdrive how would that relate to the nozzles and jets i currently have set up.
    Here is what the setup is on the car right now, the fuel system was flowed by Jimmy Rector...

    this setup burns the cad about 3/4 around the base of the plugs.

    Hat Nozzles
    1. .060 2. .060
    3. .058 4. .058
    5. .056 6. .056
    7. .060 8. .060 <--These to back of blower

    Port Nozzles
    1. .070 2. .065
    3. .060 4. .059
    5. .056 6. .060
    7. .055 8. .058

    Idle check 8 lbs
    Port check 12 lbs
    Pump Saver 155 lbs
    High Speed 55 lbs
    Barrel Valve 82%
    Main Jet 100

    I currently have a Barn door buzzard catcher, should I go to a bird catcher?

    I'm not looking for specific numbers but with the changes made described above around what total area would i be looking for and would all the check valves remain the same with the new setup? I'm just trying to get my head around this.
     
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  9. WANNABE

    WANNABE New Member

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    7 flat in poor air on that engine without a blower will be much harder than you can imagine. Be lots easier to take blower and timing out of it.
     
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  10. underby6

    underby6 Active Member

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    Well this should be easy....here goes - more fuel, less compression, less timing, more weight, shift lower, more wing/wicker attack, trans ratio, rear end ratio....lots and lots of things you can do to slow it down; I'd take a look at the most economical and go from there. Realistically with a supercharger you can get a throttle controller and only open the blades 3/4 or so, or put a solid pedal stop in it. That is cheap, easy, and wont hurt anything aside from et; this way if you get into sub-par conditions you can adjust the throttle stop/pedal stop for more e.t..

    Brandon Booher
    NHRA TAD #34
     
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  11. G Martin

    G Martin Member

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    Several years ago I was helping out on a blown alcohol funny car that ran in CIFCA (7.50 Index) and a 6.30 class. 518 CI fuel headed hemi, Std helix 14-71, 15.5 GPM pump, glide type clutch, 3 speed Lenco, 4.30 gear. We did a test and tune one day with 18% underdrive and about 26 degrees of timing and it ran a couple easy 7.50 full passes. That same afternoon we switched pulleys around to around 30% overdrive and it ran a 6.70 something with no other changes. Added a couple degrees of timing and a little more blower OD and it ran a 6.60. 4 Passes in the same day. Blower speed and timing, It doesn't get much easier than that.
     
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  12. Ken Sitko

    Ken Sitko Super Comp

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    Your hat nozzles are probably too big, I would change them to 52s to get the fuel pressure back up and not flood the motor. Ports look ok
     
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  13. Ken Sitko

    Ken Sitko Super Comp

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    oh, and the pump saver should be close to 200 psi, just to make sure it doesnt open at the wrong time.
     
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  14. alkyholic

    alkyholic Jr. Dragster

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    Thanks for all the replies from everyone. I appreciate it.
     
    #14
  15. 23T Hemmee

    23T Hemmee Member

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    Blower speed, timing and getting compression down gives you a lot wider tuning window for hitting the index. I'm running about 10.75, with a little more overdrive than has been recocommended, mainly because I havn't restripped in 4 years and between 24-27 degrees on a 5 amp Mag4. Ran 7.03 and 7.02 in first and second round of last NDRL race, pulled the pan off last year for first time in 2 years, just put it right back on. Basically plugs set valves and occasional oil change. You've got the pieces you need, just a matter of getting the right adjustments.....
     
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