Governor info

Discussion in 'The "Juice Box"' started by David Butts, Jun 24, 2010.

  1. Jim Weise

    Jim Weise EFI/DIS 482

    Good to hear that converter worked out for you David, I figured it might, that was a nice tight unit.

    JW
     
  2. David Butts

    David Butts Gold Level Contributor

    Thank you again Jim. It's time for another full wood blast video but I'll need a camera mount for that one. Gotta have both hands on the wheel when it shifts at full song now. YeeHaw indeed. :TU::3gears:
     
  3. Bigpig455

    Bigpig455 Fastest of the slow....

    It's a rainy morning in New England, so I decided to tackle the governor and document the results - we need to share more specifics about governor mods for posterity. I've done a lot of research on this on the web, but most documentation is vague.

    I have a 71 Stage 1 car, and the transmission is a 69 PS TH400 (from a 69 Pontiac 350 HO Tempest or Firebird) It seems to be unopened, and shifts well. At some point, the car was a four speed and someone cut the kickdown harness. I raced the car last season and because it had no signal to the tranny, it ran on modulator pressure and short shifted under full throttle. Manual shifts at 5500 were soft, and I ran a best of 13.62 @ 98.

    Over the winter I ran a new wire for the kickdown, and much to my dismay now it will not upshift at WOT (hasty rev limiter install!) At least I know It begins to float valves at 6k now...I temporarily installed a stock governor from a 72 Pontiac Grand Ville, and now it shifts at a safer 4500..

    Also over the winter I installed a "C115" cam from Jim Weiss. After break in and a few banzai runs, it still feels like the sweet spot for the shift should be 5500, so that's what I'm shooting for.

    I tore down the existing governor, it's stamped #12 on top. Someone has already modified the inner weights by removing material from the end farthest from the spindle, but did a good job as they both weigh 9.28 grams exactly.

    The springs appear to be stock, and match Jim's description of stock Stage 1 exactly: 9.50 free height, 9 coil, .020 wire. The outer weights are unmodified and weigh 44.85 and 44.78 respectively.

    As the governor valve moves freely (and the circuit clearly responds to a different governor) it appears I need more inner weight. Interestingly, the total weight of the inners is very close to what Jim describes as stock Stage 1 BB trans- 17 grams vs. my 18.54 grams. But every transmission is different, right?

    My research seems to turn up a combination that gives many people a 5300 rpm shift point with stock springs- the #4 and #5 weights from a B&M/TCI kit. Here's a link to an excellent article by Rocky Rotella: http://www.hotrod.com/how-to/transmission-drivetrain/hppp-1203-recalibrating-turbo-400/

    But when I weigh my #4 and #5 weights, I come up with a cumulative weight of 13.94 (4=7.43, 5=6.51) That's clearly headed in the wrong direction...I took the existing weights and the kits weights, and mixed and matched until I found a combo that took me slowly toward heavier weight. In my case, I turned out to be the B&M # 2 and #4 weights for a 1.66 gram increase over the existing set up (#2=12.77,#4=7.42). I will continue to use stock springs for now.

    The combo is in, but I'll have to wait for better weather to test. I'll keep you posted. In the meantime, if anyone has any specific results from trial and error, please post them.
     

    Attached Files:

  4. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Rhett,
    Great info. The problem is valve body calibration affects everything, so what may produce specific results for you may not produce the same for someone else with another valve body.
     
  5. Bigpig455

    Bigpig455 Fastest of the slow....

    absolutely right, Larry - I was able to road test it when the rain broke/roads dried out for a minute and the #2 and #4 weights with stock springs got me both shift points of about 5100 rpm. It's really tough to tell on the 1-2 shift because anytime I approach WOT in first it just goes up in smoke... with wheels spinning it seems to go 1-2 at about 5100, but I also had it short shift at about 4500 once - but I might have let off without realizing. the 2-3 is 5100 all day long. I'm still shooting for 5300-5500 so I changed one stock spring to a slightly lighter orange B&M spring. I made up a jig to test compression by grams/psi and the stock Stage 1 springs come in right between the yellow and orange springs for tension.

    Had an interesting conversation with David Butts on facebook too - we talked about the relation of overall weight weight vs. "nose weight" when suspended from the governor axle. I'll put my results on the board here when I'm done, but sure enough, depending on the weight configuration a lighter weight can have a heavier nose weight, and therefore could be moving in the wrong direction if you buy that centrifugal force more affects "fly weight".

    More to come when I get to road test this combo...
     
  6. David Butts

    David Butts Gold Level Contributor

    Rhett feel free to reuse any of the pics I posted on FB, All of those are on my phone and I'm not tackling trying to get them to post here. Hopefully others can also benefit from our tinkering.
     
  7. Bigpig455

    Bigpig455 Fastest of the slow....

    Thanks David, I will (when I get motivated) Great info though, and an aspect of governor tuning I've never seen discussed before
     
  8. Bigpig455

    Bigpig455 Fastest of the slow....

    Success - the lighter spring gave me about another 200 rpm, the 2-3 shifts at about 5300-5400 now, I still cant tell whats going on with the 1-2 for all the wheelspin, but it seems to be in the same neighborhood.
     
  9. Bigpig455

    Bigpig455 Fastest of the slow....

    As promised, the results of my research on the B&M kit weights and Springs, in relation to my (modified) GM governor parts:

    The first chart is the overall weights in relation to the nose weights. Dave Butts and I figured that it's really the nose of the weight (the "fly" end) that really controls the shift point as it swings away from the "axle", and it's interesting to note that two different overall weight weights can have a similar nose weight (#3 and stock) or a lighter weight can have a heavier nose weight (#3 and #4) - sorry the columns don't line up.

    weight #/ weight (gm)/ nose weight (gm)
    #1 15.05 6.1
    #2 12.77 3.91
    #3 11.15 2.67
    Stock (mine) 9.28 2.6
    #4 7.42 2.8
    #5 6.51 1.95
    #6 5.98 1.5

    Next chart shows the compression tension of the kit springs at .200/in in grams, in relation to the stock Stage1 spring (as defined by Jim Weiss)

    Spring/ Compression Rate
    Purple 1110gm @ .200
    Blue 1000gm @ .200
    Green 625gm @ .200
    Yellow 560gm @ .200
    GM Stage1 500gm @ .200 (9.50 free height, 9 coil, .020 wire)
    Orange 425gm @ .200
    Red 200gm @ .200


    Again, in my PS TH400, the # 2 weight with a stock spring, and the #4 weight with the B&M Orange spring seems to give me both shifts at 5300 rpm with no harsh shift transition.

    Hope this helps someone down the road....
     
    matt68gs400 likes this.
  10. Briz

    Briz Founders Club Member

    Dave set up a governor for my riv and its like driving a different car. Theres still some room for improvement but its world better than it was.
     
  11. David Butts

    David Butts Gold Level Contributor

    I just typed almost an entire page on info I've learned and when I tried to post it I got a page not found error message. Frustrating to say the least and not the first time. Grrrrrr!
     
  12. Jim Weise

    Jim Weise EFI/DIS 482

    Dave,

    When you made the above reply, you should have seen a "restore auto saved content" text at the bottom of the reply box.. click that, and in brings your post right back.

    Not sure if it will work now.. after you have made a post.

    JW
     
  13. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    Have to love Gil Younger trans go shift kits, some of his tips are very humorous yet effective, taking the edge off a pump vane, "a few back n forths on a cement floor" burnishing clutches and bands. Scuffing steels on a cement floor. Oll school at its finest
     
  14. Bigpig455

    Bigpig455 Fastest of the slow....

    Dave - Sorry to hear that, and still very interested in what you had to post.

    Aside from that, also interested in your opinion on where to go next:

    I was able to take the car out and confirm - got a 5100rpm 1-2 shift and a 5300 2-3 shift with a # 2 weight and stock spring and #4 weight and orange spring. If I were smarter I'd be happy with that but I'd like to bring them up another 200 rpm or so. Maybe I could have done that with another orange spring, but understanding what I've got left in my kit, what would your suggestion be? I guess I could take a 12/ gram off one of the weights, but I'd like to do it with off the shelf components. I'm thinking of swapping the #4 out with one of my original stock weights..
     
    matt68gs400 likes this.
  15. David Butts

    David Butts Gold Level Contributor

    Rhett, Go slightly lighter on your heaviest inner weight. It is the one that will move/swing first thusly it should control the first shift incident. You could also just try a lighter spring with the same heaviest weight. As far as the 2-3 goes, the same changes should help but I'd try the change to the heaviest weight first as it will also move up the 2-3 shift but not as much.
     
    matt68gs400 likes this.
  16. Bigpig455

    Bigpig455 Fastest of the slow....

    Thanks Dave - thats exactly what I did - I took out the #4 and used my lightest stock weight at 2.6 nose /fly weight....it moved the shift point to a little under 5300 to a little over 5300 at both the 1-2 and 2-3 shifts - that oughta do it for the time being, it's a mystery shortblock and I dont need to find out just how (or how not) well it's screwed together.

    One more question - where are you guys sourcing your 6d nails for the weight axles? The ones I buy at Home Depot are like .099, and the ones I've been bending back and forth in my governor are like .090. The Home Depot ones are just too thick and cant be used.
     
    matt68gs400 likes this.
  17. David Butts

    David Butts Gold Level Contributor

    I bought a small pack of 2 inch finishing nails also from Home Depot that are .090 diameter. They fit fine in most of the weights and covers but I have to slightly open up the holes in the gov itself. In my own personal stuff I have the e-clip axles from the aftermarket kits. Having raced rc cars for years I have a supply of those pesky little 2mm e-clips. governor nails.jpg
     
  18. BRUCE ROE

    BRUCE ROE Well-Known Member

    I managed to order some long skinny cotter pins to do that job. About every car I've had needed the governor/vacuum modulator adjusted, and the trans speedo gears fine tuned. Bruce Roe
     
  19. Bigpig455

    Bigpig455 Fastest of the slow....

    Bumping this for reference.
     
  20. scubasteve455

    scubasteve455 Well-Known Member

    Best thread in years! Hah
     

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