when do i shift?

Discussion in 'The "Juice Box"' started by ol skewl 67, Oct 2, 2007.

  1. ol skewl 67

    ol skewl 67 Well-Known Member

    I have a 1967 Riviera automatic. My question is, lets say i'm at a dead stop and about to race someone not that i do it but....=), when i shift into 1st gear, whats the speed limit i can push the car to before i shift into 2nd and then into drive? I know this is not a good thing to do but, curious minds want to know. haha
     
  2. flynbuick

    flynbuick Guest

    No one can answer that because the rpms are dependant on your rear end ratio, tire size etc. Rpms limit the speed in first gear. Also max first gear speed is affected by the speedo calibration.

    The better practice is to let it shift itself. Rpms are what kills an engine --not horsepower.
     
  3. gospdgo

    gospdgo Eeny, meeny, miney, moe!

    Couldn't have said it better myself...no, seriously, I couldn't have.

    Unless you have a shift kit in it that functions like a manual, your car will perform better in "D". I learned that with my Charger's torqueflite tranny. It performed much better than when I attempted to shift it myself.

    Granted, my shifts are a little off (early), I feel, but overall it still performed better. I'm running a 3:91 gear and a fairly rad cam, and I think the trans could use a bit of tweaking to get it perfect.

    Sorry for the neverending dribble.
     
  4. ol skewl 67

    ol skewl 67 Well-Known Member

    Thanks Jim and gospdgo! I think i will just keep it in D then. I dont want to mess up my motor and tranny
     
  5. nailheadina67

    nailheadina67 Official Nailheader

    It's good that you are conscientious about engine damage. It's so easy to take that for granted. Last month I screwed up and spun a rod bearing in mine by over-revving it. It was a combination of oil that was too heavy (20w-50), a relatively cold engine, and waiting too long to shift out of 1st. Needless to say, I'm through playing and I now run 10w-40......and calibrated my gov to shift at 5,000 instead of 5,300. Perhaps a rev limiter would be a good investment if you tend to be stupid like I was on a regular basis. :Dou:

    If you want to get the most acceleration, you need to shift at the point just above where you reach your peak power. Assuming you have a relatively stock setup, and your valve springs are still healthy, you may want to shift somewhere around 5,000 rpm's. Just as you feel it begin to stop pulling. This way when it hits 2nd, it hits it with the strongest punch. For me that's around 5,200 or so with my mild cam, but I've never actually experimented on a track or anything so I could be a little off. Anything too much higher than that will only slow you down and tear up your engine. Here is where a firmer shifts will help you out a little bit. :TU:
     

Share This Page