1985 Buick Le Sabre rear axle ratio

Discussion in 'Got gears?' started by cellblock_g, Nov 13, 2009.

  1. LARRY70GS

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

    The problem with the 307 is that it runs out of breath so early. The 307 in my 86 Regal would literally stop pulling at 3500 RPM. Putting higher numerical gears won't help that engine. It doesn't breathe at higher RPM.
     
  2. cellblock_g

    cellblock_g Active Member

    I understand a 307 will never be fast, you don't need to remind me. I don't plan on drag racing or running 110 MPH.

    I am trying to keep the car from downshifting more than it needs to on hills, since I live in a hilly area. At 70 MPH with 2.73 gears, my car is barely turning 1600 RPM. It is especially slow in the 45-60MPH range with the lockup engaged. Even a slight improvement is worth the money in my book.

    Another problem with the 1985 and newer 307 is the new heads that further castrated an already gutless motor. Had I known this I never would have bought the current car. The 1983 I had in high school was no speed demon either, but it would literally run circles around my current car. It literally runs as smooth as my 2008 Mustang, but very poor acceleration when compared to the older 307 motor.
     
  3. LARRY70GS

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

    Sorry if I seem to be beating a dead horse:laugh: , but I had an 86 Regal with that engine, and I despised it. Mine had the 200C with a 2.41 rear. There were several things I did that made a bit of a difference. I discovered that my timing was a bit retarded. My engine had the electronic spark timing, and there was a specific way to set the timing. The 4 way electronic connection had to be disconnected to return the engine to base timing. Not sure if the 85 is the same, but worth checking since you mentioned that your engine seems to be slow even for a 307. Another thing that made a difference was installing a chip that delayed the torque converter lock up as well as providing a faster spark advance curve. Also, I replaced my catalytic converter with a more modern high performance one. That seemed to help throttle response on the highway immensely. Just some things you might want to consider before changing gear ratio.

    BTW, I believe the torque peak on that engine is about 1800 RPM, so your cruising RPM is pretty close at 70 MPH. I think if you could put the lock up on a switch so that you could manually select lock up would also help alot. You'd gain 150-200 RPM with just that. Like I said, just some things to think about.:)
     
  4. cellblock_g

    cellblock_g Active Member

    Do you honestly think quicker gears will be no improvement at all? Even if the car can move better up to 3500 RPM I think that would be an improvement.

    Funny thing is the car seems ok for normal driving, gets up to speed ok, but when you really step on it there's not much more there. :rant: Or when I need power on the hills it is pretty annoying too.

    I think it is the 1985 and newer 7A heads that make the 307 so slow. The 1984 and older motors with 5A heads actually had some snap to them and could breathe much better, and were more close to 150 HP than commonly known.

    I would rather keep the car looking original than install toggle switches for lockup, etc, if I ever sell it little things like that scream electrical nightmare. Where was that 4-way plug for the spark timing located?
     
  5. LARRY70GS

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

    That sounds just like my Regal. For everyday driving around it was fine, but when you needed that snap, it wasn't there, at all. It's just an anemic engine.

    I think the gears will help at low speed and from a dead stop, but they will not help out when you nail it on the highway, or on hills.

    The 4 way connector is right by the distributor, you can't miss it. Take a look at the emissions decal on top of the radiator cover. It will describe the procedure for setting the timing.
     
  6. cellblock_g

    cellblock_g Active Member

    Just be glad you didn't have the standard 3.8 V6 with the 2 barrel carb.

    Now that was a truly gutless anemic motor, even by 1980's standards. I drove a 83 regal Sedan with this motor for a while in high school. It drank more oil than an old dump truck, took forever just to get up to 55, and really was not that good on fuel with a 3-speed automatic. Choke would never adjust right, guaranteed to stall when putting it in gear after starting it up in the morning. Guaranteed to stall 3 or 4 times given the same scenario in the winter. I despised this car with all my heart.

    One of my friends in high school had a 80 something Cutlass Supreme Coupe with this same motor, and it was even worse. We nicknamed it the "Gutless Supreme" The inside of the air cleaner was totally flooded with oil from blow-by. Climb a hill it would smoke. Go down the highway faster than 65 it would smoke. Pass someone on a two lane road (which took careful timing daring and skill) and it would smoke. It smelled like a tar truck going down the road. We even had an old guy in a newer Buick pass us and give us the finger one day because it took off so slow. :pp My regal seemed to mysteriously just make the oil disappear, the Cutless leaked from about every engine crevice known to man. Both cars had barely 100,000 miles on them.

    All the V8's from GM during the 70's and 80's were much more reliable than the first Buick 3.8 V6.
     

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