Trying to decide an overdrive

Discussion in 'The "Juice Box"' started by bammax, May 12, 2011.

  1. bammax

    bammax Well-Known Member

    I'm planning for next years big project. I'm looking for an overdrive for the Electra. I have it narrowed down to 2 choices but can't decide between them and need some opinions.

    It's either a ckperformance fully built 200-4r
    Or a gear vendors on the stock TH400

    Both will run about $3k or so.

    Both will be able to handle a slightly built up 455 in a 6,000 pound car being daily driven on the highway and in the city.

    Both will be fairly easy installs except for driveshaft modifications.

    Reliability and street manners are the most important aspects since it's a daily driver.

    All other trans options are out for many different reasons, so lets stay on topic guys :laugh:
     
  2. LARRY70GS

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

    Either one will work for a daily driver. I have a GV. The GV will be for all intents and purposes, bullet proof. The only downside is it's only a .78 overdrive. On the upside, you can engage it in any gear.

    The 2004R has a .67 overdrive, and a lower 1st gear, but it is not as sturdy unless you beef it up with all the good stuff.
     
  3. Nothingface5384

    Nothingface5384 Detail To Oil - Car Care

    If yyou ever plan to push more then a mild 455 i'd go th400/gv

    otherwise 2004r
    From what janis from arkon ohio of janis transmissions told me.. if you plan to make over 750/800 hp better off with a th400..

    I've read plenty of posts/sites from gn guys and they seem to have to always refreshin their trans every 3 or so years..

    ..so again, if you dont want to be opening up your trans every so often th400gv


    either or would be great for a mild bbb.

    I personaly wouldnt do a 200r4 if you plan to be over 550hp
     
  4. Nothingface5384

    Nothingface5384 Detail To Oil - Car Care

    also..if you want the equivlent of a th400/gv look at a 4l80e

    you'd need a trans dapt chevy to buick adapter and either a full manual valve body or a stand alone computer to shift it..
     
  5. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    If both were sitting at a table in front of me and I was allowed to take one, it would be the Gear Vendors. You'll never break it, and any transmission problems you "may" encounter ten years from now will be comparatively cheap to fix (TH400 vs. 2004r). And as mentioned, if you decide to go wild with the 455 (or any other engine a TH400 will bolt too), the OD will be there for you and again the TH400 would be relatively cheaper to upgrade.
     
  6. elagache

    elagache Platinum Level Contributor

    200-4R is more thrifty (Re: overdrive)

    Dear bammax,

    For durability the Gear Vendors unit can't be beat, but you lose one thing: the lock-up torque converter of the 200-4R. If gas was $3.00 a gallon, maybe it wouldn't matter. Today . . . . . ????????

    So far, nobody has made a knock-out argument against the 200-4R for the application I'm planning (mild-mannered station wagon with occasional medium towing.) So until somebody does, I'm going with the 200-4R.

    It sounds to me that you are unlikely to kill 200-4R given your application, but hey - you need to decide how gentle you are on a transmission!! :3gears:

    Enjoy (enjoy ??) your decision making!! :laugh:

    Cheers, Edouard :beer
     
  7. Nothingface5384

    Nothingface5384 Detail To Oil - Car Care

    Re: 200-4R is more thrifty (Re: overdrive)

    you dont loose a lockup if you go the switch pitch route on the th400..

    jim wise will hook ya up!
     
  8. bammax

    bammax Well-Known Member

    The car will end up with a nice top end with aluminum heads and dual plane intake and all, but it'll keep the stock '73 low compression bottom end. So I figure I'll be lucky to see 500 horses from it when it's done. If all goes well I'd love to see 500 horses and 500 ft-lbs at the wheels, but that's more of a dream than a real expectation.

    I figure the 200-4r should do great for me once it's built up, but I know it'll cost as much as a gear vendors unit. The Gear Vendors comes into play because the idea of having a piece that will last forever is kinda nice piece of mind. I figure it'll be hard to kill a TH400 and GV unit.

    If there was a way to make it do the gear splitting automatically then there wouldn't even be a question of which way to go. I like the idea of a 6 speed auto.
     
  9. elagache

    elagache Platinum Level Contributor

    What do ya' mean "switch pitch"?? (Re: 200-4R)

    Dear Nothingface5384 and V-8 Buick members,

    Well, I just sent Jim some dough :dollar: to start building my big-block V-8 so I certainly know how to reach him. However, . . . . .

    What on earth is the: switch pitch route on the th400.. ???

    Can somebody explain to me how a transmission that wasn't designed to have to have lockup torque converter would still end up with one?

    Thanks in advance for educating me on this subject! :Smarty:

    and

    Apologies for the brief detour! :3gears:

    Cheers, Edouard :beer
     
  10. sean Buick 76

    sean Buick 76 Buick Nut

    Re: What do ya' mean "switch pitch"?? (Re: 200-4R)

    \
    The switch pitch th400 works like this:

    High stall used off the line

    low stall used when at speed

    So no there is not lockup for the th400...

    The switch pitch can function similar but never 100% lockup like the 200r4. You can pick your stall speeds with a custom converter... Some run a 4000 rpm high stall and a 2000 low stall... This reduces slippage when at speed but still not locked.

    I LOVE the way the 7004R and 2004R lockup! Even with a stock stall of about 1700 rpms the difference when locked is great! I gain 2mpg on the highway with the lockup engaged using the stock converter. I now run a 3000 stall in my 7004R (in my truck) and when it is locked it is perfect on the highway. I have the best of both worlds!
     
  11. bammax

    bammax Well-Known Member

    Perfectly good detour. I never did understand the switch pitch until now. I had an idea of how it worked but I always though the converter had vanes that shifted or something. I didn't realize it had 2 different stall speeds.
     
  12. LARRY70GS

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

    http://www.buickperformance.com/switchpitch.htm
     
  13. knucklebusted

    knucklebusted Well-Known Member

    Here's my 2 cents for what that is worth. I had a turbo 400 switchpitch in my car for 28 years. I recently swapped it for a turbo 200-4r because of the lockup and overdrive.

    I loved the sp because it really smoothed out the cam in high stall and still let me bark all three gears when it was in low stall. I can't prove it actually performed any better than a standard converter or if it got better gas mileage but I suspect it didn't hurt and made the car much more drivable.

    The problem with a 1:1 top gear and 3.73 rear gears is too much RPM at 70-75MPH. I needed to drop from 3200 RPM by at least a 1000 RPM to feel good about longer drives at highway speeds.

    I looked hard at the GV OD but the mounting/tunnel mods, drive shaft shortening and all just put me off. The gearing wasn't as nice and the weight increase was the icing on the cake.

    The t200-4R was an all around simpler install (especially since I wrote a check to have it done) and only required minor mods to the carb for the TV cable and some simple wiring. I used a stock 350 turbo drive shaft and it looks factory!

    Another bonus some folks forget is the lower first gear on the t200-4r. It has a 2.78 first compared to a 2.48 t400 so that makes my 3.73s launch like 4.10s and cruise like 2.50s. There is more than enough torque for the wider gear spacing and I think the t200-4r is the sweet spot for BB Buicks within the power range of a well built t200-4r.

    Your mileage may vary but I voted with my money for the t200-4r
     
  14. bammax

    bammax Well-Known Member

    I'm thinking along the same lines as far as the 200-4r. I never really intended to look at any other options, but I hit a couple snags.

    For the 200-4r I would need a custom driveshaft. The shaft would need to be longer than stock and it's already very long. Plus the car never came with a th350 so I can't just swap it out with one of those shafts. The long tail 400 is a fair bit longer than the 200 is and that's a problem. With the GV unit the tailshaft is supposedly 9" which means I should be able to keep the stock driveshaft (in theory)

    The other problem is the rear gears are pretty bad for this scenario, like 2.93 or worse. That means the overdrive on the 200-4r may actually be too low. There's a chance the car on the highway would be running very close to idle. Of course if the car can actually cruise down the highway at 1,200 rpms than that would be pretty good for gas mileage.

    If someone could confirm the lowest gearing possible with the 200-4r and find me a way to get the driveshaft I need than I would stop asking and start planning for the 200. Otherwise it starts getting very expensive to change gears in a 9-3/8" and also have a custom shaft made.
     
  15. sean Buick 76

    sean Buick 76 Buick Nut

    If you are not wanting to change the rear gears then I would not bother with an overdrive trans....

    these are my reasons:

    At the weight of your car the overdrive gear with a highway rear end ratio will not give you much if any fuel savings unless you drive 110 MPH.

    It would cost a lot to do all this and it would take a long time to make the fuel savings worth it...

    There is nothing wrong with a highway rear end ratio and a th400, smooth reliable and good on fuel.
     
  16. knucklebusted

    knucklebusted Well-Known Member

    OK, with that additional knowledge, I'd maybe go with a switch pitch to get your massive hunk of iron rolling with high stall and then cruise with low stall. If you want a little more highway speed/less RPM, use a taller tire. 2.93 ratio rear is pretty much highway gears already. Depending on your tires, you should already be able to hit 70 MPH at a bit over 2300 RPM, which is a nice RPM in my book.
     
  17. jamhdit

    jamhdit Just nuts about buick's

    one of your questions was to be able to make it shift automaticly.

    yes the gv overdrive will do that. making it a 6 speed transmision basicly.

    you have choices of automatic shifting manual. and i believe you can change shift points for racing too
     
  18. Golden_70_Cat

    Golden_70_Cat Active Member

    I can chime in here with some applicable experience. I just completed 1600kms over 3 days with a 200-4R in my '70 Wildcat, and it was very cool! Doing 65mph at ~1200rpm was no trouble at all, although swapping to new gears would probably nice to wake up the car off the line. That's in my plans, as complete rear ends are cheap at a local wrecker, and I figure something out of an '80s Caddy will bolt right in, given that I installed a rear sway bar from one with no trouble. In other words, the width and mounting points of the control arms must be pretty darn close. Now, to find a V6 Fleetwood in the wrecker, might even have some kind of LSD...

    As to the driveshaft, I lucked into a nice option there. 1988 Chev Beauville long Wheel Base van is the EXACT correct length for the Wildcat with a 200-4R! Problem is, most of the LWB GM vans seem to be 2 piece units - the one I found is a single piece, but it is bent from the forklift at the wrecking yard. I want another, and there are no single piece shafts on craigslist near me, nor at the cheap wrecker. Might be time for the more expensive wreckers - cheaper than a "new" shaft, I bet!

    And one more reason to go for the 200-4R - it takes way less HP to run it. One of the sites that sells them lists how much HP they absorb. If you're looking for mileage OR power, it's nice if you get a "free" 20 HP just by throwing in a more efficient tranny!
     
  19. bammax

    bammax Well-Known Member

    I'm just really spoiled since the last 3 cars I've had ran highway gears with either a 700 or a 200 trans. I love the ability to cruise on the highway and not even hear the engine. Plus the mileage was pretty good considering they were all heavy cars.

    When I'm under the car checking the fuel lines next week I'm going to get a measurement on the driveshaft. I'd like to see the exact size I need to find and then start searching. If it's going to cost me $500 just for the driveshaft then I'll go with the GV.

    I'm figuring for the amount of driving I do that the trans will pay for itself in gas at about 8 years, assuming gas prices remain at $4 a gallon. I'm going to consider the wear and tear savings a bonus.

    This isn't going to happen until next summer at the earliest anyway, but I need to start saving now for it. So there's no rush on gathering info and plenty of time to decide things.
     

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