Been reading on the Gear Vendors website.

Discussion in 'Small Block Tech' started by Mark Demko, Dec 25, 2020.

  1. Mark Demko

    Mark Demko Well-Known Member

    First, Merry Christmas to all you Buick people;)
    Been doing some research on Gear Vendors website and ran across this Question/answer
    Pretty much describes my situation.

    Can I run a high stall converter in overdrive with a 3.42 axle?

    Yes, this is one of the most often confused questions (even when you ask people you would think would be knowledgeable). Here is the detail. Our example could be this 3.42 Chevy guy. In overdrive he is going to be a 2.67 final drive ratio. He is a Cutlass body with 27 inch tire and so at 75mph in overdrive the motor will be turning 2484 rpm and he has a 3500 stall speed on the back of a pretty nicely built 350ci motor making close to 400hp. 95% of the people you would ask (even tranny guys) would say no-way and yet we know this is an awesome package (drives wonderful, no high temps in the trans etc) why does it work? When his converter was made it was set up to stall at 3500 with 400hp. However if you put 600hp to it it would stall at something like 4500. Conversely if you only put 125hp to it (as when you are just crusing at 75mph not accelerating) then the stall is way down at 2,000 rpm. So his stall with a 3500 converter is not 3500 at cruise because he is not making 400hp. Car drives wonderful. If he romps on it while cruising then the trans is going to downshift to a lower gear and get him into the powerband. (note: read gear vendors passing gear in this section) So, this is why you never lie to you converter builder (because if you overstate your hp you will not get the stall you wanted).

    The package of 3500 and 3.42 with 400hp is a sweet setup with a GEAR VENDORS . Without a GEAR VENDORS the trans will not have a great passing gear because 2nd is too low. But with a GEAR VENDORS it will it will jump right into 2nd-over which will rip nicely and put the converter right in the power. You can use this setup as a guidline and say move up or down in ratio related to stall from this good setup with a GEAR VENDORS. Below you will see we have listed an actual formula for Aerodynamic load.

    Aerodynamic drag force may be defined as follows:
     
  2. LARRY70GS

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

    I have one of Jim's 9.5" converters. Works just fine with the GV.
     
    Last edited: Dec 25, 2020
    docgsx and Mark Demko like this.
  3. Bens99gtp

    Bens99gtp Well-Known Member

    We put about 3800-4000 stall behind a built 509 in 90 ss truck, 3.73 gears and a gv overdrive, works beautifully. He get 13-14mpg and thats through a 1000cfm carb
     
    Marv Marksberry and Mark Demko like this.
  4. Mark Demko

    Mark Demko Well-Known Member

    I know you have the GV, but forgot about your JW converter. you still running 3.73's?
    I may go GV after my aluminum heads, keeping my 3.42 gear and seeing how it runs.
    There explanation of starting in 1st, then going 1st over, then 2nd, and 2nd over in the quarter sounds interesting, keeping the engine rpm in the power band
     
  5. LARRY70GS

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

    Yeah:DI don't know how that is possible without some additional electronics or some super human reflexes. If you put the transmission in 1st, the switch to 1st over is automatic, but when the transmission shifts to second gear, you have to shut the GV off, then on again for 2nd over, then when you hit 3rd, shut the GV off again.

    Yes, I have 3.73's, but I run a 28" tire, so more like 3.55's. It's about 2300 at 60 MPH.
     
    docgsx and Mark Demko like this.
  6. hugger

    hugger Well-Known Member

    I would do nice 200r4,...weigh less,..has a nice OD ratio,...great gear spread,...easy bolt in,.. plus a quicker ET,...with a GV behind your 350 I bet $100 bill you lose .3

    You would go .3 quicker with a 200r with your current gear,..put a 373 in and you can drop another .2
     
    Mart and Mark Demko like this.
  7. Fox's Den

    Fox's Den 355Xrs

    That's what I did exactly and is the best thing I ever did 200r. using 373 gear
    With a 410 gear it would be a terror.

    I also have a lockup convertor so I am at 2200 rpm at 65-70mph I use a 3000 Pro Torque convertor, I do need to up this a couple hundred. I kept it at 3ooo so the nitrous would not blow it too high.
    Can also lockup in 3rd gear when driving 35-50 mph.

    The 3500 convertor and the 350 trans I used and the 125 shot of nitrous would blow it to 5 grand. Got to say that was fun out of the hole.
     
  8. Mark Demko

    Mark Demko Well-Known Member

    For awhile I had given that thought even up to the point I pulled the trans. and had Vince Janice build my 350 with all the good stuff.
    A lot of guys on here were saying to do a 2004r, so when I took my 350 trans. to Janice, I asked him about a 2004r for my GS, I dont remember his exact response but he wasnt overly enthusiastic about it.
    I told him my reasoning for staying with the 350 trans verses the 2004r.
    Stock for stock, the 350 is stronger
    Build up the 350, its WAAY stronger than a built 2004r
    Cheaper to build.
    Vince agreed.
     
  9. Bens99gtp

    Bens99gtp Well-Known Member

    The 200 does have a steeper 1st gear...2.74 if I recall. The converter lockup feature would be nice especially if you do alot of driving above 50 mph.....it would get you some extra mpg and drop the rpm another 200-400 rpm


    But your nit comparing apple to apple. Yes the 200 does cost a tick more to build, but your not dropping 2600+ for a new gv unit.

    200s live behind very fast GPS that drive around....they can be built to handle alot of power and torque
     
    Mark Demko likes this.
  10. Mark Demko

    Mark Demko Well-Known Member

    They have some super duper electronics now, I was getting a headache reading it, I gotta read it again:rolleyes:
    DRAG RACING 3-SPEED AUTOMATIC



    [​IMG]

    Splitting the ratios (especially 2nd-over) is always valuable to the 3-speed car. 1st-over can be very valuable for hooking up with our AutoLaunch circuit on cars up to about 800hp but is a big torque multiplier and so cars with higher hp may break traction depending on their chassis setup. 2nd-over keeps the converter tight and produces torque multiplication right when the aerodynamics are starting to load the car heavily. We’ve never heard of a car that didn’t run quicker going 1st, 2nd, 2nd-over then 3rd. A 1.28 deeper rear gear (the reciprocal of our ratio) can be used and the run 3rd-over for 5 to 6-speeds. With a 1.28 lower differential these cars can then also keep stock 1-2 ratio (instead of aftermarket deep gear) in the trans for less r.p.m. drop on shift.

    Consistency and E.T. are improved by operating the engine and converter in a tighter rpm range as well as having more torque multipliers through the run. The GEAR VENDORS is one of the few products that can improve both. Study the Final Drive Ratio charts in the 2-wheel drive section appropriate for your tranny make and also read the powerglide section.

    Horsepower = Torque X RPM/5252 The Gear Vendors Under/Overdrive is one of the few products you can use to boost both sides of this equation. Keeping both the torque multiplication higher (gears are multipliers of torque) and the rpm tighter with the close ratios provide by gear-splitting. Your torque converter is also a torque multiplier. One of the benefits of gear-splitting is that all converters work better with the shortest steps in gearing. With the close ratios provide by the Gear Vendors there is also less need for high stall so you can concentrate on the 60ft and the overdrive will handle all the big end of the track.
     
  11. Mark Demko

    Mark Demko Well-Known Member

    It sucks cause I already have the money in my 350 and JW convertor, I figure try the GV with the 350 and my 3.42 rear, then maybe next year change to a 4.10 or deeper gear.
     
  12. hugger

    hugger Well-Known Member

    I like Vince really nice guy,....but he wouldn't build me another trans,...just sayin
     
    Mark Demko likes this.
  13. hugger

    hugger Well-Known Member

    $1800 would get you a 200 that your 350 would never hurt,....you sell the JW converter it would sell for half it's cost pretty quick the built 350 trans would bring $350ish local I'm sure.

    If we were talking about a 600hp big block I would even mention a 200r but behind a small block it will live a long time,.... Basketball Sam runs or did run an Art Carr 200 for years and years behind in is 11.30 full weight GS
     
    docgsx likes this.
  14. Bens99gtp

    Bens99gtp Well-Known Member

    The other option is figure out what a good and converter built will cost you.......then if needed you can recouped some cost from your setup once you decide youlikr it or not.

    I'm not sure anyone local to us has a good reputation on the 200s. But I know Chris at ck performance does, im sure he could give you a quote.

    The 200 also has an OD of .67 if I recall where the GV is .78. So you will have lower rpm with the 200.

    Where I really love a GV is in a tow application that came with a 3 speed.......to be able to get 2nd od is great where one needs more rpm than just 3rd.....but not all the way to second.

    My motorhome is a great example of this even though it already has a ford OD in it.
    At 70 its doing 2500ish in od, if I hit a hill and it drops down its 4000......there is nothing between.......so i have to slow down to the low 60s b4 letting it downshift to keep the rpms in the 3200-3500 range.

    I agree with Ethan too on the bb vrs sb thought
     
  15. alec296

    alec296 i need another buick

    What not consider the 2.75 first gear set for 350. I believe it’s ati unit. With the 3.42 and your converter you would climb quickly thru first still has a 1.52 second
     
    Mark Demko likes this.
  16. STAGE III

    STAGE III Lost Experimental 455-4 Bolt Main Block.

    This is way to confusing for me, I am just going to go with a Turbonique

    2066E952-85BC-4AD8-AE6A-6A9E56EDCDB2.jpeg
     
    Dadrider, Mark Demko and alec296 like this.
  17. Bens99gtp

    Bens99gtp Well-Known Member

  18. Bens99gtp

    Bens99gtp Well-Known Member

  19. LARRY70GS

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


    HAh- hah:D Try doing that going down the 1/4 mile with your hair on fire.:D The only thing I can see is leaving the transmission in 2nd gear and activating the GV so you go through the traps in 2nd over. Even that is difficult because there is a small lag between the time you hit the switch, and the shift occurs. It will take some practice. I would love to pair my engine with a modern 6 or 8 speed trans, and let it keep my engine right at the torque peak throughout the entire pass.
     
    docgsx likes this.
  20. 1973gs

    1973gs Well-Known Member

    I have a 523, TH 400, 3500 stall converter, GV, 411 rear gear, and 31" tall tires. It's a perfect combo for me. At 60 mph, engine runs about 2200 rpm. If you run a small block, a 200r4 is probably fine, but it won't hold up to a big block. A guy at work is building a small block Nova and, after riding in my car, decided to go the GV route. This way, if he switches to a big block, he won't have to make any transmission upgrades.
     
    Quick Buick and Mark Demko like this.

Share This Page