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Gears

Discussion in 'The Hokey Ass Message Board' started by Drive Em, May 16, 2012.

  1. mgtstumpy
    Joined: Jul 20, 2006
    Posts: 9,273

    mgtstumpy
    Member

    Had 3.89:1 with a 390FE and C6 but went to 3.25:1, best of both worlds for me.
     
  2. readhead
    Joined: Dec 9, 2011
    Posts: 636

    readhead
    Member

    Those of us that cruise at 6500 feet tend to stay in the 3:50 to 4:00 range to stay in the optimum hp and torque curve to make up for loosing 20% of the hp. OD trans and deep gears are the way to go up here in the thin air. You sea level guys have it so easy.
     
  3. Bigchuck
    Joined: Oct 23, 2007
    Posts: 1,159

    Bigchuck
    Member
    from Austin, TX

    In the OT car I have a T-10 with a 2.64 1st and 3.50 rear gear. Final drive is very close to a Muncie 2.20 1st and 4.11 rear. (9.13 vs. 9.04) Fourth gear is much nore highway friendly.
     
  4. TagMan
    Joined: Dec 12, 2002
    Posts: 6,351

    TagMan
    ALLIANCE MEMBER

    You can't really discuss ring & pinion ratio needs without taking tire diameter into consideration as well.
     
  5. Mr48chev
    Joined: Dec 28, 2007
    Posts: 35,837

    Mr48chev
    ALLIANCE MEMBER

    Back in the 50's, 60's and even early 70's damned few guy thought about jumping in the car and making a 150 200 mile jaunt to a one day rod trot or swap meet if there was even one to go to. Now a lot of us do it all the time without giving it a thought. Jump in the car and run from Dallas to Little River for the drags and be back home in time to post the photos, no biggie.
    Run from Toppenish over White Pass to Chehalis for Billetproof with a breakfast stop on the way and dinner stop on the way back, nothing deal just another 400 mile day.
    In the 50's my now daily work commute was a big deal Saturday shopping trip for my mom and grandmother that they usually only did once a month.

    Most of us put more miles on our hot rods in a couple of months than a lot of guys in the 50's and early 60's put on their hopped up daily drivers in a year. The low gears and lower highway speeds didn't mean much then because most of us didn't spend a lot of time on the highway making miles like we do now.
     
  6. Hank
    Joined: Feb 18, 2005
    Posts: 234

    Hank
    Member
    from Wisconsin

    Find an old Saturn overdive unit. It goes on the back side of the T-Case if I remember correctly. I had the same set up in my 51. 60 mph was about 4k. Not real freindly on the old engine.
     
  7. Engine man
    Joined: Jan 30, 2011
    Posts: 3,480

    Engine man
    Member
    from Wisconsin

    I remember when gas was 17.9 cents a gallon in 1966 and 6 cents of that was tax. I'd take a quarter and a gallon gas can to the station. I'd fill the can and get a 5 cent cone at the Dairy Queen next door.
     
  8. hotroddon
    Joined: Sep 22, 2007
    Posts: 28,240

    hotroddon
    Member

    NOPE! If you do an inflation adjusted study of gas so that you have a relative number to work with, you will see that gasoline is still at an all time high, by about 25% over the previous worst year which was 1981 at $1.35 (with current adjustment it equals $3.37).
    from 1946 when gas averaged around 25 cents (which adjusted for inflation would have been about $2.25) through 1978 when it was average of 90 cents (adjusts to about $2.40) you can see that we are about double those years now. In fact 1986-2004 were about half of what we pay now.
    So gas today really is a lot more of a consideration than ever
     
  9. junk yard kid
    Joined: Nov 11, 2007
    Posts: 2,717

    junk yard kid
    Member

    Yes but you must factor in that most cars of today get much better gas millage so it is actually cheaper if you have a gas friendly egg shaped car. If you get bad gas millage yeah its pretty pricey. If cars got 100 mpg and gas was 20 dollars a gallon it would be pretty cheap per mile.
     
  10. Jagman
    Joined: Mar 25, 2010
    Posts: 345

    Jagman
    Member

    My old Jag came to the states with a 3:54 ratio and it was turning 3K at 70 mph, I broke the original pinion and when I rebuilt it I went with 3:07, the ratio the car came with in Europe. Now it does about 2350 at 70 mph, the engine feels more relaxed and it does get better mileage (went from 15 to 18 :D ), since the old Jag 6 cyl is a torque monster, it didn't seem to affect the around town performance - I always felt like I should start in 2nd gear with the old rear end anyway.....

    But then, I'm gettin older too......:rolleyes:
     
  11. Leebo!
    Joined: Nov 22, 2005
    Posts: 800

    Leebo!
    Member
    from Yale OK

    So if you dont have a torque monster, such as a 305, will it just wind t he RPMs way up to get going, and than just creep from there till highway speed?

    Tried a gear calculator with approx the size tires im getting, and it show 2140rpm at 65 mph. That didnt sound bad. My question is what happens from standstill until that point?
     
  12. What's your best guess?
    If its a very light car it will be ok on the way up to speed.
    If its heavy it will be about par with any other early 80's land yacht that got you where you wanted to go.

    It will be nice on a long cruise and get descent MPG either way.

    Neck snapping tire frier that tortures the seat mounts, probably not.

    Here's a funny story. At one time I had a Buick 401 nailhead with a 2:7x gear. That has something like 450 lbs torque at 2800 Rpms. It was no slouch and pretty nice to drive. Cruise fine, light the tires up when you wanted, great mileage.

    The Buick frame rusted and the drive train went into another car. That car was lighter, originally had a low torque 6 cylinder. The factory had a 3:26 gear in it to help the 6 get going.
    That car with the Buick engine was plain stupid. No traction, low weight, and GOBS of torque. You couldn't help but spin the tires.

    My mom needed to move it one day and all I heard was her pedaling it to keep the tires from spinning. She loved driving my Buick and she like the 6cyl. Firebird. With both together she called it an engine on a rollerskate.
     
  13. Leebo!
    Joined: Nov 22, 2005
    Posts: 800

    Leebo!
    Member
    from Yale OK

    Crap if I know :D

    I may stick with it for now and see what happens. The 54 isnt particularly heavy on a level surface.

    One more question and I will stop the madness>> If I do decide to change gear ratios, can I, and do it fairly affordably? I started looking at ring and pinions for it in lower ratios, most have notes that say "fits 2.73 and numerically higher carrier"

    I was told you could spacer and shim these up to the larger size. Is this feasible?

    I dont want to make all the necessary mounts for this, only to decide I have to change the whole rear end!
     
  14. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,339

    falcongeorge
    Member
    from BC

    Man, I am SO not a HAMBer...:rolleyes:
     
  15. UNCLECHET
    Joined: Dec 3, 2002
    Posts: 1,255

    UNCLECHET
    Member

    I don't like to go on road trips or go too fast. I dig a high reving SBC, four speed, and 4:10 gears. Punch it, run it up thru what ever gears you can, and then shut it down and enjoy the grin. If you want a high way cruiser this may not be the way to go.
     
  16. Leebo!
    Joined: Nov 22, 2005
    Posts: 800

    Leebo!
    Member
    from Yale OK

    I thnk George is knocking me here, just not sure how:p
     
  17. Leebo
    Your Chevy weighs about 3500 lbs.
    305 came in 130 HP to 250 HP versions.

    19 second or up to 14.9 second quarter mile times.

    My mom might beat you in her HHR

    New silverado truck in stock form with a 4.8 will run it in 16 flat.
     
    Last edited: May 17, 2012
  18. squirrel
    Joined: Sep 23, 2004
    Posts: 59,652

    squirrel
    Member

    oh yeah...you live in CA where the gas tax is $0.49/gal. You can get it for $3.37 in Tulsa.
     
  19. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,339

    falcongeorge
    Member
    from BC

    Didnt mean to target you especially. But I am not quite ready for the 2.73s, depends, geritol, and crybaby dolls yet...And if I ever am, Benno has orders to put me out of my misery...
     
  20. Leebo!
    Joined: Nov 22, 2005
    Posts: 800

    Leebo!
    Member
    from Yale OK

    No harm George! Thats why I am trying to figure out what my options are....dont want kids on big wheels, or old timers in strollers beating me from a dead stop!
     
  21. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,339

    falcongeorge
    Member
    from BC

    I really wonder if things are alot different where alot of the guys on here live, and I am not trying to be a wiseass. When I honestly look at my driving, 90% of it is on roads with moderate traffic, stop and go, and 40-50mph speed limits. Driving under those conditions, 4 series gears give up very little, if any fuel economy, because you can accelerate at the same speed as the surrounding traffic with virtually no throttle opening. And the seat of the pants feel at those speeds is like night and day. Maybe 10% of my driving is at freeway speeds (60mph+). I live in a urban area, so maybe my circumstances are alot different, but I wouldnt even consider trading off my 30 mph "WHACK POW" acceleration for 300 rpm difference in cruising rpm. If I was that worried about it, I'd just drive my wifes Toyota.
    If you guys are traveling at 60MPH+ for more than 10-15 minutes at a time everytime you take your cars out, you must sure rack up some serious mileage!
     
  22. squirrel
    Joined: Sep 23, 2004
    Posts: 59,652

    squirrel
    Member

    10k miles last year on my 55. And I see 15-20% mileage drop just going up to 3.70 gears.

    If you aren't going anywhere, then you can run some serious gear.
     
  23. UNCLECHET
    Joined: Dec 3, 2002
    Posts: 1,255

    UNCLECHET
    Member

    That's why a quick change rear end would be cool. If you were going to be on the open road just throw in some appropriate gears. Yeah, you still have to work on it a bit but I think that would be fun. Maybe on my next car.
     
  24. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,339

    falcongeorge
    Member
    from BC

    Mostly, I am driving around the valley here. My commute to work is about 8 miles, I am on the "freeway" for part of it, in rush hour that is actually probably the SLOWEST part:eek::rolleyes: This morning, I got up to around 45mph as I was exiting the "freeway" traffic was light because of the long weekend. Usually the bridge/freeway is bumper to bumper, stop and go, about 30 mph. A freeway runs down the center of the valley, but as soon as you are off the freeway, you are back to stop & go. I probably do 8-10k a year, but BY FAR the majority of it is in moderately heavy, stop and go traffic.

    I'm REALLY surprised more HAMBers arent doing this sort of driving. I know what Seattle is like, other than the I-5, its pretty much the same as here. Maybe I need to move out of the city...
     
  25. squirrel
    Joined: Sep 23, 2004
    Posts: 59,652

    squirrel
    Member

    yup. For me it's 10 miles into town, five miles across town, 75 miles to a decent sized city. 500-1500 miles to where the action is.

    also with 700 hp you dont' need much gear
     
  26. AnimalAin
    Joined: Jul 20, 2002
    Posts: 3,416

    AnimalAin
    Member

    For a non-OD transmission, I like the tire diameter and rear gear to have the same numbers. For example, my roadster ran for years with a 3.00 gear and thirty inch tires. This gives about 2000 rpm at 60 mph. A nice compromise.

    With an OD, you can go steeper in the rear end and still get the same cruising rpm as before. My coupe has 4.57 gears, but with the AOD transmission, it works out to about 3.04 (with a 30 inch tire) in fourth. My roadster is a little lighter, so I run 3.90 (again with 30 inch tires) for an overall top gear ratio of 2.60. They both work really well; short, sporty gearing around town, and a tall ratio for the highway. Of course, to get this benefit, you have to be willing to use a later transmission.
     
  27. OldsRanch
    Joined: Feb 18, 2004
    Posts: 185

    OldsRanch
    Member

    those 70s-80s skyscraper gears (2.41, 2.29 and 2.19 were common, plus the gbody getting 2.56s and OD) were only to get the "grams per mile" emissions down.

    I put 200K on a car with 2.41 and no OD, it was fine. Went 50K in a car with 2.56 and OD, it worked out to 1.71:1 overall. Miserable.


    4.56s, FTW!
     
  28. CutawayAl
    Joined: Aug 3, 2009
    Posts: 2,144

    CutawayAl
    Member
    from MI

    In the '60s and '70s a 3.9:1 gear was the compromise performance/road ratio. Today 3.7:1 is popular. If you look at the diameter of tires typically used in the '60s and '70s compared to what is common today, a 3.7:1 works out to about what a 3.9:1 was with larger diameter tires.

    The biggest difference today is the ratio spread available in transmissions. Old performance worthy transmissions had first gears that ranged from ranged the 2.2 first gear in a Muncie to maybe 2.8:1 at most. The popular Cad-Lasalle was 2.3 something. And, all those transmissions had a 1:1 high gear. Today, first gears are routinely 3.0:1 or lower, with one or even two overdrive ratios.
     
    Last edited: May 18, 2012
  29. Fuzzy Knight
    Joined: Jun 8, 2009
    Posts: 11,806

    Fuzzy Knight
    Member
    from Santee, Ca

    I run 3.25 on the street and am thinking I will go to 3.55s soon. I run 4.62s at the drags. Rear is a 8in ford so swapping gears is only about an hour job.
     
  30. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,339

    falcongeorge
    Member
    from BC

    My yet to be finished (at the rate things are going lately, maybe I should say "never to be finished" :rolleyes:) Chevy II will be the first car I have owned with an OD. 25" tall tires, 4.10s, and a 200R4 with a 9.5" lock-up converter. If I wasnt running the 200R4, I'd still keep the 4.10s, and just live with 3700 RPM @ 60 mph. The main reason I went with the od is the performance goal for this project is 20 mpg hwy, 11 second 1/4s, and a carb.
    Whatever I build, I set an expected performance goal in the planning stages. And As far as Jims comment about 700hp not needing much gear, I would amend that to "artificially aspirated 700hp doesnt need much gear".
     

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