Lets get some gear ratio input...

jjbubaboy
jjbubaboy Senior Contributor
edited May 2012 in HUDSON
Ok, so I am retrofitting an 89, 'other make', (Mustang) rear for my 36T. It has 327 gears and I was planning to put 355's in it being as thats what the imported English ones were and those that have them think its just right. (Thanks Richard!)
Would the 327 be too tall for hill climbing etc? Whats the opinions, considerations. advantages, drawbacks etc?
Thank you,
Jeff

Comments

  • terraplane8
    terraplane8 Senior Contributor
    The Light Sports Railtons had 3.3 or 3.5 to 1 but they were pretty light being open tourers.

    3.55 is probably about right. I don't think a 212 would pull a 3.27 gear in top up a really long steep hill. Depends on what sort of hills you have.
  • bob ward
    bob ward Senior Contributor
    The other thing to look at is engine RPM at say 60mph.

    Assuming your tyres have a rolling diameter of 30", with a 3.27 axle your engine will doing 2213 RPM, with a 3.55 axle your engine will be doing 2402 RPM.

    Those engine RPMs will go up with smaller rolling diameters and down with larger rolling diameters.
  • Park_W
    Park_W Senior Contributor
    Try the 3.27s and see how it does on the hills. 3.55 is a nice compromise, but if you'll be driving on the Interstates at 65 for extended periods, I'd keep the 3.27s unless there's a hill-climbing problem.
  • Ducor Kid
    Ducor Kid Expert Adviser
    Here is the calculator that I use to pick what ratio to use based on tire size and speed.

    www.accuautoparts.com/calculator.jsp

    Larry
  • jjbubaboy
    jjbubaboy Senior Contributor
    Well after some consideration and inputting differernt info into the calculators at www.ringpinion.com I am going to go with the 3.55's and see how it goes.
    Will post the results when done.
    Thanks all for the input.
    Jeff
  • Park_W
    Park_W Senior Contributor
    Jeff, if the unit is 3.27 now, why not try that and see what you think after a reasonable period. If 3.27 is too tall, then you can change out to 3.55. I think you may be surprised at how that long-stroke 212 handles 3.27.
  • [Deleted User]
    [Deleted User]
    Walt here; 52 to 54 Hornets with the 308 engine have 308 rear ratio being a DANA 44 unit. At 60 MPH the engine is turning 2400 RPM's. I changed to 2:78 ring and pinion, a DANA 44 part and now turns 2000 at 60 MPH. 400 RPM savings and have lost no torque and still make the hills like it use too. 710x15 is replaced by 215/75Rx15 radials.
  • [Deleted User]
    [Deleted User]
    Forgot to mention, had to have the speedometer repaired to read the speeds now. Took it to a speedometer repair company and they put the car on a dyno and run engine to 60 MPH on a big speedo on the wall in front of the car and my speedo was showing 52 MPH. They install some kind of transmission to my auto-matic and keep changing little gears inside till my speedo also showed 60. Cost was $92.00 and guaranteed. Also give you a letter to carry in the car. Walt.
  • jjbubaboy
    jjbubaboy Senior Contributor
    edited May 2012
    Thanks Park, and Walt! I figured it would throw off the speedo and I will have to check around and see who does that around here.
    The 3.55's will drop me 411 rpm's @ 60. (according to calculations)
    Jeff
  • Lee ODell
    Lee ODell Senior Contributor
    edited May 2012
    My speedometer error was very close to Walt's speedometer error. At 60 MPH my speedo was showing 53 MPH. I didn't have the money to have the speedo transmission adaptor installed. I asked if I could have the speed corrections written down for all the common posted speed limits so I would have a speed reminder with me in the car. It cost $35 for the service 1 1/2 years ago. This is what they gave me. I thought it interesting the odometer was 100% accurate but the speedometer was off about 9%. 52 Hornet, tires 225R15, 3.08 gears, Hydro trans.

  • [Deleted User]
    [Deleted User]
    Just means its an old speedometer, the odometer is gear driven .While the needle is driven by a spinning magmetic field. The old permanant magnets ar probbably a little weak,
    Roger
This discussion has been closed.

Categories

In this Discussion