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Axle

Discussion in 'Modified Alpine' started by PROCRAFT, Dec 2, 2019.

  1. PROCRAFT

    PROCRAFT Gold Level Sponsor

    Time to change the ratio. IMG_20191202_133133833_HDR.jpg
     
  2. 260Alpine

    260Alpine Silver Level Sponsor

    Joel, What are you changing from and to?
     
  3. PROCRAFT

    PROCRAFT Gold Level Sponsor

    Has 3.73 gear now,I've used that setup in the past after driving this awhile just not quite to my liking going to 3.27 gear will see what happens.almost went to 3.08. drop the revs maybe 600 on the road.
     
  4. alpine_64

    alpine_64 Donation Time

    Joel are you running a 4 or 5 speed? Given all your mods i always assumed a 5 speed.. A 3.7 with 5 speed would seem a nice balance.. With a 4 speed probably a bit revvy on cruise.

    Ive got a 3.07 with 195/60/14s and id love a 5th gear to knock back rpm on cruise
     
  5. PROCRAFT

    PROCRAFT Gold Level Sponsor

    I'm running a 5speed but with this car I'm thinking it doesn't like the 3.73 gear. I'm using 255/50 rears 195 fronts.well see how it works out. Doesn't really drive right?
     
  6. alpine_64

    alpine_64 Donation Time

    You are not liking the rpm or response in 5th when cruising or the balance between the acceleration in intermediate gears vs final? What o/d ratio is the 5th?
     
  7. PROCRAFT

    PROCRAFT Gold Level Sponsor

    Response is not a problem in any gear, I'm not liking the overall balance this is a 1950# car I reckon after putting a 1000 miles on it it just doesn't need a 3.7 gear.we will see!
     
  8. George Coleman

    George Coleman Gold Level Sponsor

    I use a Toyota 5 speed and the 3.7 gear worked very well for me, but the 3.7 set was a new piece from Holland and it was always noisy. Wish I could find a Alpine GT 69 or so that had the factory 3.7 gear.
     
  9. alpine_64

    alpine_64 Donation Time

    George.. Joel's has a but more torque and power than a rootes 4....

    My alpine has a 3.89 with OD and 195/65/14s.. Very good gearing for highway in an 4cyl alpine
     
  10. Barry

    Barry Platinum Level Sponsor



    I think Joel is on the right track.

    A light car with a powerful engine and short gearing can have an awkward feel. Light and powerful are pretty easy to understand; gearing not so much because people get tangled up in ratios rather than the more universal MPH / 1,000 RPM that takes BOTH gear ratios AND tire diameter into account.

    For comparison, the current manual transmission ZL1-1LE Camaro and GT500 Mustang are about 6 lbs. / HP with a 1st gear that is about 8 MPH / 1,000 RPM. A stock Mk-I Tiger is about 15 lbs. / HP and 10 MPH / 1,000 RPM in 1st gear. A stock Mk-II Tiger is about 12 lbs. / HP and 8.3 MPH / 1,000 RPM in 1st gear. A stock S-V Alpine is about 23 HP / lb. and 5 MPH / 1,000 RPM in 1st gear.

    Joel's 1,950 lb. "Alpine" with about 450 HP is only 4.3 lbs. / HP and has gearing and tire size that works out to about 6 MPH / 1,000 RPM in 1st gear. It is no wonder that the gearing "balance" does not feel right.

    Changing from a 3.73:1 to a 3:27:1 rear end will increase the 1st gear MPH / 1,000 RPM to about 7 MPH / 1,000 RPM. Better, but still pretty "short" for a car with only 4.3 lbs. / HP. A 2.95:1 1st gear and 3.27:1 rear end would be about 7.7 MPH / 1,000 RPM. A 2.95:1 1st gear combined with a 3.00:1 rear end would give about 8.5 MPH / 1,000 RPM in 1st gear which would probably "feel" pretty good.
     
  11. PROCRAFT

    PROCRAFT Gold Level Sponsor

    370 ft.lbs
     
  12. PROCRAFT

    PROCRAFT Gold Level Sponsor

    Barry
    Almost went with a 3.08 not
    together yet have to Maybe think a little more about this
     
  13. alpine_64

    alpine_64 Donation Time

    Joel i have 338lbft in my tiger wirh 3.07lsd... In the dry its a blast... In the wet... Not so much.. So in your car with such a lightweight body... The taller gearing would help calm it down.

    One of my alpines is only 1925lbs and it certianly makes it sprightly with only a 1600cc
     
  14. Barry

    Barry Platinum Level Sponsor


    Out of curiosity, which T-5 are you using?
     
  15. PROCRAFT

    PROCRAFT Gold Level Sponsor

    Old beat up world class 4 CYLINDER T5 that's been re built 3... First and .7 Fifth you were right about feel. One of the Tigers I had with a 289 I put a 3.07 gear in it it also had a 5 speed out of an S10
     
  16. Barry

    Barry Platinum Level Sponsor

    Did not realize that you were using a S-10 T-5. The S-10 T-5 shifter location works well for a V8 Alpine with the engine and firewall moved back, but the first gear ratio leaves a lot to be desired (3.76, 3.97 or 4.03) and only gives about 5 MPH / 1,000 RPM with the 3.73 rear end and 255/50-16 rear tires. Putting a 2.95 gearset in the S-10 transmission (you have to keep the S-10 tailshaft that matches the S-10 tailshaft housing) might make a big difference in the feel.
     
  17. PROCRAFT

    PROCRAFT Gold Level Sponsor

     
  18. PROCRAFT

    PROCRAFT Gold Level Sponsor

    Mustang T5 Gearbox 4Cylinder Car.
     
    Series6 likes this.
  19. Barry

    Barry Platinum Level Sponsor

    Chevy or Ford, it's still a 4-cylinder T-5 with the same problem (a 3.97:1 first gear) and the same solution (a better transmission gearset).
     
  20. PROCRAFT

    PROCRAFT Gold Level Sponsor

    My problem I reckon not yours.
     
    Series6 likes this.

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