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T5 with a 1725 motor

Discussion in 'Modified Alpine' started by Mag0152, Jan 16, 2022.

  1. DanR

    DanR Diamond Level Sponsor

    Many THANKs, Tigretr !

    Great work.
     
  2. tigretr

    tigretr Donation Time

    I just went back and re-read all the posts about this swap. There is still the flywheel / clutch question I left unanswered.....until now! I used a 8.5" Alpine flywheel which I then significantly lightened (pictures at http://turbosunbeamalpine.com/mysunbeamalpine/Parts.html). I had the pressure plate rebuilt and then had a kevlar 8.5" clutch disk made. The kevlar is great for applications where oil may be present (and well, that describes an Alpine). The only time I ever have clutch grip issues is if I am launching and I slip the clutch too much. Once it gets hot there is a perceivable delay in grip, but it still grabs and won't slip when my foot hits the floor. This is with 182 WHP.
    A few minutes later I could sidestep the clutch and it would grab up as normal. The kevlar is pretty impressive.

    https://www.moderndriveline.com/ are the T5 and clutch gods. I worked extensively with them (Bruce Couture-owner) to design my T5 and clutch package. I highly recommend utilizing their expertise.

    Brian
     
  3. spmdr

    spmdr Donation Time

    Just for clarification, Brian mentioned using a T5 from 1985-1989.

    In that time frame, Ford used 3 different T5s, V8 and 4 cylinder (with 2 different ratios).

    The bad news is they look identical at a glance!

    But they have different ratios.

    And then, on top of that, the new T5 you would buy today has yet Different ratios.


    I'll let you do some homework on the web about T5 ratios, But just know that for the example

    of Ford, the T5 could have first gear ratios from 2.95 up to 4.03.

    If you have an Alpine with a 4.22 rear gear, a T5 with a 4.03 first gear would be of questionable use.

    Brian, what first gear do you have?

    DW
     
    Last edited: Jan 18, 2022
  4. tigretr

    tigretr Donation Time

    That is a great point. I forgot to mention that my T5 is a World Class (WC) T5. Gear ratios are as follows:
    1st: 3.35
    2nd: 1.99
    3rd: 1.33
    4th: 1.00
    5th: 0.73

    My 7.5 inch rearend was a 3.45:1 which was a bit tall. My 9 inch rearend is now 3.70:1 which gets up and goes. The 3.45 was nice on the freeway because the motor was spinning around 2500RPM @ 65-70MPH in 5th gear. The 3.70:1 spins around 3000 RPM @65-70MPH which is a bit high since I rarely cruise at 65-70, more like 75-80.!

    You do have some choices on gear rations in these tranny's. Modern driveline was able to do some mixing and matching or at least find the tranny with the best gear ratios for my application. I do recall I was able to select which 5th gear I wanted. Maybe it has it's own counter shaft that enabled the ability to choose.

    Hope this helps,
    Brian
     
  5. DanR

    DanR Diamond Level Sponsor

    The T5 Brian recommends has the same ratios (3.35 1st gear) that I like in the V6 Conversion.....1352-238 (Mustang 3.8 V6) World Class.

    If you are lucky enough to find one from a 5.0 with 2.95 1st gears have at it.
     
  6. 260Alpine

    260Alpine Silver Level Sponsor

    Dan, Only ones from the factory with 2.95 were 83-84 NWC Mustang. Ford Performance and Tremec aftermarket T5Z WC is available. Also Summit and Jegs for $2200. Ouch!
     
  7. Mag0152

    Mag0152 Donation Time

    Unfortunately Brian, we cannot read the dimensions
     
  8. Bill Blue

    Bill Blue Platinum Level Sponsor

    My take on the above is that the stock 8 1/2" clutch assembly is compatible with the Ford T 5 . No modifications required. Is that correct?
    Bill
     
  9. DanR

    DanR Diamond Level Sponsor

    Mr Bill, the stock Alpine clutch disc spline hole is one (1) inch with 10 teeth, the T5 is one and a sixteenth (1 1/16") inch dia ten teeth.

    I have an OD Trannys from '79 Volvo that has the same input shaft as the Alpine. The clutch disc for the Alpine fits perfect.
     
  10. tigretr

    tigretr Donation Time

    Modern Driveline made my 8.5" clutch disc and pressure plate. There are a lot of 8.5" clutch discs for T5. I would recommend calling them or a knowledgeable aftermarket clutch/tranny shop and seeing what they recommend.

    Sorry the dimensions on the drawing aren't legible. I made the font larger and added some annotations. I hope this is better. Again, keep in mind, these numbers should be verified for each particular application, starting with the input shaft length.

    Brian

    upload_2022-1-19_21-59-3.png
     
  11. Bill Blue

    Bill Blue Platinum Level Sponsor

    Thanks for the clarification. Sounding like a good upgrade for our '69. An "invisible" improvement that makes interstate driving a viable alternative. Been thinking about doing this, your post is probably enough to make it a reality.

    Bill
     
  12. Alpine 1789

    Alpine 1789 SAOCA President Diamond Level Sponsor

    Just a hint: with original OD transmissions increasingly hard to come by, this would be a great kit for someone here to make!
     
  13. bobbo

    bobbo Gold Level Sponsor

    sitting in my garage is a T5 I had waiting for a V6 conversion I have since dismissed. A kit to install it on my 1725 would be a real gamechanger for the highway. Keeping eyes on this thread.
    Bob
     
  14. Barry

    Barry Platinum Level Sponsor

    Putting a T-5 transmission in a Series Alpine strikes me as a potentially good alternative to factory O.D.'s, but it is not as simple (or cheap) as some people seem to think.

    The "T-5 conversion" being discussed in this thread requires the use of an input shaft with a length of 7.85".

    AFAIK, the only OEM production T-5's with 7.85" input shafts were the -219, -242 and -246 with ratio's of 3.35, 1.99, 1.33, 1.00 and 0.68:1 and the -220, -236 and -238 with ratio's of 3.35, 1.99, 1.33, 1.00 and 0.73:1. Whether or not a stock-ish Series Alpine engine can pull either of those 5th gear ratios is a relevant question.

    The newest of the production T-5's listed above is over 25 years old and a rebuild with new parts (shafts, gears, bearings, synchronizers, seals, etc.) and labor is probably at least $1,500 for a ready to use transmission. Another $500 (maybe more) for the adapter plate, $100 for a clutch disc, $200 for a clutch cover, $100 for a transmission mount, $100 for a shifter and $100 for a driveshaft adds up to over $3,000 just for the major parts. Don't forget about modifying the transmission tunnel.

    If I were thinking about a T-5 conversion for a Series Alpine with a factory engine, I would seriously look into one of the aftermarket T-5's with 2.95, 1.94, 1.34, 1.00 and 0.80:1 gear ratios (1352-202 and 1352-225) which are pretty close to the factory S-V O.D. transmission ratios of 3.12, 1.99, 1.29, 1.00 and 0.80:1. Note that the aftermarket 2.95 / 0.80 T-5's had 7.18" input shafts. It is technically possible to combine a 7.85" input shaft with a 2.95 / 0.80 gear set, but that would probably require the services of a "T-5 specialist" such as Modern Driveline. Don't see any reason why a rebuilt 2.95 / 0.80 T-5 would cost any more than a rebuilt 3.35 / 0.68 or 0.73 T-5.

    Not trying to rain on anyone's parade, just pointing out some of the "opportunities".
     
    Last edited: Jan 20, 2022
  15. Bill Blue

    Bill Blue Platinum Level Sponsor

    Okay, three grand for the T5 is kind of spendy. The real question though is what is the cost of the alternatives?

    How well the Alpine can pull those ratios is a good question. About twenty years ago, Ian raved about the joy of driving one of the fast back cars setup with a 3.7 rear and O.D. Of course, down shifting with the flick of a lever is different than going from 5th to 4th.

    Bill
     
  16. spmdr

    spmdr Donation Time

    As it turns out, I have several T5s, both 3.35 and 2.95 boxes.

    Most of them are V8 boxes and None have the long input shaft.

    ...."Requires".... seems to be a challenge.

    One thing I agree with Barry about is the first choice of a 2.95 box for an Alpine.

    3.35 boxes have a BIG jump from 1st to 2nd gear, 2.95s have better gear spacing.

    The only questions are 3.89 or 4.22 rear gear, what 5th gear and what tail housing.

    If I put a T5 in an Alpine, it WILL be a short input box.

    DW
     
    Last edited: Jan 21, 2022
  17. alpine_64

    alpine_64 Donation Time

    As for stock motors pulling tall gears.. My 1494 ( admittedly slightly warmed up) runs with a factory OD box, 3.889 rwar amd i run 195/65/14 tyres on the rear.. Its very tall geared and manages fine on a long highway run, now a steep incline might require a change back to direct top .. But for me i think an effective final drive of around 3.2 is acceptable with a rootes engine
     
  18. Bill Blue

    Bill Blue Platinum Level Sponsor

    Yes, I think that 3.2 is very close to optimum, depending on the individual circumstances. What is evident is that a 3.89 combined with .73 O.D. results in 2.8 O.A. Very iffy. A 4.22 giving a 3.14 O.A. would probably be fine. You certainly would not be shopping for tall tires!

    Bill
     
  19. DanR

    DanR Diamond Level Sponsor

    The chart below identifies various T5 applications and their specifications. The choice of your transmission may be a personal preference, availability and cost. Comments following may provide you with some fodder……

    B/W Id Source Application-Torq Max (lb/ft)-Gear Ratios-Input Shaft length
    1352- Year Model Engine 1st 2nd 3rd 4th 5th R
    220 Factory 94 Mustang 3.8 265 3.35 1.93 1.29 1 0.73 3.15 7.85
    236 Factory 94 1/2 Mustang 3.8 265 3.35 1.93 1.29 1 0.73 3.15 7.85
    238 Factory 94-97 Mustang 3.8 265 3.35 1.93 1.29 1 0.73 3.15 7.85
    126 Factory 85 Mustang 5 265 3.35 1.93 1.29 1 0.68 3.15 7.18
    141 Factory 86 Mustang 5 265 3.35 1.93 1.29 1 0.68 3.15 7.18
    165 Factory 86 Mustang 5 265 3.35 1.93 1.29 1 0.68 3.15 7.18
    219 Factory 94 Mustang 5 300 3.35 1.99 1.33 1 0.68 3.15 7.85
    169 Factory 86.5-89 Mustang 5 265 3.35 1.93 1.29 1 0.68 3.15 7.18
    199 Factory 90-91 Mustang 5 300 3.35 1.99 1.33 1 0.68 3.15 7.18
    208 Factory 92-93 Mustang 5 300 3.35 1.99 1.33 1 0.68 3.15 7.18
    246 Factory 94-95 Mustang 5 300 3.35 1.99 1.33 1 0.68 3.15 7.85
    218 Factory 93 Mustang Cobra 310 3.35 1.99 1.33 1 0.68 3.15 7.18
    242 Factory 94-95 Mustang Cobra 5.0 310 3.35 1.99 1.33 1 0.68 3.15 7.85
    115 Motorsport 79-83 Mustang 5 305 2.95 1.94 1.34 1 0.63 2.76 7.18
    200 Motorsport 79-93 Mustang 5 305 2.95 1.94 1.34 1 0.63 2.76 7.18
    227 Motorsport 79-93 Mustang 5 325 2.95 1.94 1.34 1 0.63 2.76 7.18
    249 Motorsport 79-93 Mustang 5 33 0 2.95 1.94 1.34 1 0.63 2.76 7.18
    204 Service 85-89 Mustang 5 300 3.35 1.99 1.33 1 0.68 3.15 7.18

    Notice some V8 have the longer input shafts.
     
    Last edited: Jan 21, 2022
  20. DanR

    DanR Diamond Level Sponsor

    DW, in the drawing Brian furnished above his input shaft is the longer one (7.85).

    My question is why do you say "yours will be short" ?
     

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