Gtv6-1982: New 1st and 2nd gear ratios - Alfa Romeo Bulletin Board & Forums
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post #1 of 20 (permalink) Old 06-18-2019, 10:19 AM Thread Starter
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Gtv6-1982: New 1st and 2nd gear ratios

I know this is an old topic and I tried to search the forum for the correct answer, so I go again asking probably a question has been asked before, hoping someone has done what I want to do: My 1982 GTV6 has undergone a complete blueprinting, overhaul, improvements, etc. to the point that I can almost, and I say "almost" compare it to the drive feeling of driving a 4C, of which I have had the luxury and priviledge to drive two, a launch version and a spider one.

Needless to say, I fell in love with that "go kart" stiffness of its carbon-fiber tub and the quickness of the engine turbo and shift mapping. Since I cannot own one for financial reasons, I can easily content myself with my GTV6 which has brought me decades of fun driving, except.......those **** short shifting (hight ratio) first and second gears!!!

I read over the years here and there on this forum and others, that people like Larry Jr. at APE in Tracy, California have been reconditioning transaxles and gearboxes to light gears and different ratios of 1st and 2nd, from the 75's or Verdes. I can't remember which ones. My GTV6 has so much pep and bottom pick-up with lots of torque, that every time I start the car and drive it for the first 2 blocks, I feel like am in a straight jacket. The 1st is like a tractor and the 2nd. never seems to pick up speed even at 4,000RPM.

Is there a tried-and-true different ratio for the 1st and 2nd gear on these transaxles that would make the engine power expose and show itself properly without feeling like a Jack in the box getting ready to jump out? I would love to make my GTV6 drive like a properly ratioed car.

Thanks,

Namarena
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post #2 of 20 (permalink) Old 06-18-2019, 12:09 PM
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Your only realistic option is to fit a Milano Verde transaxle as first and second are a little taller. On the downside, the final drive is shorter than your 82. It's a pretty straight forward swap. You will need to put an early shift fork into the verde box to mesh with the early gear selector and change the speedo sending unit. I personally went to GPS as the amplifier for the later sending unit is hard to come by and isn't terribly accurate. I can hit 60 in second gear now which is nice but I do miss the final drive for freeway driving. I also lightened the gears which makes shifting a little quicker. I hope this helps.
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post #3 of 20 (permalink) Old 06-18-2019, 02:42 PM Thread Starter
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Thank you Gmjohns; I don't know if I want to do that though, as I have already two GTV6 transaxles, and I was hoping for just internal guts change type of improvements (gear changes, idlers, etc.). I remember someone had done that on this forum sometime ago but I cannot find the post or thread. In fact the reason why that person did it that way was the GTV6 final drive ratio as well, which I love too for highway driving.

I shall keep on searching though!

Namarena
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post #4 of 20 (permalink) Old 06-18-2019, 05:27 PM
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I read that somewhere too. Although it's my understanding you can't mix and match gears from late to early or vise versa.
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post #5 of 20 (permalink) Old 06-18-2019, 05:41 PM
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This is from an old post by Richard Jemison. There is not much that he doesn't know about Alfa transaxles.


Quote:
GTV 6 RATIOS:
---------------------
1981: 1=3.50; 2=1.956; 3=1.345; 4=1.026; 5=0.780
@ 4.10

1982: 1=3.50; 2=1.956; 3=1.258; 4=0.946; 5=0.780
@ 3.42 Source: Owner's Manual

1982: 1=X.XX; 2=x.xxx; 3=x.xxx; 4=x.xxx; 5=x.xxx
@ 3.42 Balocco - Probably same as '82 above.


1985:Late 1=3.50; 2=1.956; 3=1.258; 4=0.946; 5=0.780
@ 4.10

1986: 1=2.875] 2=1.720; 3=1.226; 4=0.946; 5=0.780
@ 4.10

1986: 1=3.58; 2=1.96; 3=1.26; 4=0.95; 5=0.780
Calloway
@ 4.10

Gtv6 3.0 1=1.3500; 2=1.956; 3=1.345; 4=1.026; 5=0.780
@ 4.10 (They listed a 3.0)


MILANO/75
Verde 1=2.88; 2=1.72; 3=1.23; 4=0.95; 5=0.78 (LSD)
@ 3.55 (39/11)

Platinum: Same as Verde (LSD)
@ 4.10 (41/10)

Silver/Gold 1=X.XX; 2=x.xxx; 3=x.xxx; 4=x.xxx; 5=x.xxx (NO LSD)
@ 4.10

1988 TS: 1=1.288; 2=1.72; 3=1.23; 4=0.95; 5=0.78 (LSD)
@ 4.10 (41/10)

1.8 IE: 1=2.88; 2=1.72; 3=1.23; 4=0.95; 5=0.78 (NO LSD)
@ 4.10

1.6 IE: 1=2.88; 2=1.72; 3=1.23; 4=0.95; 5=0.78 (NO LSD)
@ 4.55 (41/9)

1.8 Turbo 1=2.88; 2=1.72; 3=1.23; 4=0.95; 5=0.78 (LSD)
@ 3.91 (43/11)


ALFETTA:
Early: 1=3.3; 2=2.01; 3=1.37; 4=1.039; 5=0.83
@ 4.10

Late: 1=3.31; 2=1.96; 3=1.34; 4=1.026; 5=0.83 @ 4.10 (Source: '78 Owner's Manual)

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I have a Milano platinum transaxle in my 85 GTV6 and I like the slightly higher first and second gears. I have owned a couple of Milano Verdes and I would not want a Verde transaxle with a 2.5 motor.

Ed Prytherch
79 Spider
85 GTV6 3L
76 Suzuki GT500
2011 Jaguar XKR

A little government and a little luck are necessary in life, but only a fool trusts either of them. - P.J. O'Rourke
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post #6 of 20 (permalink) Old 06-18-2019, 08:27 PM
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You can swap the input shaft and lay gears from a Milano into a GTV6 transaxle. That way you can avoid messing with the speedometer and get the much better gearing spread. Make sure you measure the pinion depth of the box you are keeping before disassembly and keep the entire stack of races and shims from the pinion shaft in order.
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post #7 of 20 (permalink) Old 06-19-2019, 08:24 AM
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Does anybody know the cut-in date (VIN) for the 86 gear ratios? Is it 86 model year or 86 year of manufacture?
And it really just a Milano Platinum transaxle minus the LSD? Seems like a weird parts bin mix.

Last edited by GTV6noob; 06-19-2019 at 08:29 AM.
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post #8 of 20 (permalink) Old 06-19-2019, 09:46 AM
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Quote:
And it really just a Milano Platinum transaxle minus the LSD
Milano Silver and Gold did not have LSD. Platinums had LSD with a "normal" 4.1 axle and Verde's had LSD with a 3.55 axle.

The ratio change probably occurred when the switch was made from the simple shift mechanism to the complex one and also when the speedometer sender changed. and when the torsion bars changed - all around mid '85.

Ed Prytherch
79 Spider
85 GTV6 3L
76 Suzuki GT500
2011 Jaguar XKR

A little government and a little luck are necessary in life, but only a fool trusts either of them. - P.J. O'Rourke
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post #9 of 20 (permalink) Old 06-19-2019, 10:57 AM Thread Starter
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So much good info here. Great, thank you guys!

It turned out that after reading Alfaparticle post, I called Larry at APE to confirm what was the transaxle he had sold me (my extra one), and as far as he remember, it was from a race in Modesto, CA whom used it for racing and that it might be a Platinum (with LSD), because that was the reason I had asked for the extra transmission to him in the first place.

He also mentioned that with his son, he was never able to find out on the GTV6's any external markings on the tranny cases to differentiate them, except on the Spiders, he said they noted some paint markings that correlated to certain years of manufacture. Larry said there was no way to check externally if it was LSD or not (contrary to what I've read in this forum) and the only way was to mount it on my GTV6 82 and drive it.

Being the engineer that I am, I will open it up and try to figure out what transmission ratios it has, and the list from Richard Jamieson will help. One comment from Alfaparticle got me thinking; you said you had a Platinum on your 85 GTV6, but would not put a Milano Verde on an 82GTV6. Is that because of the different final ratios or 1st and 2nd ones? I suppose a Platinum on a 1982 GTV6 like mine would be fine then?

Thanks,

Namarena
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post #10 of 20 (permalink) Old 06-19-2019, 11:07 AM
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Quote:
Is that because of the different final ratios
Yes. The high ratio in the Verde is great for cruising and the 3L power makes the acceleration reasonable but my preference is 3l power with a 4.1 axle. It is a lot more fun. That is where the higher 1st and 2nd ratios of the late transaxles are preferable to the ones that were in my '84.

Ed Prytherch
79 Spider
85 GTV6 3L
76 Suzuki GT500
2011 Jaguar XKR

A little government and a little luck are necessary in life, but only a fool trusts either of them. - P.J. O'Rourke
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post #11 of 20 (permalink) Old 06-19-2019, 12:45 PM Thread Starter
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Thanks for the clarification. Then, since my 2.5L is not your average stock GTV6, since I lightened the flywheel by 7 lbs, ported exhaust and intake by a race shop, blueprinted injection and distributor systems, installed CSC stainless straight-thru exhaust system, it probably makes at the wheel a reasonable 15 to 20HP more than the stock. Will that compare to the power of a 3L?

And at worse case, couldn't I put the gear train of the Platinum and keep the final of the stock 2.5L? Have my cake and eat it too.

I don't want to race this car on tracks, but my driving style is getting off the line fast (street driving only) but not for street rubber burning either, just I like quick get up cars. That is why I am in love with the 4C. Never driven a car that fast off the line, production/street type of course. However, I would like the final to be where I can run the engine at the least possible RPMs while going as fast as possible (meaning an axle with a less than 4.1 ratios, somewhere?).

Thanks,

Namarena
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post #12 of 20 (permalink) Old 06-19-2019, 01:47 PM
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It's really more about torque for the gear ratio question, I think.

I have a 3.5L and it makes a ton of torque all along the rev range. The verde ratios pair nicely with it---a shorter set wouldn't be quite as much fun as I don't get to enjoy 2nd gear long enough as it is. The longer ratios are nice as 100mph comes easily. The shorter gear sets would be running out of rpm by then, I think.

But as others have said, the 3L or 2.5L are best enjoyed with shorter gears.

Stacy Faught -- Alfas: 1983 GTV-6, 2018 Giulia Quadrifoglio. Non-Alfas: 1991 Corvette ZR-1
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post #13 of 20 (permalink) Old 06-19-2019, 02:50 PM
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With a 4.1 axle, 6500 in 4th gear is about 105 mph. With a 3.55 it is over 120. 3.55 is 3 useful gears and two overdrives unless you have somewhere to drive very fast.

Ed Prytherch
79 Spider
85 GTV6 3L
76 Suzuki GT500
2011 Jaguar XKR

A little government and a little luck are necessary in life, but only a fool trusts either of them. - P.J. O'Rourke
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post #14 of 20 (permalink) Old 06-19-2019, 07:34 PM
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Quote:
Originally Posted by onethumb View Post
It's really more about torque for the gear ratio question, I think.

I have a 3.5L and it makes a ton of torque all along the rev range. The verde ratios pair nicely with it---a shorter set wouldn't be quite as much fun as I don't get to enjoy 2nd gear long enough as it is. The longer ratios are nice as 100mph comes easily. The shorter gear sets would be running out of rpm by then, I think.

But as others have said, the 3L or 2.5L are best enjoyed with shorter gears.
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post #15 of 20 (permalink) Old 06-21-2019, 05:25 PM
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To confirm what speedo drive you have. Pull out the speedo sender from the transaxle look into the hole with a light if the sender drive is a helical cut gear the transaxle is from a GTV6. All 75's/Milanos have a hall effect senders.
If you remove the diff cover from the rear of the transaxle you can easily pull the differential out, the final drive could be a 4.1 or 3.55 (there are others) there will be a number stamped on the crown wheel if the number is 11 3.9 then you have a 3.55 ratio, by dividing 11 into 39 = 3.545 that is eleven teeth on the pinion and 39 on the crown wheel.
If the number is 10 4.1, 41 divided by 10 = a 4.1 ratio or 10 teeth on the pinion and 41 on the crown wheel hope this helps.
My GTV6 has it's original 4.1 ratio main shaft with the helical cut speedo drive and the taller 1st and 2nd gears taken from a 75/milano if you have the tools and are familiar with these transaxles it is not really all that hard to swap them over and you don't have the hassle of speedo modifications
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Last edited by sportiva; 06-21-2019 at 05:29 PM. Reason: added text
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