Jonnylightening
Well-Known Member
So currently I'm running a stock 904 behind my 408. I have 4 or 5 A230 3 speeds laying around. How would the 2 compare? Other than the 904 being an automatic that is.
A904 vs A230
- Thread starter Jonnylightening
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pishta
I know I'm right....
You get torque multiplication with a convertor, not with a clutch. You can slip a clutch if your patient but it's automatic with a convertor.
Plymouth 65
I'll be in the shop
You most likely won't like the A230 over a 904. 65'
Deeper first gear IIRC.
I'm kinda fuzzy on this. Is the A230 the heavy duty unit ? It was 48 years ago.
I ask because I had a 70 340 Duster with the 3 speed and the jump from 1st to 2nd ratio had a wide gap.
It also was hard on the 2nd gear synchronizer.
I ask because I had a 70 340 Duster with the 3 speed and the jump from 1st to 2nd ratio had a wide gap.
It also was hard on the 2nd gear synchronizer.
Jonnylightening
Well-Known Member
Yea like the little brother/sister to the 833
It wasn't long I switched to the 833. The good 'ol days junk yard 4 speed price was $100 with shifter.
If you like to clutch and shift and you have everything to do it,why not ? Now for me I'd stick to the 904 because I'm lazy and a change over sounds like allot of work at my age.
If you like to clutch and shift and you have everything to do it,why not ? Now for me I'd stick to the 904 because I'm lazy and a change over sounds like allot of work at my age.
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I believe both in stock form, the A230 would have an edge on the 904 for strength. But with modern converter technology and everything else available to upgrade the 904, there'd be no contest.
It is a lot of work! But as you said, if you love banging gears of a manual, once the labor is done, It’s all love love after that.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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IIRC there were two A230s; one for the slanty, and the other for everything else.
The one was 3.08-1.70-1.00; splits of .55-.59 ; this is a wide-ratio
the other was 2.55-1.49-1.00; splits of .58-.67 ; this is a progressive ratio with a wide 1-2, and a tight 2-3.
As a comparison the A833od is 3.09-1.67-1.00-.73 ; with splits of .54-.60-.73
IIRC the slanty had the 904-sized output shaft, while everything else got the 727 sized shaft.
I would not be scared to install a long-tailed A230, with a big mainshaft, on the street.
With a small-cammed Hi-torque 408, any of these would be a fair choice. BUT
if you chose the overdrive, you have to be very very careful about gettuing into od; that gear is very small and IMO fragile cuz even my smog-era 318 has broken one. My 367 has broken two others. So for anyone who wants to argue, I say, "whatever"...
It comes with just 21 teeth, and the engagement load area with the cluster gear is understandably very small.
I have not broken one while already in od, as in accelerating/decelerating. Mine have all broken by shock, while shifting into overdrive and under too much power.
Ima gonna suggest to stay away from those with a 408 cuber. But if you do install one, you might as well line up a spare or two.
BTW
I have built hundreds of those A230s, and IMO, looking at the guts, they are on par with the A833s, and way more robust-looking than any of their predecessors. But I have never owned one (an A230), nor driven one, and know nothing about their metallurgy. But since you have 4 or 5 of them, how about you install one and give us a report.... lol.
As for ratios, the A904 is 2.45-1.45-1.00
But allowing just 60% TM @WOT in the convertor at zero mph, diminishing to 18% in Second and 8% in third;
and with say 3.23s, your road gears are gonna look something like this;
12.70 diminishing to 9.50-5.52-3.49. To compare favorably the A230 would need 3.55s. Then, to get the starter-gear in the ballpark, you would need the 3.08/1.70; and your Roadgears would look like;
.------10.93-6.04-3.55 ; But seeing as how you have a 408 engine, Ima thinking you could get away with the 2.55/1.49 and
--------9.05-5.29-3.55 ; compare these, to
12.70/9.50-5.52-3.49 all at WOT, with the A904.
However, your cruise rpm will change.
With 27" tires, 3.23s and the A904 at say 3% slip, the math says 65=2700
whereas the 3.55s math to 65=2870
Don't hate me but, if you used the A833od you could run 3.73s for roadgears of
.-------------11.52-6.23-3.73-2.72 and 65=2200 compare this to your A904 at
average of 11.10-5.52-3.49 all at WOT, and 65=2700@3% slip. and just for kicks, the Commando with 2.94s
---------------9.08-5.64-4.12-2.94 and 65=2380
Don't forget, when you swap to a manual trans, your slowest roadspeed is directly tied to your idlespeed. Using the same numbers as above, namely 3.23s and 27" tires, an in-gear idle-speed of 800 will get you
6.4mph with a 3.09 low
7.8 with the 2.55 low
So then your parading days are over.
To get to a comfortable 3.5mph, idling at 700, requires a roadgear of 16 to 1
The lowest low in any of these transmissions is 3.09; and 16/3.09=5.18 the rear gear required. You would still need to idle your engine down yet further. You're never gonna get there with 3-series gears.
With 4.10s and a 3.09=12.67, your in-gear idle would have to be 600 to get 3.8mph, and then 65=3320rpm........
Unless you install the A833od,and 4.30s; then 630rpm=3.8 and 65=2540 in .73 overdrive; Now we're talking.
The final roadgears would be;
------------13.29-7.18-4.30-3.14 compared to your A904/3.23s
average 11.10- 5.52-3.49 all at WOT,
Fun with math
The one was 3.08-1.70-1.00; splits of .55-.59 ; this is a wide-ratio
the other was 2.55-1.49-1.00; splits of .58-.67 ; this is a progressive ratio with a wide 1-2, and a tight 2-3.
As a comparison the A833od is 3.09-1.67-1.00-.73 ; with splits of .54-.60-.73
IIRC the slanty had the 904-sized output shaft, while everything else got the 727 sized shaft.
I would not be scared to install a long-tailed A230, with a big mainshaft, on the street.
With a small-cammed Hi-torque 408, any of these would be a fair choice. BUT
if you chose the overdrive, you have to be very very careful about gettuing into od; that gear is very small and IMO fragile cuz even my smog-era 318 has broken one. My 367 has broken two others. So for anyone who wants to argue, I say, "whatever"...
It comes with just 21 teeth, and the engagement load area with the cluster gear is understandably very small.
I have not broken one while already in od, as in accelerating/decelerating. Mine have all broken by shock, while shifting into overdrive and under too much power.
Ima gonna suggest to stay away from those with a 408 cuber. But if you do install one, you might as well line up a spare or two.
BTW
I have built hundreds of those A230s, and IMO, looking at the guts, they are on par with the A833s, and way more robust-looking than any of their predecessors. But I have never owned one (an A230), nor driven one, and know nothing about their metallurgy. But since you have 4 or 5 of them, how about you install one and give us a report.... lol.
As for ratios, the A904 is 2.45-1.45-1.00
But allowing just 60% TM @WOT in the convertor at zero mph, diminishing to 18% in Second and 8% in third;
and with say 3.23s, your road gears are gonna look something like this;
12.70 diminishing to 9.50-5.52-3.49. To compare favorably the A230 would need 3.55s. Then, to get the starter-gear in the ballpark, you would need the 3.08/1.70; and your Roadgears would look like;
.------10.93-6.04-3.55 ; But seeing as how you have a 408 engine, Ima thinking you could get away with the 2.55/1.49 and
--------9.05-5.29-3.55 ; compare these, to
12.70/9.50-5.52-3.49 all at WOT, with the A904.
However, your cruise rpm will change.
With 27" tires, 3.23s and the A904 at say 3% slip, the math says 65=2700
whereas the 3.55s math to 65=2870
Don't hate me but, if you used the A833od you could run 3.73s for roadgears of
.-------------11.52-6.23-3.73-2.72 and 65=2200 compare this to your A904 at
average of 11.10-5.52-3.49 all at WOT, and 65=2700@3% slip. and just for kicks, the Commando with 2.94s
---------------9.08-5.64-4.12-2.94 and 65=2380
Don't forget, when you swap to a manual trans, your slowest roadspeed is directly tied to your idlespeed. Using the same numbers as above, namely 3.23s and 27" tires, an in-gear idle-speed of 800 will get you
6.4mph with a 3.09 low
7.8 with the 2.55 low
So then your parading days are over.
To get to a comfortable 3.5mph, idling at 700, requires a roadgear of 16 to 1
The lowest low in any of these transmissions is 3.09; and 16/3.09=5.18 the rear gear required. You would still need to idle your engine down yet further. You're never gonna get there with 3-series gears.
With 4.10s and a 3.09=12.67, your in-gear idle would have to be 600 to get 3.8mph, and then 65=3320rpm........
Unless you install the A833od,and 4.30s; then 630rpm=3.8 and 65=2540 in .73 overdrive; Now we're talking.
The final roadgears would be;
------------13.29-7.18-4.30-3.14 compared to your A904/3.23s
average 11.10- 5.52-3.49 all at WOT,
Fun with math
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@AJ/FormS The OD caution makes sense and is true. If your on that throttle banging gears, it’s just a matter of time on a hot rod engine that it will break. I just state “Use with caution” when going into OD.” If someone was to use it in a high performance or race car, I’d just use the 1st 3 gears since 3rd is a 1-1 & call it good.
You said you never owned…. Is that the 3spd?
If you had the 4spd-od, it feels the same really.
The big change in first to second gear drop in both the OD and the 3spd is indeed big but fine enough for a driver or mild performance car. Not so great for racing.
Excellent for burnouts!
You said you never owned…. Is that the 3spd?
If you had the 4spd-od, it feels the same really.
The big change in first to second gear drop in both the OD and the 3spd is indeed big but fine enough for a driver or mild performance car. Not so great for racing.
Excellent for burnouts!
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