As to the floorhump;
You didn't mention cutting open the tunnel to access the shifter and rods. Is your tunnel already so modified?
What is your plan for the shifter?
The fork has it's own pivot bracket. It may or may not put the fork in the right spot to hook up with the Zbar, in a straight push arrangement. You are the trailblazer.
I assume this project is to reduce your rpm at hiway speed, and or to try and get some better fuel mileage.
I'm not sure which box you might currently have, but Ima guessing it is the A903.
This box comes in a few flavors, but again, I'm guessing it is for a 170 under the hood.
This would have the following ratios; 3.22-1.84-1.00 with split %s of 57 and 54.6 This means that at whatever rpm you rev to before the shift, then after the shift the rpm will be at those percents. Example; if you outshift at 2800rpm, then the Rs will drop to 1599, and 1529.
With the A833od, the ratios are 3.09-1.67-1.00-.73 and the split %s are 54-60-73. Outshifting again at 2800, means the next gears come in at; 1512,1652,and 2044
That doesn't sound too bad, until you translate that to a roadspeed
Say you have 3.21s
Shifting at 2800;With your current tranny, will be about(25.5tires);21,36,and topped out @66mph=2800rpm.
Shifting at 2800;With the od tranny;21,40,66, now reving 2044 in od. The question is; will your 170 make enough power on the low-speed circuit to pull that? If it gets up on the mains, you may actually get less gas mileage. Also on the mains, the manifold vacuum will drop, and this may kill the vacuum advance. Between those two, the mileage will drop for sure.
I can see no other good reason to make this swap; except reduced rpm, or the allure of better fuel mileage.
>If the engine is in real good shape, it might have to potential to make 120 ftlbs at 2800. This is
64hp. Your car might require 40hp to maintain 66 mph. So with the current tranny, you might already require 78% of the available power.
With the A833 and the reduced to 2044rpm, your maximum torque might be reduced to say 70% of peak. This would be 84 ftlbs,or
33hp. If your car requires 40hp you're just not gonna be able to pull it with 3.21s.
All numbers as to torque and horsepower are best guesses on my part, and intended only for illustrative purposes.
If in fact you come up 7 hp short, this is a 17.5% shortfall using WOT. Increasing your rear gear that same 17.5%, might get your Rs up high enough to make it. That would then be 3.73s gears. Keep in mind that I may have underestimated the torque of the mighty 170. As it here stands, the 170 barely has enough torque at 2800 to maintain 66mph at 78% of full power. This is already waaay past the mains. I cannot imagine it will be able to maintain 66 at WOT with the overdrive.
But if you have a bigger engine, then this math falls apart. I just hate to see you go thru all this trouble and be disappointed.
Here is an experiment for you; load the car up with about 300 extra pounds, and find a hill with a long enough level approach to get her up to a cruising speed of 48mph (73% of 66 mph;to simulate the od box),and head for that hill.As the car begins the ascent it will slow down. Keep giving her gas, until she is able to maintain the climb at that 48mph. If she can't do it, you are probably screwed. If you end up using more than 50% throttle, you will lose gas mileage with the overdrive. I used the extra pounds so simulate the wind-resistance from 48 to 66mph, and guessed at the amount of weight to add. The grade of the hill is to illustrate the reserve power, at 2044rpm with 3.21s.If you have different gears, the experiment would need to be amended.
>If you have a vacuum gauge, put that on manifold vacuum, and put it somewhere you can see it during the test.If the manifold vacuum at any time,falls to under 12 inches then the carb is already open past the transfers, (where the economy is). If it falls to under about 10 inches, then you are deep into the mains. By 8 inches you are well into the power valve system, and of course the vacuum advance is long g-o-n-e,gone.You are sucking gas big time.[/QU
As to the floorhump;
You didn't mention cutting open the tunnel to access the shifter and rods. Is your tunnel already so modified?
What is your plan for the shifter?
The fork has it's own pivot bracket. It may or may not put the fork in the right spot to hook up with the Zbar, in a straight push arrangement. You are the trailblazer.
I assume this project is to reduce your rpm at hiway speed, and or to try and get some better fuel mileage.
I'm not sure which box you might currently have, but Ima guessing it is the A903.
This box comes in a few flavors, but again, I'm guessing it is for a 170 under the hood.
This would have the following ratios; 3.22-1.84-1.00 with split %s of 57 and 54.6 This means that at whatever rpm you rev to before the shift, then after the shift the rpm will be at those percents. Example; if you outshift at 2800rpm, then the Rs will drop to 1599, and 1529.
With the A833od, the ratios are 3.09-1.67-1.00-.73 and the split %s are 54-60-73. Outshifting again at 2800, means the next gears come in at; 1512,1652,and 2044
That doesn't sound too bad, until you translate that to a roadspeed
Say you have 3.21s
Shifting at 2800;With your current tranny, will be about(25.5tires);21,36,and topped out @66mph=2800rpm.
Shifting at 2800;With the od tranny;21,40,66, now reving 2044 in od. The question is; will your 170 make enough power on the low-speed circuit to pull that? If it gets up on the mains, you may actually get less gas mileage. Also on the mains, the manifold vacuum will drop, and this may kill the vacuum advance. Between those two, the mileage will drop for sure.
I can see no other good reason to make this swap; except reduced rpm, or the allure of better fuel mileage.
>If the engine is in real good shape, it might have to potential to make 120 ftlbs at 2800. This is 64hp. Your car might require 40hp to maintain 66 mph. So with the current tranny, you might already require 78% of the available power.
With the A833 and the reduced to 2044rpm, your maximum torque might be reduced to say 70% of peak. This would be 84 ftlbs,or 33hp. If your car requires 40hp you're just not gonna be able to pull it with 3.21s.
All numbers as to torque and horsepower are best guesses on my part, and intended only for illustrative purposes.
If in fact you come up 7 hp short, this is a 17.5% shortfall using WOT. Increasing your rear gear that same 17.5%, might get your Rs up high enough to make it. That would then be 3.73s gears. Keep in mind that I may have underestimated the torque of the mighty 170. As it here stands, the 170 barely has enough torque at 2800 to maintain 66mph at 78% of full power. This is already waaay past the mains. I cannot imagine it will be able to maintain 66 at WOT with the overdrive.
But if you have a bigger engine, then this math falls apart. I just hate to see you go thru all this trouble and be disappointed.
Here is an experiment for you; load the car up with about 300 extra pounds, and find a hill with a long enough level approach to get her up to a cruising speed of 48mph (73% of 66 mph;to simulate the od box),and head for that hill.As the car begins the ascent it will slow down. Keep giving her gas, until she is able to maintain the climb at that 48mph. If she can't do it, you are probably screwed. If you end up using more than 50% throttle, you will lose gas mileage with the overdrive. I used the extra pounds so simulate the wind-resistance from 48 to 66mph, and guessed at the amount of weight to add. The grade of the hill is to illustrate the reserve power, at 2044rpm with 3.21s.If you have different gears, the experiment would need to be amended.
>If you have a vacuum gauge, put that on manifold vacuum, and put it somewhere you can see it during the test.If the manifold vacuum at any time,falls to under 12 inches then the carb is already open past the transfers, (where the economy is). If it falls to under about 10 inches, then you are deep into the mains. By 8 inches you are well into the power valve system, and of course the vacuum advance is long g-o-n-e,gone.You are sucking gas big time.
As to the floorhump;
You didn't mention cutting open the tunnel to access the shifter and rods. Is your tunnel already so modified?
What is your plan for the shifter?
The fork has it's own pivot bracket. It may or may not put the fork in the right spot to hook up with the Zbar, in a straight push arrangement. You are the trailblazer.
I assume this project is to reduce your rpm at hiway speed, and or to try and get some better fuel mileage.
I'm not sure which box you might currently have, but Ima guessing it is the A903.
This box comes in a few flavors, but again, I'm guessing it is for a 170 under the hood.
This would have the following ratios; 3.22-1.84-1.00 with split %s of 57 and 54.6 This means that at whatever rpm you rev to before the shift, then after the shift the rpm will be at those percents. Example; if you outshift at 2800rpm, then the Rs will drop to 1599, and 1529.
With the A833od, the ratios are 3.09-1.67-1.00-.73 and the split %s are 54-60-73. Outshifting again at 2800, means the next gears come in at; 1512,1652,and 2044
That doesn't sound too bad, until you translate that to a roadspeed
Say you have 3.21s
Shifting at 2800;With your current tranny, will be about(25.5tires);21,36,and topped out @66mph=2800rpm.
Shifting at 2800;With the od tranny;21,40,66, now reving 2044 in od. The question is; will your 170 make enough power on the low-speed circuit to pull that? If it gets up on the mains, you may actually get less gas mileage. Also on the mains, the manifold vacuum will drop, and this may kill the vacuum advance. Between those two, the mileage will drop for sure.
I can see no other good reason to make this swap; except reduced rpm, or the allure of better fuel mileage.
>If the engine is in real good shape, it might have to potential to make 120 ftlbs at 2800. This is 64hp. Your car might require 40hp to maintain 66 mph. So with the current tranny, you might already require 78% of the available power.
With the A833 and the reduced to 2044rpm, your maximum torque might be reduced to say 70% of peak. This would be 84 ftlbs,or 33hp. If your car requires 40hp you're just not gonna be able to pull it with 3.21s.
All numbers as to torque and horsepower are best guesses on my part, and intended only for illustrative purposes.
If in fact you come up 7 hp short, this is a 17.5% shortfall using WOT. Increasing your rear gear that same 17.5%, might get your Rs up high enough to make it. That would then be 3.73s gears. Keep in mind that I may have underestimated the torque of the mighty 170. As it here stands, the 170 barely has enough torque at 2800 to maintain 66mph at 78% of full power. This is already waaay past the mains. I cannot imagine it will be able to maintain 66 at WOT with the overdrive.
But if you have a bigger engine, then this math falls apart. I just hate to see you go thru all this trouble and be disappointed.
Here is an experiment for you; load the car up with about 300 extra pounds, and find a hill with a long enough level approach to get her up to a cruising speed of 48mph (73% of 66 mph;to simulate the od box),and head for that hill.As the car begins the ascent it will slow down. Keep giving her gas, until she is able to maintain the climb at that 48mph. If she can't do it, you are probably screwed. If you end up using more than 50% throttle, you will lose gas mileage with the overdrive. I used the extra pounds so simulate the wind-resistance from 48 to 66mph, and guessed at the amount of weight to add. The grade of the hill is to illustrate the reserve power, at 2044rpm with 3.21s.If you have different gears, the experiment would need to be amended.
>If you have a vacuum gauge, put that on manifold vacuum, and put it somewhere you can see it during the test.If the manifold vacuum at any time,falls to under 12 inches then the carb is already open past the transfers, (where the economy is). If it falls to under about 10 inches, then you are deep into the mains. By 8 inches you are well into the power valve system, and of course the vacuum advance is long g-o-n-e,gone.You are sucking gas big time.
