I have a 19t (Arcor style adjustable timed motor) question

I have several of the older 19t's in the Ti can, they all dyno out very consistant on a CE30 TurboDyno

The settings are @ 5.00 volts

The dyno numbers are:

15 amp - 16,313 rpm 4.8 torque 57 watt 77 eff.
20 amp - 15,159 rpm 7.1 torque 80 watt 80 eff.
25 amp - 14,323 rpm 9.3 torque 99 watt 79 eff.
30 amp - 13,552 rpm 11.5 torque 115 watt 76 eff.

I'm trying to compare these to the newer Fuji style 19t. The Fuji numbers are below.

15 amp - 25,172 rpm 1.2 torque 23 watt 31 eff
20 amp - 22,982 rpm 3.5 torque 59 watt 59 eff
25 amp - 20,434 rpm 6.0 torque 90 watt 72 eff
30 amp - 17,832 rpm 8.4 torque 111watt 74 eff

Now I've come from the OLD SCHOOL thinking that POWER & EFFICIENCY are everything.

The ROLLOUT for the fuji was being run at 2.55 and it was FAST~

My question is this. If 2.55 is the "correct rollout" for the Fuji, would the rollout for the Ti have to be increased the same percentage as the RPM drop?

(I'll use the 25 amp RPM # for example) 20,434/14,323 = 1.426%

rollout 2.55 x 1.426% = 3.638 (new rollout)

Gear ratio w/ 2.55 rollout was a 2.81 so would the NEW gear ratio for the Lower RPM motor then be a 1.97? (Wow, that's TALL)

THANKS for your ideas...

I see lots of people have looked...but no responses yet.

I'll take ideas from others than just EA and Putnam too...What do YOU think?

(Thanks Brian)

Joe

I wouldn't be affraid to be 2.95 to 3.00 with the TI

Rick Liehr

Joe,
I don't think you would have to change the gear ratio that much - 1.426. If we assume the 2.55 rollout is correct with the fuji we get these "RPM factors":

Ti
RPM TORQUE WATT EFF AMP ROLLOUT FACTOR
16313 4.8 57 77 15 1.543063814
15159 7.1 80 80 20 1.516063065
14323 9.3 99 79 25 1.426656427
13552 11.5 115 76 30 1.315820543

What amp draw are you really seeing on the Fuji? I don't think it is 25 AMPS average. Maybe look at 35, 40, or 45 amp numbers. Could it reach a 1.1 RPM factor at the higher amp loads?

Looking at the higher amp draw will also tell you what motor is better. From the dyno numbers you gave, max efficency was already reached on Ti, but not on Fuji. Normally we would see the max power number at higher amp rates than max efficency, so the Fuji probably has a lot more to give at the higher amp rates. So that could mean that Ti might not be able to pull the gear because it doesn't have the power to go that fast.

take the TI based motors fishing with you, they make great sinkers! sorry i couldn't resist.

SWTOUR: A calculation that will get you close is:

Proven Motor RPM X Proven Motor Rollout / New Motor RPM= New Rollout

For the information given, the equation would read:

17,832 X 2.55 / 13,552 = 3.35 This would be a good starting point to rollout the Ti with. You may have to adjust slightly, but it will get you in the ballpark.

Based on the data posted, your Ti will absolutley kill the Fuji on the track. The only thing that would have me concerned is why the Fuji was so poor in performance at the 20 and 25 amp loads...unless you had a ton of timing in the motor. This would explain the awful 15 amp #'s as well...15 is probably not a high enough load setting for 19 turn anyway, as their amp draw will exceed that just turning over the slave motor with no load applied. This will give errornous readings at that amp step, which looks like what happened. Your telling the dyno to read it at a 15 amp load, but the load of the motor running coupled to the slave motor already exceeds that, and the dyno can only "add more amp load", not eliminate pre-existing amp load. This confuses the dyno... You'll hear it rev way up, then fluctuate, then move on to the next step and sound normal for the remainder of steps through the higher amp loads.
Based on the results, it looks as if the Fuji has huge timing, and the Ti has less...maybe around 24 degrees.

Either teardown is excellent, and we've had huge success with both teardowns. Hope this helps...:thumbsup:

Todd,

Thank you very much. The Ti based motors are a little less on the timing, and were originally built to run in the ZERO degree class, but have been cranked up.

The Fuji, I only have one of to compare against 1/2 dozen of the Ti based. All the Ti based are within 1% of each other.

I've been getting creamed w/ the Ti's and was afraid it was poor performance from the motor but after seeing the numbers, I decided it was "ME" that's getting creamed..NOT the motor.

Can't wait to try a few NEW things...

Thanks again~

Joe Myers
www.southwesttour.com

Joe,
Your welcome...always glad to help.
Feel free to contact us if you need any additional help...