Martyn
09-20-2008, 09:39 PM
Monty:
After spending several weeks sorting out a car powered by a Parma 502 motor in a bracket car I decided to build a new motor based on the BOW 560 S16D arm you made for me. This armature was wrapped in a 502 can, Speed FX endbell and hardware, Slick 7 bushings, EXP magnets epoxied in to a 570 hole diameter and equipped with Gold Dust brushes and Speed FX springs.
For point of reference the old motor was a fully blueprinted 502 with EXP magnets, etc. Basicly the same motor was built with the exchange of end bell and armature the only difference. Magnets in both motors were within 5 gauss as a set. (the old motor actualy higher by this amount) Identical break in procedure observed. In other words these two motors were twins save the listed changes.
Bench test of both motors at 5.33 volts showed an increase of roughly 5,000 rpm!
I loaded this motor in the same car at the same weight (actually + 1 gram) after gear sorting was complete to evaluate the effect, as closely as possible of the armature change only.
Aside from the difference in diameters an aproximate 10 degrees of timing was added and a much better balance job than the Parma factory balance.
I run very low timing compaired to those running ProSlot or Viper arms.
Again in reference this on an 1/8 mile track, which, sorry, I forgot to mention on the BOW magnet zapper post.
Best gear was a bit shorter than previous and resulted in a .0377 second reduction in ET and an addtional 1.34 mph. These numbers are the average values of a minimum of ten passes per motor, 5 passes each lane. There is more here though as the test were done a week apart and the track was not in as good of shape as it was the week before. This has me 88/100 from the 5's in the mid 40 mph range in a 103 gram car. Now quickest S16D at the track and the place is littered with them. Second fastest car is over 20 grams ligther with a blue printed Speed FX set up and a hand wound Kelly high timed arm.
The biggest part of the gains came in the low to mid range power where 60 foot and half track times tumbled into the range of a single mag 20 motor!! I had to show the armature tag to get the guys to believe this was a 16. Nice job Monty.
Marty
After spending several weeks sorting out a car powered by a Parma 502 motor in a bracket car I decided to build a new motor based on the BOW 560 S16D arm you made for me. This armature was wrapped in a 502 can, Speed FX endbell and hardware, Slick 7 bushings, EXP magnets epoxied in to a 570 hole diameter and equipped with Gold Dust brushes and Speed FX springs.
For point of reference the old motor was a fully blueprinted 502 with EXP magnets, etc. Basicly the same motor was built with the exchange of end bell and armature the only difference. Magnets in both motors were within 5 gauss as a set. (the old motor actualy higher by this amount) Identical break in procedure observed. In other words these two motors were twins save the listed changes.
Bench test of both motors at 5.33 volts showed an increase of roughly 5,000 rpm!
I loaded this motor in the same car at the same weight (actually + 1 gram) after gear sorting was complete to evaluate the effect, as closely as possible of the armature change only.
Aside from the difference in diameters an aproximate 10 degrees of timing was added and a much better balance job than the Parma factory balance.
I run very low timing compaired to those running ProSlot or Viper arms.
Again in reference this on an 1/8 mile track, which, sorry, I forgot to mention on the BOW magnet zapper post.
Best gear was a bit shorter than previous and resulted in a .0377 second reduction in ET and an addtional 1.34 mph. These numbers are the average values of a minimum of ten passes per motor, 5 passes each lane. There is more here though as the test were done a week apart and the track was not in as good of shape as it was the week before. This has me 88/100 from the 5's in the mid 40 mph range in a 103 gram car. Now quickest S16D at the track and the place is littered with them. Second fastest car is over 20 grams ligther with a blue printed Speed FX set up and a hand wound Kelly high timed arm.
The biggest part of the gains came in the low to mid range power where 60 foot and half track times tumbled into the range of a single mag 20 motor!! I had to show the armature tag to get the guys to believe this was a 16. Nice job Monty.
Marty