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Sub piston induction and throttle ring
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Sub piston induction and throttle ring
Can I use a throttle ring on a black widow that has a spi ? I try it but didn't notice any great difference. How much rpm is dropping normally with the throttle sleeve?
Gordinir8- Bronze Member
- Posts : 58
Join date : 2020-08-05
Age : 47
Re: Sub piston induction and throttle ring
Unlike a muffler that will capture flue gases near the cylinder ports and force them back into the crankcase with SPI engines, a fully open throttle ring will allow the engine to inhale fresh air below the piston skirt. A fully closed throttle ring will not, and this will cost performance,but the purpose of the ring is to throttle the output down, anyway.
balogh- Top Poster
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Re: Sub piston induction and throttle ring
Y have difrent throttle ring wit difrent slit size jerobee wit tee dee cylinder dual port is allowing spi the ring slit size is smaler on sand bugy bug and other cox theter cars only rc cars y have see that large opening dont notice drop in performance just thend To run litle hot wit tink is very light drop wit tee dee type combo piston cylinder ring part match Perfect on reedee engine
davidll1984- Diamond Member
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Location : shawinigan
Re: Sub piston induction and throttle ring
davidll1984 wrote:Y have difrent throttle ring wit difrent slit size jerobee wit tee dee cylinder dual port is allowing spi the ring slit size is smaler on sand bugy bug and other cox theter cars only rc cars y have see that large opening dont notice drop in performance just thend To run litle hot wit tink is very light drop wit tee dee type combo piston cylinder ring part match Perfect on reedee engine
David, I don't understand your messages. You can use Google translation with punctuation marks.

Levent Suberk- Diamond Member
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Gordinir8- Bronze Member
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Join date : 2020-08-05
Age : 47
Re: Sub piston induction and throttle ring
Back in the early 1980's I flew my Q-Tee single channel pulse proportional with auxiliary throttled 1970's Golden Bee with SPI, using an Ace R/C throttle ring like yours. The ring didn't seem to affect top end although it narrowed the exhaust ports slightly, but it had a decent idle.
This was using the Ace R/C Pulse Commander with Adams dual magnet Stomper Actuator for rudder and KRD quick blip sequential throttle servo. The servo was actuated by a single push button. Normally it went from HIgh to MEDium to LOw throttle back to HIgh, but because of the non-linear action of the throttle ring (1/4th to 1/3rd open was half throttle), I had it set up so that at HIgh (pushrod forward) left the ring 1/3rd open (for half), MEDium centering the ring (for high) and LOw pulling ring back so only the idle notch was exposed (for idle). This basically reversed the sequence to LO-MED-HI back to LO, but it worked like a charm.
Anyway, I think you'll really like the throttle ring action, non-linear on a standard servo should work well. Regarding wanting to "detune" the Widow by using a plug head adapter, I think that although it can be done and the Q-Tee with its ample wing area will fly fine, you can accomplish the same by simple changing props (say a 5x3 instead of a 6x3) or putting one on backwards to reduce its aerodynamic efficiency.
With a throttle, the slight power increase with the Widow should be welcomed, as you can always crank the throttle slightly back, but then have the power when you need it. On a day with wind, that comes in handy.
I flew mine (before crashing it - again
) with a Norvel .061 Big Mig and Norvel tank mount. The extra zip made it a fun aircraft, truly a sportsman's delight.


With a throttle, the slight power increase with the Widow should be welcomed, as you can always crank the throttle slightly back, but then have the power when you need it. On a day with wind, that comes in handy.
I flew mine (before crashing it - again

GallopingGhostler- Diamond Member
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Join date : 2013-07-13
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» sub piston induction. what does it do?
» Cox .049 Throttle Ring
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» Cox .049 Throttle Ring
» cox 049 throttle ring
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» surestart throttle ring
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