What a Rocket III engine sounds like to a knock sensor

R-III-R Turbo

Mine is the biggest :)
Joined
Oct 12, 2010
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Location
Ireland
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2472cc Supercharged Carpenter Rocket III Stroker

Currently ignition tuning the bike, giving the Phormula KS-4 & Pro Tuning Solution a go.

I can use earbuds to listen to the engine as I ride, with all the wind & exhaust noise it would be difficult to hear knock without it. The gauge is also there as a visual.

What I'm listening for here is an electric snap type sound that's irregular, almost like popcorn popping.
As long as it sounds smooth & regular (and the engine doesn't blow up...), I believe it's knock free.

Tricky bit is to locate the Bosch knock sensor in a place where it doesn't pick up valvetrain noise so much.
 

Currently ignition tuning the bike, giving the Phormula KS-4 & Pro Tuning Solution a go.

I can use earbuds to listen to the engine as I ride, with all the wind & exhaust noise it would be difficult to hear knock without it. The gauge is also there as a visual.

What I'm listening for here is an electric snap type sound that's irregular, almost like popcorn popping.
As long as it sounds smooth & regular (and the engine doesn't blow up...), I believe it's knock free.

Tricky bit is to locate the Bosch knock sensor in a place where it doesn't pick up valvetrain noise so much.

I'm interested in your AFR gage @R-III-R Turbo. What length cable did you buy with your setup? Looks nice.
 

Currently ignition tuning the bike, giving the Phormula KS-4 & Pro Tuning Solution a go.

I can use earbuds to listen to the engine as I ride, with all the wind & exhaust noise it would be difficult to hear knock without it. The gauge is also there as a visual.

What I'm listening for here is an electric snap type sound that's irregular, almost like popcorn popping.
As long as it sounds smooth & regular (and the engine doesn't blow up...), I believe it's knock free.

Tricky bit is to locate the Bosch knock sensor in a place where it doesn't pick up valvetrain noise so much.
So where on the block did you locate it?
 

Currently ignition tuning the bike, giving the Phormula KS-4 & Pro Tuning Solution a go.

I can use earbuds to listen to the engine as I ride, with all the wind & exhaust noise it would be difficult to hear knock without it. The gauge is also there as a visual.

What I'm listening for here is an electric snap type sound that's irregular, almost like popcorn popping.
As long as it sounds smooth & regular (and the engine doesn't blow up...), I believe it's knock free.

Tricky bit is to locate the Bosch knock sensor in a place where it doesn't pick up valvetrain noise so much.

Very interesting!
 
I'm interested in your AFR gage @R-III-R Turbo. What length cable did you buy with your setup? Looks nice.

Thanks I don't think there was a choice of length, they just include "a" length, don't have a measurement of it but i think it was pretty ample for a bike anyway. Easy extend the cable anyway.

I had a Dynojet AFR gauge on it since i first started any mods (you can run it with PCV and Wideband 02 (for autotuning), whereas AEM and others is just display AFR only), but changed it out for the AEM as they closer matched the Roadster gauges;


Knock gauge, Boost gauge, Speedo, Tacho, AFR gauge, Fuel Pressure gauge (10psi is incorrect, the needle was loose on the stepper motor spindle that day)



So where on the block did you locate it?

Right now the Phormula is connected to where purple arrow points to, and the Vampire is on the yellow arrow.
I figure the yellow arrow is a much better location (closer to combustion), and the Vampire is supposed to detect knock and retard the timing so i think it should get the best spot.

The Phormula gets the 'meh' spot because I'm only listening to it.
Both Phormula and Vampire gauges read green/amber alerts at the same time so i guess both are working well.
 
So where on the block did you locate it?

Sound comparison for the 2 possible sensor locations on the engine, @850rpm, 2000rpm and 3000rpm

You can hear pretty clearly that the lower rad mount to engine bolt location gives a cleaner sound, due to being closer to the ignition/combustion, than say the throttle cover bolts, where it also hears cam noise

 
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