Anyone notice they get a different exhaust note with smoke on? It actually sounds like a loss of rpm's but my telemetry say's different. Very strange.

Smoke oil cools the exhaust gasses; changes the pressure dynamics in the muffler giving a different tone.

I have noticed it to and usually equate it to the smoke muffling the exhaust a bit more and giving it a different tone.

When your using smoke it restricts the flow of exhaust and increase the back pressure ,there is also a small power loss with smoke on,simple physics

Originally Posted by yakwards

When your using smoke it restricts the flow of exhaust and increase the back pressure ,there is also a small power loss with smoke on,simple physics

Not according to the onboard telemetry.

Originally Posted by acerc

Not according to the onboard telemetry.

Well from drag racing I know that when exhaust is restricted,filling gas engine with smoke in the mufflers will increase back pressure,that's a fact,are you referring to rpm?

Smoke oil does not restrict gas flow. It cools exhaust so more gas is drawn through the engine
Usually you pick up a few rpm

Originally Posted by TimBle

Smoke oil does not restrict gas flow. It cools exhaust so more gas is drawn through the engine
Usually you pick up a few rpm

Simple physics.

Originally Posted by Snuts

Simple physics.

Oh RLY!!

Let me see.. Hummmmmm

Hot exhaust gasses = energy
Cooling exhaust gasses = less energy

Hot Exhaust gasses = less density
Cool Exhaust gasses = higher density

I believe we all agree on this simplification right?

Now here's where it gets tricky.

You have a fixed orifice (Exhaust pipe)

Question:
Which flows easier through a fixed orfice?
1) High Energy low denisty medium
2) Low Energy High Density medium.

Air / Exhaust = Medium.

Please let us know.

(BTW, there's a reason why we wrap headers on our race cars, and if given the choice, would use coated and wrapped exhaust all the way through the system to maintain exhaust gas energy)

Originally Posted by JoeT

Oh RLY!!

Let me see.. Hummmmmm

Hot exhaust gasses = energy
Cooling exhaust gasses = less energy

Hot Exhaust gasses = less density
Cool Exhaust gasses = higher density

I believe we all agree on this simplification right?

Now here's where it gets tricky.

You have a fixed orifice (Exhaust pipe)

Question:
Which flows easier through a fixed orfice?
1) High Energy low denisty medium
2) Low Energy High Density medium.

Air / Exhaust = Medium.

Please let us know.

(BTW, there's a reason why we wrap headers on our race cars, and if given the choice, would use coated and wrapped exhaust all the way through the system to maintain exhaust gas energy)

The difference is 2 stroke vs 4 stroke engines. The back pressure can keep the incoming air/fuel mix from blowing all the way through the exhaust. That's how tuned pipes make more power. Something about harmonics creating a back pressure to keep the incoming air/fuel charge in the chamber. The smoke fluid can create the same effect.

And the exhaust path in a side dump is too short for the density to be a major factor in the 2 strokes in question. Think about what cooling does to a volume
Does the cooler slug have less or more restriction when passing through the same size orifice?