Rocket 3 Stability run down in Mexico - Bonneville 2024

[Justdad]

I'm confused, how can the elevation you are at change?

The actual altitude doesn’t but the density of the altitude that is effected by the weather does. Hot and humid days will significantly raise the density of altitude. This effects small piston aircraft too when trying to take off. The Bonneville Salt Flats is about 4236 feet above sea level but on hot muggy day the air becomes thinner or less dense so the salt flats air becomes equivalent to a higher elevation standard atmosphere.

 

[2023R3GT]

Yep 15% at 5000 feet
18% at 6000 feet
20.25% at 6750 feet
Most of the morning runs are around a best of 5500 feet and the afternoon runs as much of 7200 feet

Last year when ran first thing in the morning on the thirdrun we crashed and it was 5565 feet. The 2nd run at 3:30 in the afternoon it was 7223 feet.

for context to my top end speed, I’m at 5000 and got to 255kmph. thanks for sharing this info, very useful.

 

[Tripps]

Ah, interesting, I never thought about barometric pressure

 

[Taz]

A good article is here. Overall, less oxygen = less HP. Non-forced induction engines suffer more with altitude changes.

 

[1olbull]

Ah, interesting, I never thought about barometric pressure

Never heard Queen's Under Pressure?

 

[Gerald]

The actual altitude doesn’t but the density of the altitude that is effected by the weather does. Hot and humid days will significantly raise the density of altitude. This effects small piston aircraft too when trying to take off. The Bonneville Salt Flats is about 4236 feet above sea level but on hot muggy day the air becomes thinner or less dense so the salt flats air becomes equivalent to a higher elevation standard atmosphere.

Years ago used to use a density meter to help figure out jet changes on race cars.

 

[Justdad]

Years ago used to use a density meter to help figure out jet changes on race cars.

Being able to a good job of jetting the carbs on cars for racing is a real skill. Running at higher density altitudes you feel the bike getting fluffy with too much fuel vs too little air especially at the higher rpms. There are some crews out there who whip the computer and makes the changes for the density altitude changes on the fuel injected bikes in a few minutes. I am not one of them.

 

[Dr.D]

Yes the owner has the limiter removed. The bike was only running about 5600 rpm at the GPS 144 mph (speedometer 151 mph) according to the Dentist guy from Nashville....do you know him?

The road was rough with lots of elevation changes and a few badly filled in pot holes and the bike was rock solid so I'm happy.

I'm sure the bike will do considerably better on a longer course and when I don't need to roll off the throttle a few times.

This was a very peaceful and serene ride it will get much more energetic.

No I do not know him. I’m interested in how you perform on the salt.

 

[2023R3GT]

mine topped out at 236km in standard trim.
after removing limiter it gets to 236 in 5th gear and onto 255 in 6th. wind resistance and lack of aero is hold in back.

update- cooler temperatures with a slight tail wind and more road. 270kmph (6000rpm) berried behind the flyscreen, essentially laying on the tank.

 

[Justdad]

update- cooler temperatures with a slight tail wind and more road. 270kmph (6000rpm) berried behind the flyscreen, essentially laying on the tank.

That probably more than we expect on the salt. My speedometer was off 5% to GPS, was yours GPS?