Riva Level 2 Results

[RXDI2]

I know many are way past these mods, but thought I would post results.

Air temp 78 deg
Water temp 70 deg.
Water surface almost flat to 4" chop, some boat wakes
Gas level 7/8 full
Fuel 50% avaiation fuel 100 octane, 50% 90+ octane
RPM 8100 occasional 8150

Very first run 73.5 mph gps, trim all the way down
Best run 74.6 mph gps trim 40% from bottom

Most runs 74 mph+

No heat soak at all run after run 74 mph +(cool temps+ increased fresh air scoop CFM)
Acceleration MUCH stronger than stock
Boat handles great with RE blockoffs
I'm very happy!

[INDY27]

Great numbers! Still getting mine dialed in.

[Sirhc7897]

Your results makes me wonder just how much variance there is in the 15/20R props out of the box...

I took mine out for the first time this past weekend with the following stuff:

Riva Stage II (with the following additions/exceptions)
RR Thru Hull
PE OPAS Blockoffs
Riva Thermostat
Riva High Flow Hood
Dual 4" inline blowers in former intake tract

My results were as follows in 92+ degree heat with 82+ water at near sea level with average humidity:

Full tank: 7800-7850 @ high 73's to low 74's with a peak reading of 75.0-75.1 held for 30 seconds or so while running at half a tank...

That's the same speeds as you on theoretically the same prop...I realize every hull is different but just makes you wonder how accurate the pitch is on their "pitch blocked" props...

[Green Hulk]

Chris, i just pitched your prop tonight and it will be on the way back tomorrow.

Better hold on! Acceleration will be much stronger and i'm almost willing to bet i will get you 1.5 more MPH on top

By the way, every 15/20R i have measured is dead on consistant/accurate.

[Sirhc7897]

Good to hear... I can not wait to slap it in and try it out (may require a sick day Friday...)

That makes me wonder even more then:

Is the variance in speed vs rpms coming from somewhere else?

I would have thought with RXDI2's slightly cooler conditions and greater rpms he'd be faster but it doesn't seem to be the case...

I know the Jax group of guys with Stage II's all seem to be stuck in the 73 doldrums too but their r's are in the 7950 range...


It's certainly not the brain tickler that Jarret has with the 15/20 and the RR ECU but it does make you wonder...

I mean it's hard for me to imagine there's enough variation between the various molds to account for 300rpms between 2 setups but still run the same speeds...

[RXDI2]

7897 I know what you mean. Many level 2 kits are hitting 74-75 mph, but at different rpms. I would expect with the temps you had your rpms would be lower, but yet your speed is the same. Perhaps your hull is more efficient. Another thing I was wondering is how accurate are the tachs on these boats, although generally electronic tachs are fairly reliable. It's almost as if there is another variable of the speed equation that isn't clearly understood.

I think with a little more practice and perfect conditions I'll break 75. I feel good that at least the kit performs as advertised, so my son and I must have installed it correctly. By the way nice numbers 7897, especially in those temps. Please post the conditions and results with the GH modded prop.

[RXDI2]

Jerry, I had another thought. Could I be hitting the limiter at 8150 rpm? I am amazed how hard it pulls out of the hole with the 15/20r. I thought I would loose some hole shot with a prop that tall, but it pulls stronger out of the hole than it did stock.

[Franko]

Sounds like you are banging the rev limiter. But that is ok. When it gets warmer, you will lose some RPM.

[Green Hulk]

I would leave the prop alone. Once the heat of summer sets in your R's will drop.

[RXDI2]

Sounds like good advice.
Thanks