Supercharged 496 HO
 

Running same setup/same boat/same conditions, RPM won’t go past about 5170 running a 26 or 28 Bravo 1. Sounds like I’m on a rev limiter. Not sure what that would feel like, but runs smoothly just no higher revs with either prop. Limit was supposed to be reset to 5450. Doesn’t seem possible both props would run same revs at WOT. Ideas?

whats the mph @ 5170 with two different props ? who changed the tune.

71 with 26 and 72 with 28. Whipple says they did.

So try a 30

A quick search states 5150 soft limiter out if the box, doesn't sound like Whipple moved it

496 HO rev limiter5150 on the soft limiter, 5250 on the hard limiter.

Ray @ Raylar

Wouldn’t a 30 Pitch Prop Dr. to RPMs lower?

yes a 30 is harder to spin, less revs

I’ve read a little bit about the soft limit and the hard limit but I still don’t have a good understanding of the difference. I understand the soft limit at 5150 and my understanding is that it will just sit there and run at that RPM. I can’t imagine what would trip a hard limit if you’re already limited at 5150 unless you did something like sheared the shaft or lost a prop and the lack of torque allowed the RPMs to rise to the hard limit which as I understand, it would shut the engine down

Whipple insist. My rev limit is set at 5450 so could I have a throttle set up problem?

I just realized my original post was in error. I ran a 28 and a 26. My understanding is there should be about 700 RPM difference between those two props. I did not run a 30.

It's likely on the soft rev limiter. If it goes to the exact same RPM with both props you would think it has to be electronic. Are you getting an alarm?

...

No alarm.

Possibly, depends on how much power you are making where. I'm curious about the 1 mile an hour difference between the 26 and 28.

28 to 26 pitch should be about a 400rpm difference, but only going 1mph faster with the 28 at the same rpm also makes no sense.
It sounds to me like one of the props has prob been modified or the 28 is way under spec on pitch.

You really need to run the boat up to 5170rpm with a scanner hooked up. The scanner would verify your tach is displaying the correct rpm and will also tell you if the rpm limiter is triggering.

Agree with Griff, I'd make sure your tach is correct when you're trying to be this precise. Generally my rhinda scanner shows rpms slightly different than my dash gauge.

I run a 496HO Raylar 800 package with the Whipple. The rev limiter is set at 5,700 but with the various props I have I've only seen 5,550 with it.

Bad Influence,

I also call into question your speed at that RPM. I'm running a PQ 280 with a 496HO, M1 ProCharger and stage 2 Whipple tune, turning a Bravo 28P prop, and we get a solid 77GPS, 78 on a good day, at ~5100 RPM. Granted, we have a single stepped hull and you don't, but this, in conjunction with your getting the same speed out of a 26P and a 28P, tells me there's something off with your prop. Look for stamped numbers on the prop hub, usually on the rear face.

Thanks. Brad.