Still struggling with my Miss Geico, now what?

[miguelflores0928]

I took your guys recommendation that I add ballast batteries way up front in the sponsons of my boat but I?m still getting the porpoising at 50mph

Here is a video

https://www.reddit.com/r/traxxasV2/s/TvOI3NxFN7

My next thing I?m thinking about is maybe my props are crap?

Which props should I be running?

I just want to be able to drive 80+ without the bouncing.

Thanks!

[fweasel]

I only watched the first 4 passes, but you've never even got the hull fully on plane or gone full throttle. That's a tight body of water to be running a boat with as much speed potential as a twin geico, not a lot of room for error.

[miguelflores0928]

How is it not fully on plane at 50mph? Does it really need to be going faster to be on plane? Because any faster and it?ll go up and over. That?s why I haven?t gone full throttle because it?ll go up and over and crash

[leski379]

What props do you have on it?

[miguelflores0928]

Stock props

[fweasel]

How is it not fully on plane at 50mph? Does it really need to be going faster to be on plane? Because any faster and it?ll go up and over. That?s why I haven?t gone full throttle because it?ll go up and over and crash

The hull isn't packing enough air under the tunnel at that speed to fully "air" out and ride smooth. You're flopping around at the tipping point between your trim angle forcing the bow down into the water and air pressure pushing up on the bottom of the hull.

[miguelflores0928]

How do I sort that out? I?ve tried every strut position and battery configuration I can think of, with and without ballast

[fweasel]

The manual tells you how to set the drives to a neutral position, measuring off a flat edge extended across the rear two ride pads. I would start there, then lower the drive about 1mm. Run with all 4 batteries across the width of the hull, even with the two on the forward portion of the stock battery tray. Even with dull, stock props, that should easily put you in the 70 mph range without a sweat. If you're still not close to that, it's possible your batteries are not up to the task and a not providing the power necessary to reach those speeds. There could also be another source of drag/resistance, but that usually manifests itself with lots of heat and I don't recall you reporting those issues. Not having a proper gap between the drive dog and the end of the drive is a common issue that causes binding in the flex cable and limits RPM.

Out of curiosity, what batteries are you using, what's there capacity in mAh, C rating, and how old are they?

[miguelflores0928]

I have plenty of power. I?m nowhere near full throttle when they are freshly charged. I know how to set struts on all my other boats. I have a good drive dog gap. I understand that cables shrink under power. This is the only one of my boats that?s been giving me a hard time. I can squeeze 70 out of my hydro, 70 out of my blackjack 42, I was even getting 60 with my tiny blackjack 24 and 60 with my Shreddy. The geico has plenty of power to be in the 80+ range and I can run 8S through both ESCs with my SMC packs but it?s like a light switch is turned on at 50mph where it goes from butter smooth to horrendously unstable. Every time. 49mph is smooth. 50mph it starts bouncing. I?ve got dozens and dozens of passes with this thing and regardless of setup, it bounces at 50 and if I give it more throttle it gets worse and it?ll go up and over.

For some context, I have experience speed running road cars. My infraction does 140mph. I know how batteries work and all that.

As for the Geico, I?m using a pair of spektrum 6S 5000mah packs at the moment. I forget what the C rating is but C rating don?t matter in the real world (but that?s a proven discussion for another time) but the IR of each cell since the last time I checked was about 2.5milliohms per cell so they are plenty healthy and powerful. No significant heat or puffing when I?m done driving.

The only thing I can think of is props and ride pads. I?m willing to chalk it up to a *!***!***!***!**ty hull that needs work, I just want to know if that?s for sure my issue so I?m not chasing my tail in the dark, ya know?