Pursuit users chime in please!

[Jamey]

I love the boat, and it runs fairly well, but I have this frustrating issue with running parallel with my own wakes. It just wants to chine walk to death if I am going any kind of speed. Directly into waves it does fine. At first I kind of just thought that was the nature of the beast. Now that I have more runs under my belt and knowing folks race these hulls it doesn't seem normal anymore. Racing an oval course I would imagine you are constantly running in these conditions that would just make my boat go crazy. The first run on a flat pond it will go flat out steady as a rock. But once I make the first turn and run along my wakes boom!

Hardware is just the factory stinger set up from HK. I added a Leo 4092 1480kv and SK180. My CG is about 9" from the transom. Multiple props tried x440/3, x442, m445, m545, x548. Some are better than others but all still do it. I even bent the tips to remove some lift which definitely helped. Trim tabs are parallel with the hull and the stinger has a slight positive angle. I tried the stinger at neutral and it walked even in calm water without wakes. I assume that might mean the stinger is mounted too low? Is there anything else I should try before drilling holes to move the stinger up a tick? Would bringing the tabs up positive be worth a shot?

Another thing I am a little worried about is the bottom has a very slight amount of hook. It doesn't seem like much though. I would be surprised if they didn't all have it. EDIT: Actually just put a straight edge to the bottom and there is no hook. Must of had too many beers when I checked it lol

Any pursuit veterans with suggestions, or anyone for that matter would be greatly appreciated!

[Jamey]

Here are a few pictures of my set up. I think it is all pretty much basic stuff. Excuse all the battle scars on my rudder!

pursuit1.jpgpursuit2.jpgpursuit3.jpgpursuit4.jpg

[Peter A]

Try dropping the tabs down a little. I run a TP 4050 2200 kv on 4s, but my packs are forward of the motor with the esc near the back on the left side. I have been up over 60mph with a X548 but run at around 50 on a x443 for ovals. I have also raced this often against larger gassers and while that can be tough going in the rough water they make there has never been much problem with chine walking.

[zooma]

Also try moving the CG up a bit. Mine is 10" from the transom. I have two Pursuits on four cells.

1480KV is pretty low. Are you running six cells? That would be a lot of power for this size hull.

[Jamey]

Thanks guys, I'll move the CG up. Still learning these tuning mods and what they affect!

So a little history. My rails broke free a couple weeks ago. When I "fixed" it I moved the whole assembly back a little (1/4-3/8" maybe) so that the brass tube protruded out of the transom slightly to seal up that gap in the stinger better. Now I can put a piece of fuel line on the tube to fill in the gap. I didn't think moving it back that small amount would make that much difference to the CG but it did. Thanks to that bone head move and with my battery trays where they are I can only get to 9". I'll see what I can figure out. I may just put a couple ounces of ballast in the nose and see if that is enough.

You may have seen some of my other posts, I typically run a 3S and 2S series with 7200mah 60C batteries. So it is pretty mild this way equal to about a 1850kv on 4S. Never put a GPS in it but I would guess in the mid 40s somewhere, maybe a little faster with a big prop. I don't run 6S very often but I have. At 6S it is very close to the same RPM as the typical 2200kv on 4S. The 4092 wouldn't have been my first choice but I bought it unused from a fellow member. I can run 4 minutes on either 5S or 6S without heat issues and put back less than 4000mah in the batteries. I am not sure I would change anything about my power set up at this point. Caps seem to get a little hot but I don't think they get anywhere near being too hot. Seems pretty solid. Of course moving my CG forward might put more load on it and slow it down a bunch, we'll see.

[T.S.Davis]

My struts are significantly higher than that.

I also prefer a more level strut. Like maybe 1 degree of positive.

[Jamey]

Terry, I thought it seemed really low. I wanted to bring it more level but that of course put the prop deeper and made the chine walk worse. In your opinion do you think I should need to mess with the CG at 9". That is like 28%, shouldn't that be fine?

Is it a secret or can you tell me what the center line of your prop shaft is up from the bottom of the hull? I am very curious to know how far off mine is.

[Jamey]

Did some messing around tonight with the layout. I stuffed two 8oz lead ingots inside a couple of the short pieces of pool noodle. So had to add an entire pound to the front to get the CG to 10", OUCH! That is over 31% so hopefully it is overkill but I still want to see how it affects the chine walking. If it goes away I'll move it back some. Total weight is 8.5lbs now. I'll post how it does as soon as I find out.

I still believe the correct answer is to raise the stinger but I just don't have enough experience to know for sure. Definitely makes sense to try this first.

Thanks again for the help guys!

[Peter A]

Your cg should be around 30-32%. I can put 4s 2p in mine and it doesn't affect the handling negativey. In fact when I prop up the hull lifts higher out of the water at higher speeds. I will be looking for around 32 secs for two lap sprints in a couple of weeks with this setup, on a full size oval course.

[T.S.Davis]

I'm at 10-1/8" with about 1/2 degree of positive. The strut is very nearly flat.

[zooma]

Well, Jamey, today I ran into a similar problem as in your original post. It was a club race day. My Pursuit was a little faster than the other boats on the straights, but I was taking the turns too wide and losing my position. As I was closing on the lead boat on the back straight, I flipped in his wake. Happened on both heats. To make matters worse, the same thing happened to my P-limited Impulse. Memo to self: don't try to pass on the far side if the lake.

[Jamey]

Sorry Zooma I hope I didn't bring you bad luck!

I ran the first pack with the extra pound in the front and the strut angle slightly less. It was a pretty dramatic improvement. I could usually just power on through anything where before i constantly had to let off. It still lifted good and seemed just as fast in the straights. I haven't recharged but my finished voltage was 3.77-3.78 when it is normally 3.80-3.82 after 4 minutes. I think that was because I was able to run wide open much longer than usual. Second set I tried 8oz. Not bad and much better than before but I could still get some instability if i wasnt careful. 10" seems to be the sweet spot no doubt! Now to see if I can extend my battery trays enough for a 10" cog without an extra pound of ballast.

[Jamey]

I did a temporary rearrangement with a battery on the original tray way up front, a battery on the port and esc on starboard trays. That put me right at 10" cog. Seemed to work very well though not quite as well as having the extra weight.

Picked up a GPS too. With a slightly boogered-up M445 5S gave me 47.2mph and 6S 55.2mph . The 6S run was done with the 3S I had run previously so it might pickup another 1 mph with two fresh batteries. Much faster than I expected from the calculations done with the tool on the website. Just for conversation it would be cool to get to 50mph on 5S and 60 on 6. Not sure I'll get there but I am going to try. Thinking either a M447 or maybe even a ABC 17 if a 1.5 45mm ever comes back into stock.

I can't tell you how much I appreciate the advice. Going from a 9" to 10" cog took a lot of effort that I may not have ever tried if you guys didn't tell me too.

[zooma]

Congratulations, sounds like you're pumped. I am getting 46 on 4S2P. I am going to leave it that way until I can't run the battered hull any more, then move the hot setup into the newer Pursuit.

[Jamey]

Followed up with another 55.1 mph on 6S run. Didn't gain anything with both batteries being fresh. I guess that is a sign my batteries are healthy.

Also ran 4S and got 39.7 mph Not bad for only 22K RPM