First Cat 36'' Sprint Cat

[calcagno45]

mmm... video!

[knpc]

Video Posted

[lomdel]

Video Posted

Where...?

[knpc]

I posted them in the video section but I can post them here as well. Its the first time my wife has taken video so its not great, but the boat did run well and gps said 49.6mph.

http://www.youtube.com/watch?v=NTSWiJG8TyQ

http://www.youtube.com/watch?v=jlZ67EIWqUU

[Fluid]

The cat seems to be running great! That setup is probably about max for normal sport running, the temps are all okay after 3 minutes and the speed is right on the button. How much charge are you putting back in the packs? You can fine tune what you have by flat-sanding the ride pads with 220 grit wet-or-dry (use soapy water) to even out the surfaces and sharpen the edges a bit. That should add a mph or two depending on how bad the surfaces are now.

If you want to go faster, try a P230 prop and raise the strut another 1/16". But this will generate more heat so be careful......





.

[DISAR]

Perfect well done!

[DISAR]

I see that you use the large strut did you get it from OSE?

I use the normal Speedmaster 21 strut but my boat does not handle that well in high speeds, need to mention also that I run the boat in sea water where always are wavy-choppy conditions. Perhaps this extra length in the strut will help.

[knpc]

I ordered it directly from speedmaster. It is the large round bottom strut with extended bearing housing .187 and a .40 size rudder. It handles great, it can run WOT the entire run. I do let off for a split second before entering the turn to settle the boat but aside from that its full throttle. It doesn't seem to want to blowover either, even into the wind. I assume thats a product of cog, long strut, and a large rudder. I knew nothing about cats going into the build, I built it based on the information I got from members here and alot of advise from Jay T.

Thanks to all of you for the help and compliments.
Kevin

[knpc]

I tried the 230 prop and actually lost a few mph, also the boat seemed to run wet compared to how free it ran with the x450. I'll keep doing some fine tuning but the x450 seems like the best fit so far.
I need to get another set or two of packs, its hard to get it dialed in when I can only do two runs for every trip to the pond.

[bustitup]

Here is my SprintCat 34" (it really measures a tad over 34" - why they call it 36" is beyond me). Mid-70s on 4S.

Jay what motor is that you have in there?

[Jeff Wohlt]

Prather props do not have the lift like an Octura X does.

[Fluid]

You will have to run the P230 a bit deeper than the X450 and perhaps move the CG back 1/2". Like hydros, cats are sensitive to props and often need to be trimmed differently for each one if maximum performance is desired. Or that prop may just be over the top for your cells etc.

My SprintCat usually runs the 1521/1.5D, but for the 75 mph SAW passes I used a 1521/1D. That was enough to toast a Hydra240 after a dozen passes.......



.

[D&D]

Again, I am new to this fourm but ran highly modified OPS 67 and CMB 90 running 60% nitro. Other than where the motor mounts fitted on to the rails I used to cut the rails almost back to nothing. I raced all up and down the east coast (a lot of banging and rough running) and never had any problems with the rails cut back. My boats ran in the mid 60s to high 70s. My point is you may be able to cut back the rails so that your batteries will fit down into the sponsons. Good luck.

[D&D]

FLUID, Nice build, what motor and battery(S) are you running? If you were to cut down the rails would the batteries bit in the sponsons?

[knpc]

Thought I would post an update
I've been playing with the strut depth and angle to get the best speed and handling. I think I have it dialed in right where I want it now. Its running 52-53mph on my old packs and with my new hyperion G3 packs it runs in the mid 50s mph. Its still very stable at that speed and can run w.o.t. for the entire run.
I brought the sprintcat and df33 to the pond this past weekend, both boats running in the 50s and best of all there was no need for the rescue kayak.

Kevin