Solas 10/16 feedback

[mn_reeds]

Have a few updates on some more testing with this impeller. I finally got my y62t zeel in and am running the default wax v3 curve. The other notable change is with my steering setup - switching to an OVP straight fatbar and trimming the blowsion HD cable end to maximize nozzle throw. That moved my bars forward just under 6" and gained significant nozzle throw in both directions.

I noticed a significant increase in bottom end all the way through 2/3 throttle. It was pretty rough so I didn't get too much time testing up top. Max rpm is still right around 6890 so it looks like I will need a little impeller work.

Is my target rpm actually 7k for this setup? If so I assume bending the last 1" or so of the trailing edge up to 15 should give me that 120 rpms I'm looking for. From my notes that would also take the gap from 1.4" down to 1.3" which should reduce the load a bit too.

 

[kevbo]

Your RPM is in the range for 61x cylinders with an exhaust port under 180 degrees open. You can now judge your pump load by how quickly it gets on the pipe. Your peak rpm will vary with porting and pipe length. If you want better response and thrust, bore the nozzle before you bend the impeller. I found that as the impeller is flattened you run out of pipe first so rpm rpm tends to plateau . Low speed response and pull continue to improve, it may feel like a loss of top end even though it still goes the same speed. Its really fine tuning at this point but you may still make a noticeable difference.

 

[mn_reeds]

Would a 90mm nozzle be too large for this setup on a 144 pump? I've got an RRP sitting here that I could try. Didn't find anything from search but am assuming that everyone goes to 84/85 as that is max bore on a stock nozzle.

Also have a set of dual 44s (4 hole version) that I have been debating as well. I suppose at this point it's just going to be incremental improvements.

 

[kevbo]

Pump testing is a lot of work. I stopped when my last pitch adjustment made no improvement with the same 85mm protec nozzle. I have a 650sx that pulled harder with 84-85mm nozzles when compared to an 80. . Surprisingly there was only a 100 rpm increase going from an 80 to 85. A pair of sbn44s will work great, they will likely need to be set a little richer at part throttle when compared to 38s.