RRP trim system nozzle diameters

Although its getting late in the season in Michigan, I've been playing with the pump on my superfreak. Current configuration is a healthy jm718 with bpipe and msd enhancer. Stock 144mm pump and 9/15 hooker. Overall happy with the setup, I bored the reduction nozzle to 85mm, and felt a positive difference on getting the motor into the meat of the powerband sooner. I now swapped that over to an RRP trim system and took it out for the first time today. Overall was ok, lost some bottom end but got to feel what trim is all about. Measuring the reduction nozzle at 90mm and the trim/turn nozzle at 86mm. That size seems a bit backwards, as the turn nozzle should always be about 3-4mm larger than the reduction nozzle. On top of that, a 90mm reduction nozzle on a sub 800cc seems excessive. Is there a function to having a tighter turn nozzle? Does RRP assume most guys buying this kit have big motors, so the diameters they supply are already adequate? I'm thinking I can regain my bottom end by machining a sleeve to knock it back down to 84/85mm so I can load the pump up. I've also got a solas 144 pump to swap out as well, but I wanted to test the trim system first to eliminate an extra variable. Thoughts are welcome.
 
Location
Stockton
Don’t know about RRP trims, but I assume you bought it used? Oddly I saw another thread some time ago with similar bore diameters, not sure if that was you or possibly a previous owner of your trim or another all together..

Someone seems to have been using a small diag steering nozzle to help with a too large of a bore on the reduction or what ?

In your case, I’d do your sleeve suggestion to correct the reduction bore diam back to 85, and get your steering nozzle diam bored to match your prior set up diameters..
 
It is used, but was on my buddies ski. I machined an 85mm sleeve out of some urethane tooling plastic and epoxied it in. I remeasured the turn nozzle and it averaged 87.3mm so I'll leave that alone.
 

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Was able to test the 85mm reduction sleeve. Bottom end was gained back and made the steering feel a bit more normal. It felt like I had the original bored out nozzle until I pull the trim lever. For guys installing this on a small bore, it might be worth looking into getting it sleeved down.
 
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