gregga

anybody have any links for a 20" mid setup? Also the merc. tech went over the engine today and said it was flawless, in fact he said he hasn't seen a 99 engine that idles and sounds so well so that was a good way to start the weekend and build process... now back to setup, you guys are leaning to a 10" setback hydraulic jack plate with a 20" mid section on the engine?

Kurt Hamilton

I'd still say 6" setback will be plenty considering your going to race in big water. 10" could make it a handful when airborne. If your hellbent on the hydraulic jack plate I will recommend a detweiler brand, there design is slightly better for what you want to do. A 20" mid is a must!
Surprised to hear the engine checked out ok, definitely didn't sound like it was running on all 6 from what you described. Still not convinced, did he water test it? Coil packs and plug leads quite often idle perfect and run fine under low load but break down once you apply load eg. Planing and higher rpm. I recently went through this with my 300xs. Only ran on 5 at high load then get it back home and couldn't diagnose cause it ran perfect at idle and low rpm/no load on flushers. Ended up being a coil pack breaking down under load!

TeamSaris

Im thinking coil packs too..he jusr texted me, raised the engine a bit, lost MPHS...and it was buried before

gregga

Hey guys,

I did a consitent 5500rpm today with a 21p and could only get 48mph out of her. This morning we raised the engine 3 1/2" as well on the same bracket. Now I understand that the setback is way too far back but I still would have thought she would have gained at least mph or so but i dropped from a best of 54 down to 48mph lol but iv been consitent with rpms and now turning a steady 5500 when it used to be 5300!!! She doesn't know what she wants.

Kurt Hamilton

What was the distance below plank before again? 3 1/2" is a lot! Sounds like your too high now. The prop is slipping way more (hence more rpm) and not pushing the boat (less speed). Did the boat react to trim at that height or did it just run real flat and throw a rooster when trying to trim?
The boat should run quicker with big setback for speed runs, it just isn't conducive to being fast in the rough because the handling goes out the window.

Too Stroked

I'll toss in yet a third vote for being down on power. And if you are down on power, all of the other testing of variables you're doing will be wrong. If I can spin a 27" pitch 6,400 RPM on almost the same setup that you can only spin a 21" pitch at 5,500 RPM, something's wrong.

gregga

too stroked.. i completely agree. If this is suppose to be a 65ish mph boat i can't see this setup holding me back especially after doing some tweaking by 15 miles per hour!!!!! As of right now the bullet is pretty much dead level with the pad of the boat and running the 24" setback. I raised the engine up on Sunday a total of 4 1/2". so as of now the bullet is even with the pad and i could only run 48mph. the boat did react to trim and seemed to run best (48) at 5400 anything past 5400ish she was throwing a huge roostertail and losing speed. Anyway to do my own check on the coil packs while running? My mechanic is busy till next week and the first NJ race is creeping up lol.

ziemer

iTrader: (1)

What are others running in this sort of hull for props? With the increased prop shaft height it may be that you are now getting out of the efficiency range for that Laser. It's not meant to run high and now you're up 500 rpms yet down 6 mph.

Maybe a larger diameter, larger blade...

northernoffshore

http://www.youtube.com/watch?v=hZ-sgjuMJcg

TeamSaris

Mirage Plus will be the fastest (besides a chopper but he might be a bit too heavy), Trophy will have little bit better mid range but 2-3mph slower. I ran my Mirage Plus real high and loved it. 25P.
The BEST prop is a BBlades Blaster without a doubt, but it isnt as accessible as a stock Mirage Plus.
BTW you will need bungees for racing, HUGE difference