I just bought a 2006 28ZX with 350 mag MPI's, bravo 1.65 drives and stock 25p mirage plus props. The boat has 45 hrs on it and is like new. It will currently run 68 mph on GPS at 5000RPM WOT and will plane pretty easily as long as you are easy on the throttles out of the hole.

The slip numbers I calculated are pretty low (5-7%). My question is has anyone tried shorty lowers or nose cones on this boat and did it increase top end without hurting your planing ability? Also, I know labbing the props will help my top end but will it hurt my planing ability? Any input is appreciated!

If you put on Shorty lowers you will probably need to go to a 4 or 5 blade prop. I would like to know if this has been done.

Nose cons probably won't do much until you get into the 80's

Thanks for the response. I figured I would have to change the props. From everything I've read on here the props I have now are the right ones for the stock setup I have. I just would like to know if anyone has tried the shorty's on this hull before with the stock motors and if there was any top end gain without too much sacrifice in planing ability. Maybe Jamie at Lakeside has tried it????

Marc Boos at Precision EFI has done one with ext boxes. I would imagine that it had shortys too. The boat ran high 90's with ease. They did a bunch of other things to it so I don't know how much was gained with the higher drives.

Personally, I would wake up a ZX with power. That will give you a guaranteed gain. The heavy ZX hull responds well to added power.

I agree ZXXX a little more power would be the ticket. Is there any way to add some more HP (maybe 50?) the the late model 350 mag mpi's (300 hp) without a SC?? I like the reliability of the fuel injection and with the motors being under 75 hours, I really don't wan't to change them out yet. Are there better heads and cams or other performance mods that will wake these up?

50HP usually isn't worth adding to a marine MPI engine. The computer tune costs dough so you may as well go all out.

I have crunched the number every which way on shorties, exhaust, and almost every other mod.

2 things are the best bang for the buck. Superchargers and props. A good set of props can gain you 5 MPH. Superchargers... 10+.

Shorties are 3rd... but shorties will cost nearly what superchargers will cost and won't gain you near the speed.