INDY27

Ralph,
I have not dynoed my motor but I think I am probably around 640-650 hp. My Procharger is a stage II running 5lbs. of boost at wot. I have Stainless Marine exhaust and had the ECU reprogrammed by Mark Boos of Precision Marine in Kenner LA. Everything else is stock. I am testing the shorty next weekend and will post results on this thread.

Lee

Ralph Rast

Hi Lee
Do you have the HP500EFI? What's your X dimension from keel to prop shaft? How stable is your boat at 85 mph (gps) and which prop do you run? What's your top rpm? Is your boat the 27 Fountain? How many hours do you have on your engine with and without the procharger?
The reason I ask these, is I'm about to rebuild the procharged blower motor for the third time and I'm debating about a totally different design (different blower vs. 540 naturally aspirated). I've had my M1 procharger for 3 years before I blew the blower. Now I've blown 2 engines this summer (I use my HP500 as a back-up motor).
Thanks, Ralph

dirtlawyer

Ralph -

sorry for the dealy in response. My drive was pretty deep, so the 2" shorty greatly improved performance, especially planing. My motor is a 525 SC, which does not have huge power/torque on the low end, thus the planing problem. The shorty allows me to loosen up the prop early and get the boat on a plane. the best part of the shorty, in my opinion, is that it kept the bow down even when I'm trimmed out at 5.5 - 6 - felt like I added 2 ft to the boat. Thanks for the info re: the speedo, but unfortunately I already purchased a GPS unit. Right now I am running a 28P Bravo labbed by Mercury Racing. Turning it a 5100 RPM std 1.51 gears.

INDY27

Ralph,
My boat is 96 27 Fountain with a 502 EFI, Bravo 1 drive, 1.5 ratio. I am currently running a RH 32p Bravo four blade labbed by Throttle Up at 5200 rpm. The boat feels great at wot, very stable. I installed the Procharger when the boat had 160 hrs and now have 235 hrs.

Lee