Joe

Help! More Speed - Same Reliability


I've heard many, many different suggestions as to how I can get more speed out of my boat. So, I figured I'd throw it out here for "Everyone's" comments. They'll all be appreciated! Oh, btw.... no blower comments please - I don't want 'em! Turn-key is the focus. I run the boat every weekend (400 HRS) -- when possible.

1999 38' Scarab
500 EFI's
Upgraded CMI Exhaust w/ Dry Pipes (it sounds gooooood)!
28 Pitch Bravo's (spinning outward - not lab'd)
77-78 MPH (in salt water during warm weather)
80MPH (in salt water during cooler months)
5200 RPM's

Appreciate comments from anyone who's experienced:

-Vortec Engineering's computer upgrade
-Vortec Spark Arrestors over the stock K&N's
-Grinding/ filing down the low water pick-up inlets making them smoother
-Sanding the hull (with what grit/kind of sandpaper etc... and what does that do to the lifespan of the hull?
-waxing the hull


P.S. Also no fat jokes! Loosing weight is not an option for speeding up my boat! haha. Here's a photo.

FYI... As is everyone else's I know: It's for sale. See boattraderonline.com for photo's or just e-mail me:
[email protected]

117k Firm -- or, if you feel better negoting... 125k (and we'll negotiate down to 117k. Includes Brand new custom trailer. Boat was kept on Lake Travis, Austin, TX

Thanks in advance!

Gary Anderson

Blueprinting the bottom and having the props reworked (thinned) might pick up 1 or 2 mph. Raising your X dimension 1-2 inches could be worth 3-4 mph.
But it sounds like you're doing pretty well at 80mph now.
Gary

bobl

Joe, I don't think there is any magic horsepower to be found in those engines as they are. However, if you are willing to go into them you could find some additional HP by blueprinting, doing some good head work and raising the compression some if you're willing to run premium. A good set of aluminum heads would work well, but you boat in salt water so you'd be forced to stay with cast iron. A fully ported set of Merlins might be worth some good gains also. With 400 hours it might be time to think about freshening them up anyway.

Joe

Gary, What do you mean when you say raising the X-dimension? is that shorter lowers? I'd appreciate it if you'd say a bit more about that. Also, how much will that torque the drives (if any)?

Bobl, Unfortunatly, the boat came w/ y pipes (silent choice) and the pistons sucked water down into the motors causing me to have them rebuilt (I chose to do the bottoms as long as we were in there) at 150 hrs. Now, the pipes are gone and dry CMI's are on it. It sounds goooooood.

I've heard from several folks that Merc. sets the motors up to run appx. 20% rich. Any news on the truth to that - having the computers leaned out a bit? If so, what's been found and who's the best at doing it? I've had initial conversations with Vortec Engineering and they're claiming 3-4 MPH and their computer upgrade adds the extra fuel on the top. I just can't find anyone to verify it.

Gary Anderson

Most boats are set up with a conservative x dimension (drive height) That's so the boat will trim well with full fuel, a dozen people, and a half ton of gear up front. Raising the dive height will allow for higher speeds, but you may lose some trim controlability. Moving weight back in the boat will minimize this. I raised my TRSs on a 38 scarab 2" and gained about 4mph. But I also lightened the bow and went to saddle tanks rather than the belly fuel tank. I did't have any problems with trim with those changes.
You can buy 2" shorter drives, but you may have to redistribute some weight with those too.
I would reccomend boxes instead. They have the same effect of raising the drive with the added advantage of greater leverage from the 10" setback. You will need full external hydraulic steering with the boxes though.
Gary

HOUSTONPROP

Labbing of each prop, assuring perfection in balance,pitch,and blade cupping ect.could increase the performance by 2 mph or so ,give me a call when you get a chance.



Darin 281-580-7767

Joe

Gary:
Thanks. For some reason I never considered boxes. You got my attention...

Can you recommend anyone you know of that might get them at a below-retail price and do you know anyone w/ a stepped-hull Scarab that has tried them? I've only seen one boat over at Jay's shop (Cast-a-line Marine in Miami). That one had Bulldogs and am not sure if the boxes were added or bought w/ the motors etc... I'll call him as soon as I finish this e-mail.

Darren:
I don't want to do anything with the props until I've done everything else. Otherwise, I'll be doing them twice. I'll keep in touch.

Gary Anderson

If I could find them below cost, I would buy some!
Try Stellings. They seem to have a nice unit that allows for some height adjustment. Call, they might have info on your boat without & with extension boxes and appropriate drive height.
Also remember that full hydraulic steering will be needed. An add on will not work, although the existing rams and pump may be reused depending on the system. Extensions will be needed for the rams too.
Gary

Joe

Thanks, Gary.

HOUSTONPROP

Joe,makes since to me let me know when you are ready,Darin