Gary Anderson

What year scarab? The 80s thru mid 90s scarabs seemed to run VERY low X dimensions. Raising the drives should be worth 3-4mph easy.
BTW, dont forget to add full external hydraulic steering to your budget.

H2Xmark

a flat transom boat pick's up more than a notched transom boat, my 35 lightning[notched transom] on picked up 2.5 mph when the boxes were added, a friends 32 active thunder [flat transom] picked up almost 4 mph, with the stelling's they have 1" raise built in, or you can raise the drives even higher on them to raise your X . your 38 should pick up 4 mph maybe 5 if you install the drives high on the boxes, and you are running some nice 4 blade props[or 5 blade]
Mark

HABITUALVIOLATR

Check Your E-mail

SHAGNASTY

93 Kevlar 1.35 bravo's highest setting on the box turnin 3 blade 23 Mirage at 4900 no gain in speed, sea tested on a pancake, again not sure if these boxes come to life in flat water or not

Danny Usnik

Were always here when you need us.

LEOPAJM

Dude .... re-read my post ... I wasn't being a smartazz , for once

KAAMA

iTrader: (1)

SHAG,

I'm not sure this will help you much or not, but when I bought my boat it originally came with TRS drives, but I had them removed, and modified to a Bravo One 1.5 gear set-up. When I made the switch I thought it would be a perfect time to add the Stellings extension boxes. I mounted the Stellings extension boxes as high as they could be mounted (just under the rub rail on my boat---32' Active Thunder), but because I made so many changes I cannot tell you if my hull actually benefited from the extension boxes or not truthfully. It would seem that because my hull does NOT have a notched transom that my hull WOULD bennifit from the boxes---at least I am hoping so. At this time with no nose cones the stock length drives, the propshaft center line sits about 3.5" to 4.0" below the hull. Just before I took the boat out of the water for the season about two years ago, I also had a serious hook taken out of the bottom of my hull which I picked up about 4-5mph at 4000rpm and I obviously thought that was a pretty good gain. I couldn't get a good top end reading with the hook taken out at the time because my engines weren't operating up to RPM the last time I had my boat in the water---however, they are newly/freshly rebuilt now. I have purchased some -2" IMCO shortened lowers, and will be trying them soon to see if there would be any gains or losses, etc. I am thinking that the -2" IMCO shorties with the nose cones already molded into the casting design will work with the extension boxes, and my hull not having a notched transom---but we will soon see for sure. By the way, I've been running a labbed 32" Bravo One 4-bladed prop.

Every hull is different and I obviously have a lot of mods going on with my set-up---perhaps too much info for what you need, but perhaps it will help you out a bit or give you something to think about.

LEOPAJM

The first thing that needs to be resolved is ... why the 800 RPM loss ???

Gary Anderson

Probably not high enough. I know a couple older flat deck boats that raised their drives 1 1/2" - 2" without boxes and gained a few mph.
Are you having any ventilation or blowout problems with the current drive height? Do you have good trim control? Does the hull porpoise w/o the use of tabs?
Gary

THRILLSEEKER

I have experience with "boxes"


so exactly what is it you want to know??