Harper220

Just wondering what's all involved in adding extension boxes and shorties on bravo drives? What would be an approximate cost and would it benefit a 28 Daytona with twin 496 HO's? Always looking for gains without tearing into motors...

cobra marty

You could probably whipplecharge it for the same money and get 10-15 more MPH.

Cord

iTrader: (2)

With boxes and shorties you'd be looking at a 5-10mph increase. The boxes will cause the boat to feel larger and help with planing. Looking at your drives, it seems as if Eliminator set them pretty high from the factory. You may already be an inch or so above. I wouldn't go any higher with out talking to Eliminator about your proposed changes. Boxes and shorties have another advantage as they don't change your insurance statues. A blower sure would though. You will also need to relocate the steering rams and fill the holes in your transom. Luckly Eliminator put them in a solid color area so the job is at least feasible.

jdnca1

We just did this to my 28 with twin 500EFI's a couple of months ago. It's definately a big project. You will need to either pull the motors or "sling" them forward to get them inner transom plates loose and gimbals off. You'll have to drill holes for the wing plates in the box, depending on what length steering rams you have the "hole punches" on where to drill may or may not be in the right spot. I had the shorter rams so we had to measure...but very straight forward. You'll also need to get or make longer hydralic lines running from the boat to the steering rams. I would just get them from IMCO when you order. Also you will need to make longer water lines from the drives to your sea pump. There is no need to change the old ram supports on your transom as you will still use them for the (longer) hydralic hoses that go to the steering rams. You just won't be using the upper portion where the cylinders used to attach. If you don't have full hydralic steering (to the helm) then you will need to put that on as well with the boxes.

I haven't done a lot of testing with mine just yet, but it is DEFINATELY faster with boxes...I haven't done shortys yet. I hit the rev limiters easily now. I will be sending my ECM's out on Monday for a reflash to raise the limiters. My plan is to get dialed in the way it sits (I think hydros will be fastest) then try a set of 2" shorties a buddy has to see what the difference is "back to back".

As Cord stated the boat definately is better in the rough stuff due to the added length. I think the boat will pick up about 5 with just boxes....maybe another 3-5 with shorties, which I think it is going to need. I will know for sure on the boxes in a week or so when my ECM's come back.

Boxes, input shafts, wing plates, hoses, and steering helm kit is going to run you ~5k ish, shortened lowers another ~5k. No labor included.

Jonas

i have a set of stellings boxes u can adjust the x with those might not need the shorties,,
let me know if u want em i gotta get em out of the garage

Cord

iTrader: (2)

I have the Stellings on my boat and I'm very happy with them. The ability to adjust the x-dim is well worth it.

rbtnt

Depending on where Eliminator put your drives, the boxes could extend over the tunnel. My did and I know of another one that did. Measure this so you are not surprised. I filled my in with fiberglass and IMCO modified the boxes on the other one.