TRS to #3 Drives
 

A friend of mine is interested in swapping out his TRS drives and installing #3 drives. What problems will he encounter? Will the gimball need to be replaced and do the drives even match up?

I know absolutely nothing about either of these drives so thats as descript as I can be.

Thanks

He will have to reglass the transom and then recut it out. I know that DJD did this on his Cig so maybe you can track him down for some of the details.

Jon

I thought a #III is a TRS with a differnt lower and trans?

That would be a #2 drive

Jon

Not sure but you may not have to reglass. The old Tranny will work

Reglass the transom. New drive, gimbal, etc. Tranny will work but it requires a different tailstock. External hydraulic steering, if he doesn't have it already.
Gary

Hopefully DJD will chime in. So far it looks like a major project.

This scary, I was wanting to do this also, but only if I have too.
I was wanting to super charge my boat. i blew the port side lower out the first weekend i had it running 500 horse thru. Took half the summer to rebuilt, and that means I already out $3000 in having it rebuilt.

Looking at getting at least 200 more hp's out of the motors.
Wasn't really counting on having to this, but the thought has been i the back of my mind.
Do I neeed to change drives? :(

Biggus on the board is running 750hp or so into his TRS drives and had no problems

Jon

We swapped out our TRS drives with #2s, they bolt right up, about a half an hour a side depending how many people "are helping" We did this on a Top Gun

Becca,

Did you see any increase in speed with the #2`s???

I have a line on a pair for cheap $$, been holding back because of the parts situation on #2`s

Kurt.

You need to swap the gimbals but the transom holes for the TRS and the #3 match. I can´t say for sure if this is the same for the different versions of the TRS drives though.

Cigaretteman

Just a note on the SSM IIs. If you just swap a II for a TRS, your X dimension will be AT LEAST 2" too low. The lower on the II is actually longer than a TRS, although the II drive is intended to run much higher. You might even lose some speed with that swap.
Gary

TRS to SSM#'s
 

I am in the process of this swap from trs to SSM 3's right now on a 38 Scarab. After the drives are mounted and engines are aligned, I am removing the drives to pu extension t boxes on.
All of this requires the transom to be redone in order to move the drives up. The TRS has the same centerline dimension of the input shaft to the output shaft. Leaving them at the same vertical dimension does not require patching the transom but the 3 drive has a greater setback and will run deeper. thus not as effective.
Anyone looking to do this must know it is a major undertaking.
DOG

DOG has it right. I've done it twice.
Even without a box, you'll want to raise the drive. The III is designed to run higher. Even with the added weight of the III gimbal and drive, I gained a couple mph with the increased drive height.
One other note. The internal steering on the TRS will not work on a III without fabricating parts. The III has it own internal ram, although I've never seen one.
Even if you have an add on external hydraulic steering, I'm not sure you can modify it to work with the III transom plate.
The best solution is full external hydraulic steering. Add that to the price of the swap.
Gary

I thought I saw aomewhere that the Konrad Marine 540 drive "bolts on" in place of a TRS. Is it just the transom bolt pettern that is the same or does the drive fit on the TRS gimble?

Anyone know?

-Greg

Audiofn told me about this thread last night.
I swapped out my TRS bombs for 3A's (same deal as the 3s).
Here's what I had to do.
Strip engines, drives, gimbals and everything off the transom.
Since we raised the engines almost 6", we had to glass in the lower 4" of the old hole in the transom. Don't try & position the new gimbal to cover the old hole, the drive will be so low in the water you will probably loose several mph.
You will need speedmaster tail stocks, shift cable brackets, external steering, different tie bar & yokes, inner transom plates, gimbals and of coarse, the drives.
You will have to make new engine mounts (aluminum angle iron) because the engines will be moving back around 3" and up anywhere from 4-6".
Depending on the boat, you should have the prop shaft between 2 and 3" below the bottom of the boat. Any higher= tough getting it to plane. Any lower= alot of drag.
Let me know if you have any other questions.

Would it be better to go with some type newer/stronger bravo? As in better, I mean easier. As I understand now, you would need to redo (I think not entirely?) the transome?
Having the bravo eliminates trannys, and either way you would need to remount engine. With the trannys out and the impending set back of the motors, wouldn't you gain about the difference in mph, since engine weight has been pushed further back?
The #3A's can take bigger power, right? A lot bigger?
I also have 38' Scarab that weighs about 10000#.
Since I thinks I will be okay pushing 700 + thru TRS, I am asking for future reference. Brought up Bravo's also because my water pickups for trs are real bulky on prime running surface oof boat.

Thanks for further assistance :)

Oh and suggestions on supercharger that would be least punishment on TRS is encouraged. I always take a lot of time getting on plain so hull shots are not huge issues, but I would like the power if need be. I'm usually close enough to WOT so I am looking effecient cruising speed, throttle response from there to top end ;) Thanks again !