trs drives
 

ok all you gear-heads.why did the bravo drive replace the trs drive.are the trs drives no longer aviable.do the two drives share any parts?i am looking at a older boat that has these drives and do not know any thing about them.a guy that works on my drives says trs stands for time to replace soon.what do you guys think?

I believe merc came out with the bravo to replace trs because its alot cheaper from a manufacturing standpoint. TRS drives are very reliable when not overpowered. Keep the HP under 500, and they live a long time. They share no parts with the bravo, and as long as they are setup properly, imo, are stronger than a standard bravo. Some parts are no longer available, but most still are. And there are TONS of used TRS stuff around cheap.

+1

TRS drives are great if you maintain them properly and don't over-power them. The only real b!tch about the drive is that you have to re-do the transom if you want to replace it with virtually anything other than a Konrad.

That said, 5-10 years ago TRS parts were hard to come by. There weren't enough older boats out of commission, not enough left over parts from people doing conversions, and the internet wasn't used as much for advertising parts. You kind of had to find parts locally, and they were over-priced and hard to get. Now you can work on a TRS for a cheap or cheaper than a Bravo, IMO. That market may dry up in the next few years, but I don't see any problem getting parts now or in the near future.

To do away with trans. it allows for more room.

Lots of reasons the TRS got replaced with the Bravo.

The bravo is a much better setup as far as weight and efficiency...which translates to SPEED ! A buddy weighed all the parts during his swap, and I believe it was about 150lbs difference. The design is so much simpler - it removes complexity and the the number of separate components. The Bravo does not need a transmission - the shifting is done in the top of the drive. Bravo does not need a water pickup mounted on the transom - it's pickup is in the drive itself. THe bravo does not need a separate speedo pickup on the transom - it is also mounted in the drive itself. It was a fantastic update to the TRS - which now equates to farm equipment in the performance world. The Bravo was not much stronger, but could use less power to attain the same speeds. For example - single engine performance TRS boats will usually gain an easy 5mph when converted to Bravo drives. A 454ci/330hp big block chevy powered trs 22 donzi would run about the same speeds as a 350ci/260hp bravo setup. then theres the fact that the rear seats could be moved back more for more interior space, or for a longer bow with same cockpit size, etc, etc.........

If you like the boat for what it currently is, and dont want to make it go faster in the future, then there's nothing wrong with a TRS boat. It will have a MUCH lower "buy in" cost than a Bravo boat - these days that's usually what makes a TRS boat so attractive...the price!! But unless you are a do it yourself'er, the upgrade cost later is usually cost prohibitive......

I personally killed 4 TRS drives that had never had prior durability issues before I overpowered them, and one that was rebuilt carefully ---- with no difference in how long they lasted......due of course to the simple fact that I exceeded thier design limits :)

I think the thoughts that the Bravo replacing the TRS is not what Mercury was after. I feel the Speedmaster III replaced the TRS. The Bravo was a a step up from the Alpha. The early 454's came with Alpha drives. Mecury saw the need for a stronger drive with the Bravo and much stronger drive with the Speedmaster series to replace the TRS.

That's Right.

thanks for all of the replys.i was told long time ago that it takes almost twice the h/p to run a trs vs a bravo.i was also told that there were two styles of transmissions.the better one being the borg/warrner type.my buddy told me that merc tried to make one but was not used alot.how do the transmissions work and can you do away w/them?any feedback would be great.

TRS, Speedmaster and the NXT1 drive require a transmission. Unlike a Bravo or Alpha they do not shift. The transmission style drives are really much stronger than Bravos. The newer dry sump Number Sixes with a dry sump transmission actually use less hp than a Bravo. Much heavier, much stronger and a lot more money.
The Borg Warner Velvet Drive style is a very simple transmission used in Ski Boats, inboards and by Mercury Hi-Performance. Many of these transmissions are highly modified to handle far more HP than the stock transmission. I believe the newest version can handle up to 2000 hp.

If you are going to run the TRS drive then you must have a transmission. You can't do away with it. Through the 70's Mercury had a transmission they designed called the Merc Trans ll. It differs from the B-W as it has an aluminum case with bellhousing all as one piece. It shares some of it's internal parts with the Ford FMX transmission of that day. It is 9 inches shorter than the B-W and considerably lighter, 70 lbs. as compared to over 100 for the B-W. It has less clutch plates then the B-W so naturally you have less friction area. There fore the B-W is the choice if you plan to run higher horse power. It has a built in cooler where as the B-W requires an external cooler.However they are good transmissions for up to 500-550 hp. These are hydraulic operated transmission. When shifted from neutral into gear hydraulics move a piston to compress the clutch plates together. It's a nice smooth transition, not like the dog-clutch type transmissions found in most drives which "clunk" into gear. Parts for the B-W are much more readily available though you can get parts for a Merc Trans if you know where to look. Most of the Merc Trans parts are NLA from Merc. Here is a link to a guy that specializes in the Merc Trans. He has a lot more info about them on his site.
http://www.kcmarinetr.com/Default.aspx

As far as requiring twice the power as a bravo I think that's a little exaggerated. One thing for sure they will withstand more HP than a standard Bravo.