what to do to keep Bravo 1 alive at 525hp?
#1
I opted for the lower cost Bravo 1 drive instead of the Bravo XR with the 496HO thinking that I would get ~75mph (because that was what I was told by the dealer) and that is all I wanted. Now I find out that the speedo says 75 but the gps says 68 at 5000rpm and 26 pitch Bravo 1 prop.
According to Mercruiser 425hp is it for the Bravo 1 and then comes the Bravo XR up to 575hp. I am considering an upgrade to about 500 to 525hp to get where I want to be. It will not be a supercharger but heads, cam and the like.
Replacing a brand new Bravo 1 with a Bravo XR is not something I even want to think about. I have heard comments that increased hp from engine mods is less abusive to the drive than a supercharger at lower and mid range rpms. This is supposedly due to the lower torque at lower rpms with the engine mods versus the supercharger.
I have also heard that using WOT during planeout is the primary cause of Bravo 1 drive failure (the forward gear set)when hooked up to higher than Mercury approved hp/torgue engines.
Given my hp target I am hoping to squeek by with the Bravo 1. I would appreciate hearing about experiences with the Bravo 1 and >425hp engines. Both successes and failures so I can judge my next move.
Thanks!
According to Mercruiser 425hp is it for the Bravo 1 and then comes the Bravo XR up to 575hp. I am considering an upgrade to about 500 to 525hp to get where I want to be. It will not be a supercharger but heads, cam and the like.
Replacing a brand new Bravo 1 with a Bravo XR is not something I even want to think about. I have heard comments that increased hp from engine mods is less abusive to the drive than a supercharger at lower and mid range rpms. This is supposedly due to the lower torque at lower rpms with the engine mods versus the supercharger.
I have also heard that using WOT during planeout is the primary cause of Bravo 1 drive failure (the forward gear set)when hooked up to higher than Mercury approved hp/torgue engines.
Given my hp target I am hoping to squeek by with the Bravo 1. I would appreciate hearing about experiences with the Bravo 1 and >425hp engines. Both successes and failures so I can judge my next move.
Thanks!
#2
Registered
Joined: Feb 2004
Posts: 3,710
Likes: 2
From: MT. JULIET, TN.
As long as you don't WOT on take off you'll be alright. If you are going to be getting "air" alot you might want to upgrade to the thicker floor gears if there not already in it.
#3
My 28 Pantera (5200# dry) has a 525SC. The upper on the stock Bravo let go at 210hrs. The lower was fine. I replaced the upper with an Imco Exteme Advantage--still uses standard Bravo gears. I now have 550+hp and 210 hrs on the current drive without any issues and never any flakes of metal in the lube.
The key is change lube every 25-30hrs and run a drive shower. Don't hammer it outta hole and watch the air time.
Also, 500hps came with Bravo1 drives for many years before the XR was developed.
The key is change lube every 25-30hrs and run a drive shower. Don't hammer it outta hole and watch the air time.
Also, 500hps came with Bravo1 drives for many years before the XR was developed.
#4
I'm not an expert but with a light boat like that I can't imagine a concern......
I'm pushing a 10000 LB straight hull Tiger with 600+HPs with Bravos. Currently rebuilding and expect to have enough horse to not chance it anymore, but I just can't imagine a problem for you. Hopefully some more educated opinions will chime in....
Good luck,
Neil
I'm pushing a 10000 LB straight hull Tiger with 600+HPs with Bravos. Currently rebuilding and expect to have enough horse to not chance it anymore, but I just can't imagine a problem for you. Hopefully some more educated opinions will chime in....
Good luck,
Neil
#6
Hey guys great info all! This is what I need to know.
KEYNNO
As long as you don't WOT on take off you'll be alright. If you are going to be getting "air" alot you might want to upgrade to the thicker floor gears if there not already in it.
What / where are the 'thicker floor gears' in the drive line and how would I know if I have them or not? My Bravo 1 is out of the box stock. Are these included in Bravo 1's after a certain build date?
GRIFF
My 28 Pantera (5200# dry) has a 525SC. The upper on the stock Bravo let go at 210hrs. The lower was fine. I replaced the upper with an Imco Exteme Advantage--still uses standard Bravo gears. I now have 550+hp and 210 hrs on the current drive without any issues and never any flakes of metal in the lube.
What is the 'IMCO Extreme Advantage'? A gear set, a reinforced housing support, ujoint, intermediate drive shaft, other? Where there any flakes of metal in the lube to predict the upper failure?
The Rage is very light and unfortunately for the drive likes to catch a lot of air at speed. I had not considered that issue until you brought it up.
Does everyone run Mercury Extreme Pressure Gear lube in the lower unit or has anyone found success with a full synthetic?
Thanks again for all the advice!
KEYNNO
As long as you don't WOT on take off you'll be alright. If you are going to be getting "air" alot you might want to upgrade to the thicker floor gears if there not already in it.
What / where are the 'thicker floor gears' in the drive line and how would I know if I have them or not? My Bravo 1 is out of the box stock. Are these included in Bravo 1's after a certain build date?
GRIFF
My 28 Pantera (5200# dry) has a 525SC. The upper on the stock Bravo let go at 210hrs. The lower was fine. I replaced the upper with an Imco Exteme Advantage--still uses standard Bravo gears. I now have 550+hp and 210 hrs on the current drive without any issues and never any flakes of metal in the lube.
What is the 'IMCO Extreme Advantage'? A gear set, a reinforced housing support, ujoint, intermediate drive shaft, other? Where there any flakes of metal in the lube to predict the upper failure?
The Rage is very light and unfortunately for the drive likes to catch a lot of air at speed. I had not considered that issue until you brought it up.
Does everyone run Mercury Extreme Pressure Gear lube in the lower unit or has anyone found success with a full synthetic?
Thanks again for all the advice!
#7
Originally Posted by Back4More
Thin out the blades and prop it to the high side of your rpm peak.
#8
Originally Posted by drypipetiger
I'm not an expert but with a light boat like that I can't imagine a concern......
Neil
Neil
#9
Use Redline Shockproof Heavy gear lube. I have 650+ hp engines in a 11,500 lb boat (dry) and only one minor malfunction in three years (broken thrust washer). Gears still look like new.
#10
Originally Posted by PatriYacht
only one minor malfunction in three years (broken thrust washer). Gears still look like new.




