Drive Upgrade on a charged HP500
04-14-2004, 01:15 PM
#11
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DP:
I switched to XRs after I blew a Bravo I on my first run with superchargers (750 HP). No problems ever since, except for some adjustment to a pretty crappy forward/reverse actuator.
If you really want to go the extra mile, #6 dry sumps will give you a bulletproof drive with the equivalent of 800-830 HP. Of course you'll need some Cyborg trannies. Nevermind. It was just a lot of fun going crazy on your budget.
I switched to XRs after I blew a Bravo I on my first run with superchargers (750 HP). No problems ever since, except for some adjustment to a pretty crappy forward/reverse actuator.
If you really want to go the extra mile, #6 dry sumps will give you a bulletproof drive with the equivalent of 800-830 HP. Of course you'll need some Cyborg trannies. Nevermind. It was just a lot of fun going crazy on your budget.
04-14-2004, 02:50 PM
#12
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Tom,
Here is what Imco does to the drive to beef it up:
-Heat treated and hardened spiral cut gears.
-Steel Tower insert to support the lower gear.
-Stud kit top cap to keep the gears stable.
-Rigid pinion
-Heavy Duty retaining clip for left hand rotation drives.
-Heavy duty retaining nut on pinion.
-Heavy uty yolks.
-Larger heat treated prop shaft.
-Entire case and drive is blue printed for maximum strengh and reliability.
As far as your steering, there shouldn't be any problem with just unbolting your current drive and bolting the new drive on. Since you are taking your drive off make sure to check that your coupler is in good shape. This is what is bolted to the back of your motor. It is the female housing for the male shaft of your drive to go into. There is a zerk fitting on the coupler that needs to be greased at least once a season (if you live in the midwest as I do that means every 4 months). If this gets dry your input shaft from your drive will destroy the inside of the couple and the motor won't be able to turn the input shaft on your drive and as a result you wont go anywhere. I detroyed one of these a few years back and you generally have to take the motor out to replace it unless your motor is moved forward. Most are very close to the transome.
You asked a question of Jay as to what the difference between an Imco Extreme and an XR is. The Imco Extreme is the Bravo 1 (spiral cut gears) that has had all of the above modifications done to it. It is substantially stronger than a stock Bravo 1 and a stock XR. The XR is stronger than the stock Bravo 1 but it is still quite limited. Some people have had good luck with high HP applications while others have had problems with there stock 500's. The Imco Extreme SC's Drives that I currently have are a beefed up version of the XR drive. You can find a stock XR for $5500 to $7000 and the Imco Extreme SC runs about $10,000. A friend of mine just bought a 2004 Fountain with 525's and XR's. The boat had about 40 hours on it and both XR drives had to be replaced prior to him buying the boat. These XR drives are made for the 525's but as I mentioned if you are not careful you don't need a lot of power to detroy them. I mention this because I would be careful going to just an XR. You may get lucky and have no problems but chances are they are going to fail. With the Imco's being Blueprinted, the tolerences are a lot tighter and therefore make the drive a lot stronger and reliable than the stock XR. Mercury makes a good drive but it is a production piece. Let me know if you need any other information.
Bill
Here is what Imco does to the drive to beef it up:
-Heat treated and hardened spiral cut gears.
-Steel Tower insert to support the lower gear.
-Stud kit top cap to keep the gears stable.
-Rigid pinion
-Heavy Duty retaining clip for left hand rotation drives.
-Heavy duty retaining nut on pinion.
-Heavy uty yolks.
-Larger heat treated prop shaft.
-Entire case and drive is blue printed for maximum strengh and reliability.
As far as your steering, there shouldn't be any problem with just unbolting your current drive and bolting the new drive on. Since you are taking your drive off make sure to check that your coupler is in good shape. This is what is bolted to the back of your motor. It is the female housing for the male shaft of your drive to go into. There is a zerk fitting on the coupler that needs to be greased at least once a season (if you live in the midwest as I do that means every 4 months). If this gets dry your input shaft from your drive will destroy the inside of the couple and the motor won't be able to turn the input shaft on your drive and as a result you wont go anywhere. I detroyed one of these a few years back and you generally have to take the motor out to replace it unless your motor is moved forward. Most are very close to the transome.
You asked a question of Jay as to what the difference between an Imco Extreme and an XR is. The Imco Extreme is the Bravo 1 (spiral cut gears) that has had all of the above modifications done to it. It is substantially stronger than a stock Bravo 1 and a stock XR. The XR is stronger than the stock Bravo 1 but it is still quite limited. Some people have had good luck with high HP applications while others have had problems with there stock 500's. The Imco Extreme SC's Drives that I currently have are a beefed up version of the XR drive. You can find a stock XR for $5500 to $7000 and the Imco Extreme SC runs about $10,000. A friend of mine just bought a 2004 Fountain with 525's and XR's. The boat had about 40 hours on it and both XR drives had to be replaced prior to him buying the boat. These XR drives are made for the 525's but as I mentioned if you are not careful you don't need a lot of power to detroy them. I mention this because I would be careful going to just an XR. You may get lucky and have no problems but chances are they are going to fail. With the Imco's being Blueprinted, the tolerences are a lot tighter and therefore make the drive a lot stronger and reliable than the stock XR. Mercury makes a good drive but it is a production piece. Let me know if you need any other information.
Bill
04-15-2004, 12:36 PM
#14
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Tom,
You can just replace the gears but if you are going to run real horsepower you better do more than just the gears. You will have stronger gears but you will just break something else, like your tower, the entire case, the prop shaft, the pinion, ect. I have owned my Baja for 6 years and have done all the band aid items. If you want to save yourself a lot of headaches and money do it right the first time. What kind of boat do you have, a vee or cat? There is a big difference in the stress on a drive with a cat vs. a vee. The cats put a lot less stress on the drives and thus you can put more power thru them with less failures. I am not telling you all this just to get you to buy my drives. If the drives work for you great if not that is fine also, but as a fellow boater I am trying to help you avoid pitfalls that I have already experienced. Where ever you get you nw drive or upgrade make sure you know who they are and what their experience is with your type of boat.
Drill It
You can just replace the gears but if you are going to run real horsepower you better do more than just the gears. You will have stronger gears but you will just break something else, like your tower, the entire case, the prop shaft, the pinion, ect. I have owned my Baja for 6 years and have done all the band aid items. If you want to save yourself a lot of headaches and money do it right the first time. What kind of boat do you have, a vee or cat? There is a big difference in the stress on a drive with a cat vs. a vee. The cats put a lot less stress on the drives and thus you can put more power thru them with less failures. I am not telling you all this just to get you to buy my drives. If the drives work for you great if not that is fine also, but as a fellow boater I am trying to help you avoid pitfalls that I have already experienced. Where ever you get you nw drive or upgrade make sure you know who they are and what their experience is with your type of boat.
Drill It
