B-1 what breaks first?
08-24-2011, 10:39 PM
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B-1 what breaks first?
I'm wanting to add whipples this winter to my carb HP500's. Nothing crazy, just 8-10psi. My B-1's are 1.5 ratio with nose cones lowers and the boat is VERY light. Will adding imco lowers be enough to keep the bravo's alive or am I looking at spending $50k on drives?
08-25-2011, 09:36 AM
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The upper is the most problematic piece.....you'll have to do something
with that.
with that.
Last edited by JaayTeee; 08-25-2011 at 09:42 AM.
08-25-2011, 11:06 AM
#5
Uppers break 1st. Specifically the gear-sets. They break at 3000rpm and break without warning. Actually, the warning is the whistle the superchargers make.
There is a set of ASD-7 conversion kits in the classifieds.
There is a set of ASD-7 conversion kits in the classifieds.
08-25-2011, 08:23 PM
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Xr's are a lot tougher than they are given credit for. The biggest things are backlash setup, Gearlube (quality and the frequency that you change it) shafts and of course if you are reasonable on how you treat the drive. I have several customers with drives that have lots of hours behind Blown and naturally aspirated engines that have never had an upper failure. Internal shafting plays a role as bigger is not always better! Just my experiences, Rob
09-06-2011, 08:04 AM
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Just had an XR gear set fail. Only had 8.5 hours on a completely rebuilt drive. Never went past 3/4 throttle as I was waiting for a 10 hour break-in. One tooth broke off and took out the case... I'm working on sectioning the gear and looking at the grain flow from forging to see why it broke off. I was easy out of the hole and never opened it up. There was no reason for it to break but it did. The drive service that built it had a shelf full of XR gear sets that have done the same thing.
Even with a better steel tower that was part of the rebuild upgrade, bigger clutch bearings, max machine worx top cap...., still broke off a tooth. Word is that about 4 years ago the XR gears were a lot better and did not have the failures people have seen within a few hours of use. They would flake and then go but that was after 100 plus hours.
Heard it is a crap shoot if you get a good set. I went with XZ gears this time Cryo'ed and surface treated to give it a shot. Have a friend that has been running XZ gears with 750hp and they are still holding up after two summers and guessing 80 hours, he is not easy on it either.
Even with a better steel tower that was part of the rebuild upgrade, bigger clutch bearings, max machine worx top cap...., still broke off a tooth. Word is that about 4 years ago the XR gears were a lot better and did not have the failures people have seen within a few hours of use. They would flake and then go but that was after 100 plus hours.
Heard it is a crap shoot if you get a good set. I went with XZ gears this time Cryo'ed and surface treated to give it a shot. Have a friend that has been running XZ gears with 750hp and they are still holding up after two summers and guessing 80 hours, he is not easy on it either.
