Borg Warner 71C Limitations
06-19-2007 | 02:26 PM
#11
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Joined: Dec 2002
Posts: 2,195
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From: Dallas, TX
You could stay with the 71's if you expect 500-600HP. They can handle this by adding two more clutch plates. I raced 8 years with this set-up with 500-525HP...never touched them again. BAM would be a safe choice for the upgrade. Mercury used the 71's (red tag) with the 370 TRS package.
06-20-2007 | 05:46 AM
#13
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Joined: Jun 2001
Posts: 710
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From: Babylon N.Y.
You could stay with the 71's if you expect 500-600HP. They can handle this by adding two more clutch plates. I raced 8 years with this set-up with 500-525HP...never touched them again. BAM would be a safe choice for the upgrade. Mercury used the 71's (red tag) with the 370 TRS package.
The 72 has bigger internals and may consume more HP to run. But is an excellent piece.
You could do all kinds of things including installing brass tank clutch plates, even if you warp them, the trans will finish the poker run or race, but be stuck in gear, but get you home.
What the shops do is surface grind the steels to allow for more plates to increase the co-efficiency of friction ( surface area) and try to drill oil passages out to make clutch pack work faster and reduce slippage in engagement.
This is also done by modifying pumps.
Yes , I've been inside of a few transmissions too. BBB
06-20-2007 | 05:48 AM
#14
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Joined: Jun 2001
Posts: 710
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From: Babylon N.Y.
Thanks guys - the current set up has a 1" spacer between the trans and the drive shaft so I might be okay without moving the motors. The 72C can handle 450hp I think per the spec sheet.
Can it beefed up a bit somehow/somewhere if I want to run another 100 HP though it?
Can it run in both directions (one counter rotating motor) or is it two different models I need?
Can it beefed up a bit somehow/somewhere if I want to run another 100 HP though it?
Can it run in both directions (one counter rotating motor) or is it two different models I need?
06-20-2007 | 08:26 PM
#15
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Joined: Oct 2006
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If needed i am in orlando and know how to work on these. If you want to order the parts i would be happy to work on them for you. email me at [email protected]
12-30-2008 | 08:54 AM
#16
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if you decide on getting different trannys, let me know when you are going to sell the 71c. [email protected]
