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  #1  
Old 09-12-2018, 07:32 AM
calvin calvin is offline
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Default 11 or 12" rear rotors?

Hi,
Doing an RS FastTrack chassis with an LSA/Magnum combo on a 66 Chevelle. I'm guessing weight will around the 3500 mark

As for brake bias would 14" front with 12" rotors be too much/little for this combo? My question is about the rears. 11" or 12" or do you suggest bigger?

Last edited by calvin; 09-12-2018 at 09:12 AM.
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Old 05-28-2020, 03:36 PM
python python is offline
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12" will fill the open wheel area better.
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Old 11-15-2020, 12:50 PM
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pannetron pannetron is offline
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The Baer 13" front and 12" rear brakes on my LSA '66 Chevelle are a good match. The prop valve on my Baer Remaster m/c is set to mid range to balance front/rear braklng. IMHO the 11" rear would be too small unless you're running small diameter wheels and can't fit 12" rotors.
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Old 11-16-2020, 12:57 PM
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12” rear rotors all the way.
For the proper appearance
Just use smaller calipers and a proportioning valve.
My two cents
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Old 11-23-2020, 07:46 AM
Peter McMahon Peter McMahon is offline
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I think the proportioning valve only controls when the rear wheels lock relative to the fronts, not actual braking bias.
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Old 11-23-2020, 11:41 AM
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Wut?

How could you control wheel lock without controlling bias with a passive mechanical system?


Here is what it looks like on a graph. https://wilhelmraceworks.com/blog/br...rtioning-valve

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Old 11-23-2020, 12:41 PM
Peter McMahon Peter McMahon is offline
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Well, as explained to me way back when by my auto shop teacher, don't shoot me if I'm wrong,...
the proportioning valve is there to slow the locking of the rear wheels, to make sure the front locks first. After the initial slowing of the locking [ by means of the spring loaded internal portion ] the valve does not perform any more function.
This is incorrect?
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Old 11-23-2020, 06:53 PM
JKnight JKnight is online now
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You’re accurately describing the function of a different part. It’s a common terminology issue. On cars with front discs and rear drums a “metering” or “hold off” valve was used to delay the engagement of the front brakes until the rear drums could build pressure. It was shaped like a barrel on old GM stuff. You’ll not need this when going to 4 wheel discs. But you will still need a proportioning valve.
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