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Doctor Diff Viper-Style 13" Front Disc Brake Kit


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9:19 PM
Sep 30, 2020
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Wondering if this is still a viable way to go? The 2003 and up calipers are getting scarce on eBay. Is there a better place to find them? I'd prefer factory calipers over aftermarket, but if they can't be had, they can't be had.
I used to buy them from the local dealer but I haven't done that in a while. They might not be available anymore over the counter.

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I switched to Porsche "Big Reds" for my Coronet build. The Big Reds used to be very easy to find since they were a super popular swap for many years onto a lot of different cars. The Porsche calipers are very similar to the Viper calipers. Both are made by Brembo and the specs are fairly close.

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I was hoping to find the Viper calipers in black. I used to see them on eBay all the time, now it appears they are available nowhere.

Looks like MoparPartsGiant still has them?
Will the 85 Riviera calipers the Scarebird conversion uses be sufficient in the rear? Probably should have asked this question before installing them - but since the rears do so little, I assumed they'd be o.k., which may prove to be incorrect.

This thread mentions "Varga calipers" in the rear. I don't know what those are, but DoctorDiff sells this rear brake conversion kit with "cobra" calipers which appear to be a single piston design similar to the 85 Riviera caliper. The Scarebird conversion also uses an 11.7 inch rotor. Thanks to RockAuto I picked up a pair of slotted and drilled Lincoln Mark VII rotors for the low low, and performance pads.
I've bought several sets from Viper wrecking yards. I've been using them with 14.25" SRT rotors up front and the 11.75" rotor and single piston Ford/Varga caliper in the rear. I use Carbotech pads with different friction compounds for front and rear. The hydroboost and 50% pressure to the rear with the 1 1/8" plastic master is absolutely perfect. The bias and outright capability is outrageous.
Does "hydroboost" mean power brakes? I've got a manual setup. Somewhere I read that the big Viper brakes behave like self-energizing drums. Have you found that to be the case?

The Doctor Diff kit says "2003 and up," does that include 2013-2017?
Hydroboost is a unit that uses the power steering pump to generate assist instead of engine vacuum. These units develop more line pressure than any old style booster. I don't know what you mean by self energizing. Viper calipers are made by Brembo and are a 4 piston unit not unlike many other OE calipers produced for higher end production vehicles.

The calipers Dr Diff refers to are gen 2, 1996-2002. His bracketry was developed years ago so I'm not sure if any of the later generations are compatible.
From Doctor Diff's web page for the 13" Viper kit -

"Customer must source 2003 and newer Viper front calipers and pads"

It'd certainly be easier to find the pre-2003 calipers.
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