99 R/T 10
Enthusiast
I have Tom's Brake upgrade and want to install a Prop valve. I want more braking in the rear. Never tackled one before, are they easy to install?
Looking for brake advice
- Thread starter tucker
- Start date
I have Tom's Brake upgrade and want to install a Prop valve. I want more braking in the rear. Never tackled one before, are they easy to install?
I have DBB 14 inch kit on all four corners on my 97 and the braking improved tremendously. I was advised against using 14 inch in rears on a non abs car but it worked out perfectly. I even got a custom bracket made to run 15 inch rotors in the front using the SRT calipers but never got around to setting it up.
I think some of you might be confused abou the Prop valve situation with the Gen1/2 setup with or without Tom's40rears.
There is a Factory Prop valve that limits the rear bias as you apply more and more brake pressure.
The diaphram in this valve can be removed to allow full(equal) flow to the rear. But its still not equall overall braking because the front has 4 pistons as where the rear only has one. So no matter what you will have more braking force up front(where it should be).
Putting in an aftermarket Prop valve would do nothing but take bias away from the rear which is not needed.
When i purchased my 40mm from Tom i was told by him and later verified by a couple racers at viperdays that the Stock prop diaphram should be removed to achieve maximum braking force and that you shouldnt have any issues with the rears locking up first(BAD) unless you have something limiting rear traction such as extreme rear camber or old tires.
I have ran two trackdays with my 40mm's to get a baseline feal for the slight improvement and plan on removing the prop valve diaphram next time i bleed the brakes to see the full potential of the setup.
There is a Factory Prop valve that limits the rear bias as you apply more and more brake pressure.
The diaphram in this valve can be removed to allow full(equal) flow to the rear. But its still not equall overall braking because the front has 4 pistons as where the rear only has one. So no matter what you will have more braking force up front(where it should be).
Putting in an aftermarket Prop valve would do nothing but take bias away from the rear which is not needed.
When i purchased my 40mm from Tom i was told by him and later verified by a couple racers at viperdays that the Stock prop diaphram should be removed to achieve maximum braking force and that you shouldnt have any issues with the rears locking up first(BAD) unless you have something limiting rear traction such as extreme rear camber or old tires.
I have ran two trackdays with my 40mm's to get a baseline feal for the slight improvement and plan on removing the prop valve diaphram next time i bleed the brakes to see the full potential of the setup.
dave6666
Enthusiast
Wheels are iForged Classic thanks Dan at Viper Specialty Performance for supplying those and all the brakes too.
Chuck 98 RT/10
Enthusiast
I don't. I really don't feel there is a reasonable compromise. That's why I run EBC (horrible performance but clean and quiet) on the street and PFC 01 (awesome performance) on the track. If I only had one Viper I would have a spare set of rotors and pads.
Chuck 98 RT/10
Enthusiast
I'm not a fan of adjustable prop valves. To me, it is just one more piece of an already complicated puzzle. Instead I chose to experiment with different rear compounds and found one that works perfect for me.
But to each their own.
Fatboy 18
Enthusiast
Thanks for the feedback
GTS Warp
Enthusiast
Got it Dom. Good info. Which pads are you running?
SoCal Rebell
Enthusiast
I've always used the Brakeman 3 for the Gen II, excellent street/track pad, very "progressive" pad for non-abs Vipers, not a "grippy" as some to avoid flat spotting.
Chuck 98 RT/10
Enthusiast
Ron is correct. If you absolutely, positively have to compromise, B3 is probably the best choice. I tried them on both my GTS and my RT/10.
Proportioning valves can really come in handy to compensate for a lot of variables that change from track to track and day to day. Brake-heavy environments mean your pads are operating at higher temps and may perform differently......heavy braking zones downhill can make the rear dance around (which can sometimes be fixed on-the-fly by adding a smidge more front bias)....etc.
As Chuck says, it does make it more complicated but if you're willing to make littly-bitty adjustments (not big ones) you may find that you can rebalance things with a prop valve.....where without it you'll be stuck dealing with the imbalance.
Adjustable Prop valves: It is very important to know that Adjustable Prop Valves do NOT improve braking at either end of the car. They simply DIMINISH Braking at one end of the car, altering the Bias of the system. In other words, they 'dial out some braking' they dont dial IN better braking.
And 'rear end dancing around' can mean you need MORE rear bias, not less!
There can be valid reasons for an advanced driver to do this, but it can be a way for a less-experienced driver to simply "Dial Yourself Off The Track." Especially if you try to 'fix on the fly'
Be careful Out There!
JonB ~~~:<~
And 'rear end dancing around' can mean you need MORE rear bias, not less!
There can be valid reasons for an advanced driver to do this, but it can be a way for a less-experienced driver to simply "Dial Yourself Off The Track." Especially if you try to 'fix on the fly'
Be careful Out There!
JonB ~~~:<~
MTGTS
Enthusiast
For everyone that wants to get the rear more stable under braking. Buy a set of the anti-toe brackets. Amazing what a difference what those little pieces of metal can do.
GTS Dean
Enthusiast
The left side bracket won't fit anymore after the rear 998/999 recall strut is installed.
