I just got back from the track with my 2000 GTS and I was really amazing with how little the rear brakes aid in braking. We did a braking exercise where we accelerate to 50 and then go to maximum braking. There was a ton of smoke from the front tires, but several people came up and said my rears never locked. We then did a J turn while hard braking with wet asphalt and the results were similiar.
I've looked into getting a bigger brake kit, installing a proportioning valve, etc, but I was curious if anyone has had any luck with installing high friction pads in the rear to help balance things out. I just ordered a set of pagid RS15's which are the company's highest friction pads. From what i've researched a lot of people couldn't run them because they were too agressive and locked the brakes too quickly. Has anyone tried something similiar with good results? I'd be curioius to see what other have done before upgrading to either 40mm sets or SRT ones, which would require more $$$ and more proportioing valve work.
If you try and get aggressive rear pad bite what you will find is that the back end will bounce and hop terribly when threshold braking, they are doing what they can within reason. If you run an aggressive pad and have to trail brake into a corner you also run the risk of snap over steer.
I just got back from the track with my 2000 GTS and I was really amazing with how little the rear brakes aid in braking. We did a braking exercise where we accelerate to 50 and then go to maximum braking. There was a ton of smoke from the front tires, but several people came up and said my rears never locked. We then did a J turn while hard braking with wet asphalt and the results were similiar.
I've looked into getting a bigger brake kit, installing a proportioning valve, etc, but I was curious if anyone has had any luck with installing high friction pads in the rear to help balance things out. I just ordered a set of pagid RS15's which are the company's highest friction pads. From what i've researched a lot of people couldn't run them because they were too agressive and locked the brakes too quickly. Has anyone tried something similiar with good results? I'd be curioius to see what other have done before upgrading to either 40mm sets or SRT ones, which would require more $$$ and more proportioing valve work.
I have a 2000 also, you have to be real careful about flat spotting on a road course, I've had to have my tires shaved more then once to make them round again. The pad choice is very important, you do not want a "grippy" pad, you want more of a "progressive" pad.
I have well over 50 track days under my belt and I went with the Stoptech Big Brake system (from Woodhouse) with the 355 mm (14.2") rotors for $3,600. Calipers on the front are the same size as on the rear, braided lines, no proportioning valve. I use Brakeman 3 pads (from Woodhouse), the pad surface is much larger then stock. The stopping power is incredible, put in some Castrol SRF brake fluid because you'll definitely boil the stock fluid and make sure you bed the pads in correctly.
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Last edited by SoCal Rebell; January 28th, 2013 at 04:22 PM.
If you try and get aggressive rear pad bite what you will find is that the back end will bounce and hop terribly when threshold braking, they are doing what they can within reason. If you run an aggressive pad and have to trail brake into a corner you also run the risk of snap over steer.
Started typing a reply before you posted Mark, How dare you use the same terminology as me, what makes you such an expert
Mark and So Cal - thanks for the replies. I'm assuming at this point, putting on the higher friction pads would be more of a death wish than a cure. Do you think it's worth trying out, or just scrap the idea, return the pads, and go with a bigger brake kit? I've heard we lose a lot of brake feel when bigger brake kits are installed, something I was hoping to avoid. It is promising to hear you could run without the proportioning valve
Mark and So Cal - thanks for the replies. I'm assuming at this point, putting on the higher friction pads would be more of a death wish than a cure. Do you think it's worth trying out, or just scrap the idea, return the pads, and go with a bigger brake kit? I've heard we lose a lot of brake feel when bigger brake kits are installed, something I was hoping to avoid. It is promising to hear you could run without the proportioning valve
The BBK is definitely an option, I chose the Stoptech BB kit because at the time that was pretty much the only option and have not regretted it since. I don't know where you heard you lose brake feel if you go big but on the contrary it give me great feed back and have never flat spotted a tire since. The kit with the addition of the Brakeman 3 pads is the best combo I've found.
I had a 2000 GTS, OEM brakes, toms 40MM rear calipers along with a porportioning valve. BBDave's kit which can be had from Partsrack now.
I ran different pads at the track than on the street. Real race pads that needed heat to work and different compounds front and rear. The felt wet on the street and didn't stop as well as the OEM pad when cold. Also I did a lot of tuning and had the bias set different on the track vs the street. You really don't want the rears locking up first in a panic. I ran BBK on another Viper. It gave me no greater stopping that the original set up.
I just got back from the track with my 2000 GTS and I was really amazing with how little the rear brakes aid in braking. We did a braking exercise where we accelerate to 50 and then go to maximum braking. There was a ton of smoke from the front tires, but several people came up and said my rears never locked.
If the front tires lock up and smoke, wouldn't that be an indicator that the front brakes are working? That would seem to indicate that the tires were unable to provide enough grip on the road that the calipers were asking for, correct? All cars are set up to provide more stopping power from the front to prevent the back from locking up and coming around. The wider and stickier the tire the better the stopping power, no matter if you have 4, 6, or an 8 piston set up. Physics overrides seat of the pants feeling everytime.
If you haven't done it yet, remove the spring from your proportioning valve and bleed the system well.
If you're juggling compounds, what you want is a rear pad with high initial bite and then a flat torque curve and slow release. Failing that, better bite than stock and more overall friction is good.
I found that a PFC 90 rear pad combined with a 97 (not made anymore) or an 01 PFC front pad is a great combination. The 97s would get up to almost 1400F and were hard on seals. The 01s run about 1200F. With the 40mm calipers, I get up over 500F rear rotor temps and they actually wear, turn a little bluish and dust up. I use AP 600 racing brake fluid and almost never have to bleed them at the track. Short of SRF, it's the best stuff there is.
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Last edited by GTS Dean; January 29th, 2013 at 06:03 PM.
If you haven't done it yet, remove the spring from your proportioning valve and bleed the system well.
If you're juggling compounds, what you want is a rear pad with high initial bite and then a flat torque curve and slow release. Failing that, better bite than stock and more overall friction is good.
I found that a PFC 90 rear pad combined with a 97 (not made anymore) or an 01 PFC front pad is a great combination. The 97s would get up to almost 1400F and were hard on seals. The 01s run about 1200F. With the 40mm calipers, I get up over 500F rear rotor temps and they actually wear, turn a little bluish and dust up. I use AP 600 racing brake fluid and almost never have to bleed them at the track. Short of SRF, it's the best stuff there is.
Dean, Thanks for the info, I've been looking into doing exactly this. Have you done this on your car, before upgrading to the 40mm calipers and how was the balance? Is it too much to remove this spring and add the 40mm calipers later? I sent a message to Tom, but haven't heard back, I hear he's had a new addition to the family so he's not building the rear sets as much anymore.
After 5-pt belts, brake fluid and SS/teflon brake lines, removing the prop valve spring was one of the very early mods I did on my GTS. It wasn't until I increased the rear piston diameter that the rear brakes REALLY began to work.
Dean, would you recommend removing the spring to people with the Stoptech kit? From my research Stoptech designed the kit where piston size controls bias.
Can you confirm where on the proportioning valve to remove the spring? I'm too new to post pictures, but basically on the valve you have an area to unscrew that is facing the driver, an electrical connection, two inlets from the MC, and 3 lines coming out. I'm assuming it's the threaded connection facing the driver, but want to make sure before unscrewing the wrong part. Thanks!
After 5-pt belts, brake fluid and SS/teflon brake lines, removing the prop valve spring was one of the very early mods I did on my GTS. It wasn't until I increased the rear piston diameter that the rear brakes REALLY began to work.
How so you remove the prop valve spring on a stock non-abs set up?
Can you confirm where on the proportioning valve to remove the spring? I'm too new to post pictures, but basically on the valve you have an area to unscrew that is facing the driver, an electrical connection, two inlets from the MC, and 3 lines coming out. I'm assuming it's the threaded connection facing the driver, but want to make sure before unscrewing the wrong part. Thanks!
You are correct. I think it's about a 3/4" hex plug under pretty good stress. Use a rag to capture it when it comes loose and control the fluid leakage. There's a spool inside the spring and it can stay in. It won't leak much, but bleed the rears carefully.
Dean, would you recommend removing the spring to people with the Stoptech kit? From my research Stoptech designed the kit where piston size controls bias.
If you have a fully engineered package, probably not. Check with them directly.
The basic shortcoming of the GenI/II rear brakes was because of Dodge's engineering manager Francois Castaing's suggestion to use a Chrysler Corp. parts-bin disc brake/e-brake caliper. It came from the AMC Eagle line and was manufactured by Brembo. The bias in brake piston diameter guaranteed that the rears would NEVER lock up on their halo car, but that the things functioned reliably on a basic level and didn't have to be OEM engineered for the application to pass muster by bean counters and lawyers.
Last edited by GTS Dean; January 30th, 2013 at 06:14 PM.
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