SRT-10 Brake Swap to Gen. II?
- Thread starter RedGTS
- Start date
CitySnake
Enthusiast
I asked the Wiz the same (excellent) question and he said the configuration is completely different so it cannot be done. I'll bump this and hope someone chimes in with a more precise explanation...or better yet, tell me I'm wrong
Janni
Enthusiast
Anyone can grab a set of calipers and throw them on a car. One of the most significant contributions to improved braking on the 2003 is in the area of suspension - NOT calipers. The suspension has been freed up enough that it allows the car to plant each of its massive 4 tires squarely on the ground to get maximum use out of that precious contact patch.
onerareviper
Enthusiast
Here's the thing that makes me mad
.
From my research, the big downside to the Gen II Viper brakes (stock) are the following:
1.) If use on track, can boil fluid. Need better cooling.
2.) Brake bias is not optimal. Too much front, not enough rear. Fronts tend to lock very quickly in panic stop situations.
Problem 1 only is a concern if you are tracking the Viper. Even so, some duct work, better rotors, and better brake fluid solves the problem. No big deal.
Problem 2 is the tough one. Our calipers are designed by Brembo (I think), and should be plenty good enough. But when the bias is off, optimal performance cannot be realized. Some people remove a spring from the master cylinder to help with the situation, but it is still not optimal. Therefore, the aftermarket sells us entirely new front calipers (actually smaller - I think) to solve the problem. In essence, we are switching to a less aggressive front caliper, so the rear brakes are more involved (solving the front/rear bias problem). There has to be a better way, IMHO. Proportioning values are talked about like the devil, with people fearing rear brake lock up. I'm no expert here, so opinions are welcome.
Therefore, our options are:
1.) Upgrade braking system - big bucks.
2.) Try playing around with the bias (spring removal) or (proportioning valve). I haven't been able to find concrete information as to the effectiveness and safety of these mods.
3.) UPGRADE THE REAR BRAKES. This seems to be a logical choice. One of the VCA members has a procedure to upgrade the rear caliper to use a larger piston. Problem is, I haven't heard how well this works.
SO WHAT DO WE DO? It is a shame for us street drivers to achieve better braking bias, we a told to go out and buy $2,200 Stoptech front brake upgrade kit. No offense to Stoptech, as they seem to be a kick-asp company. But $2,200 to achieve better braking bias does not seem to be worth the investment. Now in Stoptechs defense, they do include rotors (better cooling for track guys) and stainless steel brake lines. But for a good majority of us that don't track our Vipers, we really just want better stopping distances (better brake bias). OK experts. Help us street drivers out, that rarely track our Vipers.
From my research, the big downside to the Gen II Viper brakes (stock) are the following:
1.) If use on track, can boil fluid. Need better cooling.
2.) Brake bias is not optimal. Too much front, not enough rear. Fronts tend to lock very quickly in panic stop situations.
Problem 1 only is a concern if you are tracking the Viper. Even so, some duct work, better rotors, and better brake fluid solves the problem. No big deal.
Problem 2 is the tough one. Our calipers are designed by Brembo (I think), and should be plenty good enough. But when the bias is off, optimal performance cannot be realized. Some people remove a spring from the master cylinder to help with the situation, but it is still not optimal. Therefore, the aftermarket sells us entirely new front calipers (actually smaller - I think) to solve the problem. In essence, we are switching to a less aggressive front caliper, so the rear brakes are more involved (solving the front/rear bias problem). There has to be a better way, IMHO. Proportioning values are talked about like the devil, with people fearing rear brake lock up. I'm no expert here, so opinions are welcome.
Therefore, our options are:
1.) Upgrade braking system - big bucks.
2.) Try playing around with the bias (spring removal) or (proportioning valve). I haven't been able to find concrete information as to the effectiveness and safety of these mods.
3.) UPGRADE THE REAR BRAKES. This seems to be a logical choice. One of the VCA members has a procedure to upgrade the rear caliper to use a larger piston. Problem is, I haven't heard how well this works.
SO WHAT DO WE DO? It is a shame for us street drivers to achieve better braking bias, we a told to go out and buy $2,200 Stoptech front brake upgrade kit. No offense to Stoptech, as they seem to be a kick-asp company. But $2,200 to achieve better braking bias does not seem to be worth the investment. Now in Stoptechs defense, they do include rotors (better cooling for track guys) and stainless steel brake lines. But for a good majority of us that don't track our Vipers, we really just want better stopping distances (better brake bias). OK experts. Help us street drivers out, that rarely track our Vipers.
CitySnake
Enthusiast
Ditto...<FONT size="1">as in DAYUM, I wish I could have said all that!</FONT s>
Ron
Enthusiast
<FONT face="Comic Sans MS">While the stats on our brakes are weak, using them (100% stock) in a recent Viper Days event gave me new respect for them. I have never used brakes so hard for so long with zero fade with decent modulation.
As good as the SRT-10, no way. Good enough for street driving, absolutely. Room for improvement, no doubt. Should they have been better right from the factory, yes.
Perhaps I'll try Tom's mod to the rear calipers over the winter, but for now I'm content.
You want to experience bad brakes, try driving a 1970 Trans Am aggressively...</FONT f>
As good as the SRT-10, no way. Good enough for street driving, absolutely. Room for improvement, no doubt. Should they have been better right from the factory, yes.
Perhaps I'll try Tom's mod to the rear calipers over the winter, but for now I'm content.
You want to experience bad brakes, try driving a 1970 Trans Am aggressively...</FONT f>
Tom F&L GoR
Enthusiast
Sorry, I forgot to post the update on the larger rear calipers.
I built 38mm rear calipers because the piston area ratio front to back mimics the successful StopTech stage 1 kit. Instead of 36/40mm pistons in the front and stock 36 in the rear, this keeps the 38/42 fronts and increases the rear to 38mm. Therefore it is totally undetectable, you can use all the stock mounting points, and use factory size brake pads. I run without the brake proportioning valve cup seal, and it is better on the street, was better at a Lime Rock and Pocono track event, and an improvement in AX. Except for whatever the difference in heat rejection rates might be, it fundamentally has to be the same performance as the StopTech system.
No surprise, if some is good, more is better. For AX especially, I want more rear brake bias, probably more than some might like. So I went back to the machine shop and we agreed that we could go out to 40mm rear pistons.
Once again, a very nice improvement. After another Lime Rock event, I can go about 1.5 numbers deeper at the end of the straight without losing control or locking a front wheel. And for AX, it's better yet.
In my experience, without the cup seal, a 40 mm rear caliper still allows the front to lock first; this after two months on the road including rain, one track event, and a few AX events. I have not played with different pad compounds between front and rear, I use the same all around, so that may be a final fine tuning method.
The cost? For a do-it-yourselfer about $534 a pair, plus a set to start with. I've found them on eBay for $130-$150 a pair. Of course, you can always get Renault Alliance/Dodge Monaco rear calipers from the junkyard - it's that same thing. The machine shop still charges me $500 a pair because it's a one-at-a-time (although they have jigs to make them quicker if they get a run of 10), $22 for two Brembo piston seals, and $12 for two Renault Alliance caliper rebuild kits. Of course, your labor is priceless. After about 4 sets, I can get the calipers apart in 6 minutes, back together in about 40 minutes. The 40mm size may take longer, the stock dust boot is still used and you have to be very careful not to pinch it. I have instructions I'll share, since the service manual claims the calipers are not serviceable. Email me.
While the onlooker can't tell, the driver will notice a very, very slight increase in pedal travel. You are increasing the volume of the rear calipers, so it takes a little more to fill them. And bleeding them the first time is a little problematic; there is a long horizontal bore in the piston to house the parking brake self adjusting mechanism and I suspect that air might get trapped in there. I need to remember to pour brake fluid in while assembling.
I have two 38mm pairs left over from my little R&D effort. If anyone's interested, wants more details, questions about how good it really is, let me know.
I built 38mm rear calipers because the piston area ratio front to back mimics the successful StopTech stage 1 kit. Instead of 36/40mm pistons in the front and stock 36 in the rear, this keeps the 38/42 fronts and increases the rear to 38mm. Therefore it is totally undetectable, you can use all the stock mounting points, and use factory size brake pads. I run without the brake proportioning valve cup seal, and it is better on the street, was better at a Lime Rock and Pocono track event, and an improvement in AX. Except for whatever the difference in heat rejection rates might be, it fundamentally has to be the same performance as the StopTech system.
No surprise, if some is good, more is better. For AX especially, I want more rear brake bias, probably more than some might like. So I went back to the machine shop and we agreed that we could go out to 40mm rear pistons.
Once again, a very nice improvement. After another Lime Rock event, I can go about 1.5 numbers deeper at the end of the straight without losing control or locking a front wheel. And for AX, it's better yet.
In my experience, without the cup seal, a 40 mm rear caliper still allows the front to lock first; this after two months on the road including rain, one track event, and a few AX events. I have not played with different pad compounds between front and rear, I use the same all around, so that may be a final fine tuning method.
The cost? For a do-it-yourselfer about $534 a pair, plus a set to start with. I've found them on eBay for $130-$150 a pair. Of course, you can always get Renault Alliance/Dodge Monaco rear calipers from the junkyard - it's that same thing. The machine shop still charges me $500 a pair because it's a one-at-a-time (although they have jigs to make them quicker if they get a run of 10), $22 for two Brembo piston seals, and $12 for two Renault Alliance caliper rebuild kits. Of course, your labor is priceless. After about 4 sets, I can get the calipers apart in 6 minutes, back together in about 40 minutes. The 40mm size may take longer, the stock dust boot is still used and you have to be very careful not to pinch it. I have instructions I'll share, since the service manual claims the calipers are not serviceable. Email me.
While the onlooker can't tell, the driver will notice a very, very slight increase in pedal travel. You are increasing the volume of the rear calipers, so it takes a little more to fill them. And bleeding them the first time is a little problematic; there is a long horizontal bore in the piston to house the parking brake self adjusting mechanism and I suspect that air might get trapped in there. I need to remember to pour brake fluid in while assembling.
I have two 38mm pairs left over from my little R&D effort. If anyone's interested, wants more details, questions about how good it really is, let me know.
ggc
Viper Owner
I believe Sean Roe has a rear brake upgrade. Has anyone tried it. I have never seen any comments re that kit in all the brake upgrades discussed?
At the VOI.7 PVO seminars, I asked the PVO brake engineer, and he said:
NOPE.
NOPE.
