Rear brake upgrades...?

[Larry Parker]

So has anyone done rear brake upgrades to the VR4? I would like to upgrade my rears and would like to see if anyone has done this... I have a set of brand new MINT alcon 4 piston calipers with small (32mm) pistons sizes. Alcon lists these as WRC rear... These may sound great but may be a bit much for me and the fit will be tight... My issue is that the stock VR4 rear is just TOO small and the pins hang up and wear in an uneven fashion... Not to mention it has like the smallest pad area ever... The 2G eclipse is lager, but the lugs are different and wont work...


LP

 

[464/2K]

try Ebay, many circle track cars and nascar teams part out on there. i found a set of willwoods for like 275 and they were just out dated so they have to get rid of them.

 

[Hertz]

I think the typical issue (for street cars) is engineering the e-brake mechanism, so not too many out there I don't think.

 

I do but I don't have any with a mechanical ebrake. You could set one up hydrolic but it adds stress and shortens the life of the caliper before servicing.

 

[Larry Parker]

I have no parking brake in my car, but did have a line lock on my talon... I think I only used it when my car was on the trailer....

LP

 

[Dialcaliper]

If you want to get creative and do a little custom fab, you might be able to get one of these to work for the parking brake, and then use whatever rear caliper you want:

Rear e-brake caliper
Rear e-brake caliper
Wilwood E-brake Caliper

There are a few others out there like it. How well they hold up to heat and e-brake rally turns I really don't know, but you could always set it up so you can simply remove them for a race, leaving you with no parking brake.

FYI, I believe Wilwood stopped selling their model in the size wide enough for cars (the one on the JEGS link) due to heat issues. Also, the pads are designed around static loads (parking) and may not hold up to actual braking.

The only other option is a 1-pot caliper by Wilwood, but the piston is only 34mm compared to our 41.3mm (1 5/8") rears, which means you'd need a 16" rotor to even match the current brake bias:

Wilwood Combo Parking Brake Rear Caliper

 

[SleepinGVR4]

TCE has upgraded calipers for the rear. Maybe you should give them a call Larry.

 

[atc250r]

tce?

 

[SleepinGVR4]

TCE Performance Products

Click on products and then go to calipers, and you can see what the DL caliper that they use on their rear kits looks like. Plus their $150 a pop.

 

[kartorium]

It seems like you'd want to run a 2 or four piston caliper and then have a second bracket and second caliper on the other side of the rotor for hand brake purposes. Probably just a little single piston for the hand brake.

 

[Dialcaliper]

From TCE's website under the 1G rear kit: "Any replacement of the stock caliper howeve (sic) will remove the parking brake.*"

So, the Dynalite calipers have the same problem - only the 2G, which has drum parking brakes can retain the stock e-brake.

So basically, the options look like

1) Either a line-loc (sketchy at best) or a spot caliper (slightly better) combined with whatever caliper you want.

2) Otherwise, you could use the wilwood single-pot combo caliper with a 12-13" rotor (1" width) and fix the horrible forward bias with an adjustable prop valve to increase the pressure to the rear. It'll probably mean more heat, even if the rear pad is slightly bigger, but a bigger vented rotor with higher thermal mass might give you reduced fade tendency. hard to say

The wilwood rear pad is 3.43" x 2.08" - anyone have the dimensions on the stock rear pad?

If you're going to use a spot caliper, you could probably manufacture a single steel bracket that holds both calipers.

Larry, since you don't have a parking brake anyway, you can use whatever rear upgrade you want.

Just plug in the stock caliper/rotor/pad setup into the spreadsheet on this webpage by Dan Wagner from Circle Track:

click

Then put in your front calipers, and you can compute what size rear rotors you need for those alcon calipers.

If you have an adjustable prop valve, you can fudge a certain amount, but it's best to get as close as you can to stock bias.

Honestly though, I think you'll be wanting the smallest rear 4-pots you can find (25mm pistons) or else you'll want a lot of front brake to make up for it. Those alcon 32mm rears are probably matched with some pretty huge front brakes. Even 25mm 4-pots are about 46% too big, on the same rotor.

You might look into the 3000GT VR-4 2-pot (38.1mm) rears (1994+ only)

If I recall, the stock GVR4 setup is:
2-pot front (2x41.1mm) with 10.9" rotors
1-pot rear (1x41.3mm) with 10.4" rotors

Which gives a 68/32 bias (not counting the prop valve)



Quote:
TCE Performance Products

Click on products and then go to calipers, and you can see what the DL caliper that they use on their rear kits looks like. Plus their $150 a pop.

 

Has anyone on here actually seen what the TCE "brackets" look like?



If you want a REAL brake kit upgrade for the rear AND not to get ripped off Larry let me know.

 

[Dialcaliper]

Also, larry, I was just looking up your car, and I noticed you have a balance bar setup. You can really run whatever rear brakes you want as long as you adjust the bias properly.

 

[kartorium]

Quote:
Has anyone on here actually seen what the TCE "brackets" look like?



If you want a REAL brake kit upgrade for the rear AND not to get ripped off Larry let me know.



I have seen the brackets, in fact i use them on the front of my car. They are great from my experience (however I do not know anything about the rears). Todd's customer service is beyond anything I have had in the dsm world, only short of a few, like road race engineering. I can't say enough about his product or service.

Can you inform us what a "real" brake kit upgrade is. I assume you are basically knocking TCE's kits and would like to know why.

Also, that picture doesn't really look relevant to what is being discussed...doesn't look like the rear hub of our car to me/ Please explain your opinion more so I can understand your POV/attitude towards TCE a bit better.

 

[Rausch]

+1

That is a 4 link rear from something. Obvoiusly not RWD even....And judging by the thickness of the rotor, (from what I can see) a small car at that. The backing plate that it's bolted to does not seem to be much, if any, thicker that the bracket, so I doubt that it is an issue in that application. /ubbthreads/images/graemlins/dunno.gif

 

[Larry Parker]

Thanks for all your input guys! Here are a few key things in my setup...

1. NEEDS TO FIT UNDER 15" WHEELS
2. I dont care about and e-brake, but I have a Hydro hand brake as of now... SEE



3. I think getting a larger pad area is KEY! My issue is seeing that I left foot brake the sh*t out of my car I am burning up rear pads in an event! Carbotech xp-10's cost 160.00 bones a set and I think thats too much... I know plenty of people that can get 2 or 3 events out of a set...

Again thanks for your input... You guys have TONS of info on this stuff and its a hell of a lot easier to just ask....

Regards
LP

 

[Larry Parker]

watch this... click

This was my first time out with this car and we did have some brake issues, but this is not uncommon.... Look at the rear rotors during the night shot...

 

Quote:
Quote:
Has anyone on here actually seen what the TCE "brackets" look like?



If you want a REAL brake kit upgrade for the rear AND not to get ripped off Larry let me know.



I have seen the brackets, in fact i use them on the front of my car. They are great from my experience (however I do not know anything about the rears). Todd's customer service is beyond anything I have had in the dsm world, only short of a few, like road race engineering. I can't say enough about his product or service.

Can you inform us what a "real" brake kit upgrade is. I assume you are basically knocking TCE's kits and would like to know why.

Also, that picture doesn't really look relevant to what is being discussed...doesn't look like the rear hub of our car to me/ Please explain your opinion more so I can understand your POV/attitude towards TCE a bit better.



The picture title is the 2g 12.2 rear upgrade kit.

Yes I am knocking their brackets cause I personally think they are a joke. It's one flat piece of metal, with two rods cut to length then bolts and washers. So you have 7 pieces of metal in your brake bracket setup. Also if you look at that the bolt goes in from the back and the nut goes on the front.

Its far from what I would call a "solid" brake "bracket". I purchased one of their front kits a long time ago and I got what pretty much looked like picture and I was far from pleased. Hence why I make my own brackets now which are a full solid one piece design. It's what I would call a "real" brake bracket, not some 1/4" piece of metal with cut tubing thrown together. IMO

 

Quote:
watch this... click

This was my first time out with this car and we did have some brake issues, but this is not uncommon.... Look at the rear rotors during the night shot...



In all honesty I would suggest some cross drilled rear rotors with twin caliper setups to help dissipate as much heat as possible. This however would be costly and require frequent upkeep.

What do most of the other teams run for the rears?

 

[thecman02]

wow... your done racing for this season aren't you.... if money isn't "too big" of a concern you could probably contact some of the brake companies and see if they can meet your needs. Just tell em what you told us.... fit under 15" rims.... needs to dissipate heat like crazy, and last more than one rally event. Just tell them what they have to work with... I'm thinking stoptech or even some other peeps like digit can get some good custom brackets then all you need to do is the homework on whatever setup you want. I don't know if US rally's get fast enough to make custom ducting worth it... but if you were to get cross drilled, you'd want some high quality rotors that are cryo treated so "hopefully" you wouldn't have to replace as often, but like most people say you have to check them often for cracking, but that is probably something you already check before stages anyways. Let us know what you end up with.