Downgrading my Brembo GT Kit

[NewfoundlandDude]

I'm considering downgrading my Brembo GT front brake kit. I'm all about useable power, useable mods, and useable braking power, and I just don't utilize the kit 100%. The brakes are large, and I'm sure are designed to withstand full day track events without fading, but realistically I won't be doing that any time soon.

Right now, I push the car hardest at AutoX every weekend. I've been playing with some of the setup, and I've seen some improvements that I need to make with the car. The front brakes however are more than the car needs to perform at its best, so I'm thinking about trying another setup.

Right now, I run into the problem of the front inside wheel locking up with minimal pedal pressure on the track during heavy braking. My problem is that I can't hear them locking up, and usually can't feel it, as they don't fully lock into a slide when this happens. The wheel locks for a second and it smokes the tire a little entering the corner, costing me time and r-comps....lol. I have noticed, even on the street sometimes, that when I get into the brakes, they can fully lock up pretty easily if I don't modulate correctly.

I've bled the brakes a bunch of times and went back to the "stock" Brembo pads from the Endless Blue track pads, but the brakes are just way overpowered compared to the rears. I don't have ABS, but this is happening at minimal peddle pressure, so there's more going on than just driver error.....i.e. I'm not mashing the brakes. I'm probably not the best driver out there, but I do have enough seat time to know how to brake properly.

I haven't tried any brake bias valves, and I have no experience with them, so if anyone can school me a little on their effectiveness, I'd love to hear it. I obviously understand what they do, but I just wonder if it's the bias that's causing my issues or just too much braking power. If I were to guess, I'd say that a little rear bias wouldn't hurt my overall braking setup, but even with the adjustment, the GT kit may be more than I need.

What are your guys thoughts on some of the popular brake upgrades for the 240SX. I used J30 calipers and Cobra rotors last year with my Maxima, and I liked that setup a lot. It was a great improvement over stock, and didn't overpower the rears a whole lot. It was "just right" for that car. I have some Z32 rears and the 300zx MC, maybe some Z32 fronts would do the trick. I haven't ever used the Q45 brakes either.

What are some of your setups, and your opinions of them? Maybe getting a set of bias valves for the front lines, and re-installing the ABS system will help out a little. I'd like to hear any experiences using proportioning valves on our cars, and any advice.

I guess if all else fails, I could sell these brakes and try out something smaller. Although at an MSRP of $3195.00 US, I'm not sure I'd find a lot of people willing to pick them up right away.....

[NewfoundlandDude]

So about installing a proportioning valve.......everything that I've read up on is basically for cars that have undergone rear drum to disc conversions, and have too much rear bias. The valve will then dial down the rear pressure for a better front bias.

The problem that I'm having is exactly the opposite, I need less front pressure. I think that our front brakes have two separate lines coming from the oem "bias or combination valve" no? The obvious thing to say is install two proportioning valves in these lines, but I've also read that you should never install a proportioning valve in the front lines.

I don't see why you couldn't install dual front proportioning valves, the only problem I can see is tuning them to both react with the same pressures, which may be difficult. It would be great to hear from someone who has done this, and see what they say about it.

Am I incorrect in saying that our cars would need dual valves, is there another place in the line that would capture both fronts and not bump down the rears?

[Wc240]

Why dont you just try a wilwood proportioning valve? about 30-45 bucks and you can adjust it exactly to what you need

[NewfoundlandDude]

Yeah I've looked into that, but as I mentioned the only things that I have found have been accounts of using them to dial down rear pressures after a rear hub to disc conversion. I've also come across instances of articles saying never to use them on the fronts for whatever reason.

Have you used a proportioning valve before on a 240?Where in the system did you install it?I took a look this morning, and it seems that from the bmc, 2 lines run to the combination valve (term?), then form there 3 lines exit, one to the rear and 2 to the fronts. Before then, I had only seen the 2 fronts with 3rd rear, and was thinking I'd need 2 valves for the fronts. Now that I looked closer, it seems that one may do on the front line leaving the bmc.

I'd still like to hear at least one account of this from a 240 owner, where it cured a similar problem, and hear some feedback.