Tim..
Just want to make sure your not under the impression that I was slandering your company in any way. I had no intention of naming names and starting some kind of beef between stoptech and the company stated above. I have used your product before on my 1.8t jetta and in some ways regret not having gone with the same setup for my wrx.. I remember the bite that my stoptechs had on my jetta and my brembo setup right now does not compare.. If you have any advice on the matter I would greatly appreciate it..
-nathan

 

rock on tim i just bought stage two kit from mpj getting installed on tuesday.... i am sure soren ordered one from you already

 

Nathan,
I apologize that my post came across as though I thought you were slandering StopTech, because that is most certainly NOT what I was trying to convey.

I can tell you from experience, as an end user myself (before I worked for StopTech), that it is normal to assume that people who work for aftermarket brake system suppliers are both knowledgeable and honest when they speak about aftermarket brake systems. After all, I’m still an end user with respect to every part I buy for my car that isn’t for the brake system, and I sure as hell don’t want to have people lying to my face to try to sell me their turbo, ECU, seats, wheels, or anything else.

Unfortunately, at least in our specific segment of the aftermarket industry, the “honest” approach to selling products is no longer the case and end users must now be a bit more aware that they may not be getting accurate information from people who are willing to distort the truth to put more money in their own pockets.

Regardless, I do not believe that end users should bear fault for listening to the words of what should be an expert in the field of aftermarket automotive brake systems. The fault should rest solely on the shoulders of those who originate these false, and in many cases slanderous, statements.

At this point, I’d like to get back to the type of thing you’re supposed to discuss in the Brakes section of an automotive message board: BRAKES!!!

Nathan, you have quite a few options here, but before I get into solutions let’s take a look at what you already have, talk about what you’d like to improve, and then talk about what specific modifications make the most sense to reach your goals. The STi Brembo front calipers you have on your car generate about 110% of stock front brake torque, ignoring friction. Due to the fact that the coefficient of friction of any friction material is a variable of temperature, pressure (clamping force), and surface velocity, Cf is a difficult variable to quantify. For this exercise, we will approximate the level of friction that the pads in your Brembo calipers provide as being 10% higher than that of the stock pads. That 10% increase in coefficient of friction, or mu as I will refer to it, translates into a 10% increase in front brake torque (it isn’t always a 1 for 1 increase like this). So, you’ve currently got about 120% of stock front brake torque and 100% of stock rear brake torque.

EDITED FOR ACCURACY
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From the aforementioned testing we’ve done on the WRX, we have determined that the optimum brake balance for the WRX is actually similar to stock. More specifically, we use piston sizes that result in a torque output of about 90% of the stock front system. The fact that Axxis Ultimate has about a 10% higher coefficient of friction than the stock pads means that we are closer to 100% of stock front brake torque. So basically, we either need to reduce your front brake torque by about 20% or increase your rear brake torque, or both.
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These changes can be achieved fairly easily by a change in friction material in the front or rear. Since it’s cheaper to do rear pads than fronts (especially considering your fronts are a Brembo pad shape), I would recommend changing rear pads rather than fronts. If you were to buy the pads from us, I would recommend Axxis Ultimate for its increase in mu and low price point. As an alternative, you could try to find the friction material that you’re running up front in the pad shape for your stock rear calipers (either D770 or D1004 depending on which stock rear calipers you have).

Once we have the balance issues sorted out, we can focus on the pedal feel and “bite” issues you mentioned. The Brembo STi front calipers have 28% more piston area than the ST-40 calipers we use for the WRX, and for this reason you are noticing a longer pedal throw due to the fact that you must move a greater volume of fluid in order to extend the pistons a given distance. That also translates into something called “over-amplification” which stems from the fact that to achieve a given force output at the caliper, the system now requires less pedal pressure. The result of an over-amplified system is a longer, softer pedal that is more difficult to modulate, or more “twitchy.”

Also, comparing the characteristics of the braking performance of your Jetta to those of your WRX can be difficult because some platforms exhibit inherent advantages in pedal feel that can sometimes be very difficult to replicate. For example, our general manager’s E36 M3 with our 332mm front wheel kit and stock rears has absolutely phenomenal pedal feel. I have driven very few cars with brakes that feel as good. I am certainly satisfied with the pedal feel in my WRX with our 328mm front kit and stock rears, but it just isn’t the same as the M3 and I’m not sure it would be possible to achieve that level of feel without redesigning the entire system from the ground up.

I know there are quite a few guys up in your neck of the woods who have our front kit on their WRX, so to get an idea of the pedal feel that our kit provides it might not be a bad idea to go to a meet and ask to drive a car with our kit. That way, you’ll know whether you’ll be happy with some SS rear lines (if you don’t already have them), new fluid, and new rear pads.

I am going to stop myself from talking about going to the STi Brembo rears because I’ve blathered on for long enough right not.

Either way, I would be interested to hear which route you decide to go, so be sure to post your experiences on this thread if you get a minute.

Oh, and nic3krnnamja83, ROCK ON BRUTHA!!!

Best regards,
Tim Kelsch
StopTech LLC

 

lol i love being at the end

 

And that ^^^ is why I'll be getting a Stoptech Stage 2 kit.

These guys know their stuff. That and I can't afford $2200 for a bbk..