<insert hackneyed comment about power needing control, and/or new shoes>
Yeah, that, and Project Evo X's stock brake pads were wafer-thin and making angry grumbling noises. It was time for new ones.
Stoptech "309" pads are a very recent aggressive street pad we've used with great success on another application, and the 309s happen to be made in an Evo X fitment... for the fronts only. They're working on the rear caliper fitment.
Still, we went ahead with the Stoptech 309 fronts and matched them to Project Mu B-Force rear pads. By matched I mean we confirmed that the friction characteristics are similar enough that we won't have brake bias issues.
Brake bias is important. Get the bias wrong and you'll overheat your front brakes. Get it really wrong and you'll be looking out the side window if you brake hard when there's a significant amount of lock in the steering.
Braided stainless steel brake lines by Stoptech also went in at the same time, and Road Race Engineering did the dirty work of installation. Stock Evos have a pretty solid pedal from the factory so it's not really lacking in that regard. Still, any bit of compliance that can be removed from the braking system--like the effect of squishy stock rubber brake lines--is goodness in my book.
Likewise, new pads are more about initial bite and fade resistance than outright braking power. Tires are what stop the car--not the brakes--and a few months ago we replaced the worn stock tires with Bridgestone RE11s. We wanted to re-run Project Evo X's braking numbers to assess this change, plus we've altered (lowered) the car's center of gravity with our AST coilovers. This will have an effect of braking performance too.
In any case, we recently ran a pipin'-fresh batch of numbers on Project Evo to quantify the net effect of these changes and get cozier with the pads' behavior once they'd seen the heat of multiple braking runs back to back. Click the jump.
Last time we ran the Evo's braking numbers, the brakes and suspension were bone stock. Here's how things shook out:
Now Stock
60-0 mph: 111 feet 113 feet
30-0 mph: 28 feet 28 feet
Two feet isn't a lot, but to be honest I didn't expect the RE-11s to match the braking distance of the sticky stock rubber. Not a bad showing at all.
As for the nuance of the pedal itself, well, that too is better than before. The initial bite at the top of the pedal is much brighter than it was when it was stock. And the pedal is indeed more solid now. You can just lean lightly on the brakes and get some meaningful stopping power. Fade resistance is excellent too.
Plus, these pads don't need a lot of heat in them to function in the first place, which means two things.
First, the stopping power is right there when you apply the brakes for the first time on a cold morning. Anyone that's run an aggressive track-biased pad on the street knows that this can be a real sphincter-clencher. Not to worry with these Stoptech 309s. The second benefit of a pad that works cold is that they won't grind away the transfer layer between the pad and rotor. This means these pads are rotor-friendly on the street.
Everything is hunky-dory except for an obnoxiously loud screeeeal from the pads when they're cold. It appears to be from the front pads. Odd because normally the 309-compound pads are really quiet, like a stock pad in fact. It might just be a case of needing some anti-squeal gloop applied.
Jason Kavanagh, Engineering Editor @ 25,105 miles.
DCuerpoJr says:
10:26 AM, 09/24/09
Thanks for the Evo update. Do you have numbers on acceleration and slalom?
hybris says:
10:45 AM, 09/24/09
Good to see that the Evo is still street worthy.
spdracerut says:
12:02 PM, 09/24/09
Yeah, probably just needs more goop on the backing plate. Had the same thing happen when re-installed from Ferodo DS2500 pads. First time, lots of goop, no squeal. Second time, got lazy on the goop, got squeal.
wayno_san says:
12:20 PM, 09/24/09
How much?
I'm also interested in the updated acceleration and slalom numbers.
s197gt says:
12:47 PM, 09/24/09
car looks great from that angle. especially clean w/out the wing.
cx7lover says:
03:09 PM, 09/24/09
You can still see the wing holes
So the initial bite is stronger? You don't always get that when going away from stock pads.
hybris says:
07:07 PM, 09/24/09
With all the power that you guys have added I think you need to either put the old wing back on or get a aftermarket one.
jlittlefield says:
07:55 PM, 09/24/09
"Stoptech "309" pads are a very recent aggressive street pad we've used with great success on another application"
I just ordered a Stoptech stage 2 kit with the 309 pads for an Audi A3 and would be interested in knowing what other application you used the 309 pads in, as well as the results.
stovt001 says:
07:57 PM, 09/24/09
So I'm just starting to learn about braking systems. Can someone explain to me what benefits stainless steel braided brake lines give and why they give those benefits? Thanks.
slickersdrip says:
09:39 PM, 09/24/09
I wish those taillights were different. They are looking up and it just makes it look wrong from behind without the wing. Believe me, I go for the wingless look. But maybe an M3 style type of lip would be better?
I just went all wingless on my hilariously oversized winged SRT-4:
http://img.photobucket.com/albums/v169/TheModestWizard/DSCN1138.jpg
hybris says:
10:01 PM, 09/24/09
@stovt001
The main thing about the OEM rubber lines is when you hit the brakes the fluid puts pressure on the calipers but some of the force is lost because the rubber expands as well thus wasting some of the braking force.
Steel braided lines resist the force of the fluid so all brake force is being sent to the brakes.
I'm fairly sure I got that right.
dragonflight says:
11:26 PM, 09/24/09
@slickersdrip
I gotta give you props for the license...clever