The Cat-Back Challenge: Comparing Top Exhausts for the BRZ
GETTING TRACK READY
The wait is over at IAG Performance, and we couldn’t be more excited to finally get started on our BRZ project car. As we’ve been easing our way into some light modifications, we wanted to test out a few different cat-back exhausts, but before we could, we needed to make sure that it was track-ready. Since we’d be putting the car through its paces at Summit Point, we couldn’t risk running with a factory braking setup. Equally important, putting power to the ground would be crucial, so we mounted some super sticky tires ahead of any testing to be done. Finally, because we’re taking a scientific approach and recording all our findings, we installed an Aim Solo 2 Data Logger to keep track of everything from lap times to brake pressure and more. In this blog, we’ll provide a complete rundown of the steps we took to prepare our BRZ for the track, along with a detailed report of our cat-back exhaust testing, sharing how each system impacted performance on the track and the street.
THE BARE-BONES BRAKE SETUP
The ability to drive fast is limited by the ability to brake fast. That being said, we felt it was imperative to address the factory brake situation before hitting the track in our BRZ. Our setup, while basic, will make all the difference when it comes to putting down some solid lap times without the worry of brake fade. We installed Hawk DTC 60 brake pads all the way around, which has given us consistent stopping power, even in the face of aggressive usage and subsequent higher temperatures. We also swapped the OEM DOT 3 brake fluid for ATE Super Gold DOT 4 brake fluid, which has a higher boiling point, making it ideal for rigorous testing out on the track.
GET A GRIP
Without traction, our horsepower would be useless, so we equipped our BRZ with a new set of Bridgestone RE 71RS 200 treadwear tires. 200 treadwear tires are extreme performance tires, and while they won’t last as long as a regular commuter tire, their super sticky compound is perfect for the track. Most racing organizations consider 200 treadwear tires to be the lowest treadwear that can still be considered a street tire, as opposed to a full-on racing tire.
AIM SOLO 2
If you know us, then you know that we’re firm believers that the proof is in the numbers. To keep track of lap times and data, we’ve installed the Solo 2 DL from Aim. This versatile little device does a lot more than timing, it provides a real-time visual of current lap times versus previous lap times and routes, so there won’t be any guessing when it comes to staying on pace. For our own purposes, this will be super useful as we try to recreate testing conditions and record the data. For consumer purposes, the Solo 2 is a cool product that provides tons of helpful information that will help to improve your track times, as well as give you the option to keep track of brake pressure, G force, throttle and more.
CAT-BACK EXHAUSTS
Once we were confident that our BRZ could effectively handle a day out on the track, we moved on to our main objective of putting a few cat-back exhaust systems to the test. Why upgrade the cat-back, you ask? Taking the approach that a new BRZ owner might take, we decided that a cat-back would be an easy bolt-on mod that could potentially improve the car’s performance while making it even better suited for the occasional track day. Generally speaking, replacing the OEM cat-back with an aftermarket performance version both improves the airflow and reduces back pressure, which ultimately means that the car can produce more power. The sound produced by a cat-back also just sounds cooler, giving your car that more aggressive, throaty rumble that is not just a subtle reminder that your car is a force to be reckoned with, but actually serves a purpose; the sound of a stock BRZ can be easily drowned out on a busy track, making it tough to hear when to shift. A cat-back is just the thing to provide the audio queues needed to shift the car at just the right moment.
THE CAT-BACK CHALLENGE
In our cat-back challenge, we tested three of the top-rated cat-back systems on the market; the Invidia N1, a sport-touring version from Remark, and finally, COBB’s titanium cat-back. We weren’t comparing horsepower numbers or anything like that. Instead, we focused on what we considered to be the most important characteristics of what a good cat-back should deliver. We judged on things like volume, tone, and drone, all of which factor into whether your car is just sporty enough to be heard, but not so loud or tinny so as to become a nuisance to drive. We also judged on fitment as well as value for money because there is nothing more disappointing than shelling out a paycheck or two on a poorly manufactured part. Finally, we weighed each unit to see which one was lightest and compared them against each other, along with Subaru’s OEM version.
THE RESULTS
Volume
★★★
★★★★
Tone
★★
★★★★★
★★★★
Drone
★★
★★★★
★★★★★
Fit
★★★★
★★★
★★★★★
Value
★★★★
★★★
Total
15 out of 25
20 out of 25
21 out of 25
COBB TITANIUM CAT BACK EXHAUST
While each of these cat-backs had their strengths, one clearly stood out as the best fit for our BRZ. We hope this comparison has given you some helpful insights into each of these setups. Of course, if you're looking for more ideas, tutorials, and the latest in Subaru mods, make sure to check out our YouTube channel for more in-depth coverage on the BRZ project and beyond. As always, if you have any questions or need a little advice on your own Subaru project, we're happy to help. Feel free to call us at (410) 840-3555 or email us at sales@iagperformance.com.