Exhaust Design

Now, I’m not about to bore you with technical information on exhaust designs since there is already a plethora of information and opinions on the benefits and downsides of each type of design. But exhausts play an important role in power production for our cars. I cannot say outright that it is an area most people tend to overlook. However, it is a factor that is often overlooked when it comes to the expectations we have. There are so many exhaust brands out there, and all of them follow their own tuning style.

For most of us, our cars are our daily drivers. And maintaining drivability is a very important aspect. I don’t know about you, but I like keeping the powerband nice and smooth, as well as accessible from the 2500 to 4000 rpm range. I definitely don’t spend a bunch of time motoring at redline. No thanks.

But really, it seems that we are all convinced by advertisements and forum posts (if you follow those) that show that bigger piping size is better. Is it, though?

When we had an engineer from Fujitsubo stay with us in the U.S. to develop exhausts specifically for the North American market, we learned a bit more into exhaust design and what makes Fujitsubo exhausts unique. Of course a main factor would be to make more power. Second was material selection for their Stainless Steel and Titanium exhausts. Third was reduced weight over factory exhausts. And lastly, a combination of great sounds and great looks.

Taking a look at the RM-01A I have on my car (part number FJ 190-63055), I never knew how much attention to detail Fujitsubo had put into it. They really do stand by their quality.

Inside diameter is 76.3mm, but it retains the donut-type flange from the downpipe, which matches my aftermarket downpipe (as well as stock) perfectly. Even though this means there is a slight step in piping diameter at the flange (63.5mm), it also means less stress at the flange where the two pipes meet. The rear canister also has a reducer of the same size. This helps to reduce decibel levels to a very low 86dB. Fujitsubo does sound tests using SAE J1169 standards.

Weight reduction comes in the form of 1.0mm thick SUS304 for the piping, resonators, and cansiter. Also, hollow hangers are used, as well as stamped 1.5mm thick gusset flanges (Fujitsubo’s SuperEX exhaust manifolds use Lost Wax formed flanges).

Minimal bends in piping also help to reduce restriction, and the rear canister is slighly canted. Fujitsubo even paid attention to ground clearance, and create an exhaust package that fits factory mounting points as precisely in the stock location as possible.

Overall, I am quite happy with the performance and sound. As I had mentioned, I like a very drivable range of power at relatively low to mid rpm range. I kinda threw that out the window with my turbo selection (a bit laggy for a 2 liter). But with this exhaust, I have regained good midrange power. Torque is nice and flat from 2800-6000 rpm and the motor pulls nicely up until 6500 rpm, at which point my injectors begin to max out. But again, I keep it low rpm on the street. Afterall, that’s where it spends most of its time. The RM-01A is aimed towards users that want good mid to high end power gains, which more or less suits my needs. Since I asked my tuner for a conservative tune, I feel like I was able to achieve what I was looking for, even with the extra lag my turbo gives.

So, while I won’t be needing max power right now, this setup seems to be a great match. As a consumer, you have a lot of resources to find what will suit you best. So do your research.

I suppose there will be a day when I’ll want a crazy high horsepower, flame-spitter of a car. When that day comes, I’ll be doing this

Imagine being able to spit out shock diamonds like this!!! I’m a nerd.

Bye bye

My Evo X and Fujitsubo Legalis R

I bring to you another progress update/product review regarding my personal Evo X.

Previously, I had written about the Mono Flex Dampers that I am using.
This time I bring to you Fujitsubo’s Legalis R for the CZ4A.

My goal for modifying my car was to obtain as much power as possible while keeping the car completely street legal; and I remember when the Legalis R was first being tested on an Evo X, the sound level and power gains were impressive, unfortunately I didn’t have my car back then.
Of course, whenever anyone puts at least a cat-back exhaust on their car they are hoping to gain some power out of it; and I knew, from having seen the before and after dyno runs, that there was power to be made over the stock exhaust with the Legalis R.

Another thing that was important for me was the aesthetics of the exhaust.
Before deciding on the Legalis R, I actually tried out the RM01A that had been on Elliot’s TEIN Sponsored EVO X.

But after driving around with it for a week or so I decided that I wanted something a little less aggressive looking and flowed better with the rest of the car.
(If you desire the aggressive dual canister look, the RM01A is available for special order.)

And finally the sound level.
According to California Vehicle Code 27151 the decibel level of the exhaust cannot exceed 95dbA.
The Legalis R falls well under 95dbA. It is a very quiet exhaust, no drone when cruising at highway speeds or any speed at that.

A Legalis R Promotional Video was recently filmed using my car, so keep an eye out it’ll be released soon.

My Evo X as it sits now:

Special thanks to Mackin Industries for helping me obtain a set of TE37’s.
Also, special thanks to Evasive Motorsports for their masterful fender rolling abilities and for carefully mounting tires onto my white wheels without leaving any marks, always true professionals.

(None of that fender rolling with a baseball bat at Evasive)