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The weak-sauce stock exhaust sound is about the only shortcoming I can think of on my new car. I searched RL to learn about my options for an upgrade. I identified 10 different brands available; 5 of which offer a system that retains the OEM cats. My understanding is that on a tune-only car, the stockers are not very much of a bottle neck, so I'm not drawn to going outlaw with non-OEM cats.
I quickly ruled out Akropovic due to requiring change-out of the rear valance. That left SharkWerks, SpeedTech, FVD/Brombacher and Soul. SpeedTech and Sharkwerks' designs have no muffler or resonators of any kind, that made me wary that they might be too loud for my taste. Sound clips of these stock-cat models are limited, but I used clips of their sport-cat versions to get some impression of each brand's sound. I believe that my new video linked at the end of this post, is the first youtube posted of the Soul Turbo X-Pipe. I personally dislike rumbling/brappy exhaust notes, and favor smoother wailing tones. I thought Soul sounded the best by that criteria.
Soul's design of 4 small resonators but no traditional muffler made me wonder if it might be too loud for me. I wanted something sportier than stock, but I did not want to risk anything that would drone, make conversation at highway speeds difficult, or otherwise be obnoxious. It has turned out that for me, everything about this exhaust's sound hits an absolute bullseye. It brings to the forefront a beautiful tone that is present but much too subdued in the stock system. And somehow the Soul suppresses the awful "hairdryer" sound that the stock system highlights. I doubt that anyone wanting an aftermarket exhaust could find this one to be too loud. I can assure you that it is definitely enough louder and sportier than stock to be an excellent upgrade, but I can imagine that for some guys it wouldn't be loud enough.
Soul's customer service was A+. Mike and John were not only readily available and helpful, but were downright fun to talk cars with as well! They had my exhaust built and shipped in a single week.
Install notes: I installed the exhaust myself at home, with a lift. Per the instructions provided, I did not remove the rear bumper. Content to work slowly, it took me 7 hours; as with all such projects I could do it in 5 hours on a second go. For me, 100% of the PIA factor was related to removal of the 6 sensors (O2 x 4, EGT x 2). Despite liberal use of PB Blaster, regular open ended wrenches could not budge any of these 6 sensors without starting to damage the soft brass nuts. I had to stop to go buy flare wrenches (14mm and 22mm). The shop had the right sizes only in a "crow-foot" type (see pic below) but these worked well. The O2 sensors further in towards the front of the car, are tipped at an angle that makes them really hard to get a wrench on. Especially the driver's side. I had to have the stock cats basically completely detached from the turbo housings before they were tipped enough to allow an angle on those sensors.
A tip for when you are ready to pull the muffler downwards, be sure to have the two big straps that hold it not just detached, but completely removed from the area before proceeding. You have to pull the front of the muffler straight down forcefully enough that it will flex the rear valance a bit, but it did not look to risk damaging anything during the process.
The fitment of the Soul piece was superb. Once the PIA of removing the stock components was done, re-installing the new parts was a cake-walk. I expected a hassle to get all the parts to align nicely with putting the stock tips back on, but that ended up going smoothly.
IMO, this product's quality, appearance, sound, support, as well as it's price, are all as good as it gets in the world of performance car parts.
For my car, Flare-wrench was mandatory, crow-foot style helpful
That wrench in action, on the most troublesome of the O2 sensors
Progress
Weigh-in stocker. I should have had the stock clamps on the scale for a more direct comparison. Prob would add a pound or so.
Weigh-in Soul (in the video, I made a typo listing the Soul weight as 19.5 lbs, but 19.0 is correct)
Nice write up. Your comment about stock cats even on a tune car is incorrect. There is a reason why Kline, EP and several others upgrade the cats to allow for reduced back pressure and more free flow of gasses. It helps make more power. If just looking to save money and get a little sound maybe this is a better option.
tb - I well understand how less restrictive cats contribute to more power, I didn't say they don't. But how much difference this mod makes can vary greatly depending on just how restrictive the OEM cat design on any given car actually is. For example, stock cats on a tuned Supra incur a 20 -25 % HP penalty, while on a tuned Gen II Ford GT, the stock cat design flows so well that deleting them entirely gains only 2-3%.
I'd very much like for someone to point me to actual data on how much more power is gained by the single change on a tuned 991TT of OEM cats to 200 cell. I've read comments indicating that it is less than 30 hp, and when I asked Soul this question, they said even less than 20 hp. That's about 3%. This general information supports my non-specific comment that "it is my understanding that the stock cats are not very much of a bottle neck".
Congrats - that is definitely an improvement. Great video. Did you use a GoPro for the external clips? I've never done that - just curious..
Thanks! Yes, actually used the GoPro for all the clips. Attached with a clamp for interior, and suction cup to the rear bumper. Wish I could have used some type of outboard microphone for better audio, but that would have bogged down the project.
Nice video and great info. So changing out the mufflers alone doest giv e any power when combined with the tune.
Thx! I'm not sure how much power this exhaust might pick up. But I recalled that FVD/Brombacher says their sport muffler picks up 25 hp / 19TQ. Seems reasonable to expect the Soul to be similar. I just now went back to the FVD website to double-check this info, and spotted a remarkable report from their testing: FVD sport muffler
"Our exhaust and software testing in Germany indicated that the stock cats actually flowed just as well as sport 200 cell cats up to about 680 Hp."
wow - I can double-down on my statement that stock cats apparently are not much of a bottle neck!
On my flow bench the factory cat flows 425cfm at 28” of h20. My 100 cell cat flows 497cfm at 28” h20. That’s a 17% increase in flow per cat. So 34% more flow. A 2.5” open pipe Flows 514cfm. So a 100 cell is very close to open pipe flow. That is a significant upgrade.
On my flow bench the factory cat flows 425cfm at 28” of h20. My 100 cell cat flows 497cfm at 28” h20. That’s a 17% increase in flow per cat. So 34% more flow. A 2.5” open pipe Flows 514cfm. So a 100 cell is very close to open pipe flow. That is a significant upgrade.
I don’t sell stuff.
That is really something that you have your own flow bench data, cool. Would be a better apples/apples with FVD's report if you could test a 200 cell. I'm sure FVD would prefer to sell their many more expensive exhausts that do include sport cats, so it doesn't seem fair to imply they fabricated their data to sell their cheaper muffler. Also seems worth noting that there must be a flow rate beyond which the tuned stock system is at its max efficiency and doesn't pick up additional power. 34% increased flow doesn't tell us what the % increase in wheel power is. Ultimately the results reflected in dyno or better yet road performance measurements are what matters to most enthusiasts.
Would be a better apples/apples with FVD's report if you could test a 200 cell. I'm sure FVD would prefer to sell their many more expensive exhausts that do include sport cats, so it doesn't seem fair to imply they fabricated their data to sell their cheaper muffler.
You took the post wrong. I’m not implying anything. Just making sure that anyone reading my post understands my Flowbench Dyno is truly independent.
If I test Kline, I don’t sell Kline. In this world of fake news it is important to know if you sell. Doesn’t mean you are biased. But if you don’t sell parts period. Or are given parts. It should be more independent.
I would love to flow their 200 cell. Would also love to flow the 50 cell from Europipe. If you go back through my posts in 2019, I begged for a stock cat to flow. Had to take mine off to test it.
Another flow data point. At 28” a 2.25” pipe will open flow ~ 417cfm.
The stock cat is basically equivalent to a 2.25” pipe.
If you bolt a 3” pipe to a stock cat, you will get a 2.25” open pipe flow. If you bolt a 4” pipe to the stock cat, you will get the flow of a 2.25” pipe.
The factory muffler, with the twists and bends could be the equivalent of a 2.0” pipe (pure guess) so an aftermarket exhaust could show power improvement by reducing that restriction.
On my flow bench the factory cat flows 425cfm at 28” of h20.
My 100 cell cat flows 497cfm at 28” h20.
That’s a 17% increase in flow per cat. So 34% more flow.
.
Just a note... Having two cats doesn't double the flow percentage increase... Assuming this is correct data, it's still just a 17% increase in flow (cats only)
05-13-2020, 12:05 AM
Soul Turbo X Pipe Exhaust - review and video
