*Another* JRSC review in combination with a full exhaust, daily driver
 

Howdy folks. Just want to quickly share my experience after spending a good deal of money on my current setup with a word of caution.

I have a 2014 MT FRS. My first new car. My first sports car -- previously, I drove a bone stock 1997 Honda Civic coupe for 9 years. I only got into cars about two years ago, a year prior to purchasing the FRS.

First, modifications. I have a JDL uncatted UEL, nameless fp/op w/ hi flo cat, and a dezod catback. I also recently had the Jackson Racing supercharger installed back in May.

I recently had a custom tune done at R/T tuning (they did a great job), and with redline limited to 7100RPM (MAF sensor apparently couldn't read past 7200RPM, so set it to 7100 for safety), I put down 270whp peak on a dynojet, with about 205wtq.

I've had absolutely no problems with the JRSC kit in terms of reliability so far. I DID have some boost leaks, but R/T caught and corrected such prior to the dyno pulls.

So how does a JRSC fitted, full exhaust, custom-tuned FRS behave? Power from 5k to 7k rpm is great, the car definitely pulls nicely in that area, but its not "holy shit" fast.

My main caution of warning actually is not with the JRSC by itself. Its largely daily driving a full exhaust FRS and being somewhat conscientious. With a full exhaust setup with only one cat, you've got a fairly loud automobile when it comes to these cars. The SC, being centrifugal, doesn't really start to go until 5k. So, if you shift at 3k-3.5k as to be courteous and not subject your motorist neighbors to the sound of your boxer soaring, you will still be neck to neck with the minivan accelerating next to you. Below 4.5k you're making a lot of noise with not much to show for it. It is only from 5k-7k that a loud FRS with the JRSC finally is able to have its bite match its bark. If you try driving like a reasonable human being, moderately increasing the revs and shifting 3.5k or below, the car is very much like stock -- you won't be accelerating particularly fast. Either you're going too slow, or you're extremely loud and obnoxious (albeit moving).

My exhaust sounds great, but when you're not doing full out enthusiastic driving, and trying to be a reasonable human being and not look like a hooligan/asshat, the powerband of a JRSC (or stock) FRS with a full exhaust does not make such a task easy -- if you want to keep up with the pace of traffic. I will also note that there are a lot louder FRSs out there than mine. Its loud, but its certainly not crazy loud.

And while the acceleration from 5-7k is great, its still not crazy fast. Nor is it effortless to go fast either. You can't just mash the accelerator -- you need to make sure you are in the 5-7k area, and thus will need to downshift. Now if only Subaru could make a 8 cylinder boxer a slap it into a 2000lb. version of the FRS/BRZ. One can dream!

TLDR: think twice about going with a loud exhaust setup. Of course what I have said applies not just to the JRSC w/ a full exhaust, but to any full exhaust setup up, SC or NA. Its just that with the car's stock or JRSC powerband, and a full exhaust setup, its not particularly easy to keep things civil. If you're looking for a fast reliable car that will last a long time I would probably look elsewhere than the FRS/BRZ. True, you could turbo for more power but who knows how long your engine / tranny will hold up. I went with the JRSC wanting more power but also wanting to keep things relatively safe. And while straight line performance is not everything about a car, having a generous amount of power certainly doesn't hurt.

If I had to do it again, I might consider the JRSC, but I would have gone with a different exhaust setup (or left it stock). I love the style and relatively lightweight design of our cars, but as everyone has recognized (else why would there be such a large FI market), our engines really do not have impressive output.

For track junkies, as long as you meet relevant regulations obvious the sound level of your exhaust doesn't matter, but for daily drivers -- trust me, while it may sound awesome at first, it can also be embarrassing when your car is making a lot of noise but the 90's honda accord next to you is keeping up.

A video of the car pulling from a driver's perspective would be greatly appreciated.

@ATL BRZ I will try to get one for you, but I do have a video of a dyno pull: [ame="https://www.youtube.com/watch?v=P9H7V1vAgDI"]FRS Dyno - YouTube[/ame]
video doesn't do the sound volume any justice. when i was standing there it was damn loud

Have you considered putting your stock exhaust back on? You should see how difficult it is to get under 90dB for some Laguna Seca days.

I'm surprised your tuner didn't recommend getting an upgraded MAP sensor (~$100 or less), so that you can rev to your heart's desire.

my tuner did mention it to me but only after the tuning had largely been done (poor guy spent 3+ hours on my car -- he had never done a JRSC before, completely new map for my car). It was nearing the end of their hours so they told me that I could come back in the future for the upgraded MAP sensor.

alas, due to not having the space I got rid of the stock exhaust parts

Ok so it doesn't really bite until you're in sky high rev zone but it is still a supercharger? Um doesn't that defeat the point of it being a supercharger? Did you know that could be the result going in? Or could the other mods in part be the cause for that?

that's correct. I did know that the centrifugal chargers had that characteristic, but I went with the JRSC because reliability was a big thing for me.

When driving once you reach 3400rpmish it starts to pull but you're still not accelerating fast; once you hit 4500rpm you are really moving and then from 5-7 it almost feels like a burst of power, as if the engine becomes free-er and free-er the higher it revs (which is in part because boost is growing and growing as you rev it)

its definitely quicker than stock, and its definitely fun doing 2nd and third gear pulls, its just that there are many cars out there that would murder a JRSC frs, despite it being quick

Get tuned for e85, it helps alot in the midrange. Also get a quieter exhaust. UEL + anything free flowing is going to be ridiculously loud. The rotrex kits give the car vtec pretty much.

no E85 easily available in my area -- i think the closest is newark, way too inconvenient. and yeah I think i might have to switch out my exhaust but it really sucks because i already spent a lot on my exhaust (and switched out my catback)

Very well written and reflects my personal thoughts very closely. I applaud the OP for being so open and honest.

I've been bouncing back and forth with the JRSC for a while now. Being in CA, CARB is a huge part of my decision and having so many options come out is great, but definitely makes it much more difficult to decide. The gains combined with the reliability and simplicity of the design is a huge plus and is a main draw for others shopping around, but as you mentioned, not a lot of current owners talk about its real-world day to day behavior. As you pointed out, not everyone is at red line all the time and completely inconsiderate to other people.

The way you describe power delivery is very much inherent to a rotrex type of SC, which is perfect for someone who spends most of their time high on the rev range (ie track). This was a little bit of a trun-off for me. For somebody who plans on mostly using it for street use, such as myself, a roots/twin screw type would be a better option, which is why I've been following the E-force thread very closely.

Yeah it's a bit of money lost to sell but if you're not enjoying the sound level - you are going to continue to convince yourself you don't like your car anymore. If you go back to the stock exhaust, you might enjoy revving it out without your fear of being obnoxious. The sleeper exhaust also jives well with the sleeper power band of the jrsc... Seems stock until it doesn't.

I upgraded the exhaust on my last car, and that was enough for me to decide to keep the exhaust stock on this one. I much prefer to not be noticed while I'm putting around town.

My suggestion, sell the exhaust - or at least the stuff past the headers to quiet it down and enjoy the boost more often!

thanks for your input, great points and advice! the "sleeper" way has been becoming more appealing

First off thanks for the review. What gas was used on the dyno?

There is always something else that is quicker and faster. Its a never ending chase for power, chassis, balance, etc.

Humor me what other cars were popping in your head when you said there are many other cars that would murder the FRS/BRZ? I'm genuinely curious:

EVO?
350z/370z?
Wrx/STi?
Focus ST?

Maybe others can chime in on this?

I feel JRSC hit on all notes when it comes to making a good increase in power while not sacrificing reliability. I know Kraftwerks has a SC available that can make more power but that setup shreds belts left and right and has some reliability issues.

If you are going to change your catback go with Invidia Q300 or even Perrin RESONATED. Hopefully that quiets it up a bit.

Have you considered installing silencers on your Dezod catback?

I have basically the same exhaust setup as you and I've considered getting these to try and quiet it down on demand: http://www.speed-element.com/tsudo-4...ment-silencer/

They are 4.5" and should fit the Dezod tips after drilling small holes in them.