Jackson Racing Supercharger Owners Thread

[sw20kosh]

Originally Posted by M23

"No" ...I wasn't even asking a question. Your comment and opinion is purely subjective. But, sounds like you're jus trying to talk sht anyways.

I think overly bassy exhausts sound like "ass." Like they're trying too hard to sound cool.

Diff strokes.

No. You don't understand. The stock muffler baffling cannot handle the increased amplitude of a supercharged fa20 with no cats. It litterally sounds like the baffling is rattling around against each other. Sounds like it is broken. How do I know this? From personal experience on my car and others like CSGs car.

Be my guest and try it out lol. You can find video of this happening floating around.

[Jackson Racing]

Originally Posted by M23

Last question ( @Jackson Racing ):
What's the current pulley's boost? 6-7psi correct?

The Jackson Racing CARB Factory Tuned system is 9psi. I am guessing this is for your SoCal street car, so the CARB Factory Tuned system is really your best option.

-Oscar Jr.

[ScionOfHorus]

Originally Posted by sw20kosh

No. You don't understand. The stock muffler baffling cannot handle the increased amplitude of a supercharged fa20 with no cats. It litterally sounds like the baffling is rattling around against each other. Sounds like it is broken. How do I know this? From personal experience on my car and others like CSGs car.

Be my guest and try it out lol. You can find video of this happening floating around.

My car sounds perfectly fine

[M23]

Originally Posted by sw20kosh

No. You don't understand. The stock muffler baffling cannot handle the increased amplitude of a supercharged fa20 with no cats. It litterally sounds like the baffling is rattling around against each other. Sounds like it is broken. How do I know this? From personal experience on my car and others like CSGs car.

Be my guest and try it out lol. You can find video of this happening floating around.

First...no one ever said "no cats." Me? I never said I would run full uncatted ..I would run at least one cat at all times - for less rasp/noise/loudness, as well as less stink.

The sound you are describing is not from your assumed subpar oem muffler baffling imo. It is from running no-cats.

Yes, I've read that a few times before from CSG. But, the stock baffling may or may not be able to handle the increased sound...it has never been extensively tested honestly (it's not a Porsche or LFA, etc). All the things you've read about this are just opinions from non-engineers and observations of how the stock exh/resonators/mufflers/pipe-diameter is designed and built. In all honesty, nothing beats the stock exhaust in terms of being the most quiet (aka: "handling amplitude/volume"). Prove me wrong and show me an exhaust that is quieter (ie: "handles more amplitude" as you say). Just because the stock exh doesn't have giant 2.5"-3" piping or 2.5-3" muffler inlets/outlets, doesn't mean it can't handle extra amplitude. And also, so what you're saying is that straight-through canister mufflers handle amplitude better? Lol..those are the loudest types of mufflers and always will be.

The point I am trying to make: Amplitude Handling (Lower Volume) ≠ More Flow

It's common sense... the bigger the pipe/mufflers/flow, the bigger the noise.

Lastly, Does adding 7-9psi from a SC really make the exhaust sound that much louder? I doubt it. All the videos I've see with a SC sound pretty much the same as NA. It's not like we're talking about a 2bar boosted 800whp monster.



.

[sw20kosh]

Originally Posted by M23

First...no one ever said "no cats." Me? I ever said I would run full uncatted ..I would run at least one cat at all times - for less rasp/noise/loudness, as well as less stink.

Yes, I've read that before. But, the stock baffling may or may not be able to handle the increased sound...it has never been extensively tested honestly (it's not a Porsche or LFA, etc). All the things you've read about this are just opinions from non-engineers and observations of how the stock exh/resonators/mufflers/pipe-diameter is designed and built. In all honesty, nothing beats the stock exhaust in terms of being the most quiet. And, if it's still the quietest, that means it's "handling that extra amplitude." Just because it doesn't have 2.5"-3" piping or 2.5-3" muffler inlets/outlets, doesn't mean it can't handle extra amplitude. And also, so what you're saying is that straight-through canister mufflers handle amplitude better? Lol..those are the loudest types of mufflers and always will be.

I am not talking about what other people theorize or post on the forum. I am talking about real life experience on my once supercharged setup with no cats and stock muffler + CSG's supercharged setup with no cats and stock muffler. It is anything but quiet when it starts rattling/rasping up a storm when you get under load.

So yes, the extra flow from the supercharger does make it so the cannister is inefficient at dampening certain sound waves.

I would deffinitely leave in one or both of the cats if you are going to use the stock muffler.

Does adding 6-7psi from a SC really make the exhaust sound that much louder? I doubt it. All the videos I've see with a SC sound pretty much the same as NA. It's not like we're talking about a 2bar boosted 800whp monster.

I was at 8 psi and 230 whp when i tried the stock muffler. It came off immediately.

[sw20kosh]

Originally Posted by CSG Mike

Well, when you have no cats and a free-flowing header... the noise is dramatically louder The honeycomb (square in the BRZ/FRS) of the cats kills sound waves that are longer, but when they'er gone, they get to the exhaust/muffler, and wreaks all sorts of havok on the sound level.

This.
@M23

[M23]

Well...I agree with you there. No cats will def sound much louder, raspy, like "ass" ...especially with a stock muffler. Been there with 5+ cars.

When you add an aftermarket exh...it "balances" and hides/overpowers that uncatted loud raspy "Ass" sound ...with and underneath the louder 2.5-3" exh sounds.

[M23]

Also..I think he meant "shorter" and taller high freq sounds and wave lengths (I study some sound engineering) gets killed with the cat. That's why you can still get a bassy exhaust with a catted setup (the cat still lets longer and low freq sound to pass through; but kills short, spikey, high freqs... ie: rasp). Remove the cat..and now it's letting both the super spikey high freq wave lengths (rasp), as well as the longer bass wavelengths, to pass through.

[M23]

You can do a little experiment at home if you have instruments or songs/sounds with separate bass and another with super highs.

Record each with audacity or something - one pure bass and the other, something very short, high pitched, with a lot of attack, maybe shriek'y. (heck..you can probably record a youtube video of a bassy q300, and the other, a full uncatted no muffler test-pipe race set up).

Now look at the wavelengths of recorded results. Maybe zoom in and stretch it out. The bass will be much smoother, longer and flows. The high freq, attack sound, will be super short, peaky and sharp.

Now imagine these were actually physical and held it's shape passing through a cat. The cat will kill or smooth out the sharp, peaky, attack, high freqs (the rasp).

[CSG David]

Try it out first and then report back. Experimentation is what we do and data/facts/experiences are what we report. Some believe and some don't. The best bet is to try it out yourself and figure out what works for you.

[M23]

If you guys are getting "rattling/rasping" it's because you're not running any cats and not because of the stock muffler.

You'll still get that "rattling/rasping" sound with aftermarket exhausts running no cats. Just, not as apparent, and hidden/underneath the bigger/bassier sounds the bigger diameter exhaust pipes produce (think short/thin vs long/thick pipes of a pipe-organ, trumpet/tuba, diff keys of a marimba/xylophone, guitar, piano, etc., etc.).

[CSG Mike]

Originally Posted by M23

But, the stock baffling may or may not be able to handle the increased sound...it has never been extensively tested honestly (it's not a Porsche or LFA, etc).

Lastly, Does adding 7-9psi from a SC really make the exhaust sound that much louder? I doubt it. All the videos I've see with a SC sound pretty much the same as NA. It's not like we're talking about a 2bar boosted 800whp monster.



.

Yes we have, and no, it cannot handle the unregulated flow of not cats. One cat will still be quiet.

Yes it does. Sound is determined by the shape of the wave. Loudness is determined by the amplitude of the given wave, which is determined by the amount of airflow in the system. Yes, I've taken engineering classes in college.

If you're going to disregard our input, why ask for it to begin with?

[CSG Mike]

Originally Posted by M23

If you guys are getting "rattling/rasping" it's because you're not running any cats and not because of the stock muffler.

You'll still get that "rattling/rasping" sound with aftermarket exhausts running no cats. Just, not as apparent, and hidden/underneath the bigger/bassier sounds the bigger diameter exhaust pipes produce (think short/thin vs long/thick pipes of a pipe-organ, trumpet/tuba, diff keys of a marimba/xylophone, guitar, piano, etc., etc.).

I think you do not quite differentiate between rattling and rasping. Rasp will always be there. Rattling should NOT be there.

The stock exhaust, without cats, both rasps AND rattles. The rasp cannot be eliminated; the rattling can.

If deep, bassy exhausts are what you consider a proper exhaust, then you've never ventured into high end exhausts. Deep, baritone exhausts are universally quiet at high flow, high RPM. Think about it.

[ApolloSki]

The SC does make the car louder. I drove NA with a catless header for a long time and recently added the JRSC. I also added an additional resonator and the exhaust is noticeably louder when I downshift.