Regardless, the headers are going to be the most restrictive part of the exhaust, so changing the cat-back isn't going to really do anything in terms of flow/power. Just buy whatever exhaust you want for the sound. It's a bit old, but BOE did tests across different headers on a built motor 2ZZ with a REV 400 here: 2ZZ-GE Header Shootout – BOE Fabrication. So if you're looking to make power, I would start with the headers.

 

I'm mostly motivated by sound on this one. It just got me wondering about restrictions.

 

I like this question, but i certainly don't know the answer to it. I think if i wanted to figure it out, one way would be to put some delta-pressure sensors along the (post supercharger) intake path and along the exhaust path to see where the biggest pressure drop occurs. These would be hard to compare directly, unless you could normalize for ideal gas law-like parameters. So interpretation would be difficult.

Also with how tight the component packaging is
this sounds like a tricky experiment to set up, too. I wonder if there's space on individual intake and exhaust runners to attach a sensor port (and with what means? Is a torch braze or weld practical?).

I'm just brainstorming into the Internet void... But i think I'm convincing myself that such a test is more trouble than it's worth. This is more like the kind of thing an oem would do on an engine dyno. Or via CFD.

 

I love the concept of instrumenting a real test. But a more practical solution would be to hear from the many folks here who have played with both intake and exhaust mods. They should know from their personal experience.

 

Noticed the old BOE test that @BD9892 posted started out by removing the cat from the baseline setup - NO impact. Different headers did have impact ... Hmmm

 

Yep, a useful article. Clearly the actual OEM headers aren't going to let a different exhaust do much except change the sound. And since we're already supercharged, the intake is already getting boosted past NA levels.

Sounds like @BD9892 is right: Buy the sound you prefer. Question is, Larini B or SC?

 

I have a Larini Group B on my 07 Exige S ... Not impressed with the sound, very tame, and no back burble ... Of course I am driving on the street most of the time, so not fully 'on cam' a lot ... Was thinking of trying a Sonic Fury?

 

I don’t think it’s clear cut

In isolation changing the exhaust but not intake will give you negligible gains.
Likewise , changing the intake but not exhaust the same.
I noted gains when using a high quality sports cat, komotec manifold and a custom exhaust.
However I also had a tune to make the most of it and I was already modded.

 

Presumably "just" an exhaust change won't affect the ECU tune, since it's downstream of all the sensors. Plus the intake hasn't changed so the ECU idea of how it controls air and fuel won't have changed either (same adjustments by the ECU will yield the same air and/or fuel amounts that are allowed into the engine). A more open exhaust should just let the engine exhale easier. Though there might be a backpressure effect on how the cylinders get scavenged after combustion. I'm just not enough of an engine guy to be able to predict this.

 

You do both with tune to give you the highest power. You can only go so far with exhaust system porting, but with a built and ported head, ported SC you'll be getting the highest HP possible when combined with tune.
The real limiter is the transmission.....

 

The trans failures are strange.
Some cars fail under low power mods , others seem to take some hammer.

There is no hard and fast rule

 

modified, I am nice-ish to mine until 4th gear.

 

Muffler Showdown! What's the Best Muffler for Your Engine ...YouTube · MotorTrend Channel480.9K+ views · 3 years ago

The Power of 2.5- vs. 3-Inch Exhaust - Engine Masters Ep. 9YouTube · MotorTrend Channel5.8M+ views · 8 years ago

might help?

 

cai n Exhaust are ferl goid items. As with all Toyo Power Plants, the precast are cheap castings. Headers change the game. My Evora is very different now......

 

since you specifically called out sound and growl, I think it comes down to taste.

Power is really only going to come from a tune... that's been proven ad naseum in these forums.

BUT - I think sound is a big part of the experience, and I happen to love intake noises from force induction cars... so for me, cup airbag with a foam filter opened up a good amount of whine when applying my right foot. (that and some straight cut gears in 3rd and 4th... ).

I run a stock muffler. I pull the cat off for track days, as cats and tracks don't mix. But the sound that gets me grinning is all whine...