Question about headers and exhaust
 

Do all of the 1st gen headers and exhaust fit the 2nd gen? Someone said only the catback exhaust will fit? Thanks in advance

i've heard the opposite - that the headers bolt right up. However, the bigger question is whether first gen headers provide improvements over the oem header. Car is still so new with many people waiting to get theirs because of supply issues so not a whole lot of information yet a lot of people that were able to get one are still in break-in phase prior to modding

I agree. If the first gen headers bolt up i’m sure there’s a improvement. The oem headers are heavy and very restrictive. As far as exhaust goes I had a q300 paired up with a front pipe and uel headers on my gen1. It sounded perfect in my opinion so i’m hoping i can do the same with the new one

Apparently the 2nd gen header flows decently for an OEM piece and is already slightly unequal length to improve the torque dip. Personally I will be waiting for a header designed specifically for the 2nd gen. There’s no rush.

Headers swap over almost*** universally. Lots of information floating in the BRZ 2nd gen subsection.

Here's a reasonably indepth comparison of the OEM BRZ 2022 Header vs Borla UEL header.
With the video starting at the dyno comparison:
https://youtu.be/2TjlpLVTQ0I?t=411

The channel also does an interesting comparison of the 2.0 Header vs the 2.4 Header bolted to the FA20. Looks like our 2nd gens used some exhaust tuning to deal with the torque dip.
https://youtu.be/7C_W6PoabzE?t=461

Thanks for sharing the video!

They swap but until there is a tuning solution they won't make much of a difference beyond sound.

Very true!

Car seems to be under rated compared to the last gen, 205-209 hp vs 165 on the fa20. So we may not have as much room for improvement this round.

Not sure what that has to do with increases from headers.

Besides, header hp/torque increase from Gen 1 mostly comes from removing the cats or replacing with high flow cats as well as tuning solutions that don't have the same constraints stock tuning does. I personally expect a similar percentage-wise increase from decatted headers, tune, and e85 on Gen2 that we had on Gen1.

Tuning with pump gas and no parts was maybe 10 hp. Full exhaust with a one cat system would net roughly 30 hp from stock as well as remove the infamous dip.

If the 2nd gen stock manifold has a freer flowing design then less hp may be available when tuning. It also is closer to flywheel hp stock meaning there might be less available to optimize with.

We have no idea how the 2nd gen stock manifold flows compared to the 1st gen stock manifold at this point (unless I am missing something). And besides, I don't think the manifold is, or ever was, the issue. Yes, the 2017+ manifold is generally considered slightly better flowing than 2013-2017, and some have attributed small gains to the addition of spacers - but that is small potatoes.

We also know that there is no real problem with the flow of the stock headers on Gen1 as decatted Gen1 stock headers performed almost identically to most aftermarket decatted headers. The real issue, as well as the reason for the torque dip, was the combination of catted headers and a tune that was created to meet emissions using 91 or 93 octane gas.

As we all know, if you don't care about emissions, improve header flow, and tune specifically for e85 octane, you can get a pretty significant HP/TQ jump on Gen1 and there is no reason to believe you won't be able to get a very similar (maybe a little less, percentage-wise or maybe a little more) jump for Gen2.

As for your second point, how in the world do you know that wheel HP is closer to flywheel HP on 2ndGen than it was on 1stGen?? More importantly, you realize that decatting the headers and then tuning for decattted headers and e85 gas changes the flywheel HP, right? It has nothing to do with driveline losses. As for driveline losses, once again, there is no reason to believe they aren't very similar on Gen2 as they are on Gen1.

First the de catted headers did almost nothing just like borla. Other companies managed decent gains, although they were also catless. Having a mid pip high flow cat still allowed for these gains and would pass a sniffer test....

There are already several dyno charts of the new cars and they run closer to the stated hp. Most people interchange flywheel and manufacturers spec hp.

The new cars are mostly 200-209 with a stock gen 1 car in the 160s which is well over a 23 hp jump.
The torque dip appears to be shorter and shallower than the gen 1 as well.

So yeah it seems like the new car has a better designed exhaust manifold.