Manifold for sound and gains?

[Leejay-b 1]

I understand aftermarket manifolds are good for naturally aspirated tuning on the 86.

With a decatted equal length manifold and remap, is 220-230 flywheel bhp achievable, while keeping the standard 2nd cat in the front pipe? What about standard catted manifold and decat front pipe instead, is 210 bhp fair?

Also is the sound much different or louder with either of the above, I like loud cars but a catback exhaust just for sound and minor gains is a lot of money. Could the manifold or front pipe (not both) add a decent amount of volume on its own?

Cheers.

[Tareim 343]

think the best option for performance and sound without being too obnoxious would be decat mani + sports cat secondary

[KevinA 695]

think the best option for performance and sound without being too obnoxious would be decat mani + sports cat secondary

I have similar set up, Tomei EL decat manifold, Cobra overpipe, Berk sport cat front pipe and ARK DTS exhaust. Fairly loud so just had another resonator welded in. I think the exhaust is bery important as some do a very different job of silencing than others.

[Church 209]

Check this thread. It's OP covers most things related with NA bolton parts. If one takes stock flywheel power as 200bhp, then NA you can get up to +35-40. (Or if dyno shows ~ 155whp, 190-200 whp with most of main exhaust & intake bolton parts + tune). Most gains are from header(manifold)+tune. Last extra whp-s usually show diminishing returns while NA.

Decatted header and/or decatted frontpipe indeed will add loudness (another reason to do catless header first, as i've seen posts where guy first installed catback exhaust, then later on catless header. Result was too loud to his tastes, and sometimes resulted in installing quieter catback or even stock one back).

[Subota Boy 402]

think the best option for performance and sound without being too obnoxious would be decat mani + sports cat secondary

Agree with this.I have the Tomei EL with a sports cat and remap.  It is quite a bit louder, but over time as the exhaust silts up I have found the sound gets deeper..

[Ztox 230]

Personally I wouldn't worry about figures while n/a, just fit exhaust parts for the sound you want. 

It is a lot of money for not much in terms of gains but that's n/a and the price of exhausts parts in general isn't it? The question is just how much do you like loud cars?

I like them a lot so spent a lot