Exhaust Setup Suggestions

[Lakitu]

What exactly is a downpipe..? I keep seeing that term pop up but when I search for its exact definition no distinct classification shows up.

@Iantsalot thanks for the tips with the catted vs non-catted sound related stuff. I think I might leave the frontpipe alone, and just do headers for the sake of staying within a moderate sound profile. So I guess the largest boost in sound would be when you start messing with front pipes when you have already swapped the stock exhaust manifold for an aftermarket header.

[Lakitu]

Originally Posted by NRXRaptor

The advantage of keeping at least one cat somewhere is for smell. Check the for sale section and you will see many catless headers/frontpipes for sale because the owner got tired of the smell. Cats also cut rasp and volume (and uncombusted fuel obviously) at the expense of power

Hmm, interesting point. Will there be a noticeable smelling of gasoline in the cabin with a catless header and the stock fp?

[Lakitu]

Originally Posted by lantsalot

So having just got my catted headers and tune done, I still have the differences pretty fresh in my mind. I'm not refuting what other people have said because everyone has their own experiences, but based on what I did, here's some insight, keep in mind that I already had a resonated dp and an axleback :

- with the addition of the catted headers, no tune, I noticed that the famed 'torque' dip was much, much less...well....noticable. I drove around with the headers for almost a week without tune, CEL never came on. Probably about 100-150 miles or so of driving.

- got entire setup tuned 5 days later, and with the headers + resonated fp + axleback + drop in filter ended up getting a +30 hp gain.

- Even catted, headers are LOUD on our cars. Especially if you've got a decent aftermarket exhaust set up. I like loud cars--i really do, but hearing this setup--I would have regretted going catless. I suspect that this is largely because I have the nameless downpipe. I can almost guarantee that no one would ride in my car if I had chosen the catless and everyone on the road would hate me. If you want to avoid this, may want to stick with stock downpipe / frontpipe or do the JDL ultra quiet.

Hope this helps!

+30hp is quite remarkable if I must say so. I wonder how much do you gain over that if you go catless headers. I also wonder how much gain came from the resonated fp alone versus stock fp.

[EndlessAzure]

Originally Posted by Lakitu

+30hp is quite remarkable if I must say so. I wonder how much do you gain over that if you go catless headers. I also wonder how much gain came from the resonated fp alone versus stock fp.

The supporting piping (overpipe, down/front pipe) all together don't add a ton of horsepower. I would gander on the order of 5-10 HP with a tune. It's the header that has the greatest immediate impact (with a tune)


Link to exhaust components: http://www.ft86club.com/forums/showp...01&postcount=3

[lantsalot]

Originally Posted by EndlessAzure

The supporting piping (overpipe, down/front pipe) all together don't add a ton of horsepower. I would gander on the order of 5-10 HP with a tune. It's the header that has the greatest immediate impact (with a tune)


Link to exhaust components: http://www.ft86club.com/forums/showp...01&postcount=3

Love that link. Took me forever to figure out what the hell the "downpipe" was that Nameless makes xD. After stumbling across that diagram I realized, oh they are just calling it that when it's actually front pipe + over pipe.

But yea, I would wager that most of it came from the headers + tune. The high flow cat in the "DP" might help too.

[lantsalot]

Originally Posted by Lakitu

+30hp is quite remarkable if I must say so. I wonder how much do you gain over that if you go catless headers. I also wonder how much gain came from the resonated fp alone versus stock fp.

Agreed, the gain was much more than I expected. I was very pleasantly surprised. The gain is predominantly above like...6500 rpm? Which honestly I don't see a lot of with how I drive xD. I've seen people claim 10-12 hp gain from the nameless parts that I have (resonated fp/op with hi flow cat and axleback), but I have no validation for that--and honestly it seems a little high to me. The only dyno I have is my entire setup before / after tune.

[dhuang]

Originally Posted by Lakitu

Thanks for all the info guys. I have purchased and installed an FT86 SpeedFactory V1 resonated exhaust. Stock all else and it sounds AMAZING!! Nice and deep like a lady working the street.

So based on what I've read here, I'll be leaving the frontpipe alone and changing the headers after I get an OFT. I'm going for catless UEL for some cabin rumble and power (hopefully). Don't want it -too- loud as I'm going for moderate profile. I'm in FL so cat delete is legal.

I have the setup you are going for: FT86SF V1 Resonated + UEL + OFT

Here an idle cold start after I made my "Quiet" OFT tune:

[ame="https://www.youtube.com/watch?v=8rrfXthK_dc"]Scion FR-S Cold Start "Quiet" Tune - YouTube[/ame]


My car sounds eerilely similar to this setup, but this V1 does sound unresonated.

[ame="https://www.youtube.com/watch?v=cI1zZyt4mu4"]Scion FRS/Subaru BRZ FT86SpeedFactory V1 Catback Exhaust - YouTube[/ame]

[Lakitu]

Hmm.. This video has me second guessing my choice for catless headers. This person is running all catted (headers/front pipe) and resonated catback exhaust.

[ame="https://www.youtube.com/watch?v=iT07pqzE8g8"]BRZ Driveby FT86Speedfactory UEL Catted Motiv Over and Catted Front Pipe Perrin 25 Catback Resonated - YouTube[/ame]

Listen to that thing purr like a tamed lion!

Ugh... I'm back to square one again. FML

[mav1178]

Originally Posted by Lakitu

What exactly is a downpipe..? I keep seeing that term pop up but when I search for its exact definition no distinct classification shows up.

Downpipes were used describe the piping that connects from the turbo to the catalytic converter/exhaust.

For a long time it was like this:

exhaust manifold
turbo inlet/up pipe (if your car has one due to layout of turbo/exhaust system)
turbo outlet/elbow
downpipe
catalytic converter
exhaust system

[Lakitu]

So I thinking about:
- speedfactory catless headers + tune
- motiv overpipe & catted/resonated frontpipe!

to go with my newly installed speedfactory resonated catback

VRUUUUUMUMBLERUMBLERUMBLE!!



Just really hoping the smell of gasoline isn't too excessive. Really my only concern. I'm sort of expecting the car to be a bit louder than it is, and I think I'm ok with loud as long as its not raspy/weed whacker loud.

[Lakitu]

Sigh.. Scratch that, after watching a ton of videos I think I am going catted headers and fp all around, boys. I know I'll lose some power (and it kinda bothers me to not know exactly how much), but I think its the right thing to do overall, in hopes of not losing the low rumbling exhaust note, and in hopes of not too much cabin drone/sound, and if I somehow need to relocate to a state where emissions testing is a thing, I'm good to go.

UGH. The world of car modding is frustrating!