Rookie Exhaust Question
 

So I'm finally getting ready to pull the trigger and order my exhaust for the BRZ, and I just wanted some extra insight on if everything's going to work.

I'm planning on a 1320 Header with their OP, then doing a catted motiv front pipe and then a Dezod cat back.

Now, I know that I'll be throwing a code for not having the cat in the header, but it's my understanding that that will go away with a tune. Am I missing any other exhaust parts, like do the exhaust gaskets usually come with the parts or is that something I should just pick up on my own?

Also, I know this setup is going to be loud but does anyone know just how loud it's going to be?

Thanks in advance for reading this huge mess of a post.

Well, Chloroform, I'll check the newspaper and if JBLM isn't firing artillery and I hear loud sounds up here in Puyallup, I'll figure it's your car ...... :D


humfrz

You will need new gaskets, iirc studs and nuts. Your combo will sound nice deep, growl rumble. Also need a tune to erase cel

Oh dang, I didn't even think about getting new nuts and studs. Is there a website where I could order the whole set? Or should I just go to a dealership and order them?

Dealership have them in stock, still you can buy them online.

You might want to hang on to your stock exhaust pieces just in case. I'm pretty sure it's gonna be loud as fuck.

Fteightysix sells oem gaskets. Much cheaper than grimmspeeds

In for the sound clips you post when it's all done!

just installed one of these with a buddy, you'll want to invest in a swivel socket.

that and some long extensions for the ratchet. other than that, everything is a piece of cake. gaskets from dealership were like 8 bucks each I think. definitely don't cheap out and reuse them. also, instead of buying the catback, I'd invest in a used OFT so you can get the benefits of your header first while also seeing if you want to go any louder. if you do header, FP and catback all at once, you might regret it. piece by piece for the exhaust starting at the headers would be my advice.

Yeah, I figured on keeping the stock stuff around just in case I get a fix-it ticket =/


Thanks for the input, I'll probably buy an OFT at the same time just so that I can install it all at once and not have to worry about a CEL. I'm pretty used to loud cars (had a straight piped VR6) but I'm not sure how bad it'll be with this car haha. If it does end up being too loud I'll probably ask in the forums again about which parts I should swap out to quiet it down.

Advice, leave the stock front pipe

You'll need new gaskets unless your new exhaust pieces come with them (mine did), id reuse oem bolts and studs if you can. Header to over pipe i had to buy a couple bolts but that should be it. Gaskets and re use stock bolts if you can. if your headers are UEL you may want to invest in a u-joint for your socket as some of the bolts con be hard to get to if not. OFT is the easiest way to go tune wise, I love mine i highly suggest it!

Enjoy man!

I have a slight exhaust leak and you would assume they would have gaskets ready n hand. I went today they don't have any, might as well place an order.

I have the stock ones in front of me, but I'm iffy on re-using them. It looks a little rusty and worn.

dont reuse exhaust gaskets, they will leak after a while. they are designed to crush to shape and can only be used once

Fteightysix.com sells the oems cheap. Or villagescion.com

The dealership already has some in the way. Might as well stick around for that, as it will be quicker.

It's actually not too bad, the cold start can be kinda obnoxious but is fine after 20 seconds. It's only loud when I get in on it :)


I filmed it with my phone and an old go pro, so the sound isn't the best lol

[ame="https://www.youtube.com/watch?v=uKJmcTFBi1o"]Subaru BRZ UEL Dezod Exhaust - YouTube[/ame]

Oh, OK, ..........I'm glad to hear those sounds were from your car and not just the HMARS test firings at JBLM ......... :D

Yep, your car sounds like it's on a track ...... :thumbsup:


humfrz

Hey, Cholofrom sorry about this but im also new to exhausts.. when you get a exhaust do you need a tune for it to run properly?

If it's a cat back, no. If it's headers yes.

Can you elaborate a bit more on this? I understand that without a tune, it will most likely throw a CEL. And I know that a tune will make the most out of the header. But you can still put one on and not tune it, right? I'm in this situation and as long as no damage will come of it, the tune is coming a little further down the road.

Essentially there are two sensors in the manifold (headers) that look for differences in the exhaust gasses before and after the cat in the manifold. When you go with a decat manifold the sensors don't read the differences they are expecting and the engine will throw up a CEL. don't worry, no damage will be done, no limp home mode or power drop, all that happens is the cruise control will be disabled.

The stock map on the ECU was designed with the catted factory manifold in mind, including accounting for the restriction of the cat etc etc. The freer flowing exhaust allows a modified and better mix to be combusted, but the ECU needs to be told this through an aftermarket tune.

Basically, without a map the engine can breathe better but the ECU doesn't know how to make the most of it. With a map, the ECU is given parameters to capitalise on a freer exhaust.

As for the catback, this system is installed after all the factory sensors so will have no effect on what the ECU sees. A small gain may be had from it however, due to the fact that again the aftermarket component will tend to be freer flowing and allow better passage of exhaust gas.

If your going to start engine mods suggest you read Basic Bolt on Mods guide below

I have read that previously. So it is correct to say that if I change the header, but don't tune right away, the only risk is to possibly have a CEL? (The header I ordered is catted)

Someone once told me off the forums some theory about changing the header without a tune messes with cylinder temps/firing or something like that. Just looking for confirmation that my motor won't blow up which I don't think it would..

It probably won't hurt anything but I wouldn't push it till you get a tune

people run catted and even uncatted headers without tune (they use 02 spacer to help wil cel code)

the fueling and timing is uneffected by header ie the ecu will run same timing and fueling it ran before header, the ecu will adjust fuel trims itself so it runs the same fueling even if header flows better. the main thing tune does is adjust the intake and exhaust valve timing to take advantage of the better gass flow of the header and they will also adjust many other parameters.

no it wont blow up :-), you just miss out on a lot of the possible gains

intakes can upset ecu much more than headers

Perfect, that's exactly what I was wondering! Thank you for the information. Hopefully it won't be long until I get it tuned. Was hoping to use the OFT but I don't have Windows..

talk to the openflash guys they all run mac,s,so ir can be done with a mac running parallels or something, oft come pre loaded with most popular ecu rom tunes, but you may need to load up specific tunes. you only need to do this once as they are storred on oft 5 tunes. so just use a friends pc.