Rookie Exhaust Question

[steve99]

Originally Posted by ShadowReaper

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

[Ashikabi]

Originally Posted by ShadowReaper

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.

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

[ShadowReaper]

Originally Posted by Ashikabi

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.

[Chloroform]

Originally Posted by humfrz

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 ......


humfrz

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

Originally Posted by Brayden_23

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

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]

[humfrz]

Originally Posted by Chloroform

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

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

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


humfrz

[rocket12]

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?

[Ashikabi]

Originally Posted by rocket12

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.

[Brayden_23]

Originally Posted by Ashikabi

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.

[secret.squirrel]

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.

[steve99]

Originally Posted by Brayden_23

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.

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

[Brayden_23]

Originally Posted by steve99

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..

[Ashikabi]

Originally Posted by Brayden_23

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

[steve99]

Originally Posted by Brayden_23

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..

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

[Brayden_23]

Originally Posted by steve99

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..