Exhaust Setup?

[m3dragon]

Hello gang,

Trying to see what is the better setup for US. Run SS (Evolve) down pipes to the stock center section or leave the stock down pipes and run a Mad Dad mid pipe.

From my chats with Evolve they said run the down pipes but my concern is I need to run software as well to not throw any codes.

As this is a DD my thoughts are run GIAC and cat back. Less chance of codes and so on.

[Venom]

If by SS you mean supersprint, their DPs are cat less. Cat less DPs will throw a few codes but a lot of tunes are designed to continuously reset the ECU to never let these codes pop up. So yes, you will need a tune to suppress codes if you dont want to see a CEL light on the dash(this does not mean that you will pass a smog check in CA).

If you are after gains, DPs are a bigger restriction. Most who go the DP route are after power, so consider if you go that route adding a tune too. If you are mostly after sound the midpipe back is easily reinstalled.

I am not sure if GIAC suppresses the CEL light for DPs but their X2 software lists full exhaust and intake as requirements so I would hope so.

[m3dragon]

That is what I thought about the CEL light. I will go with mad dad and GIAC tune as planned to keep the DD aspect.

Just wanted to make sure I did not miss anything.

[Snertz]

If you're planning on running a tune either way, get the DP's, you'll see much more gains performance wise. It will create secondary O2 codes but these are taken care of by the tune such as the GIAC you mentioned.

The issue is getting the car inspected, the car should still be able to pass sniffer with the stock catted mid pipes in place. Problem is OBD readiness, to get that you'll need to use some sort of DP fix (Shiv posted a DIY on how to make one for $2, or get one from BMS or CP-E) or run a piggyback tune which has the o2 sim built-in.

Edit : Doh, Venom beat me to the punch!

[MDORPHN]

If you're looking for more power, then the only significant gains to be had are by going with a catless dp.

As pointed out above, most tunes will eliminate the check engine light but you would need a "dp fix" in order to show readiness for purposes of an inspection.

Neil

[Stratus650]

Im running catless OEM setup and lovin' it. Has a rasp at 2K, which i personally like, other than that good for DD compared to after market full setup

[m3dragon]

The setup I was told from Evolve was use SS downpipes and leave the stock center section in to keep the smell down. Muffler was not specific as that is more for sound.

So explain to me how are the gains better using DP than a mad dad section? Is it because the DP are by the turbo's and allows them to spool easier?

Trying to understand which is better as I have herd two setups that make sense but not sure which is the best for a DD.

[MDORPHN]

Originally Posted by m3dragon

The setup I was told from Evolve was use SS downpipes and leave the stock center section in to keep the smell down. Muffler was not specific as that is more for sound.

So explain to me how are the gains better using DP than a mad dad section? Is it because the DP are by the turbo's and allows them to spool easier?

Trying to understand which is better as I have herd two setups that make sense but not sure which is the best for a DD.

The stock downpipes are the most significant constriction in the exhaust system. Therefore, the greatest gains are achieved by replacing them. Faster spool up and more power.

Although the primary cats are in the stock downpipes, there are secondary cats in the stock midpipes.

By going with catless downpipes but maintaining the stock catted midpipes, you'll see power gains without having the odor of a fully catless exhaust system.

Neil

[m3dragon]

What about the whole 1M down pipes are the less restrictive than 135 yada yada?

So what advantage is the other setup, change after the mid pipes back? Just don't need a software tune to make it work?

[Stratus650]

Cats at the turbo causes increased temperatures too, so increased boost doesn't have negative affect on the turbos

[Venom]

Originally Posted by m3dragon

What about the whole 1M down pipes are the less restrictive than 135 yada yada?

So what advantage is the other setup, change after the mid pipes back? Just don't need a software tune to make it work?

essentially the 1M downpipes are high flow http://www.1addicts.com/forums/showthread.php?t=725506
but you will still get bigger gains with cat less DPs on either car

if you changed just midpipes back you will lessen the restriction a little, since our cars are FI the gains don't need to be tuned for; you will notice a mild gain but nothing significant. For "smaller gains" you will need an optimized tune and not an OTS map to maximize for them.

[m3dragon]

I just checked the forum sponsors. Is there anyone that offer thigh flow of a Mad Dad mid pipe with cats?

Also what CEL are the mid pipe cats. I am guessing 400?

[Stratus650]

Originally Posted by m3dragon

I just checked the forum sponsors. Is there anyone that offer thigh flow of a Mad Dad mid pipe with cats?

Also what CEL are the mid pipe cats. I am guessing 400?

Mid pipe wont throw a CEL code

[m3dragon]

Originally Posted by Stratus650

Mid pipe wont throw a CEL code

I did not say CEL as in code, I asked what CEL are the cats

IE: 100,200.300, my guess is they are 400 or 200.

[1911A145]

Originally Posted by m3dragon

I did not say CEL as in code, I asked what CEL are the cats

IE: 100,200.300, my guess is they are 400 or 200.

What's the "Cell" count ont he Cats? CEL mean "CHECK ENGINE LIGHT" around here...

The rear converters are 200, I believe. They are so un-needed BMW got rid of them.

[m3dragon]

For Down pipes is any one brand better than the rest or are they all the same? SS is 1K where are AR is 900 and look the same. So are you paying for a name in the end?