3" downpipe with stage 1 problems?

[keano]

Hi guys,

I'm on the path to stage 2 so the downpipe is on the cards. The car is already mapped to stage 1, but will I experience any problems (flatspots/codes etc...) with a 3" downpipe whilst I wait for a stg2 map?

Thanks in advance,

Nick 

[Homer]

There are diff views on this, having spoken to a tuner he says that most tuners are able to set up the stage one to be able to use a donwpipe. You might want to speak to the people who did your remap to see if they can do this for you.

[alexperkins]

Im running a full TBE with 3" downpipe on a Stock map and I dont have any problems at all....though its screaming for a remap 

[keano]

What size is the system after the downpipe Alex? Just for curiosity's sake. 

My exhaust guy wants to make me have a 3" system throughout! I'm scared haha

[alexperkins]

3" all the way through.

Milltek ED30 specific turbo back (the later 3" version)

Bloody massive pipework - scared me when I fitted it compared to the original

[keano]

Ooo gosh. That is big! (that's what she said)   

I feel abit better about it now then. 

Cheers Alex!

[alexperkins]

  No worries

It certainly makes it alot louder. Stage 2 on a non res milltek TBE is quite a unique sound thats for sure 

[keano]

What would your views be on a  3" downpipe and center section. But leaving the back section on.

It'd work out hundreds and hundreds of pounds cheaper for me, but I believe i'd still have the same power benifits?  

[alexperkins]

Personally, if you are going to do it, do it properly

The rear silencer is slightly restrictive, plus to have a 3" downpipe and center youd need a special adapter to reduce it down to 2.5/2.75 (i cant remember which it is atm lol), and as the factory silencer has the rear silencer and center silencer as one piece, youd have to cut the silencer out and join it up.

The main bottleneck is the factory downpipe as its smaller and has a precat which impedes exhaust gas flow, so yes there will be big benefits just from that.

[keano]

This is something I found the other day which put the ideas into my head 

an intake is fine on stage 1. If you fit the exhaust you will need to get a stage 2 map

Ed666999 is correct that if you want performance you only need the downpipe.  All you get with the cat back part of the exhaust is more noise

Just been on the milltek website and it says down pipe must be fitted with Milltek cat back....??

What downpipes can be fitted with the standard exhaust?

thast rubbish.  Purely to make you buy the full system  from them.  All you need is a reducer from 2.75" to 2.5"(for the GTI 200ps) and 3" to 2.5" (k04 TFSI) is all that is required to mate it to your standard system.  My Pipewerx downpipe had the reducer built in and went from 3" to 2.5".  Sounded great as well.

Janner- why would I need to go to stage 2 to fit a new exhaust? I have known people to fit a new exhaust without even having a remap. Do you mean its only worthwhile if I was to get a remap stage 2? Thanks

When you fit the downpipe, it removes the pre-cat and fits a free'er flowing 2'nd cat.  This means that the lambda sensor readings on the exhaust will be outside the normal range and more often than not you will end up with an engine management light flashing up.  This doesnt necessarily mean you need a stage 2 map, as a stage 1 car can have those sensors mapped out with no issues, but if your sticking on the downpipe you may as well go stage 2 IMO.

Quite alot of guys on here have run the Miltek with a reducer with zero issues, same with blueflame and pipewerx.

[alexperkins]

Milltek downpipe and a 3" to 2.5" convertor and your sorted 

I get no emissions lights on mine either!

[keano]

I may have a decat at the moment (but it doesn't include the PRE-cat) and I don't have a light. 

Do you have a sports cat in your system?

[alexperkins]

So you may have a decat downpipe or was the cat removed further down and the precat left in place?

Aye i do. 200cell  

[keano]

The main cat may have been was removed and replaced with a straight pipe.

But i believe the pre-cat is right next to the turbo right? (which is still there)

[alexperkins]

Correct

So either a straight through from the downpipe to the center, or replace the downpipe with a 100 cell sports cat one, which is as good as a decat anyway on performance measures

Or a 200cell normal one for MOT passing exhaust emmissions