The great big MK6 Golf 118TSI tuning thread

[Guy_H]

How feasible and beneficial is it to remove the stock cel and install a 200 cel in the converter as opposed to getting a new downpipe with 200 cel already installed?

Go see a good exhaust fabricator & let us know! - It's a very tight fit & there is a bunch of restrictions in the factory downpipe.

[Rawcpoppa]

Go see a good exhaust fabricator & let us know! - It's a very tight fit & there is a bunch of restrictions in the factory downpipe.

Ha. I'll keep searching for a downpipe then.

[Rawcpoppa]

https://www.jetex.co.uk/website/downloads/2014/exhausts/jetex_exhaust_catalogue_28_2014.pdf

Have a look. I really feel this should be universal to CAVD/CTHD engines. Part number T27-1AR. Designed for the Polo GTI CAVE engine but also fits Skoda Fabia 1.4 TSI and Ibiza Cupra 1.4 TSI. See here for Fabia product page: Downpipe and race cat for a Skoda Fabia II 1.4 TSI 2010+

The shape resembles pretty closely what I have seen on my Jetta.

I have seen references to SuperSprint and Velocity downpipes from older threads.

[Rawcpoppa]

Also came across this thread showing how to remove the catalyst from the downpipe for our engine. It's a beetle but it looks exactly the same as the golf and Jetta in terms of component layout.

VWVortex.com - [HOWTO] Empty pre-cat on 1.4TSI Beetle

[ope126]

Also came across this thread showing how to remove the catalyst from the downpipe for our engine. It's a beetle but it looks exactly the same as the golf and Jetta in terms of component layout.

VWVortex.com - [HOWTO] Empty pre-cat on 1.4TSI Beetle

Interesting DIY! I wonder what the outcome is???

[Rawcpoppa]

More flow but smelly exhaust I gather. Just saw in another thread that the catalyst is quite thick. Removing it surely reduces back pressure.

[Lucas_R]

You will likely end up with a CEL (check engine light) on your dash if you remove the cat, but you will definiltely reduce some restriction in the exhaust and get the heat away from the engine/turbo more easily/quickly.

[Rawcpoppa]

Wait... are you saying there is a full exhaust and downpipe available for the 118TSI Golf now??

I checked ETKA recently and started to compare part numbers and diagrams for exhausts between the Polo, Jetta, Golf and Scirocco for the 118tsi/125tsi engine (CAVD/CAVE). The bad news is the Polo has a different exhaust pipe with catalyst compared to the others so downpipes for the polo, fabia and ibiza will not work.

The Jetta, Scirocco and Golf 1.4 TSI all share the same catalytic converter. Part number 1K0254200RX for 2012 or latest version 1K0254201GX which then bolts onto an exhaust pipe afterwards (1K0254303D). So we basically have to look for systems designed for these models...Came across this for a scirocco on Milltek's website: Volkswagen Scirocco 1.4 TSI Milltek exhaust
It's listed as the 4th option. Turbo back with hi flow catalyst. The only problem is it's a complete exhaust and not just a downpipe so the price is high. Milltek system number SSXVW125.

Came across this site while searching the system number: SKN Tuning ChipTuning EcoTuning Turbo Kompressor MILLTEK Auspuff Fahrwerk Bremse CHIP & ECO

It lists all the components of the SSXVW125 with part numbers.

KIT consists of the following components:
MSVW310 Hi-Flow Sports Cat & Downpipe <----- Jackpot

MSVW311 Flex Pipe
MSVW312 Front Connecting Pipe
MSAU283 Front Silencer
MSAU284 Rear Connecting Pipe
MSVW330 Rear Silencer

[ope126]

It also say's that it requires a Stage 2 Tune...

Time for a Tune is guess!!!

[Rawcpoppa]

I'm guessing because of the change in catalyst. I'm stage 1.5 I guess so 2 has been on my mind a lot.

A friend of mine in Singapore is stage 3 on this engine....which is basically a new turbo and map plus new spark plugs and possibly forged pistons....

[The_Hawk]

So what sort of performance benefits would be expected from a better exhaust + stage 2 tune??

I know the returns per $ get less and less as you tune further... but based on that link plus some guess work we are quickly heading towards $5k here ?? Which is probably why most people will sell the 1.4 and grab a GTI if they really want more power

.. which in my case would mean an engine swap if I wanted to keep the Cab...

But this doesn't sound bad at all
[youtube]G2S7QwJcDfU[/youtube]

[Lucas_R]

I'm guessing because of the change in catalyst. I'm stage 1.5 I guess so 2 has been on my mind a lot.

A friend of mine in Singapore is stage 3 on this engine....which is basically a new turbo and map plus new spark plugs and possibly forged pistons....

You could likely get away without changing your tune if you use an oxygen sensor spacer. This works on the 2.0T Engines in the GTI's and R''s to prevent a CEL.

[Rawcpoppa]

You could likely get away without changing your tune if you use an oxygen sensor spacer. This works on the 2.0T Engines in the GTI's and R''s to prevent a CEL.

Been reading up on decats and O2 sensor spacers. It should work on the 118tsi as well but I have issues with potentially high smelling vapours in and around the car with no cat.

I've been seeing other cat converters designed for the 118tsi that look pretty much like the milltek one but significantly cheaper and both using hjs 200 cpsi catalyst. If I find one at a reasonable price I'll try it as a diy.

[Lucas_R]

You could always just knock out part of the stock cat (say 1/2 of it for example) which would increase flow by removing some restriction but still allow the section of cat that remains to do its job.

In regards to the cat missing altogether - some people say that it smells badly, and others say that they dont notice it. Another alternative would be to knowck out your stock cat, use an o2 spacer to prevent a CEL and then have a 100 or 200 CEL hi flow cat welded into the exhaust further along.

[Rawcpoppa]

I quite like the idea of the latter. Supersprint's 118 turboback does it this way with the cat going in a section of straight intermediate pipe. They say it's for heat reasons that the moves the cat further away but I still have to read up on why Vw puts the cat so close to the turbo in the first place and if moving it lower down has any detriments.