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Model specific boards => Golf mk6 => Topic started by: RocketRossUK on 19 January 2014, 17:33

Title: Pre-Cat Removal on OEM Downpipe
Post by: RocketRossUK on 19 January 2014, 17:33
Hey guys,

After doing the pre-cat removal on my MK5 GTI 18 months ago I thought as I had a few spare hours today me and my mate would do the same on my MK6.

It worked great on my MK5, but it seems to make even a bigger difference on the MK6 (maybe because of a different turbo) not too sure.

On my MK5 it gave an average of 8bhp more over 2 runs. (same roler, same day, sam ambient temp) so hopefully it will be the same on my MK6.

Also, the turbo spools about a second quicker and has also added a deeper tone which non mint with my 3" Race Milltek

Decided to do it today as im swapping from Superchips to REVO stage 1tomorrow @ Statllers. Finger crossed with pre-cat delete and REVO stage 2 intake I should be somewhere around 270-280bhp.

Pics of pre-cat removal - that cat is so restrictive.

(http://i1112.photobucket.com/albums/k489/rocketrossuk/IMG_0517.jpg)

(http://i1112.photobucket.com/albums/k489/rocketrossuk/IMG_0515.jpg)

(http://i1112.photobucket.com/albums/k489/rocketrossuk/IMG_0518.jpg)
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: Poached on 19 January 2014, 18:58
I did this on the MK5 too, post up your results tomorrow :cool:.
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: Hobojim on 19 January 2014, 20:40
very interested in this one!
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: andygo on 19 January 2014, 22:02
What happens at MOT time?
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: RocketRossUK on 19 January 2014, 22:12
What happens at MOT time?

Nothing, it still has the 800 cell cat in, this is just a Pre-Cat that sits right next to the turbo and restrict airflow like crazy.

It is only in the car for emissions in country like germany. A car can pass over here with a 100 cell cat. So not even 1% chance of failing

 :cool:
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: GS WAX on 19 January 2014, 22:30
Might have to do this on the 35, after hearing the new owner drive my ed30 away yesterday, it sounded alot more purposeful than 35, not really liking the false engine sound thingy...

Any way of it beind detected without removal inspection for warranty purposes?


Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: r32tev on 19 January 2014, 22:35
Would like to know what happens regarding warranty aswell actually
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: RocketRossUK on 19 January 2014, 23:02
seriously guys, its just a pre-cat. It wont void warranty or fail any test. Unless you take of the downpipe you would never know. And even then 9/10 mechanics wouldnt even know it was there in the first place not alone missing....

2 hour job and you get 5-10bhp for free - Some people spend £350 on an intake to try get 5bhp....

deffo worth doing everyday of the week
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: wigit on 19 January 2014, 23:06
i thought you never wanted Revo as it would kill your clutch
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: RocketRossUK on 19 January 2014, 23:27
i thought you never wanted Revo as it would kill your clutch

Stage 2 would....30% of stage 1 - couldn't resist (ps - You have a good memory bro)
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: r32tev on 20 January 2014, 09:14
So I will see gains on a standard car regardless ? if so, looks like im doing it on Saturday morning !!
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: RocketRossUK on 20 January 2014, 09:25
So I will see gains on a standard car regardless ? if so, looks like im doing it on Saturday morning !!

Yep deffo gain, quicker turbo spool and a slightly deeper exhaust tone....all for free (well, 2 hours labour)
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: RocketRossUK on 20 January 2014, 16:14
Sadly I couldnt get on the dyno today at Statllers, too many porches in  :angry:

But after to speaking to Steve (Head Tech - and 15 years experience) told me he had one in the other week with near identical mods and it made 274bhp, so i believe him but just need to get on some rollers and see whats what.

either way, the map feel really good and the torque is insane. finger crossed my clutch will last six months so i have time to save.
 
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: Hobojim on 20 January 2014, 20:10
So you've just upgraded your intake and pre cat that's it? Then the map takes it to C. 270 BHP ! I must say that is impressive and I think I might follow suit.
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: RocketRossUK on 20 January 2014, 20:35
Yep thats all mate, these engine are so under tuned from the factory, especially the torque. But they dont really have scope to go big numbers without throwing some big money at it, ie 350bhp would need a few thousand. but 270 bhp for £500-£1200 is good value  (buy parts second hand like me)

Also, dont get a sh!tty intake, try get a decent brand.
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: Hobojim on 20 January 2014, 22:33
I was thinking of going Superchips Stage 1. Seems nice and easy and pretty cheap. But I am now considering what you've done. How is the Revo map compared to the Superchips?

Does the Revo map require an intake? Or would a drop in panel filter change do the trick?

My engine has only done 2k miles as it was replaced when the timing chain tensioner failed  :angry: so I now have a 2yr Guarantee on it and don't want to bugger that up. So trying to keep it subtle.
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: RocketRossUK on 20 January 2014, 22:39
up to you mate, everyone is different. Superchips is fine and has some good mid range torque, but dies off a bit near top end of the revs and when dyno'ed they only make a bit more than stock, about 220bhp -230bhp, (mine got 225bhp) but is very safe on the engine.

Revo on the other hand will give you a higher BHP and torque figure but may add 5 % more stress. It not all about the numbers, its what your looking for as a driver. I just wanted it to be as raw and powerful as possible (staying within stage 1).

And yeah and intake will help, bit more airflow over stock. A decent panel filter is also an ok option though.
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: Hobojim on 20 January 2014, 22:51
Did you you get the Revo switch thingy that lets you put the map back on if the dealer deletes it when serviced ?
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: RocketRossUK on 20 January 2014, 22:55
Did you you get the Revo switch thingy that lets you put the map back on if the dealer deletes it when serviced ?

My dealer knows i have Revo, they wont delete it mate  :cool:
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: Raffe on 21 January 2014, 07:32
So I will see gains on a standard car regardless ? if so, looks like im doing it on Saturday morning !!

Just be careful when removing the bolts to the turbo, due to the heat cycling they can become brittle and snap, requiring the remainder to be drilled out....complete pita and quite common.
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: RocketRossUK on 21 January 2014, 08:56
So I will see gains on a standard car regardless ? if so, looks like im doing it on Saturday morning !!

Just be careful when removing the bolts to the turbo, due to the heat cycling they can become brittle and snap, requiring the remainder to be drilled out....complete pita and quite common.

Good point to bring up Raffe. Best thing to do is warm the engine for 5 mins and spray with WD40 or any decent penetration oil. Leave to coil and spray again. Then throughout the process keep squirting each bolt / nut and take it easy, dont ever go to heavy on the cranking. If you felt it getting really tight, back up and spray again.
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: Hobojim on 26 January 2014, 01:12
Will you be putting your car onto the dyno Ross?
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: RocketRossUK on 26 January 2014, 11:09
Will you be putting your car onto the dyno Ross?

Probably sometime in spring mate. Having revision 5 REVO stage 1, Revo stage 2 intake and Pre-Cat removed show be between 270-280 im hoping.
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: Obbzi on 26 January 2014, 22:47
With this mod what do you replace the pre-cat with? Or do you just "fettle" the existing pipe?
Title: Re: Pre-Cat Removal on OEM Downpipe
Post by: RocketRossUK on 26 January 2014, 23:49
With this mod what do you replace the pre-cat with? Or do you just "fettle" the existing pipe?

Yeah just knockout the precat out, then Fettle the pipe where is was. The 800 cel main cat stays as is.