4x4 Cat on a vRS?

[rk696]

I've just been thinking.

Giving that the 4x4 octy has a less restrictive twin cat setup, rather than the single one found on the vRS, would it be worth fitting a 4x4 cat to a vRS?

I guess it won't be as good as a proper sports cat, but it would surely be better than the vrs one.

Idea?

[4x4 1.8t Octy]

would that not mean changing the downpipe too, I assumed as the 4x4 has twin cat then the downpipe will split into two for the cat, or is it just the pipe with the cat in it that splits and joins for twin cat?

Also from what i've been told the standard VW cats are just as good as a sport cat, don't know if skoda use the VW cats or not.

EDIT: Asking about the 4x4 cat and i've got one sat on the drive lol, bit dark to look now

Edited 29 April, 2011 by 4x4 1.8t Octy

[rk696]

I'm not sure what it looks like, I've just heard that it has a twin cat setup. The downpipe is probably different though.

Can you have a look when its light?

[4x4 1.8t Octy]

yea they are twin cat,

found this on ebay

should give you an idea of what it's like, looks like the down pipe will be a 'twin' type pipe too

[rk696]

Hmmm... Thought as much!

I wonder if the 'effective' diameter of the twin dowmpipe is bigger than the vRS?

[4x4 1.8t Octy]

my neighbours must think i'm mad(if they saw me :wonder: )just had a quick look/feel of the cat, think it's the same size pipe all the way through from the downpipe. The downpipe is a single pipe that splits just before the cat, the left of the pic is actually the front of the car. so will need a 4x4 or custom downpipe too. don't know what size the pipes are though on either the 4x4 or vRS

[rk696]

I guess it's probably easier to buy a sport cat, unless you can find a scrap 4x4, or even an audi tt (4wd, so presume they have a twin cat too)

[4x4 1.8t Octy]

the TT quattro has twin cat and so does the mk4 golf R32, and the audi S3, might give you a few more choices for finding scrap cars, may require more research though for the downpipes

[rk696]

Was gonna say, the R32 donwpipe wouldn't be much good TBH

[4x4 1.8t Octy]

why don't you think the R32 pipe would be anygood?

[rk696]

It's not a 1.8T engine

[snow_muncher]

Thats the downpipe (turbo to cat)

downpipe back

[4x4 1.8t Octy]

It's not a 1.8T engine

Yea downpipe probably no good on the R32 but its still the same cat from what i've seen.

Thanks snow-muncher was going to post some pics myself but you've saved me the hassle

[Steevie Wonder]

Surely one single large pipe is better for flow? Where the two pipes rejoin there will be a restriction/disturbance of the air flow.

For ease why not just get a 2.5" or 3" performance down pipe off the shelf?

Steve

[Bowders1]

I guess it won't be as good as a proper sports cat, but it would surely be better than the vrs one.

Idea?

Why do you think that? you have 2 restrictions and not 1. The overall mas of the 2 may be bigger than the VRS one.

would that not mean changing the downpipe too, I assumed as the 4x4 has twin cat then the downpipe will split into two for the cat, or is it just the pipe with the cat in it that splits and joins for twin cat?

Also from what i've been told the standard VW cats are just as good as a sport cat, don't know if skoda use the VW cats or not.

It would indeed mean messing with the down pipe to get 2 cat on and then messing with the other side to get the centre pipe lined up correctly.

Also the 2 areas of the std downpipe / cat that is resrictive on the VRS is just the same as the 4x4. The small width and joins on the downpipe and the cat itself. A sport cat is something like a cell 200 or even cell 100(race cats) which is higher flow than a std vw/skoda cat.

Surely one single large pipe is better for flow? Where the two pipes rejoin there will be a restriction/disturbance of the air flow.

For ease why not just get a 2.5" or 3" performance down pipe off the shelf?

Steve

+1

sorry but imho a bit of a pointless exercise to try an do it.. but OP good to have thoughts buddy....

Interesting why a 4x4 has 2 cats though?

[andy68]

Interesting why a 4x4 has 2 cats though?

1 for front wheels and 1 for rear wheels

[Steevie Wonder]

Interesting why a 4x4 has 2 cats though?

Because of the height of the prop shaft. You can just about make it out in the pictures.

Steve

[SimonJ]

Any chance you could measure the diameter of the inlet pipe to the cat and the distance centre to centre of the studs on the flange for me?

[Bowders1]

1 for front wheels and 1 for rear wheelshttp://ww1.briskoda.net/forums/public/style_emoticons/default/emoticon-0136-giggle.gif

You are on to something there.........

Because of the height of the prop shaft. You can just about make it out in the pictures.

Steve

Ah yes, forgot the drive train to the rear axle.

So then the 4x4 does probably have a wider tunnel to take the prop and twin cats, and therfore as the VRS does not have the same tunnel, I doub't those twin cats would fit to the VRS, without some reforming.

[Andy_VRS]

also the seat cupra 225 has twin cats and its front wheel drive :wonder:

[snow_muncher]

Any chance you could measure the diameter of the inlet pipe to the cat and the distance centre to centre of the studs on the flange for me?

Ø43.17mm

Ø9.75mm

3mm

distance centre to centre of the studs on the flange

not quite sure what measurement you mean there

[SimonJ]

distance centre to centre of the studs on the flange for me?

not quite sure what measurement you mean there

The distance in yellow please.

Edited 30 April, 2011 by SimonJ

[snow_muncher]

66mm

[rk696]

Wow, you can see how restrictive the cats are, can't you.

I guess the downpipe is the same diameter (before it splits) as the vRS anyway, I just thought the twin cats might be less restrictive, that's all. Obviously the ideal solution would be a proper sports cat, but if you could find a twin cat car in a scrappy, it might be worth a shot.

[SimonJ]

66mm

Thanks buddy