2.0 TDI - backbox from 1.9 TDI?

[skard]

Hi guys

I'm in the process of changing the rear end of my 2.0 BKD diesel from standard hidden to exposed twin pipes on the exhaust (with valance cut out).

I've found a couple of new 1.9 TDI silencer's from an A3 and was wondering if anyone knew if this would cause issue - as in a loss of performance/efficiency?

The boxes look the exact same as what I have fitted.

Cheers

[vRS_Pagey]

I saw an A3 back box on ebay but the seller said it wouldn't fit, I'm not convinced.  Even if the pipe work bore is different a reducer could be fitted.  Something to note, I think the back box from a mk6 will also fit. 

[Andy]

had a look in the exhaust book at work..the audi 1.9 is 50mm and the golf gttti is 55mm so you will need to get a reducer made

[skard]

Nice one!

The seller states it's listed as A3 only but that can't be an extensive list?
I was concerned about a change of pressure with the smaller bore.

[vRS_Pagey]

Nice one!

The seller states it's listed as A3 only but that can't be an extensive list?
I was concerned about a change of pressure with the smaller bore.

If you are only fitting the back box, the amount of pipe running 50mm will be very small, I shouldn't think it will make any difference.

[skard]

That's what I thought (and hoped as a response!), but there's still something mentally bugging as it's technically downgrading bearing in mind I have mine remapped also.

[vRS_Pagey]

You could always have a larger pipe welded directly to the back box.  Tbh the cat back doesn't effect power output, its between the turbo and cat that diameter is important as this is where the gases are hotter and flow is restricted by the pre cat filter or dpf and the cat itself.

[skard]

had a look in the exhaust book at work..the audi 1.9 is 50mm and the golf gttti is 55mm so you will need to get a reducer made

Just to confirm before I order a reducer, you are talking about the outside diamater of the pipe being 55mm on the 2.0 and 50mm on the 1.9?

[Andy]

 

[skard]

Quick update, bought a brand new backbox designed for a 1.9 TDI A3 S-line and it fits perfectly (1K6 253 609 AQ).

The mounting points are exactly the same. I just chopped the pipe with a grinder, slid on a 55mm to 50mm reducer sleeve (ebay about £10 delivered) and job done.

[vRS_Pagey]

Sorry mate, not sure I like the way the pipes bend downward, did you consider going for a 2nd hand GTi back box.

On the plus side, nice work on the bumper if you cut it yourself. 

[skard]

If I see a GTI/GT box cheap enough/in good order I'd consider it. I could always chop the ends and put straight pipes on but I'm happy with it (for now).

I got a GT valence. I've seen some DIY cut ones and they generally looked bad.

[vRS_Pagey]

If I see a GTI/GT box cheap enough/in good order I'd consider it. I could always chop the ends and put straight pipes on but I'm happy with it (for now).

I got a GT valence. I've seen some DIY cut ones and they generally looked bad.

I took a second look and realised the valance was the GT170.  I should be getting a GTi back box sometime this week, if you are near Lincoln there is one in the for sale forum, the guy only wants £50.

As you say you could add trims, my mecahnic modified my OE exhaust by cutting off one of the outlets and welding a staright pipe, then he added a bridging piece for the twin outlet, and the result -

[skard]

How come you're getting a GTI box? Your current exhaust looks good.

[vRS_Pagey]

Cosmetically it looks good, but when you look underneath its catastrophic.........I know 99% of peeps won't see it, but I know its like it and it was always a interim solution until the right back box turned up.