[gladiahtorr]

I've tried to look for other threads but this crap is so confusing
Okay so all of the cat-delete pipes say they are either full 3" or 3" inlet and 2.5" outlet, they claim it is a direct bolt-on while stock exhaust is 2.25" as far as im concerned. I need a larger downpipe, correct? or how the heck that works. It's a bolt on so is the pipe wider with gasket/bolt on that fits stock exhaust or what.
All i want is to get rid of my catalytic converter.

 

[sirwired]

I'm fairly certain that NJ still does a visual check as part of their emissions inspections, so you'll fail your next check and be unable to drive your car.

Why do you want to get rid of the catalytic?

 

[hotfoot]

I never under stood why people remove the cat's on modern cars. Back in the 70's and 80's I do - those early cats were highly restrictive parts of the exhaust. But cats today have come along way in terms of flow...

 

[scotts13]

I will point out (for the umpteenth time) that removing the catalytic converter is a violation of federal law, as is the removal of ANY pollution control equipment. Granted, in some states you may not get caught by the yearly inspection; but if it IS discovered, you'll have a vehicle that can't be registered for use on public roads, or sold. That's why "test pipe" manufacturers are careful to always state "for off-road use ONLY." That's the only way they can legally sell them.

And, as previously pointed out, these are not the CATs of the 70's & 80's - I was there. Modern ones have little-to-no affect on the engines performance or operation. They DO have an effect on global warming and the air we all breathe. Don't do it.

 

[hotfoot]

I must side with other people on this, please don't be removing the CAT as a "performance improvement". Removal of the catalyst really won't affect performance and you'll wind up with all sorts of legal headaches and add to the air pollution.

But on another note, if we where talking about removing a cat (as in Felis catus or Felis silvestris catus) that's a totally different matter... :lol:

 

[gladiahtorr]

Okay thank you for your concern guys

Could someone answer my question now?

 

[TurboJim]

...they are either full 3" or 3" inlet and 2.5" outlet, they claim it is a direct bolt-on while stock exhaust is 2.25" as far as im concerned. I need a larger downpipe, correct? or how the heck that works. It's a bolt on so is the pipe wider with gasket/bolt on that fits stock exhaust or what.

If you are going to put in a 3" downpipe then yes you will need a 3" inlet / 3" outlet test pipe. If you intend to hook the test-pipe up to your stock exhaust or a 2.5" exhaust then you should choose the 3" inlet / 2.5" outlet testpipe.

 

[gladiahtorr]

But will the 2.5 fit fairly enough to my 2.25?

 

[TurboJim]

But will the 2.5 fit fairly enough to my 2.25?

Yes

 

[gladiahtorr]

okay so i found this:
Buy 034Motorsport Test Pipe (1.8T) - by 034Motorsport | Europa Parts

and they claim it fitting directly on stock exhaust.
"A direct bolt-in for OEM cat-back exhausts or aftermarket cat-back exhaust systems designed to fit with the OEM catalytic converter."

 

[zak99B5]

I think you're getting confused because of the term 2.25" or 2.5" or 3" exhaust.

In the OE setup, off the manifold is the turbo. Off that is the cat. Off that is a downpipe. Then the rest of the exhaust. The sizes you are seeing refer to 'the rest of the exhaust. The stock downpipe's exit is smaller than its opening.

When you buy an exhaust system, you have to order one that fits either the stock or an aftermarket downpipe. The difference is whether or not the front end has a small reduction in size or not where it clamps onto the downpipe.

 

[TurboJim]

It appears that the 034 test pipe has a 3" inlet and a 3" outlet. Unless you were also going to install a 3" down pipe I don't think this is what you want.

 

[gladiahtorr]

The stock downpipe's exit is smaller than its opening.
When you buy an exhaust system, you have to order one that fits either the stock or an aftermarket downpipe.

which would mean that exit is 2.25" but it's bigger at the opening?

It appears that the 034 test pipe has a 3" inlet and a 3" outlet. Unless you were also going to install a 3" down pipe I don't think this is what you want.

it more looked to me like the piping is 3" but the ends are made to fit turbo and stock downpipe

i'll call them and see what they gonna tell me. i just see a lot of crappy test pipes around there and almost all of them are full 3". i found only one that was in 3" and out 2.5". 90% of them have a wrong o2 sensor plug placements, which i've seen before on this forum as an issue. this 034 looks the way it's supposed to, im just confused over that size stuff

UPDATE

Well he told me that it should definitely fit and if it won't then i can always return it. I guess it's not an issue, luckily this store has it's warehouse only 10 miles away so i wont have to pay for shipping or anything

 

[gladiahtorr]

UPDATE

034 3" TEST PIPE DOES FIT THE STOCK DOWN PIPE.

I haven't put it on yet but I took out the cat and down pipe and made a quick "put together" and it seems that it fits the way it's supposed to
Now the connection from turbo to pipe is the same but the connection from outlet to down pipe is shaped differently. However, the gasket that comes with it fits around the outlet and holes for the screws and it is of exactly the same shape as down pipe's inlet.

 

[TurboJim]

If the test pipe's outlet is 3" and the inlet of the down pipe is 2.25" how were they expecting this would ever work?

 

[gladiahtorr]

If the test pipe's outlet is 3" and the inlet of the down pipe is 2.25" how were they expecting this would ever work?

Ill out a pic up tomorrow