Alfa Romeo Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
2,083 Posts
Discussion Starter #1
Has any one done this? Is it just a matter of taking off the manifold, chopping out the Cats and replacing with straight pipes? Anybody then had issues with MOT emissions test?

Cheers
 

·
Registered
Joined
·
1,555 Posts
Has any one done this? Is it just a matter of taking off the manifold, chopping out the Cats and replacing with straight pipes? Anybody then had issues with MOT emissions test?

Cheers
The cats are not part of the manifolds but connected to them with flexible pipes. So no 'chopping' involved. And yes, the cats can be replaced with straight pipes, several on here have done it. Do a 'search this forum'
 

·
Registered
Joined
·
2,083 Posts
Discussion Starter #3
The cats are not part of the manifolds but connected to them with flexible pipes. So no 'chopping' involved. And yes, the cats can be replaced with straight pipes, several on here have done it. Do a 'search this forum'

Cheers for the reply. I thought the manifolds looked like this _57.jpg and then came the downpipes with flexi pipes.

I did try a search and only got 8 results, non of which seemed to de cat the manifold on the v6, so I might have done something wrong there.
 

·
Registered
Joined
·
1,555 Posts
Just noticed that the thread said there were manifold cats, as well as inline cats on the cf3 models, so we were both right!
 

·
Registered
Joined
·
4,627 Posts
I saw a thread on the 166 forum recently about removing the maniverters on a cf3. You have to weld in bosses for the upper lambda sensors into the replacement manifold and ensure the post maniverter lambdas are also in place after the underfloor cat.

I'll see if I can find the thread ...

EDIT : That was a bit too easy!

http://www.alfaowner.com/Forum/alfa-164-andamp-166/917290-166-3-2-conversion-to-cf2-exhaust-setup.html

It talks of 3.2 V6 but the advice is the same. Also recommends looking in the GTA forum as it is quite a common mod there.
 

·
Registered
Joined
·
2,083 Posts
Discussion Starter #8
I saw a thread on the 166 forum recently about removing the maniverters on a cf3. You have to weld in bosses for the upper lambda sensors into the replacement manifold and ensure the post maniverter lambdas are also in place after the underfloor cat.

I'll see if I can find the thread ...

EDIT : That was a bit too easy!

http://www.alfaowner.com/Forum/alfa-164-andamp-166/917290-166-3-2-conversion-to-cf2-exhaust-setup.html

It talks of 3.2 V6 but the advice is the same. Also recommends looking in the GTA forum as it is quite a common mod there.
Cheers for the link, a good read. It seems like emissions won't be a problem. I wasn't actually going to go down the CF3 to CF2 conversion route, rather just modify the existing CF3 manifold. But it was good reading never-the-less.

Maybe my search issues are because I limited the search to the 916 forum, any thanks again.
 

·
Vendor
Joined
·
46,131 Posts
You're talking about doing something like this?

If you're a skilled enough welder/fabricator then no problem.
 

Attachments

  • Like
Reactions: cgc

·
Vendor
Joined
·
46,131 Posts
  • Like
Reactions: cgc

·
Registered
Joined
·
2,083 Posts
Discussion Starter #11
You're talking about doing something like this?

If you're a skilled enough welder/fabricator then no problem.

Heavens no, I couldn't fabricate a thing. I am going to change the engine soon and thought it might be something worth doing while the engine was out. So I thought I could take the manifolds off when its out, take them to a reasonably local powerflow exhaust type place and just say can you chop that out and weld in the relevant tube section and add a lambda bose.
 

·
Registered
Joined
·
2,083 Posts
Discussion Starter #12
In case you weren't sure, GTA decat manifolds are also a direct fit on the GTV V6 CF3:

http://www.alfaowner.com/Forum/alfa-gta/798914-wizard-exhaust-manifolds-for-156-147-gta.html

They DON'T fit the 166, and 166 manifolds don't fit the 156/147/GT/GTV, but the principles of doing the work is all the same.

Early CF2 manifolds from a 3.0 GTV are an option, but you also need to get custom downpipes made to fit between the CF2 manifolds and CF3 mid cats.
Oh they look an excellent idea at the right price (pm me with it if you would), I don't really want to get into changing the downpipes as yet because there are more important things that could be done while the engine is being changed.

I take it you work for autolusso? I'll be ring you guys again soon for a second hand engine, but I have now saved the money to have the belts, tensioners, water pump, alternator and spark plugs done at the same time. Of course while the engine is out I really should change that radiator that looks on its last legs and get some of your silicone pipes at the same time.

Then my local garage said 'well you might as well change the clutch at the same time, because labour will be very little with the engine and gearbox out'. And that got me thinking about a lightened flywheel (do you do them?) and a limited slip diff at the same time. I'm going to make an actual list of parts and prices in the next couple of weeks and see where the budget is at. 3-4k maybe?
 
1 - 12 of 12 Posts
Top