Cf2 Headers Into A 147 Gta

[06gta 1]

I've got a hold of a set of 166 headers (CF2) and understand that it's a fair deal to install them (unless you're due a clutch). Whilst it can be done with engine in there's about 6-8 hours labour...

So I'm weighing up the pro's v cons. Has anyone done the CF2 install - was there any real worthwhile improvement?

I was also thinking of ceramic coating them as well to further reduce the under bonnet temps.

The CF2's don't meet up with the stock center pipe so a visit to the exhaust shop is also needed for a custom connection pipe.

[smiffy 99]

Hi mate I had cf2's done not long ago but had my cam belt done at the same time, it can be done without taking the engine out, the bottom sub frame has to come out along with the steering rack. There is a notable difference in mine but don't know if that's due to the cf2's or cam belt change. I heat wrapped mine couldn't afford the ceramic coating. If you get a exhaust place to make your down pipes you need to get them to put lambda bosses in unless the 166 manifolds have them in. His at alfatune does downpipes to fit 166 headers but be careful of equal length pipes as they hang low

[06gta 1]

Thanks smiffy. I'm on holidays so have not sited the headers yet so not sure re lambda's

 

I've not heard good reports re ELFPs due to drone or canceling of back box sounds (plus low ground clearance), so will just do the exhaust shop downpipes

 

So how many seat of the pants extra HP did you get

[smiffy 99]

Havent had a RR done on it yet but I have been told to expect a 15-20hp increase with the downpipes I've got. Think it would benefit a re-map tho. I think I am having trouble with the secondary cats at the mo keep getting mscf come up and it's to do with lambda and cat fault only happened since cf2's

[Clem Fandango 71]

Havent had a RR done on it yet but I have been told to expect a 15-20hp increase with the downpipes I've got. Think it would benefit a re-map tho. I think I am having trouble with the secondary cats at the mo keep getting mscf come up and it's to do with lambda and cat fault only happened since cf2's

There's a rr day in Yorkshire soon if you fancy a run ooop north.

[smiffy 99]

There's a rr day in Yorkshire soon if you fancy a run ooop north.

 

I know mate down as a maybe might be a yes

[Smaky 73]

Don't expect any more than 10-12bhp increase, if you want a little more also replace the main cats with sportscats, but remember its not all about letting stuff out as the engine is ALLWAYS throttled by the inlet system and not the filter

[06gta 1]

...If you get a exhaust place to make your down pipes you need to get them to put lambda bosses in unless the 166 manifolds have them in. ...

The 166 headers definitely do not have lambda bosses

[Smaky 73]

The main thing being forgotten here is that the down pipe end flanges are different, the main time consuming thing in a manifold swap is replacing the flanges as CF2 are 2 stud and cf3 are 3 stud, so it is not as simple as one off one on, it can be done by removing the front mnifold first then removing the gearbox and lower engine mounts and swinging the engine round, the other issue is heatshields and wiring route, everything is slightly different and as the wires in question are 12V lives then you don't want them banging off the nice earth which is the exhaust like I found on a recent 147 GTA clutch change.

[06gta 1]

Don't expect any more than 10-12bhp increase

Fair enough, but the throttle response would also improve? After I installed my Unicorse II backbox, I thought I got more HP (say 7-10ish) but also a better throttle response, or was I just so taken with the exhaust note I got this all wrong!

, if you want a little more also replace the main cats with sportscats,

Something like 100 or 200 cell?

but remember its not all about letting stuff out as the engine is ALLWAYS throttled by the inlet system and not the filter

Do you mean increase the plenum - such as the ACT one discussed on AO?

The main thing being forgotten here is that the down pipe end flanges are different, the main time consuming thing in a manifold swap is replacing the flanges as CF2 are 2 stud and cf3 are 3 stud, so it is not as simple as one off one on, it can be done by removing the front mnifold first then removing the gearbox and lower engine mounts and swinging the engine round,

Was never going to change the flanges, rather have my exhaust shop make up connector pipes from the CF2 2 bolt to the 3 bolt centre pipes

the other issue is heatshields and wiring route, everything is slightly different and as the wires in question are 12V lives then you don't want them banging off the nice earth which is the exhaust like I found on a recent 147 GTA clutch change.

Sounds like I should spend my money and time elsewhere... :-)

[Smaky 73]

Fair enough, but the throttle response would also improve? After I installed my Unicorse II backbox, I thought I got more HP (say 7-10ish) but also a better throttle response, or was I just so taken with the exhaust note I got this all wrong!

 

I would suggest it was all placebo, throttle response will not have changed as the TB will still be opening the same ammount at the same speed due to the electronic control, plus the diameter going in remains the same.

 

 

Something like 100 or 200 cell?

 

Along those lines, yes.

 

 

Do you mean increase the plenum - such as the ACT one discussed on AO?

 

No, that provides no benefit at all, the air is still throttled by the stub manifold and head ports, the only way to increase flow in is to have some serious head work done, enlarging the ports and valves, which also means replacing the pistons due to the loss of overlap through the stroke and thus requiring remapping to accomodate the new flow characteristics. Effectively if your going this far you may aswell open up the capacity to around 3.5l to get the real benefit.

 

Was never going to change the flanges, rather have my exhaust shop make up connector pipes from the CF2 2 bolt to the 3 bolt centre pipes

 

Sounds like I should spend my money and time elsewhere... :-)

 

That is what I would do too, I believe Gus at Alfatune already makes sets of pipes like this andI think they are the equal lenth version too, but they do sit lower under the car so that is another consideration.

Edited January 15, 2013 by Smaky

[06gta 1]

Thanks Smaky

Any thoughts on catless centre pipes as an alternative? Or will I be chasing MSCF errors

[smiffy 99]

I'm chasing a lamba error at the mo need to take the cats of and have a look to see if there fooked

[Smaky 73]

06gta - If you remove the center cats then it would have no effect is the precats are still on the down pipes, and yes you would end up with lambda errors. To run no cats at all is an MOT fail due to year of manufacture.

 

Smiffy - I'll plug her in if you need.

[smiffy 99]

Had the codes read and reset

[06gta 1]

Thanks Smaky

 

smiffy - I had those errors on the wife's 2005 156 SW JTS but I'm sure it's a completely different issue

[Smaky 73]

Dead secondary cat, that'll certainly need replacing.

[smiffy 99]

Dead secondary cat, that'll certainly need replacing.

 

Bum holes, it only does it now and again would that give a horrid renonace Noise?

 

[Smaky 73]

Yep as that is the honeycomb bouncing around inside the can.

[Smaky 73]

Is this GTV or GTA?

[smiffy 99]

GTA

[Smaky 73]

Ouch, need to identify which of the four is ratling. It may not be the secondary cat as the almbdas can be confused in this case, also ensure there are no leaks between the lambdas.

[smiffy 99]

Haven't any pre cats, also I need a bottom rad pipe for the GTA cheapest place please

[Smaky 73]

Are we talking the steel 1" pipe along the bottom?

 

£65 from Alfa.

Edited January 16, 2013 by Smaky

[smiffy 99]

Yep