Decat headers

[Gazwaz]

Anyone gutted there standard header cats in gen 2 Cayman??

Unlike some exhaust sellers will have you believe..  there's only 2 cats in gen2 Cayman.. they're in the headers..  none in silencers..

Save me spending £1200 on aftermarket headers..  I'm going to remove my standard ones and cut them open  this weekend.. gut them and weld back up..  

Don't bother replying saying that it's wrong ... it'll fail mot... etc etc  

I ain't interested.. I want more noise and thats that..

It has a PSE system fitted so any early morning start ups can still be quietened down to keep neighbours happy.. 

 

Anyone else been down this route ???

[crafty1]

I'd be interested to hear how easy this is, then you just need to find a friendly mot station each year,  Gert at Carnewal reckoned his modded headers with 200 cell cats are an easy 10hp addition too so no cats should be even better.

Edited January 30, 2018 by crafty1

[Gazwaz]

I'll keep ya posted @crafty1

 

[Aaron]

You could remove just one cat and still pass emissions tests.  They're both 600 cell IIRC and overkill.

 

Be ready to grind some bolts.  The exhaust bolts are notorious for corrosion, despite not being that old.

 

You'd get more noise with an aftermarket or custom cat back but gutting the cats is pretty much free, I suppose.  Not sure how much extra noise you'll get with the stock PSE system on there.  

 

Vids and dB readings, please!  Eager to hear how this pans out.

[Mavrik]

16 hours ago, Gazwaz said:

Don't bother replying saying that it's wrong ... it'll fail mot... etc etc... I ain't interested.. 

 

 

Have you a "friendly" MOT tester then? ... I'd fit de-cats to my Gen1 if I could get away with it!!

[Bushman]

I've got a set of Gen 1 exhausts in pieces in the welding suite a work. the plan is that I've carefully split the cans and secondary cat housings, keeping the positions of all the pipework and baffles by not disturbing the bottom skin of the silencers. Ive removed the secondary cats and will be re-welding  housing back together to give me an expansion chamber per side to reduce pressure pulsing and smooth out flow of gasses whilst retaining the standard mounting system that clamps round these chambers. Ive got a pair of 300mm long stainless round cans, 150mm dia with 75mm through holes on order ( about £40 ea) some 75mm stainless bends to connect the expansion chambers to the cans then a couple of straight reducers to weld onto the exits of the cans to connect back to the tail pipe that I made last year that fitted the stock system. once everything is tack welded into position, I will cut away the remains of the old cans.  Just got to find the time now to stay after work and get dirty. 

I was amazed how tough the cell structure of the secondary cat was and ended up plasma cutting most of it into kit form before getting the tube out.

surprised to hear that a gen 2 does not have secondary cats too.

pics when I can of progress but realistically a couple of months away.

[Gazwaz]

Yeah @Bushman  no secondary cars in gen 2.. only 2 in headers...(1 each side)..

Was going to attempt it this weekend but son is working on his car in garage and it's bloody freezing outside.. so will have to wait for it to warm up a little.. or my son to get his track car finished.. 

[Aaron]

Not sure if I'm misreading your post but there's four in total on a gen 1 and gen 2.  Gen 1 is manifold and rear section, gen 2 is two cats in each manifold.

 

From Gert (Carnewal) himself:

 

"Our 200 cell  “Exchange Sport Cats” is a pair of original manifolds of which the primary and secondary elements are removed and the primary elements are replaced with HJS 200 cell sport cats, the HD version which is especially developed for Porsche DFI and high performance engines."