Anyone fitted a double H pipe to the Cerb

[RichC83]

Anyone fitted a double H pipe to the Cerb.

Would it work ok?

What would the benefits be vs the losses?

PS I know little to nothing about exhaust so sorry if this is a daft question

[pmessling]

I done lots of research and found yes it would increase power slightly.

I made an H pipe decat, but recently removed them in favour of cats due to the excessive exhaust smell, I may get round to adding another and moving the cats back slightly

[Imran999]

pmessling said:

I done lots of research and found yes it would increase power slightly.

I made an H pipe decat, but recently removed them in favour of cats due to the excessive exhaust smell, I may get round to adding another and moving the cats back slightly

“Exhaust smell”?
Curious, why/how does removing the cats increase exhaust smell?
I bet I’m about to learn something here…

[ukkid35]

Imran999 said:

“Exhaust smell”?
Curious, why/how does removing the cats increase exhaust smell?
I bet I’m about to learn something here…

Car absolutely stinks without cats, especially in confined spaces

It's not great with cats, but it is less stinky

[MattPlaneCrank]

Are there bigger cats with better flow characteristics that reduce the power less than the standard ones?

[Tony91]

Took off my H pipe and fitted these cut down on noise also MOT friendly, and only £112 each new.

[MattPlaneCrank]

Are they just a straight swap?

[Tony91]

Yes straight swop as they are round an not the type with the pressed flanged edge. These are for my 4.5 whether they fit the 4.2 not sure I had in my mind the 4.2 had longer cats. The come from European Exhaust and Cats EEC.

[egilkv]

On the subject of H-pipes, since the engine V is 75 degrees and not 90, the phases of the two banks are not perfectly opposed, so surely the interconnect should be offset a bit to compensate. So for an H-pipe and an X-pipe, seen from above, something like this:



An exact match would depend on the RPM and the exhaust velocity, but I imagine something like this would be beneficial over quite a useful band. Has something like this ever been tried?

[spitfire4v8]

Ive tried most things over the years and funnily enough have though about a staggered link but for the sp6 rather than ajp8 .. their cats are not mounted side by side due to the design of the exhaust manifolds.

You won't get a s bend pipe in like the left hand drawing, there's only a few inches between the pipes so once you've got your pipe diameter in there you'd never s bend it tight enough.

The one on the right might work, but again you're working in a length of around 16 inches so getting that bend in without introducing back pressure from the bends (the ajp8 hates any back pressure) would be inetesting.

The best I've come up with so far is my merge H pipe which is half an H pipe and half an X pipe.

Top of picture is manifold exits, bottom of picture rest of system to tailpipes.

[Jhonno]

I ended up with something almost exactly like that as a link pipe! Uncanny! (I modified an X-pipe as it was crap).