Decat pipes

[viku]

What is the best way to decat 4.5 AJP. Individual pipes or linked?
If linked, should it be some kind of X-pipe or simple H?
The rest of the exhaust is ACT system.
Any advice would be great,
Viku

[brakedust]

I have linked de-cats on my 4.5, standard H design with mine, makes a good noise when the engine isn't in bits!

[Vee8ight]

I thought due to the nature of the ajpv8, being flat plane crank, that having a cross link will rob power and a cross link is only for normal v8's

[Gazzab]

We've been here countless times before. Have a search.

[optimax sniffer]

H style pattern decats are meant to be a touch quieter and produce more power (a couple of bhp), than non linked decats.

I went to non linked decats

[spitfire4v8]

Vee8ight said:

I thought due to the nature of the ajpv8, being flat plane crank, that having a cross link will rob power and a cross link is only for normal v8's

you'd probably be right if it was a 90 deg V 8 (though if the link pipe was massive you'd still see a gain I reckon because of the smoothing effect of what would then become a large expansion chamber) .. but the engine isn't a 90degree V8 so the pulses arent exactly overlapping. There is a small amount of gas sharing across the link. Not much, but it's there.

[viku]

Thank you for all your opinions.
I will weld a simple cross pipe to my current de-cat pipes and do some dyno runs. (We have 15cm snow so anyway the safest way to drive Cerb is on rollers)
Power is the first priority but if it makes the car a little quieter then even better.
To my eyes the pipe diameter of the de-cat pipes and the section before rear mufflers is a little small for a 200+hp/bank and the first mufflers in the center pipes will smoothen the pulses, so in theory I believe giving more flowing area should help power.

[Gazzab]

Spitfire above is the world expert on ajp tuning (mapping, breathing etc) so no need to experiment in most areas as the evidence is there, as are the products.
If you want more power beyond this the speak to Apm re a 4.7