VW Golf R32 Forum banner
1 - 6 of 6 Posts

·
Senior Member
Joined
·
760 Posts
Discussion Starter · #1 ·
Hi all,

So next week im booked in to tweak the exhaust a bit. Mainly removing some silencers, adding a new one and creating a bypass system. For now that aint a problem, the exhaust is 3.5inch at the moment and it will stay 3.5inch.

But now the difficult part: I am running the HGP460 setup with a R30 turbo. On the exhaust system I have a dual 200cells cat fitted at the moment.

Would a decat make sense and free up some horsepower? I wont go decat if it wont make power since its just extra noise then I think. But if it does free up some power it would be welcome. I dont mind changing the cats back in for MOT time.

Plans for the future also include HPA Competition intercoolers and increasing boost to 1.2 bar if that makes a difference? (dare I even say biturbo someday?
)
 

·
Registered
Joined
·
1,704 Posts
I had custom mapping done on my big turbo 1.8t with cats, and when i decided to run without it made a big difference when i went for more mapping!

The quicker the gases can escape, in theory the quicker the turbo can spool up!

Wez
 

·
Senior Member
Joined
·
148 Posts
Hi West... I'm running decatted and the turbos do spool up slightly faster then an equivalent twin turbo that runs twin 200 Cats.
I'm also Air to Water though so I have less restriction on the charge air side of things, so this also contributes to an earlier spool.

I can tell you from experience that in side by side runs, my car pulls on the other twin turbo due to the increase in midrange torque and power even though we both make similar peak power.



just remember though, your exhaust will stink to the high heaven without cats and anyone behind you will not have a pleasant experience, and with the HGP 460 I expect that's a lot of people...


here's a rolling road session where we were checking fuel trim with a new MAF, so we weren't doing a power run. It gives you a flavor for the sound when we get on it though.

 

·
Senior Member
Joined
·
760 Posts
Discussion Starter · #6 ·
Sounds like its gonna be a decat then


Worst case I'll have to change back to 200cells for MOT.
 
1 - 6 of 6 Posts
Top