For MY97 UK turbo
As informed opinion seems to be it's not worth bothering with a decat centre only (as this with the standard d/p and P1 (STI) oh-so-quiet bb results in minimal gains in power and noise), then how about investing in a K&N 57i induction kit? Is this a better bet? At the moment I have an ITG panel filter.

 

IMHO a decat centre is going to give you slight increase in performance. You would be better off changing the down pipe though and the back box for performance gains.
Regarding the induction kit - there are two schools of thought about them

1. - Dont do it they knacker the MAF sensor
2. - Do it, it sounds great slight increase in performance

You have an MY97, like myself, which I am led to believe has a stronger MAF sensor so maybe school of thought No1 may not be AS important. I also have an induction kit fitted.

I am sure that other people will contribute to this, but I hope this helps

 

I've read that the standard induction system is good for about 350bhp and most of the higher performance factory Japanese cars use the standard system. So I think the normal system with a replacement K&N filter is easily good enough.

Also understand that the accepted mods are down pipe first then bb. However I've only had my car 4 days and I've seen conflicting reports on MOT emissions after down pipe CAT is removed.

Will a 97 UK car pass with just the centre pipe CAT, does it even have a centre pipe CAT ? Short of hack sawing the exhaust system apart I'm not sure who to believe at the moment

Also trying to find out about Knock and MAF sensors and Knock sensors, just need to get over the new car paranoia and start enjoying it I guess

 

Yes they do have a centre cat and some cars have passed with just the centre cat in however you need to make sure it is very hot when the emission test is done. Even then though it might be touch and go.

Knocklink should be high on your list of priorities as it warns of detonation in the engine, whereas MAF sensors tell the ECU how much air is entering the engine and it adjusts the fuel to suit.

Hope this helps

 

Thanks, knew what a MAF did, but didn't realise a duff one could make your engine eat itself Knocklink very high on list of priority now!

Exhaust truth comes out so thanks again

 

I have a STI MY03 with magnex bb and center decat, 265Hp before and 285 after on the rollers. additional custom ECUTEK-map-> 320Hp and 400Nm

I still have the std downpipe in place in order to be able to swap back to original exhaust-part when it is time for the German equivalent for MOT!

/L-O