...the engine breathing?

I mean, they claim to improve the airflow considerately, which in my book means about 20-30 percent and then the gain in performance is about 1-2 percent.

is the access of air to the engine limited by other things than the air filter?

If so, is there an improvement in acceleration at least?

Please help


Ralf

 

Hi Ralf

I'll post my experiences. In my old MY00, at various times, I ran the following: standard air filter, standard air filter without the in-wing resonator, K&N replacement filter, HKS 'cone' filter and an ITG panel filter.

The biggest difference seemed to be the noise! Of all of the filters I fitted I would guess that the HKS had the most effect, both in terms of noise and performance.

What must be considered is that there are things considerably more restrictive to the air flow than the filter - namely the catalytic converters. If you want to improve the 'breathing' of your engine, then only changing one part will give limited improvements. On the MY00 I ended up with a full Scoobysport exhaust (no cats) and an ITG panel filter. The combination gave a very useful improvement and a lovely noise

On my new MY01 I run the same setup - full Scoobysport exhaust with ITG panel filter. To be honest I wouldn't change the air filter again unless it was really worthwhile.

Cheers
Chris

 

So..(asks for forgiveness in advance if Im being VERY dumb :P, but if I am I dont know WHY )..how does a de-catted Scoob get on with the emmissions part of the MOT procedure? Isnt that what the CATs are there for?

If is makes no odds, then surely the CATs must be a waste of time and money to make and install in the first place..so should we be lobbying government (HA!) to make CATs illegal and legislate for Straight Through pipes as compulsory?

 

De Catted exhausts generally fail MOT tests, unless either :

-You put your cats back on for the emission test,
-You give the tester a bung,
-The tester's your mate

Ian

 

Recently replaced standard filter with ITG. Immediate difference was an increase in pull off-boost i.e 1000 to 2500 rpm. Very noticeable in slow traffic. At the same time though mpg seemed to drop from 24 to 22. Car is more driveable but, as I STILL have standard exhaust can't comment on the 'breatheability'.

 

Exactly Which goes to prove you shouldn't accept an MOT certificate as an indication of the condition of a car. They are so easy to get hold of it's frightening. They are really not worth the paper they are written on.

Always been a little unsure about catalytic converters and their perceived benefits (ever since I found out that one of the companies that did the original research into cats also happened to own the largest platinum mines in the world...conflict of interest anyone?). A recent German study attributed the reduction in roadside plants and trees directly to the 'heavy metal' by-products of catalytic converters. I thought they were meant to be good for the environment?

The converters are very restrictive to meet the latest emission laws in Europe (christ knows how Mitsubishi managed it with the new Evo VII). Don't forget that it was cats that killed the original (and best) Pug 205GTI 1.6, as the catted exhaust robbed the car of so much power, they decided to discontinue it rather than re-engineer it.

As far as I remember, the law is a little unclear on the use of cats. I believe it is not necessarily illegal to run a car without cats, but your car must be capable of passing either a roadside emmissions test and the MOT test - which would require you to have a cat! We'll just have to cross that bridge when we come to it...

So in answer to the original question, you will see a limited effect when using a 'free flowing' filter in isolation.

Chris