Exhaust power?

[Majesticpower]

So,

some opinion on this is often divided from what i hear- But do you think, a upgraded full exhaust system would release anymore power from your car?

Have you actually had an full system mod and could tell the difference, and did you feel it was worth it?

Would the sports cat make a big difference, etc?

MP.

[p fandango]

i noticed the revs free up alot easier when i had a cat back fitted

[SaffronC70]

After bypassing the rear box on my C70, the turbo lag BETWEEN gearchanges has reduced noticably.

I recommend getting a good make down pipe, with a quality race cat in it, Ferrita is good, BSR is value, and have the rest custom made with a small box at the rear.

I have kept the mid box, but lost the backbox, so the car sounds quite deep and droany, like an 850 auto estate, which is exactly what I was after.

However, it is not overly loud and cabin noise is the same as a full system with two boxes.

Chris

[vt5]

Majestic, the biggest power gains you get are from free'er flowing exhaust manifolds the twisty tubing ones (horribly expensive and often only custom made) and removing the cat is another good way to bigger power, sometimes up to 20 or 30 bhp can be added on some cars, however i believe on the T5's you cant remove it cos it will fail emissions tests.

Normally on removing CAT's id say try it but VT have tried it i believe and it does fail and they do MOT's so its perhaps not an option on the volvo's

A stainless cat back may release about 3bhp but nothing you will notice.

Stainless systems are good though and sound awesome.......i love em.

if im wrong on anything please feel free to correct me :)

[After_Shock]

Failing the MOT isnt the issue with removing the cat its the fact the car wont run right if its a later model car with the sensor after the cat.

I had a custom downpipe made along with a race cat fitted and a 2.5' catback system fitted and saw 255bhp on the rolling road without a remap, the car didnt feel massively quicker but as pedro mentioned the revs free'd up massively and it sounded awesome.

Saffron im sorry but £750 for a downpipe and race cat is ridiculous or whatever they cost, im sure its good quality but can easily get them made to the same quality and the cats on their own are only about £100 for a decent one, some go upto about £150 depending on spec so thats £600 for a bit of mandrel bent metal!

[gezR]

I took the CAT off my old car, the difference was incredible. It used to pop and bang like a good 'un. One thing to be aware of is that if you remove the CAT there is no way it will pass an MOT. It's not too much hassle to replace the CAT once a year just for the test (or to find a tester with no morals) BUT if you have a crash and the insurance find out they may refuse to pay out as the car will not be considered road legal as it would be unable to pass an MOT. This may be the case even if you have declared the modification.

[SaffronC70]

If you can get a custom 3" downpipe with decent CAT and 3" cat back system - then you'd be talking ! But you'd probably get the Police knocking on your door due to noise !

How loud were you looking ? or is it mainly for performance reasons ?

You can get a free'er flowing ported mainfold from SW Autos I believe - imported from Japan, however I don't have much detail on this.

Chris

[After_Shock]

I think one of the US companies does ported manifolds but easy enough to get it done locally, however tubular ones are nearly impossible to fit in!

[volvotuning]

The thing about the exhaust manifold - it needs to be as short as possible. The reason for this is that the gases must remain as fast as possible before they reach the turbo. If the exhaust manifold is too long, the gases will slow down.

Adam.

[Majesticpower]

How loud were you looking ? or is it mainly for performance reasons ?


I was more intrested in the performance gain side of things. Altho i wouldnt mind a more throaty sound to my exhuast as i think the original sounds abit muted for what it is.

So would it cause a problem if you de-catted an S60 T5 due to the sensor? Must be some way around it if so, no?

These guys have been recommended to be, and ive been told they are brilliant- http://www.haywardandscott.com/services.asp (http://)

MP.

[volvotuning]

As Aftershock says, if you decat the ME7 cars, they will throw a wobbly (not the dave variety!!!), basically due to the fact that it registers a catalytic converter efficiency problem.

Adam.

[After_Shock]

Their is possibly a way around fooling the sensor but I got sick of trying with constant problems with the way the car ran, constantly in limp home mode and running very rich.

Your better off going with a race cat, for the small few bhps you will loose over not having one your gaining in reliability and the fact it will pass an MOT were without it wont.

Hayward scott are meant to be excellent but you will pay an absolute fortune for their systems. AAS in Newcastle are of a similar standard just not aswell known and alot cheaper.