Exhaust tuning specifications

b85fmd

HI ! I'm a new member on this forum and I'm writing from far away in Romania but I think the main ideea is that we all have the same passion for cars; anyway I would like to excuse myself for any future mistakes. Thank you.

This is my first post but I will try to get to the point. I'm the proud owner of an Astra Coupe (2.2 of course) and yesterday I went to a nerarby shop to install a new exhaust. I removed the precat, the middlebox and the backbox and installed a 57mm (I think that's 2.25") stainless steel pipe with a sport back box. The ideea is that the sound volume is too low(lower than my old 1.4 8v Renault that had no cat) and I want a racelike sound.

Has anybody removed the cat without installing a sport one or anybody knows how is gonna sound i I take it off?
I'm opened to any suggestions regarding this matter.
Thanks a lot.

vocky

you will need to modify the lambda sensor wiring if you wish to remove the main cat.

you will need to buy an O2 sensor simulator...http://www.o2sim.com

to increase the exhaust noise, it might help if you replace the air filter to allow the engine to breath better

xinitialz

ecotech engines are quiet

b85fmd

Another concern of mine is that I exagerated with the diameter.
The original had 45mm (from the cat backwards) and I installed 57mm.
Do you think that I have now a decrease in power?(I don't have a previous dyno sheet and the engine has about 200k km so 147bhp are hard to reach anyway)
If I remove the cat I now I will get an EML but would it affect my performance(it doesn't matter if I pass the inspection or not)

Thanks again

vocky

removing the cat will cause 'limp mode' so power will be down

I had a 57mm [2.5"] exhaust, it was quite noisy dunno..

philip1

I have 2.25in exhaust from the manifold back with a sport cat and its quite loud. I am not sure how loud you want it but mine makes me want another muffler.