A bitter lesson for me :D Don't simply change exhaust system

[bazet]

Yesterday I put back original OEM E39 exhaust system with new catalytic converters ( used ) and today the driving experiance is just perfect as E39 should be.Months ago, I changed the from middle to muffler using custom made exhaust by local shops- lower end torque gone- excessive petrol usage- no more midrage powerLuckily I kept the OEM system from the middle + Y pipe + rear muffler ( m sport ori ) and...peace of mind.So if you really want to upgrade your exhaust system go for real aftermarket that made for E39...like Eisenmann Race.BTW my 2 inlet Supersprint muffler now rocking on my E30..... no regrets

 

[sewell]

bro,

i also cut my Y pipe, i only gave the sound but no power increase. luckly i also kept it. after i install back to it, ya, the BMW driving experience is back.

 

[Jules]

As an engineer - i can appreciate that everything that goes to production would have gone through many many hours of R&D, market research, competitive benchmarking, engineering evaluation, streamlined decision making. The same would be for a piece of pipe called the exhaust.......

Of course, the design would be a compromised design befitting the intended ROAD use ie. driven by the enthusiast, uncles, aunties or even the occassional teenager in the instance of your BMW. If you want to put this car into the track, then its a different "use" ie. differing sustained rpms, less emphasis on fuel economy, emissions etc. ( my race car drinks 2 litre/lap at Sepang...and its a 4 cylinder! )

So the moral of story is....its horses for courses, so mod ur car at your own peril!

 

[seewai]

Exhaust should be placed at the 2nd last of mod cycle, the final stage being engine tuning.
Preceding above should have been engine mods.