catless downpipes= drone and same hp?

[Trolln]

@op

Had the same problem with mine, you can try adjusting the piping (vbands and exhaust hangers) away from the engine crossmember as it will be rattling on there. I tried this which seemed to alleviate the issue a little but not completely and it slowly came back anyway.

I found on another forum using 2 5" radiator clamps around the two pipes right near the crossmember, I got these from bunnings for a few dollars..
You don't need to tighten them too much, just enough to give it a little clearance and hold it there.
So I gave it a shot and Wow what a difference, no more rattle and it killed most of the drone also! I guess it prevent the pipes from vibrating and exacerbating the drone? But either way, I recommend trying that if you are all out of ideas!

[BMW Gator]

Originally Posted by kiysersosae

You will see gains of around 15 bhp without a tune, I've carried out dyno comparison. The car will also run fine without a tune and decatted pipes, with afr values almost identical across the rev range.

If you get a tune (like everyone is suggesting) you will benefit greatly from it in regards to more bhp.

+1 I have akra dp's with resonated mids with stock rear. Very happy - check mid pipe clearance to body also - I had to adjust.