Hi all

I am shortly going to be fitting a Twin Dump Downpipe to my Legacy, however i have stumbled across, well not so much a problem but a quiery.

Since getting the downpipe which has a 4" long wastegate pipe, i have seen some downpipes with the wastegate pipe running all the way down to the centrepipe almost (Tony Law does them i think), and ones that finish half way down the downpipe. I have a Magnex one, but i have seen magnex make one with a longer wastegate pipe.

So whats the deal here, does it really matter where it joins the main pipe, if so does any one know what the length means in terms of power gains, laminar flow etc?

I just need to clear it up in my noggin

Cheers
Comper100

 

I am not sure these down pipes will perform as well as a 3" open neck downpipe from the likes of Hayward & Scott or Roger Clark Motorsport. For best results the smaller diameter wastegate pipe should extend for at least 24" but it would be preferable if the join was closer to the flange with the centre section. The wastegate join should be at as shallow an angle as possible.