If its the HKS then its just a bigger bore single pipe, that marries up with the compressor wheel side of the turbo, it still has a flat flange that covers the wastegate side of it. Heard that this is more restrictive than the 2 below.

Open flange/Open neck has an opening the size of the turbos exhaust port, basically completely open to both the compressor wheel side of the the turbo and the wastegate. Approx opening is 4" x 2".

Twin dump is like your HKS one, one big pipe on the compressor wheel side of the turbo, but then a smaller pipe on the wastegate side, they then join up later down just before the centre section.

As for which is best, some would argue there is no difference between the open neck and the twin dump system.

Personally i have always gone with the open neck type.

Hope that helps

[Edited by P20SPD - 11/6/2002 8:58:33 AM]

 

Can someone tell me whats the diference between a twin dump and a open flange downpipe.What are better.Am i right in saying that there are diferent type single opening downpipes.The one ive brought has a single hole and a flat metal flange,its HKS looks lurvly and has a tag on it with Racing use only printed on it,Anyone know what type this is please

 

Thanks very much,that has explain all.
I didnt realy know what i was buying and now realise i have the one you listed 1st.Its brand new and now for sale as i would be better off getting the open flange type.I guess i should have asked this before buying.Any idea how much its worth?

 

I had the HKS unit but then swapped it for a 3 inch open flange unit from Scoobysport.

HKS was better than standard but not a good as a proper open down pipe, be it twin dump or open flange.

 

Try returning it.

Worth i guess between £100 and £150