which down pipe gives the beter response/power, scoobysports or hks, bearing in mind the scoobysorts pipe has the bigger opening at the turbo end and the hks does not.

 

I wouldn't go for those - go for a BPM TD-38 Twin-dump downpipe instead.

 

The Scoobysport gives better response - spool up can be better than other d/ps.

HKS is not so hot, BPM is very quiet and reputedly better for top end - personally I found it killed spool up.

Trout

 

Of the two downpipes originally mentioned, the Hayward and Scott one has a better design than the HKS one, unless the hks downpipe design has been radically altered recently.

Christian R will now give you an in depth technical description of why you should go for a bpm twin dump in place of the ones you mentioned, being that he is obviously so sure that it is the best one to have. (drumroll for christian)

 

Id buy the Magnex, as its one of the cheapest, and lots better than the plain HKS one which is cheaper. I have drove a few cars with different designs of front pipe, and IMHO, there is very little, if any difference between them. I even removed the 'twin dump' bit on my old mongoose front pipe on my car ( which was given to me for free, which is the only reason I am using it ) as it fouled the steering knuckle. There was absolutely no difference in performance with it removed.

 

twin dump designs without a gas seperator with the proper length for the turbo you are using do absolutelly nothing to the spool up time and efficiency of the turbo.