Hi all - noticed this thread
David, let me say that I respect your products, and have followed your tuning ever since we were running a Galant VR-4...
I do have to differ with the statement that 3" into 2.5 sucks. In some cases it may.... but let me explain what we do that is known to be very effective.
Krillz - by what you wrote, I'm guessing that you are assuming our downpipe is 2.5"... it is actually larger, and what you are after may just be our pipe, or one like it.
The ScoobySport is actually a 5.5" wide bellmouth downpipe, tapering down to 3". The system then later tapers to 2.5" to go to the next pipe in line. The beauty of this is that it gives you flexibility... but has developed a pretty legendary reputation for area under the torque curve. It doesn't suck.
Dave, perhaps you dynoed a 3" only downpipe, like the HKS, that doesnt have the same flow properties as ours (or other good bellmouths like TXS).
In any case, I wanted to make the point that we vary the diameter, and that the ScoobySport is not just a 2.5.
Regards,
Ken Cole
Rally Performance /
ScoobySport North Amercia