| vs. non split 3" dp's. I just recently changed from a 3" RT downpipe and highflow cat setup to a 2.5" split downpipe and 'test' pipe setup. I changed them incrementally so I could note any differences using my sport 600's and Labree exhaust.
These are just my street driving experiences, no dyno numbers or anything scientific but I've had my car 10+ years and am very familiar with it. Test pipes vs. Hi Flow cats:
A noticable improvement in hi RPM power - it now makes sense to shift later. Spool up with sport 600's seems about same. I was surprised that the noise level was not much different with test pipes vs. hiflow cats on my LaBree with silencer "H" pipe setup. I already posted about difficulties with passing smog tests with hiflow cats and so to find a performance penalty on top of that makes them seem especially lame to me...
RT 3" vs. Split downpipes:
No noticeable improvement in power or full boost spool up RPM. Primary difference is that 2.5 split pipes are soooooo much easier to install, and tend to leak less than the RT's with that weird middle bolt design. Only other difference is a MINOR increase in boost pressure at low RPM's with split pipes - for example, they seem to generate 3-4 pounds at 2500 RPM when RT's only developed 1-2 at 2500K, but both kick in full boost hard at 4200 RPM.......
Hope this info helps anyone considering these upgrades...
|
