Originally Posted by
ANDY black s13
the cast manifold don't flow well for performance, the unequal runners design works ok on a stock or near stock engine,
No1 runner goes very small ID as it meets the collector then makes a sharp 90 degree turn,it creates a hot spot it is so restrictive
and the manifold can crack in that area and/or the divider will crack (and potential for bits to drop into the turbo)
same as others mentioned I would look at tubular manifolds in an unequal length runner designs to lower spool time & keep response
, if you go with a V band it will need a support brace so the turbo is not hanging on the V band or it will open up the v band come loose and leak.
the set up in last pic looks good and not saying it wont work,it probably makes a good responsive low lag fast road set up
but if want big numbers the stock manifold will hold it back and loose top end power as it can't flow enough exhaust gases