Leave the header. The restrictions start where it connects to the collector then to one pipe that I think is 2 1/4". I went 3" from the collector back and it flows...
Quote:
Originally Posted by Christian  I've read over and over again that the stock BMW M44 header is so good that it's not worth investing in a performance header. This may be true on a naturally aspirated car, what about a car running the DASC? I'm almost certain that a header such as the Supersprint (or Ebay clones) would free up some horsepower, but I can't find any data to support this.
My Z3 has a DASC with the 3.6" pulley and the Technique Tuning stage III kit, so I'm getting about 9-9.5 psi. The only other engine mod is a Supersprint cat-back. The supercharger forces far more air than stock into the motor, so I think that opening up the exhaust can only help, right? I'm interested in trying a header (and cat delete), but before I do so II really want to hear from someone who's done it or has seen dyno graphs, etc. Any input would be very much appreciated. |