Z34 Header Test & Tune

Joe came in from Vegas earlier this week to do some testing for the Fast Intentions crew and for us to tune his slick white 370.  These cars are growing on me more and more.

Interior build is sooo much nicer than the old Z33 especially an early (03-04) Z33 for that matter.  The extra power it puts down definitely doesn’t hurt either.  We did a couple baselines to get an idea of where the car stood before F.I. installed a set of their new headers for the HR\VHR platform.  Joe’s already installed mods included Stillen Gen 3 C.A.I., F.I. HFCs, and catback.  This baby sounded wicked on the dyno.

Some stats on the headers:

  • They are long tube that will bolt directly to the catback.
  • Eliminates the OE CAT pipe.
  • Weighs in at 17 lbs lighter than the OE header & CAT pipe.
  • Made from 304 SS and includes a lifetime warranty.
  • No CEL(s) to worry about.

The set pictured above is a prototype using a different sized collector.

This is the 2nd set of headers installed and the first production unit installed on a Z.

These are the results from stock headers to F.I. headers & tune.  The AFR on this VHR was whacked out.  Rich down low and lean up top.  The Stillen intakes aren’t helping that.  Looking forward to doing some before and after results on those intakes to see how much power is made and how drastically the AFR is changed.  I’d also like to see stock air boxes on Joe’s car with some K&N drop ins.  Joe’s VHR was in dire need of tuning especially after feeling, hearing, and conversing with his engine.  It had a terrible drop in power resulting in a nasty hesitation that could be felt right around 4k RPMs.  This was taken care of luckily with a custom flash.  AFR after just the header install stayed the same as before with stock headers in case any one was wondering.  Peak power didn’t change much.  However a majority of the power-band saw a nice increase of around 10-15 whp and 10-18 torque.

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  1. […] tubes installed by Seb and a dyno run..long tubes picked up great mid range but 0 on the top end.. Z34 Header Test & Tune | […]

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