What do we know about the z1 lower intake manifold?

Originally Posted by Mysilverz

I got your hint. I honestly think it's the part. So I still have the ported Z1 lower manifold on. I have a friend in Birmingham who was selling his Z1 ported upper plenum. So for the hell of it we swapped from the stock one I'm running now to his Z1 plenum. It gained 2whp. The procedure was the same. We reset the ecu and did two runs with the Z1 ported lower and the stock upper plenum. The car made 303whp. Then we swapped to the ported Z1 upper, reset the ecu, let the car warm up to normal operational temperature and did two more runs. Final number was 305whp. So read into that what you want. I'm speaking with someone at Z1 now. As soon as I swap back to the OEM lower manifold I'm going to do another run and ask for a refund in some way from Z1. I can't seem to get back to my previous numbers since I put their parts on.

Originally Posted by Elmo370z

Its got to be your tuner. Are they doing a custom pro tune? My first tune with Fast intentions long tubes i made 316whp i only gained 5whp from my Untuned baseline and i barely picked up across the board. 3 weeks i scheduled another tune with a different person and come to find out I was running super lean from 2-3 and kinda rich across the board. He ended up fixing that problem and i picked up huge from 2-3 and gained 18whp at the end. For some of us we have great tuner close to us for some you have to travel. That guy in tampa made crazy numbers with ported lower and z1's upper. Hope you find a solution to your problem.

Originally Posted by ajcool2

This^^. I've gained 12 hp between tuners before with no changes to my car.