Question Concerning my Dyno Graph
09-25-2006, 09:57 AM
#1
Question Concerning my Dyno Graph This is a bolt-on C5, 99 M6 with LG Pro Headers, no cats, Corsa Indy cat-back, Callaway Honker, LS6 Intake Manifold, Powerbond underdrive, Hypertech 160° T-Stat, NGK TR55's and Magnacore wires.
Now, here's the thing. When I was putting the manifold back on, I saw a plastic tube back there, and thought it was a vent tube, so I left if off. The car was dyno tuned with it off, to the above numbers. No running issues or anything.
As it turns out, that tube was part of the A/C vacuum harness, and I had completely overlooked the 90° rubber fitting under the map sensor. Obviously, there was a small intake vacuum leak because of that. I hooked it up on Sunday and when I started the car I IMMEDIATELY noticed it was searching for an idle, unlike before (I hadn't disconnected the battery either). So my question is:
How much of an impact could this little vacuum leak have had when we did the dyno tune??? Any ideas???
Now, here's the thing. When I was putting the manifold back on, I saw a plastic tube back there, and thought it was a vent tube, so I left if off. The car was dyno tuned with it off, to the above numbers. No running issues or anything.
As it turns out, that tube was part of the A/C vacuum harness, and I had completely overlooked the 90° rubber fitting under the map sensor. Obviously, there was a small intake vacuum leak because of that. I hooked it up on Sunday and when I started the car I IMMEDIATELY noticed it was searching for an idle, unlike before (I hadn't disconnected the battery either). So my question is:
How much of an impact could this little vacuum leak have had when we did the dyno tune??? Any ideas???
