Contour Enthusiasts Group Archives Forums General Dyno and Drag Reburn coming up: tips and prep

That fluttering is unusual and could be from fluctuating fuel pressure maybe??

I would tune leaner than 12.5:1 for an N/A SVT, Try shooting for about 13:1 to 13.25:1 then richen up a little bit about 6500+ , say back down to about 12.75:1

You can gain several Ft-lbs of torque in the midrange, perhaps enough to throw you solidly into the 180's HP range.
Richening up above 6500 is based upon my personal experience with my car since I tuned mine to 13.5:1 . It would ping just a little if it was really hot right about 6500rpm. So I just added a tad fuel to bring it back down to about 13:1 right there.
It worked great and gave minimum 6HP gain on my 3L. That's probably worth 3-4 on a 2.5L.

Remember, this is just my experience and may or may not be accurate for you. I do know that SVT's that make good power safely run A/F in the low 13's. I've got probably 30 dyno scans supporting this.

Tom