The Performer intake definitely made an improvement in low end response. (I'm still awaiting the printouts as they finished the tuning Friday late and I picked it up Saturday morning - I missed my toy!!!- with only office help present.) They still owe me a dyno run with my old 15 1/2" filter and then a comparison with a new "extreme top" that technically should breath twice as much but is 1 1/2" taller. I now have 1" clearance under my scoop yaaaaay! I had them dyno it before changing over to my new muffler internals and they said that the increase in muffler baffle ID size from 1 7/8" to 2 1/2" ID resulted in a gain of over 50 peak RWHP to over 450. I don't think I'll change my pipes to 3" for more horses just yet.
Of course all I'd done is allow the builder to dyno tune it before delivery and I just bolted it in, so it may have left quite a bit to desire just left that way. It ran rather sluggishly below 3500 RPM and didn't have the low end response I had anticipated from 533 CID.
But the tune...wow! I took it to Performance Dyno Tuning (PDT Motorsports) in Oakdale, California on the strong recommendation of a friend of mine. The workover they did on my carb and tuning gave it a whole new personality! They build race cars, sandrails, custom street rods and haha! they also specialize in finishing car projects that have been given up on, so they've seen and finished a few cobra kits. It took them a week to get the car worked into their schedule and done (the Performer manifold had a fault in it that leaked and they took care of replacing it) but if I'd have known the difference it was going to make I'd have gladly waited a month
Still the original Mighty Demon 850 carb, still mechanical secondaries, but omgoodness what a difference!
Smoother, stronger, more responsive and virtually lagless.
I still haven't gotten the new higher CFM fan installed, but the car runs 195-200 in traffic now on a hot day instead of the 225 it was running before.
I'm as pleased as punch
Dirk