Join Date: Nov 2013
Location: San Antonio, TX
Re: It's Dyno Time
Wonder why the vacuum seems so low? My "race-ier" street/strip 427w runs 10-11lbs at 1000rpm idle (58cc AFR's, 10.7cr, 255/266SR cam, 1.6 rockers, Super Vic intake, 1 3/4" headers, 93 octane.) Would have thought yours would be higher--even at a guesstimated 700-800rpm idle. How much initial timing are you running? Mine's between 20 & 22*.
I agree that the cam (and intake) are pretty much done on your big windsor (a told you so moment.) With the larger cam my car is shifted at 6600, which is near the top of the motor's power band (also close to your dyno'd goal.) As recommended you should try less timing and perhaps experiment with carb spacers. IIRC my timing is at 30* now. The track times (what's important to me) are definitely better than when it was tried at 34*. Consistency improved too.
Don't be afraid to put a Victor Jr. intake on there if you opt for a better cam. Mine had absolutely perfect street manners with the Vic Jr and a 950hp carb and ran great at the track too. The Super Vic is a little overkill on my current motor, but my goals are loftier in the long run and it will be needed for future growth.
Finally, I suggest that you don't overly rely on wheel dyno results. Use it as a guideline and don't be afraid to vary away from it in actual usage. A timed track is a better environment to get real world results from your changes.
Idle is about 850. Don't forget, the rockers are 1.7's so that added some lift (and duration?).
What are the plugs supposed to be gapped to for a motor like this? I'm currently at 45.
If I change intakes, I'm thinkin' I'm gonna go dual quads. It's kinda more about the eye candy and sound than anything else. The guy that helped me with the motor swap thinks I should put a 6/71 on it, but he's crazier than I am.
2012 Mustang "Earth Killer"
427w, Tremec Magnum XL, Trickflow Stage 3, 850cfm Quickfuel