25thannivZ28

First and foremost, I don't have TPI anymore, I have a 427 sbc with an Edelbrock Super Victor II and QF 850 SS carburetor. So, I just dyno'd my car and I came up with 481rwhp/445 rwtq. At the time of my runs, my Jet Sizes were 77 Primaries and 90 Secondary's. My AFR Readings at WOT were 11.06, 11.07 and 11.16 on 3 various runs, clearly too rich. Now, I know I have to drop my secondaries (which I have done) down to 84. I haven't dyno tested it yet, but what type of HP gains can be seen in your experience from having an out-of-tune AFR that provides too rich of conditions at WOT? If I am almost 2.0 full AFR Points away from optimum Performance at WOT, is that typically "X" amount of HP lost or is it all relative to other engine mods?

NoEmissions84TA

iTrader: (1)

See if these help. Looks like a 4% gain in TQ going from 11.0 to 12.5 AFR.
Remember, dynos measure TQ, and HP is a derived calculation from that number at a particular RPM.

GeneralDisorder

iTrader: (1)

The answer is that it's not going to make all that much difference. A little maybe, but not huge gains from going 11 to 12.

That said it's richer than I would suggest for NA that's for sure. We target about 11.2 for 14lb of boost. For NA I would be ok with 13.0 generally. Unless you start to see any detonation.

Slight correction on the DynoJet information above - the DynoJet actually does measure HP. Being that I own a DynoJet chassis dyno I can speak with some authority on this subject. So the DynoJet can render a HP curve just by strapping down the car and making a run. You don't need anything else hooked to the car and the Dyno is not told anything about the car (gear ratios, weight, drag coefficients, etc - literally NOTHING - unlike Mustang Dyno's). It will faithfully produce a HP graph (quite accurately in my experience), It will only give you torque if you have an RPM pickup attached.

As to how it does this - I believe it uses a lookup table. At it's core the DynoJet is an inertia dyno. It measures the time taken to accelerate the drum (2,250 lbs each), and from this acceleration derives HP required. Once it has HP and an RPM signal it can also create the torque curve.

One interesting difference with the DynoJet is that because there are NO inputs to the Dyno computer, you cannot alter the results by trying to fool it with inaccurate data about the car. Mustang dyno operators are notorious for altering "correction factors" to give higher numbers. With a DynoJet this is impossible.

GD

Orr89RocZ

iTrader: (20)

It really depends and varies from combo to combo but at that power level i may guess 20-30 whp

25thannivZ28

I will post results when I get them, end of September. I'm just curious in advance, how much I can anticipate because I was surely hoping to tip the 500 mark with this years upgrades. Thank you for that information!

skinny z

There may be other places where your engine could be tweaked in the pursuit of 500 HP. It's not all that difficult to produce 1.2 HP/CI. Doing so with 350 cubes gets you 420 HP. Lots of people have been there and done that and with engine specs that don't stress all of the parts all that much. Get the same kind of results out of 427 CI and you have your 500 HP. 512 to be exact.
Dialing in the WOT AFR will help. Look into your total spark advance as well.
I'm curious as to what the rest of your engine package is like.

Orr89RocZ

iTrader: (20)

Hes talking at the tire which is a bit more involved but it still isnt unheard of for a good 400+ inch sbc to make near 500 whp but thats alot thru an auto trans

skinny z

True. That IS rear wheel horsepower isn't it.

25thannivZ28

Sorry for delay, was on vacation.

I've got AFR 220 (Eliminator 1110) Heads, Super Victor II Intake, Quickfuel SS850 Carb, hooker LT Headers w/3" collectors merging to a single 4" Mufflex Exhaust.

Camshaft, card pictured.