What should I expect from 450hp?
Got a 408 a 3350# Duster, estimate 450-475hp. This is a street only car--4spd, 3:23 gears with 245/60-15 BF Goodrich's. I got a Holley sniper so can look at datalogs. If I am in first gear rolling along at about 2000rpm and mash it, it takes about 1.75 seconds to get to 6000rpm. Only traction addition is the pinion snubber, but seems like it hooks up, tires aren't squealing or leaving black marks . Just seems to me it should be quicker or am I expecting to much?
Sniper with WOT a/f at 12.8, Edelbrock rpm heads & intake. 235/239 @ .050, 535/550 lift. 9.5 compression
What's your elevation?
Time to dig out the compression tester.
IDK about 450/475, but my 367 with 3.55s spins the 325/50-15 BFG DRs to, they say, 90 plus mph. and it takes about 8and change seconds to hit a hundred.
With 295/50-15s that 367 busts the tires loose at 40,45,and 50 mph with 3.55s in second gear, with just a stomp on the ol' go-pedal...
Ima thinkin' that's what you should expect.
Ima thinkin when you go around a corner on those skinny wiener tires, you should go easy on the pedal else she will spin you around in a circle leaving you pointed backwards up on the median with at least one bent rim. That's what you should expect.
With 3.23s I would expect rubber into third gear, more than a chirp.
I would expect to have to baby the throttle below 35 mph in second gear so as not to spin those pizza cutter 245s.
I would expect a foot stomp in third gear to get you 85mph when you pass the driver's door, having pulled out to pass some slowpoke going 60 in a 65 zone.
I would expect in first gear with the line-loc applied, to bust the tires loose at little more than idle, and then you can reduce the throttle to churn the tires at 800 rpm, you laughing hysterically.
My 367 does all these things and more with 3.55s and a 230* cam.
Ima thinking your stroker with 3.23s should do the same ...... at least.
Ima thinking the 3.23s are just fine.
Ima thinking your tune is off. starting with your elevation.
My secrets are;
180psi cranking cylinder pressure.
Loose pistons and adequate ring gaps
fresh cold air, you gotta have it!
minimum coolant temp of 205 degrees, and a maximum of 207*.
87E10 fast burning gas,lol
full-length 3" duals.
a 750DP carb
Quick as a cat on fire, three guys are gonna jump in and say I don't need dual 3s all the way. And almost as quick one will say 207*F is too hot.
I'm not here to debate that. My car went 93 in the Eighth with these specs at 3457 pounds raceweight and at 930 ft elevation, on a HOT July afternoon, with a teensey weensey 230* cam; so tell someone who cares,lol.
If I had just one guess, I'd say you need more pressure and or to run a hotter water jacket..
Guys argue with me all the time, and I respect their opinions as most have more experience than me, but I'll tell you what I believe;
I believe that those aluminum heads suck tremendous amounts of heat out of the chambers, and when you stomp on the gas a lot of the energy in the fuel goes straight thru the heads and into the surrounding atmosphere, including cooking your intake.
To me it seems that they take a long time to heat up; in third gear I sometimes think I can feel it when the heat is finally staying in the chamber,and she starts to make power.
I did not know this when I originally assembled my engine, and I cannot even prove it's true. But I believe it.
To combat this behavior, I painted the heads three coats. and
I bumped the coolant temp up twice. Along the way, I had to loosen the pistons and loosen the ring-gaps, and figure out how to stabilize the coolant temp. And I increased the pressure and decreased the Quench, and I fed her air from above the hood, which made a radical improvement. All these things were done in an effort to reduce the heads from shedding heat thru the aluminum . And the results I think speak for themselves.
As to the full length 3" duals. I agree that they are generally overkill for the production of power. That's not why I choose them. I chose them to be heat sinks, to suck heat out of the exhaust as it is on the way to the mufflers. This reduces the volume of the gasses and they hurry thru the muffs. And then they cool some more on the way to the bumpers.
What this does is it reduces the pressure in the pipes which allows the overlap period to actually work.
Does it work?
IDK but the car went 93 with a stinking lil 230 cam.
Now; lets talk about your pressure. I looked it up and Wiki says you are up around 1900 ft elevation. And you stated 9.5 Scr, and said a 235* cam. Ima gonna translate that 235* @.050 into a 284 advertised, and I'll guess it's on a 114Lsa; you sound like a 114* kindof guy.And so I'll install it at 110 and get an Ica of 72*.
Here's what the Wallace has to say about that
Static compression ratio of 9.5:1.
Effective stroke is 2.92 inches.
Your dynamic compression ratio is 7.21:1 .
Your dynamic cranking pressure is
132.74 PSI.
V/P (Volume to Pressure Index) is
119
Notice the crappy 133 psi cylinder pressure, which translates to a VP of 119 which is what a LA318 makes. If this is correct, then you can fully expect your stroker to perform just like a 318 up to about 3000 rpm.
read about VP here; V/P Index Calculation
If I'm right, and sometimes I am, then this is your major problem. You will need to prove your pressure, and then figure out a way to pump it up into the 160s at the minimum, 170s preferred, and into the 180s to wake that beotch up!
Some guys here on FABO, claim pressure at or over 200psi still on pump gas.
My combos at up to 185psi, have all run on 87E10 with 32/34 degrees of power-timing, as early as 3400/3200 rpm.
Time to dig out the compression tester.
BTW, my BFGs don't leave blackies either after about one afternoon of driving them,lol. Not 245s, not 255s, not 275s, and not 295s That first few burn outs cooks em hard and after that, they are rollerskates. But they can last several summers like that, which makes it hard to justify taking them off. Good thing I have other cars to put them on.