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Re: Disappointment at the dyno
[Re: 70Drop]
#1628820
06/04/14 11:26 PM
06/04/14 11:26 PM
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Joined: Nov 2004
Posts: 3,544
Syracuse,NY
CompWedgeEngines
master
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master
Joined: Nov 2004
Posts: 3,544
Syracuse,NY
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Your cars performance is exactly what it should be doing with 410 RWHP. At 3200#, it should be running 11 teens, and your MPH is good for that.You may not like the numbers the engine put out, but its doing what it should at that horsepower. You'll simply need more HP and torque to do what you want to do, and I'm not sure its in that combo as it sets right today.
Your heads are a mystery, and with a 500" motor, probably trouble.
Keep this in mind, Stock eliminator cars, at almost 3800 pounds, and .490 cams, can run under 10.50s. They do this with efficiency, all the way thru the cars set up. And before all the naysayers jump on the " yea, but thats one of those trick stockers", it doesnt matter. The math is the math. They work with way less cylinder head, and way less cubic inches. There is always MORE in the chassis etc.
What are the 60' times, and 1/8 th mile et and mph?
RIP Monte Smith
Your work is a reflection of yourself, autograph it with quality.
WD for Diamond Pistons,Sidewinder cylinder heads, Wiseco, K1 rods and cranks,BAM lifters, Morel lifters, Molnar Technologies, Harland Sharp, Pro Gear, Cometic, King Engine Bearings and many others.
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Re: Disappointment at the dyno
[Re: AndyF]
#1628823
06/05/14 12:27 AM
06/05/14 12:27 AM
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Joined: May 2008
Posts: 5,399
Aurora, Colorado
451Mopar
master
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master
Joined: May 2008
Posts: 5,399
Aurora, Colorado
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Quote:
500 inches with standard port heads will have a torque peak in the low 4000's and a HP peak in the low 5000 range so I don't see a problem there. That is just how the physics works out.
My guess is that the heads aren't very good even though they have a ton of work and they probably cost a lot. But it could be a bunch of other little items that are dragging you down.
Do all of the normal stuff and see if you find any clues. Leak down test, look at the plugs, double check the valve lash, double check timing, AFR, etc. I've seen a lot of weird stuff over the years such as a collapsed muffler, or a sticking e-brake that cost 50 hp on the dyno. I had a Mopar ignition system once that ran fine on the street but cost me over 60 hp on the dyno when compared to a MSD ignition. A burnt plug wire costs 30 hp on my Coronet and isn't noticeable when driving.
Andys right. Reference the Mcfarland formula.
Jim McFarland's formula for calculating the torque peak in and engine. The formula is: the smallest CSA of the intake track x 88200 divided by the cubic inches of one cylinder.
RPM at torque peak = cylinder head cross section area X 88200 / Cylinder volume.
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Re: Disappointment at the dyno
[Re: 70Drop]
#1628825
06/05/14 01:22 AM
06/05/14 01:22 AM
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Joined: Nov 2010
Posts: 1,397
Carson City, Nevada
Biginchmopar
pro stock
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pro stock
Joined: Nov 2010
Posts: 1,397
Carson City, Nevada
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4 tenths throughout the run, that tells me the same weight to horsepower between the two cars just one left better then the other. It happened in the 60' time. Getting the combo exactly right is real important. Converter,Cam,Gears all have to work together. 
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Re: Disappointment at the dyno
[Re: RobX4406]
#1628827
06/05/14 01:53 AM
06/05/14 01:53 AM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
10 second car that leaves like a 12.00 car.
The converter and chassis need a ton of work.
Yep
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Re: Disappointment at the dyno
[Re: 70Drop]
#1628831
06/05/14 08:20 AM
06/05/14 08:20 AM
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Joined: Feb 2005
Posts: 4,313
Prospect, PA
BSB67
master
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master
Joined: Feb 2005
Posts: 4,313
Prospect, PA
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Quote:
The fuel pressure is 7.5 and there hasn't been any problem with fuel delivery. Holley Blue pump.
7.5 psi in the traps? Fuel delivery usually shows up as low power 
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Re: Disappointment at the dyno
[Re: BSB67]
#1628832
06/05/14 09:28 AM
06/05/14 09:28 AM
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Joined: Dec 2006
Posts: 1,178
Indy
FlyFish
super stock
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super stock
Joined: Dec 2006
Posts: 1,178
Indy
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The car in the other lane is probably close to a "best case" scenario. His 60' is REALLY good for the ET. You could get your car down to the low 1.5's or high 1.4's without too much trouble...that should get you into the high 10's.
What is your tire size and gear?
67 Barracuda street car, 408, e85, 1.38 60', 6.44 @105.9 in the 1/8 mile, 10.19 @130.5 in the 1/4...so far....
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Re: Disappointment at the dyno
[Re: FlyFish]
#1628833
06/05/14 09:43 AM
06/05/14 09:43 AM
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Joined: Dec 2006
Posts: 1,178
Indy
FlyFish
super stock
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super stock
Joined: Dec 2006
Posts: 1,178
Indy
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I would also add that if you want 10.60's, you will need more power....and like others have said, it is probably your heads that are holding you back.
For what its worth, I have the little brother to that cam (Comp cams XR286R) in my 10.8:1 compression small block stroker with 90 less cubes that runs mid 10's in a 3200 lbs car...but my heads flow really well (thank you Ryan Johnson @ SDSS), that's why I think its your heads that are the bottle neck.
67 Barracuda street car, 408, e85, 1.38 60', 6.44 @105.9 in the 1/8 mile, 10.19 @130.5 in the 1/4...so far....
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Re: Disappointment at the dyno
[Re: FlyFish]
#1628834
06/05/14 10:20 AM
06/05/14 10:20 AM
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Joined: Oct 2008
Posts: 492
South Jersey, NJ
DragDart360
mopar
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mopar
Joined: Oct 2008
Posts: 492
South Jersey, NJ
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It was mentioned earlier and I'll repeat, you need more carb,ie. a 1050 Dominator, an 850 is not adequate for 500 inches. When you get enough air and get the chassis sorted out where it will hook I think you'll be close to where you need to be. At that point the heads may become the bottle neck to more power.
70 Dart Swinger, 2850 lbs
SB 408, Bullet roller 264/268 @50 .636 SSDS stage 2 Edelbrock heads, 1 7/8 Headmans, 1050 dominator by Dom, 9.867 @ 133
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Re: Disappointment at the dyno
[Re: Mr.Yuck]
#1628836
06/05/14 11:14 AM
06/05/14 11:14 AM
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Anonymous
Unregistered
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Anonymous
Unregistered
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Anyone that works with Mopars on the dyno knows that 35 is not enough timing--that is at the point where a few more degrees means big leaps in HP usually--many like around 41 or so in my experience--now I know it all comes down to combustion chamber--piston top etc but 35 will not get it when seeking best power numbers in most cases
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Re: Disappointment at the dyno
[Re: ]
#1628837
06/05/14 12:42 PM
06/05/14 12:42 PM
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Joined: Jan 2003
Posts: 13,363
Marion, South Carolina [><]
an8sec70cuda
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 13,363
Marion, South Carolina [><]
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Quote:
Anyone that works with Mopars on the dyno knows that 35 is not enough timing--that is at the point where a few more degrees means big leaps in HP usually--many like around 41 or so in my experience--now I know it all comes down to combustion chamber--piston top etc but 35 will not get it when seeking best power numbers in most cases
 With those heads, I'd start at 38° total timing and go up from there. It'll like the extra timing.
Don't be tempted by the big B1 intake you mentioned in the classifieds...it will KILL your lowend torque.
I think the power it made is right in line w/ what you have and what the car runs. Get the 60' down w/ either some chassis tuning and/or torque converter and it'll run much better.
When you decide you want to go faster and make more power, I'd do a big heads/cam/intake/carb change.
CHIP
'70 hemicuda, 575" Hemi, 727, Dana 60
'69 road runner, 440-6, 18 spline 4 speed, Dana 60
'71 Demon, 340, low gear 904, 8.75
'73 Chrysler New Yorker, 440, 727, 8.75
'90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt
'06 GMC 2500HD LBZ Duramax
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