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Help Make Sense of my Dyno numbers (fuel problems)

  • Thread starter Thread starter 65racecoupe
  • Start date Start date Aug 24, 2004
6

65racecoupe

Founding Member
Mar 24, 2002
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45
Tempe, AZ
Aug 24, 2004
#1
  • Aug 24, 2004
  • #1
I recently took my car to the Dr Gas dyno in Sandy Utah. You really find out alot about your car when you dyno it.


Anyways, my numbers were
289 hp and 289 ft lbs torque at 5100 rpm. After that, it drops off the face of the earth. 289/289 is really good at that rpm concidering my peak should be 2000 rpm higher.

This would explain my 14.2 in the 1/4. I was shifting at 6800 rpm. I will be down in the mid to high 13s shifting at 5000, even though my engine has a ton left in it without the fuel problems.

My 331 is made to rev to 68 - 7000 rpm. Neal, the dyno guy, said that my fuel delivery is to blame. It could also be the alternator not being able to keep up (making the fuel pump not keep up as well).

I have a 140 GPH Mallory electric fuel pump, fuel filter, and fuel pressure regulator.

I have an autolite alternator. I guess it wouldn't hurt to get a 140 amp alternator while I am at it.

Am I on the right track?
 

dodgestang

Active Member
Dec 15, 2003
1,360
0
37
53
Cecil County, MD
www.dodgestang.com
Aug 24, 2004
#2
  • Aug 24, 2004
  • #2
That's quite the wall....I know it sounds simple, but did you confirm

1. You had a full throw on the throttle
2. The secondaries are actually opening
 
6

65racecoupe

Founding Member
Mar 24, 2002
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Tempe, AZ
Aug 24, 2004
#3
  • Aug 24, 2004
  • #3
Actually, no. We went straight to the fuel problem because the FPR guage was going crazy at 5000 rpm and higher.
 

brianj5600

Active Member
Sep 19, 2003
1,964
2
39
Middle TN
www.cardomain.com
Aug 24, 2004
#4
  • Aug 24, 2004
  • #4
A/F ratio is most helpful as well. If it is electrial it would go pig rich. Fuel related pig lean?
 

69Rcode_Mach1

Active Member
Apr 20, 2004
1,473
1
37
Salt Lake City, Utah
Aug 24, 2004
#5
  • Aug 24, 2004
  • #5
Hey 65 racecuope i didn't know that neal had finally got the chassis dyno up and going. Finally we have a chassis dyno in Utah. How much did it cost for a pull i think i might want to try it out later on for the same reasons you did. Also do you have an AIM account or anything i would really like to get to know some more stangers in my own state. Sorry didn't mean to hijack.
 
S

slapper

Founding Member
Mar 6, 2002
447
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Aug 25, 2004
#6
  • Aug 25, 2004
  • #6
Is the fuel supply line big enough?
 
B

bull999999

New Member
Jun 26, 2004
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Aug 25, 2004
#7
  • Aug 25, 2004
  • #7
From several dyno articles I've read in the past, there's been many cases where an engine will experience a sudden drop in power at high RPM due to the valve float or the valves bouncing open after it closes due to the weak springs.
 
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