Help me analyze these dyno numbers....

[arbailey]

If it matters these runs were made on a portable dyno. Both runs were made with all the mods in my sig EXCEPT the pulleys, and fuel pump which I just installed. Does anyone know why the A/F ratio would lean out with the higher fuel pressure? I'm wondering if the old stock pump couldn't keep up under the higher pressure. Also, now that I installed the 190lph pump where should I set FP, and can I expect a HP increase?

Run #1 @ 44psi FP ------------------------------------- Run #2 @ 47psi FP

RPM-----HP-------TQ------A/F RATIO -------------- HP---------TQ---------A/F RATIO
2300---102.4----233.9----13.3 ------------------- 102.6-----234.2-----14.2
2400---109.7----240.0----12.8 ------------------- 110.5-----241.9-----13.8
2500---114.8----241.2----12.1 ------------------- 116.0-----243.8-----12.9
2600---119.5----241.3----12.1 ------------------- 121.0-----244.4-----12.8
2700---125.1----243.3----12.3 ------------------- 126.5-----246.1-----12.9
2800---131.8----247.3----12.4 ------------------- 133.3-----250.0-----12.9
2900---140.0----253.5----12.3 ------------------- 141.2-----255.7-----12.9
3000---148.0----259.0----12.3 ------------------- 149.1-----261.0-----12.9
3100---154.9----262.4----12.3 ------------------- 156.3-----264.8-----12.9
3200---160.6----263.5----12.4 ------------------- 162.0-----265.8-----12.9
3300---166.4----264.9----12.4 ------------------- 167.7-----266.9-----12.9
3400---173.3----267.8----12.3 ------------------- 174.6-----269.7-----12.9
3500---179.9----270.0----12.2 ------------------- 181.6-----272.5-----12.9
3600---186.3----271.8---12.3 ------------------- 187.6-----273.7-----12.9
3700---191.4----271.6----12.4 ------------------- 193.0-----273.9----12.9
3800---195.4----270.0----12.5 ------------------- 197.9-----273.5-----13.0
3900---199.8----269.1----12.7 ------------------- 201.8-----271.7-----13.1
4000---203.4----267.1----12.8 ------------------- 205.5-----269.9-----13.1
4100---206.5----264.6----12.8 ------------------- 208.5-----267.1-----13.2
4200---209.7----262.2----12.8 ------------------- 211.5-----264.5-----13.2
4300---213.0----260.1----12.8 ------------------- 215.1-----262.7-----13.1
4400---215.0----256.6----12.7 ------------------- 217.1-----259.2-----13.2
4500---216.4----252.6----12.8 ------------------- 218.3-----254.7-----13.3
4600---217.6----248.5----12.9 ------------------- 219.2-----250.3-----13.3
4700---217.5----243.0----13.0 ------------------- 219.7-----245.5-----13.4
4800---217.9----238.4----13.0 ------------------- 219.8-----240.5-----13.4
4900---218.3---234.0----12.9 ------------------- 221.0-----236.9-----13.3
5000---217.8----228.8----12.8 ------------------- 221.2 ---232.3-----13.1
5100---217.3----223.7----12.7 ------------------- 220.3-----226.9-----12.9
5200---215.1----217.2----12.5 ------------------- 218.2-----220.4-----12.8
5300---212.3----210.4----12.4 ------------------- 215.5-----213.5-----12.6
5400---208.2----202.5----12.3 ------------------- 210.7-----204.9-----12.4

Date/Time 09/25/04 @ 12:13PM ---------------- Date/Time 09/25/04 @ 12:20PM
Barometric Pressure 30.32 in.Hg ---------------- Barometric Pressure 30.31 in.Hg
Vapor Pressure 0.27 in. Hg --------------------- Vapor Pressure 0.26 in.Hg
Intake Air Temp 85.4*F ------------------------ Intake Air Temp 86.2*F
Correction Factor 0.98 SAE -------------------- Correction Factor 0.98 SAE

 

[9250stang]

To me, it looks like you are losing a lot of torque really early.

Anyone else agree?

 

[89CopCoupe]

The higher setting is the more ideal A/F ratio for your combo.
Your analysis is on the money ... the factory 88lph pump doesn't carry the volume and struggles with the increased pressure ... but a little leaner makes more power too.

With the 190 I would set it at 40-43 and adjust up and down until the car feels good to you (if you're avoiding a dyno tune) ... I used to run mine a little fat, because the exhaust tone was deeper while in open loop ... yup, I'm a gear head Running it fat just to hear those few intial minutes of depth

 

[arbailey]

Thanks for the help. After I installed the pump I set it back to stock which I believe is 39. I'll go up a little at a time and see what happens.