MAF/FUEL/HP questions - MustangForums.com



4.6L (1996-2004 Modular) Mustang Technical discussions on 1996-2004 4.6 Liter Modular Motors (2V and 4V) within.

Reply
 
 
 
Thread Tools Search this Thread
Old 03-26-2011, 10:59 AM   #1
disposablehero27
4th Gear Member
Thread Starter
 
disposablehero27's Avatar
 
Join Date: Jul 2009
Location: Virginia
Posts: 1,216
Unhappy MAF/FUEL/HP questions

Forged internals, stage 3 MMR ported heads, intake, intake spacer, IRMC DELETE,BBK Long tube headers, BBK H-pipe, P1SC procharger, 3 core intercooler 1600cfm throttle body, and a few other mods. I'm not sure on the psi because of these questions. 96 Cobra with these mods. At the moment i am researching and purchasing items for the build. I had a plan of 500hp, however im thinking its going to be closer to 6/700hp. Right now I have an in tank 255lph fuel pump, the inline pro pump from procharger....(what is that LPH?) 60lb injectors, and a 90mm Lighting MAF. Is this MAF going to hold or able to be tuned around? how close are these 60lb injectors going to get me? and planning on bigger fuel lines, and rails... but the pumps? enough or way off?

Thanks in advance for the advice.
disposablehero27 is offline   Reply With Quote
Old 03-26-2011, 01:57 PM   #2
cliffyk
TECH SAVANT
 
cliffyk's Avatar
 
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,930
Default

Quote:
Originally Posted by disposablehero27 View Post
Forged internals, stage 3 MMR ported heads, intake, intake spacer, IRMC DELETE,BBK Long tube headers, BBK H-pipe, P1SC procharger, 3 core intercooler 1600cfm throttle body, and a few other mods. I'm not sure on the psi because of these questions. 96 Cobra with these mods. At the moment i am researching and purchasing items for the build. I had a plan of 500hp, however im thinking its going to be closer to 6/700hp.

Right now I have an in tank 255lph fuel pump, the inline pro pump from procharger....(what is that LPH?)
Litres/hour; 1 lph = 0.264 gallons/hour = 1.64 pounds╣/hour. So, your 255lph pump could theoretically deliver 418 lb/h of 93 octane fuel. Actual delivery will be more or less depending on fuel pressure and supply voltage--here's a chart of Walbro's standard pressure 255 lph pump delivery rates at selected voltages and pressures:



You can see that at 40psi the delivery rate is 58 (@12V) to 68 gal/h (@13.5V), assuming 13.5V thats 418 lb/h of 93 octane. Running f/i that will support 690fwHP, or 590rwHP--flat out with NO headroom, making 500rwHP a practical limit for that pump.

Quote:
60lb injectors, and a 90mm Lighting MAF. Is this MAF going to hold or able to be tuned around? how close are these 60lb injectors going to get me? and planning on bigger fuel lines, and rails... but the pumps? enough or way off?
At 90% duty cycle and 40psi the 60lb/h injectors will be able to move some 414lb/h of fuel [(40/43.5)^.5 * 60 * 8 *& .9], Running f/i that's 690fwHP or 585rwHP, well over the pump's 500rwHP practical limit.

The Lightning MAF pegs at 3800lb/h or so, which is also the PCM's air flow limit. At 11.5:1 AFR 3800 lh/h of air would have 330lb/h of fuel being mixed with it. Running f/i, 330lb/h of fuel would support 550fwHP, or 470rwHP.



In summary:
  • the 255lph pump can support 500rwHP;
  • the 60lb/h injectors (if enough fuel were available) can support 585rwHP;
  • the 90mm Lightning MAF can support 470rwHP;

Now these are all theoretical and rule-of-thumb based calculations. Real world results could be easily ▒10%, they are nonetheless the numbers I would use as guidelines if setting fuel and air systems for a target HP.

----------------------------------------
╣ - 93 octane gasoline weighs approximately 6.2 lb/gal at STP.
cliffyk is offline   Reply With Quote
Old 03-26-2011, 03:03 PM   #3
disposablehero27
4th Gear Member
Thread Starter
 
disposablehero27's Avatar
 
Join Date: Jul 2009
Location: Virginia
Posts: 1,216
Default

hey thanks cliffy, now if i have the in tank 255 plus that pro pump inline with the charger kit.. whatever that is... would that support more HP? lets say if its a 255 in line... could i push more HP or doesn't matter, to much for the in tank.
disposablehero27 is offline   Reply With Quote
Old 03-26-2011, 04:56 PM   #4
97stanger
5th Gear Member
 
Join Date: Dec 2005
Location: NJ
Posts: 3,767
Default

your build is very similar to mine. (97 GT, forged, MMR stage 3 heads, SI trim, meth, blower cams, edelbrock manifold, etc)

No way your 90LMAF will support that hp range
I personally run the SCT BA3000

As for an idea for fuel, this is what I run:
Dual Walbro 300lph pumps
y block
inline fuel filter
sumped tank
edelbrock fuel rails
8 feed lines, 6 return
adjustable fpr

I am expecting to be in the 600rwhp range thru a built auto fyi
97stanger is offline   Reply With Quote
Old 03-26-2011, 05:15 PM   #5
disposablehero27
4th Gear Member
Thread Starter
 
disposablehero27's Avatar
 
Join Date: Jul 2009
Location: Virginia
Posts: 1,216
Default

Thats awesome, very impressive. Yeah seems I need to get rid of the 90mm MAF, just not going to do it. May as well swap for 80lb injectors too. Not a huge deal. What about the second posted question, anybody know what the 255lph + a 255lph inline pump can handle?
disposablehero27 is offline   Reply With Quote
Old 03-26-2011, 07:01 PM   #6
disposablehero27
4th Gear Member
Thread Starter
 
disposablehero27's Avatar
 
Join Date: Jul 2009
Location: Virginia
Posts: 1,216
Default

anyone?
disposablehero27 is offline   Reply With Quote
Old 03-27-2011, 05:27 PM   #7
disposablehero27
4th Gear Member
Thread Starter
 
disposablehero27's Avatar
 
Join Date: Jul 2009
Location: Virginia
Posts: 1,216
Default

*****bump
disposablehero27 is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Intake manifold replacement Dokilar 4.6L (1996-2004 Modular) Mustang 15 10-16-2015 08:13 PM
Win $1500 Worth of RTR Parts - AmericanMuscle AMAlexLazarus AmericanMuscle.com 3 10-02-2015 08:06 AM
October Sale - AmericanMuscle AMAlexLazarus AmericanMuscle.com 0 10-01-2015 10:29 AM
Hot Lap: 2015 Roush RS3 Test + Build a Supercharger! - AmericanMuscle.com AMAlexLazarus AmericanMuscle.com 0 10-01-2015 09:21 AM
Hello, new user with an older Mustang and a question treesloth New Member Area 4 09-28-2015 07:03 AM


Tags
05, 600, 80lb, 90mm, blow, dual, flow, gt, horsepower, hp, injectors, lightning, limit, maf, mustang, rate, stock, walbros

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump


All times are GMT -5. The time now is 12:36 PM.