Fuel PSI and horsepower... - PowerStrokeNation : Ford Powerstroke Diesel Forum
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 22 (permalink) Old 10-19-2008, 11:55 AM Thread Starter
PSN Veteran
 
DZL JIM's Avatar
 
Join Date: Sep 2007
Location: Northeast Ohio
Posts: 2,079
Fuel PSI and horsepower...

Thought I'd play with fuel pressures on the dyno at our dyno day yesterday.
230cc hybrids, custom fuel system with 5/8" supply from tank to heads, 1/2 regulated return.
TW Extreme tunes.
4 consecutive runs, made changes as follows:

1) Stock SD electric pump at 50 psi.
2) A-1000 pump at 50 psi.
3) A-1000 @ 65 psi.
4) A-1000 @ 75 psi.

1) was a base line. Same spotter watched all 4 runs. He said the pressure only dropped 1 to 2 psi max during any of the runs with wither pump. SD pump, I thought, did pretty well, not to loose pressure at all (basically).
2) Picked up 2 hp and almost 30 ftlb.
3) Picked up another 2 hp and 15 ftlb.
4) Dropped 2 hp, picked up 2 ftlb.

What's interesting to me is the increase in torque, and the graph shows the power coming in quicker for each pressure change, by about 100 rpm. Not much difference in power between 75 and 65psi, but the pump sure strains more.

I just wanted to see for myself if 65psi gets more power than 50 psi.
Thought I'd share for those curious as well.
DZL JIM is offline  
Sponsored Links
Advertisement
 
post #2 of 22 (permalink) Old 10-19-2008, 12:25 PM
FORD..THE ROCK CRUSHER
 
Ron's power stroke's Avatar
 
Join Date: May 2008
Location: Whitefield,NH (The White Mountains)
Posts: 2,342
Re: Fuel PSI and horsepower...

when you say 3) Picked up another 2 hp and 15 ftlb. is that over stock pump ??
in other words.. new pump at 65 PSI you gained 4 more HP and 45 FT of TQ over the stock pump at 50 psi??

Early 99 7.3 F350 auto,TN T-4 mount with a s467 for air,H-11's stud's SRP 1.1 for oil all supplied by unlimited diesel..beehives, DI push rod's, new alliant 315/200 hybrids,Driven diesel fuel system with a fuel lab 41401. ...tuned by Gearhead..
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


88 F250 7.3 IDI plow truck 112k - bone stock.
Ron's power stroke is offline  
post #3 of 22 (permalink) Old 10-19-2008, 01:29 PM
Banned
 
Join Date: Jul 2007
Location: Twilightzone
Posts: 7,764
Re: Fuel PSI and horsepower...

Cool Jim. If that's good data (and it seems to be) then it backs up the fact that the truck just feels crisper at 60 than at 50 or 75. More power down low.

Which also falls in line with the fact that I saw less smoke like that.

Now if someone could just explain it.

Charles is offline  
 
post #4 of 22 (permalink) Old 10-19-2008, 03:16 PM
<-- it's like that
 
Join Date: Jul 2007
Location: Parker, CO
Posts: 6,567
Re: Fuel PSI and horsepower...

Quote:
Now if someone could just explain it
If you want even more of a headache, explain why some types of injectors run better at pressures closer to 50 psi, and others run better at closer to 70 psi.

Curtis
2002 F-250 PSD
Gambling with 250/200's on PMR's.
478hp/851tq on Haller's dyno - 7/28/12
Your connection to the
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.
Pocket is offline  
post #5 of 22 (permalink) Old 10-19-2008, 03:47 PM Thread Starter
PSN Veteran
 
DZL JIM's Avatar
 
Join Date: Sep 2007
Location: Northeast Ohio
Posts: 2,079
Re: Fuel PSI and horsepower...

Quote:
Originally Posted by Charles View Post
...Which also falls in line with the fact that I saw less smoke like that.
Now if someone could just explain it.
You know, people at the dyno said the truck smoked a lot more at 50 psi than it did at 65 and 75 psi.

As for trying to explain it, I've been scratching my head on that one...
I would think as long as there's fuel at the injector, it should work just the same.

Ron's PSD,
Each step added to the previous, not to stock, per say. Sorry for the confusion.
Quote:
...in other words.. new pump at 65 PSI you gained 4 more HP and 45 FT of TQ over the stock pump at 50 psi??
Yes.
DZL JIM is offline  
post #6 of 22 (permalink) Old 10-19-2008, 04:11 PM
HP Junky
 
Join Date: Jul 2007
Location: Hooper, UT
Posts: 4,927
Re: Fuel PSI and horsepower...

That info follows with the non-formal testing I've done as well. I dynoed mine with the pressure dropping down to around 35psi then again with it holding a constant 65psi when I was running my mini me's. Picked up 27hp once the pressure stayed constant.

As for the different pressures themselves, my truck seemed to like 65psi the best with the hybrids, but the SHO Hybrids seemed to like 57-58psi better
RockinJW is offline  
post #7 of 22 (permalink) Old 10-19-2008, 04:16 PM
FORD..THE ROCK CRUSHER
 
Ron's power stroke's Avatar
 
Join Date: May 2008
Location: Whitefield,NH (The White Mountains)
Posts: 2,342
Re: Fuel PSI and horsepower...

Quote:
Originally Posted by DZL JIM View Post
You know, people at the dyno said the truck smoked a lot more at 50 psi than it did at 65 and 75 psi.

As for trying to explain it, I've been scratching my head on that one...
I would think as long as there's fuel at the injector, it should work just the same.

Ron's PSD,
Each step added to the previous, not to stock, per say. Sorry for the confusion.

Yes.
thanks for that..ill be putting SS stage 2 with moded nozzles and a DI regulated return in a week or two..now i know what to shoot for...

Early 99 7.3 F350 auto,TN T-4 mount with a s467 for air,H-11's stud's SRP 1.1 for oil all supplied by unlimited diesel..beehives, DI push rod's, new alliant 315/200 hybrids,Driven diesel fuel system with a fuel lab 41401. ...tuned by Gearhead..
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


88 F250 7.3 IDI plow truck 112k - bone stock.
Ron's power stroke is offline  
post #8 of 22 (permalink) Old 10-19-2008, 04:26 PM
green member
 
roosterdiesel's Avatar
 
Join Date: Aug 2007
Location: Yellow, TX
Posts: 297
Re: Fuel PSI and horsepower...

Quote:
Originally Posted by DZL JIM View Post
As for trying to explain it, I've been scratching my head on that one...
I would think as long as there's fuel at the injector, it should work just the same.


It's called charge pressure in the industry. The fuel pressure "charging" the P&Bs can affect delivery in various ways ie atomization and actual start of injection a degree or soo when I played with high pressure phasing pressures on inlines.


I've played with it on rotary Stanadyne and Bosch's. Also with electronic governor inline bosch pumps. I can change nothing but the inlet pressure to any pump and it affects the delivery in the graduated cylinders. The rotaries are affected the most when you change the internal supply pump that charges the pumping plungers....that would essentially be the same as our head rail pressure.

Why the higher pressures probably show drops....could be some injector internals are worn...anytime you have a moving part theres leakage in the injector. You have to find the right pressure to where the p&b's charge to their happy point....not too high and not too low.

2001 F-250 handshaker
#54
Stealth HPOPs
Alliant ACs
Forged rods with other junk to make it work

Thanks to TDP, BDP, RDS, PHP and TDGrp
roosterdiesel is offline  
post #9 of 22 (permalink) Old 10-20-2008, 03:19 AM
 
Join Date: Dec 2007
Posts: 349
Re: Fuel PSI and horsepower...

This may solve a problem I am having. I am going to back mine off from the 70psi I am running and see what happens.
Tenn01PSD350 is offline  
post #10 of 22 (permalink) Old 10-20-2008, 06:10 AM
PSN Veteran
 
urbanwheeler's Avatar
 
Join Date: Nov 2007
Location: Chico, CA
Posts: 2,031
Re: Fuel PSI and horsepower...

i guess i'll be bumping mine up to 65, currently have it set at 58.

'96 f-250, auto, shackle flip, solid axle, rsk, high/crossover steering, 3.73's, true trac's front and rear, trac bars, gt4202, 7.3 ic, idm mod, ccv mod, A1000, 4-line DIY Gen3, dual ipr's, casserly 350/200's, arp studs, 910's, pushrods, elec. fan, 2-stage nitrous, fluidampr.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
[SIGPIC][/SIGPIC]
urbanwheeler is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the PowerStrokeNation : Ford Powerstroke Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome