Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums - Camaro5.com
 
Emblempros
Go Back   Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums - Camaro5.com > Engine | Drivetrain | Powertrain Technical Discussions > Forced Induction - V8

Forced Induction - V8 V8 Supercharger, turbo, nitrous discussions

Reply
 
Thread Tools
Old 08-31-2013, 12:04 PM   #1
pdiddy
 
Drives: 2011 2SS
Join Date: Jun 2013
Location: Kansas City
Posts: 473
fuel pressure/duty

I am curious how everyone that is FI is reading there fuel pressure through the rpm range and how they are determining if they are dropping off are you data logging or what to determine this I had my car dyno tuned but only say the AF ratio and the hp/tq numbers and nothing more. I want to be sure everything is and stays good as I continue to do more to my car.
__________________
2011 2SS JBA LONG TUBE, JBA HIGH FLOW CATS AND 3" EXHAUST, CAI CAI, 3.91 GEARS 18" cf5 NITTO NT555R, Bmr TRAILING ARMS, AND BUSHINGS, DYNO TUNED AT 408 RWHP/ ADDED A MAGGIE WITH 3.6 PULLEY ZL1 PUMP FIC 63# injectors ADM FPCM DYNO TUNED AT 570 RWHP AND 550 RWTQ ADDDED CUSTOM CAM FROM TICK AND OD COG WITH 3.8 FRONT MAKING 650RWHP AT 10psi
pdiddy is offline   Reply With Quote
Old 08-31-2013, 01:11 PM   #2
DarkCry956
 
DarkCry956's Avatar
 
Drives: 2011 Camaro 2SS/RS
Join Date: Oct 2011
Location: Texas RGV
Posts: 580
I tried logging it with SCT and none of their equations worked for fuel pressure. Now i use HPTuners and was told by my tuner we can but AFR should do. I have more than enough fuel pump (Squash) so its not like I'm testing the limits of the stock or ZL1 pumps otherwise I'd want to know fuel pressure. I also got a fuel pressure gauge but I don't think I've ever looked at it at WOT

Edit: My bad. I deleted the stock FPCM so I was trying to log fuel pressure according to my gauge that reads pressure from the fuel regulator.

Last edited by DarkCry956; 08-31-2013 at 02:44 PM.
DarkCry956 is offline   Reply With Quote
Old 08-31-2013, 02:24 PM   #3
TriGun
 
TriGun's Avatar
 
Drives: Camaro 2SS/RS Ice Silver
Join Date: Oct 2009
Location: Kuwait
Posts: 209
You can use SCT or HPTuners.

Injectors duty cycle IDC= RPM x IPW / 120000

RPM = engine RPM, IPW = injectors pulse width.

You have to set your scanner to log for fuel pressure, RPM and IPW for bank 1.

In SCT the fuel pressure is in KPA and the logged value you have to multiply it by 3 for the correct fuel pressure.

During WOT watch the fuel pressure dropping specially near the end of the WOT run.
TriGun is offline   Reply With Quote
Old 08-31-2013, 09:17 PM   #4
Nitroman28

 
Nitroman28's Avatar
 
Drives: 2010 Camaro SS A6
Join Date: Oct 2010
Location: Arkansas
Posts: 1,544
People talk about watch for pressure drop but know one says what that magic psi number you're looking for on N/A and Boosted. 58? 48? Whats to low.
Nitroman28 is offline   Reply With Quote
Old 08-31-2013, 09:22 PM   #5
Supercharged SS
Account Suspended
 
Drives: 2010 Camaro
Join Date: Feb 2010
Location: Sandy Hook, CT
Posts: 12,021
Quote:
Originally Posted by Nitroman28 View Post
People talk about watch for pressure drop but know one says what that magic psi number you're looking for on N/A and Boosted. 58? 48? Whats to low.
I thought mid 50's and up is safe. 55-50 is start watching and below 50 I think you need to upgrade.

Need a tuner to step up and answer.


I have no problem logging fuel pressure with the SCT.
Supercharged SS is offline   Reply With Quote
Old 08-31-2013, 10:31 PM   #6
Matt @ FSP

 
Matt @ FSP's Avatar
 
Drives: 2011 Camaro SS
Join Date: Dec 2012
Location: Bradenton, FL
Posts: 2,536
Quote:
Originally Posted by Nitroman28 View Post
People talk about watch for pressure drop but know one says what that magic psi number you're looking for on N/A and Boosted. 58? 48? Whats to low.

Of course depends on every situation, but yes you want to keep FP up. Once you hit the dip into the 4x range then I would consider the upgrade and of course base that on your future goals. This does not really matter so much for boost or N/A, it's a generic comment. Fuel pressure is one of the lifelines to the motor, this is nothing to play around with.
Matt @ FSP is offline   Reply With Quote
Old 09-01-2013, 10:06 AM   #7
pdiddy
 
Drives: 2011 2SS
Join Date: Jun 2013
Location: Kansas City
Posts: 473
Thanks all I have an sct tuner that gets a error wen I try to use it so I am going to work with sct to get it fixed then try to data log and check my pressure
__________________
2011 2SS JBA LONG TUBE, JBA HIGH FLOW CATS AND 3" EXHAUST, CAI CAI, 3.91 GEARS 18" cf5 NITTO NT555R, Bmr TRAILING ARMS, AND BUSHINGS, DYNO TUNED AT 408 RWHP/ ADDED A MAGGIE WITH 3.6 PULLEY ZL1 PUMP FIC 63# injectors ADM FPCM DYNO TUNED AT 570 RWHP AND 550 RWTQ ADDDED CUSTOM CAM FROM TICK AND OD COG WITH 3.8 FRONT MAKING 650RWHP AT 10psi
pdiddy is offline   Reply With Quote
Old 09-01-2013, 10:24 AM   #8
Nitroman28

 
Nitroman28's Avatar
 
Drives: 2010 Camaro SS A6
Join Date: Oct 2010
Location: Arkansas
Posts: 1,544
Quote:
Originally Posted by Matt @ FSP View Post
Of course depends on every situation, but yes you want to keep FP up. Once you hit the dip into the 4x range then I would consider the upgrade and of course base that on your future goals. This does not really matter so much for boost or N/A, it's a generic comment. Fuel pressure is one of the lifelines to the motor, this is nothing to play around with.
My motor just don't seem to be very efficient. After the maggie I put the ZL1/ADM controller in and pressure was dropping to 39-40psi. AFR was holding good but would lean out past 6000. So I bought the Livernois dual pump. FP still drops 47psi at 6000+.IDC is around 75%. I put a KB on it but it seem to have no affect on it. I finally just said the hell with it. AFR holds good thru the run.

Last edited by Nitroman28; 09-01-2013 at 10:36 AM.
Nitroman28 is offline   Reply With Quote
Old 09-01-2013, 12:56 PM   #9
pdiddy
 
Drives: 2011 2SS
Join Date: Jun 2013
Location: Kansas City
Posts: 473
Ya my af was good through the dyno pull not sure about a full track run though...
__________________
2011 2SS JBA LONG TUBE, JBA HIGH FLOW CATS AND 3" EXHAUST, CAI CAI, 3.91 GEARS 18" cf5 NITTO NT555R, Bmr TRAILING ARMS, AND BUSHINGS, DYNO TUNED AT 408 RWHP/ ADDED A MAGGIE WITH 3.6 PULLEY ZL1 PUMP FIC 63# injectors ADM FPCM DYNO TUNED AT 570 RWHP AND 550 RWTQ ADDDED CUSTOM CAM FROM TICK AND OD COG WITH 3.8 FRONT MAKING 650RWHP AT 10psi
pdiddy is offline   Reply With Quote
Old 09-01-2013, 01:15 PM   #10
TriGun
 
TriGun's Avatar
 
Drives: Camaro 2SS/RS Ice Silver
Join Date: Oct 2009
Location: Kuwait
Posts: 209
Not only fuel pressure matters. Injectors size and boost matters too. Size of injectors matters because they flow differently at the same pressure. Also boost works against your injectors. So, fuel flow depends on more than 1 factor and mainly the delta injector pressure and injector size.
TriGun is offline   Reply With Quote
Old 09-01-2013, 03:28 PM   #11
pdiddy
 
Drives: 2011 2SS
Join Date: Jun 2013
Location: Kansas City
Posts: 473
so I guess a question I have is if your AF reads good at WOT and through the rpm range then would you even worry about fuel pressure and duty cycle and all that
__________________
2011 2SS JBA LONG TUBE, JBA HIGH FLOW CATS AND 3" EXHAUST, CAI CAI, 3.91 GEARS 18" cf5 NITTO NT555R, Bmr TRAILING ARMS, AND BUSHINGS, DYNO TUNED AT 408 RWHP/ ADDED A MAGGIE WITH 3.6 PULLEY ZL1 PUMP FIC 63# injectors ADM FPCM DYNO TUNED AT 570 RWHP AND 550 RWTQ ADDDED CUSTOM CAM FROM TICK AND OD COG WITH 3.8 FRONT MAKING 650RWHP AT 10psi
pdiddy is offline   Reply With Quote
Old 09-01-2013, 04:28 PM   #12
Crime2
Got Boost?
 
Crime2's Avatar
 
Drives: 2010 1SS RS
Join Date: Aug 2011
Location: Clearwater, FL
Posts: 611
Quote:
Originally Posted by Nitroman28 View Post
My motor just don't seem to be very efficient. After the maggie I put the ZL1/ADM controller in and pressure was dropping to 39-40psi. AFR was holding good but would lean out past 6000. So I bought the Livernois dual pump. FP still drops 47psi at 6000+.IDC is around 75%. I put a KB on it but it seem to have no affect on it. I finally just said the hell with it. AFR holds good thru the run.
What injectors are you using?


Sent from my iPhone using Tapatalk. If it is spelllled wrong, deal with it.
Crime2 is offline   Reply With Quote
Old 09-01-2013, 05:56 PM   #13
dan0617
 
dan0617's Avatar
 
Drives: 2011 Inferno Orange SS Convertible
Join Date: Apr 2012
Location: Tyrone, PA
Posts: 624
Quote:
Originally Posted by Nitroman28 View Post
My motor just don't seem to be very efficient. After the maggie I put the ZL1/ADM controller in and pressure was dropping to 39-40psi. AFR was holding good but would lean out past 6000. So I bought the Livernois dual pump. FP still drops 47psi at 6000+.IDC is around 75%. I put a KB on it but it seem to have no affect on it. I finally just said the hell with it. AFR holds good thru the run.
Is your tune commanding higher fuel pressure?
__________________
2011 SS IOM Vert. ECS Vortech 14 psi, Water/Meth, Wideband with Firewire to SCT, 2800 stall, LT headers, Drag radials, Drag alignment, Cradle Bushings. Details in Garage. I hack it up, Ted tunes it in.
dan0617 is offline   Reply With Quote
Old 09-01-2013, 07:03 PM   #14
stevieturbo
 
Drives: Slow
Join Date: Nov 2010
Location: Northern Ireland
Posts: 294
Quote:
Originally Posted by Nitroman28 View Post
People talk about watch for pressure drop but know one says what that magic psi number you're looking for on N/A and Boosted. 58? 48? Whats to low.
It's simple. Fuel pressure should be rock solid at your chosen pressure at all times.

If it fails to keep up with this, there is an issue. This is totally different than monitoring AFR's.
Anyone who says AFR's alone are sufficient are wrong. Changes in AFR can be caused by many things.
But monitoring FP can help diagnose problems in the fuel system that looking at a wideband will never do.

On a return style setup with boost referenced FPR, you would expect to see FP track intake manifold pressure at all times.

ie 60 psi base FP ( no vac ) + 20psi boost should see 80psi FP.
Obviously when there is intake vacuum at low loads, it will be less than 60psi.

If your system is a dead end or runs a fixed rail pressure, then that should stay solid pressure at all times. Unless there are some sort of closed loop controls in place that reference to intake pressure same as a basic mechanical return style.

But basically, anything that deviates from what is expected is deemed a problem.
__________________
stevieturbo is offline   Reply With Quote
Old 09-01-2013, 07:54 PM   #15
killmode_on
 
Drives: 2011 2SS/RS/TT
Join Date: Feb 2011
Location: AZ
Posts: 128
The factory E38 ECU monitors and compensates for dropping pressure delta with increased duty if you have enough injector available. I've tested from 43psi to 58psi changing nothing but fuel pressure. No difference in AFR's or power output. Using pressure the way you want, to make your huge injectors idle well or to make your fuel pump deliver some more volume or to get your too small of injectors to keep up with demand, it's all up to your tuner.
__________________
Be vewy vewy quiet, I'm hunting GT500's.
killmode_on is offline   Reply With Quote
Old 09-01-2013, 08:02 PM   #16
Nitroman28

 
Nitroman28's Avatar
 
Drives: 2010 Camaro SS A6
Join Date: Oct 2010
Location: Arkansas
Posts: 1,544
Quote:
Originally Posted by Crime2 View Post
What injectors are you using?


Sent from my iPhone using Tapatalk. If it is spelllled wrong, deal with it.
Got FIC 60lb.

Sent from my HTC One using Tapatalk 2
Nitroman28 is offline   Reply With Quote
Old 09-01-2013, 08:03 PM   #17
Nitroman28

 
Nitroman28's Avatar
 
Drives: 2010 Camaro SS A6
Join Date: Oct 2010
Location: Arkansas
Posts: 1,544
It's commanding 67psi.

Sent from my HTC One using Tapatalk 2
Nitroman28 is offline   Reply With Quote
Old 09-01-2013, 09:52 PM   #18
Nitroman28

 
Nitroman28's Avatar
 
Drives: 2010 Camaro SS A6
Join Date: Oct 2010
Location: Arkansas
Posts: 1,544
Quote:
Originally Posted by killmode_on View Post
The factory E38 ECU monitors and compensates for dropping pressure delta with increased duty if you have enough injector available. I've tested from 43psi to 58psi changing nothing but fuel pressure. No difference in AFR's or power output. Using pressure the way you want, to make your huge injectors idle well or to make your fuel pump deliver some more volume or to get your too small of injectors to keep up with demand, it's all up to your tuner.

I've tried setting the duty cycle to 100% like Livernois suggested but no change. I even put a KB on and noticed no change.
Nitroman28 is offline   Reply With Quote
Old 09-02-2013, 12:46 AM   #19
killmode_on
 
Drives: 2011 2SS/RS/TT
Join Date: Feb 2011
Location: AZ
Posts: 128
Quote:
Originally Posted by Nitroman28 View Post
I've tried setting the duty cycle to 100% like Livernois suggested but no change. I even put a KB on and noticed no change.
Maybe you have in in tank leak. Dual pumps should be way more than enough.
__________________
Be vewy vewy quiet, I'm hunting GT500's.
killmode_on is offline   Reply With Quote
Old 09-02-2013, 03:01 AM   #20
stevieturbo
 
Drives: Slow
Join Date: Nov 2010
Location: Northern Ireland
Posts: 294
Quote:
Originally Posted by killmode_on View Post
The factory E38 ECU monitors and compensates for dropping pressure delta with increased duty if you have enough injector available. I've tested from 43psi to 58psi changing nothing but fuel pressure. No difference in AFR's or power output. Using pressure the way you want, to make your huge injectors idle well or to make your fuel pump deliver some more volume or to get your too small of injectors to keep up with demand, it's all up to your tuner.
That's ok up to a point, but blindly allowing closed loop changes without monitoring for safety carries it's own risks

If you did have a fuel supply issue, just like the in-tank leak you mention, you'd happily carry on thinking because AFR's seem ok, all is well. Then all of a sudden engine goes bang because fuel pressure kept dropping as you had no idea there was a problem. Trying to use closed loop to band aid a problem is not the correct way to do things

If you monitor FP, then you'd see straight away there is a problem. Even better if the ecu can monitor it real time and relative to intake manifold pressure, and alert you or cause a limp mode if there is a problem to report.
__________________
stevieturbo is offline   Reply With Quote
Old 09-02-2013, 04:16 AM   #21
sting808

 
Drives: 4 wheels
Join Date: Apr 2009
Location: Honolulu, Hawaii
Posts: 790
Quote:
Originally Posted by Nitroman28 View Post
Got FIC 60lb.

Sent from my HTC One using Tapatalk 2
I have a LS3 w/KB 2.8. With the KB BAP, boost at 10.5, FP would drop to 45-46 PSI. This is using the kit Deka 60lbs injectors running at 78%. AFR was good throughout the dyno runs, but didn't like FP dropping to 45PSI. Also, idle and low speed driveability could've been better. This was with a custom tune.

Recently, I added the ZL1 pump/ADM FPCM, ID1000 and now the car runs great. Boost dropped a little to upper 9s, but FP stays solid +58 to 4500rpm, then bumps to +65 and doesn't dip. Commanded is 66.7. Kept the KB BAP. ID1000s are running at max 41%. I know the L99s require more pressure, but would think the ZL1/ADM would keep up, let alone the dual pump setup.

I thought the ID1000s would be too big, but what do I know... The IDs helped my idle and low speed driveability where FP was not an issue. AFRs were always good before and after. Something doesn't sound right if FP is dropping to 47. Wonder if larger injectors will help you with better efficiency.
sting808 is offline   Reply With Quote
Old 09-02-2013, 08:24 AM   #22
JANNETTYRACING
PRESIDENT CALIBRATOR JRE

 
JANNETTYRACING's Avatar
 
Drives: YELLOW 2013 ZL1 AUTO
Join Date: Jun 2009
Location: ON THE DYNO WATERBURY CT.
Posts: 9,258
Quote:
Originally Posted by Nitroman28 View Post
My motor just don't seem to be very efficient. After the maggie I put the ZL1/ADM controller in and pressure was dropping to 39-40psi. AFR was holding good but would lean out past 6000. So I bought the Livernois dual pump. FP still drops 47psi at 6000+.IDC is around 75%. I put a KB on it but it seem to have no affect on it. I finally just said the hell with it. AFR holds good thru the run.
The injectors Play a big roll in Fuel pressure at high duty cycles.

With the ZR1 injectors that come standard in the maggie anything above 550 RWHP a single pump has a hard time keeping up because the injectors are Maxed out.

Also Keep in Mind Richer AFR causes Lower Fuel Pressure simply due to fuel consumption is higher.

We have seen this with the ZL1 Pump and ADM controller Just add ID-850s and the fuel pressure no longer drops.

This is because of recover time is increased between injector events.

With small injectors they Nearly can all be open at the same time.

With large injectors the injector events are shorter increasing the close time allowing the fuel pump to keep up.

Ted.
__________________
Technical information, Parts Sales, Professional Installation, and Custom Dyno Tuning.
Please vist our web sites for all your performance needs!
Ted Jannetty
Jannetty Racing Ent Inc.
2984 East Main St.
Waterbury Ct. 06705
203-753-7223
tedj@jannettyracing.com
www.jannettyracing.com
www.turboaddictionparts.com
Performance Parts
JANNETTYRACING is offline   Reply With Quote
Old 09-02-2013, 09:52 AM   #23
pdiddy
 
Drives: 2011 2SS
Join Date: Jun 2013
Location: Kansas City
Posts: 473
good info thanks, I am probably going to the zl1 pump and adm fpcm and run the 3.6 pulley over the winter but I have a feeling I will need better injectors also as I am making 540 now so I will be just under 600 and it sounds like the zr1 injectors will not be good enough to keep up then
__________________
2011 2SS JBA LONG TUBE, JBA HIGH FLOW CATS AND 3" EXHAUST, CAI CAI, 3.91 GEARS 18" cf5 NITTO NT555R, Bmr TRAILING ARMS, AND BUSHINGS, DYNO TUNED AT 408 RWHP/ ADDED A MAGGIE WITH 3.6 PULLEY ZL1 PUMP FIC 63# injectors ADM FPCM DYNO TUNED AT 570 RWHP AND 550 RWTQ ADDDED CUSTOM CAM FROM TICK AND OD COG WITH 3.8 FRONT MAKING 650RWHP AT 10psi
pdiddy is offline   Reply With Quote
Old 09-02-2013, 10:15 AM   #24
JANNETTYRACING
PRESIDENT CALIBRATOR JRE

 
JANNETTYRACING's Avatar
 
Drives: YELLOW 2013 ZL1 AUTO
Join Date: Jun 2009
Location: ON THE DYNO WATERBURY CT.
Posts: 9,258
Quote:
Originally Posted by pdiddy View Post
good info thanks, I am probably going to the zl1 pump and adm fpcm and run the 3.6 pulley over the winter but I have a feeling I will need better injectors also as I am making 540 now so I will be just under 600 and it sounds like the zr1 injectors will not be good enough to keep up then
Your Welcome!

It is very Unlikely your making 540 RWHP with a 3.8 pulley, Unless of coarse your running an Overdrive Cog or a 3.6.

But I agree that the ID-850s are your best investment.

Ted.
__________________
Technical information, Parts Sales, Professional Installation, and Custom Dyno Tuning.
Please vist our web sites for all your performance needs!
Ted Jannetty
Jannetty Racing Ent Inc.
2984 East Main St.
Waterbury Ct. 06705
203-753-7223
tedj@jannettyracing.com
www.jannettyracing.com
www.turboaddictionparts.com
Performance Parts
JANNETTYRACING is offline   Reply With Quote
Old 09-04-2013, 05:35 PM   #25
Nitroman28

 
Nitroman28's Avatar
 
Drives: 2010 Camaro SS A6
Join Date: Oct 2010
Location: Arkansas
Posts: 1,544
Quote:
Originally Posted by JANNETTYRACING View Post
The injectors Play a big roll in Fuel pressure at high duty cycles.

With the ZR1 injectors that come standard in the maggie anything above 550 RWHP a single pump has a hard time keeping up because the injectors are Maxed out.

Also Keep in Mind Richer AFR causes Lower Fuel Pressure simply due to fuel consumption is higher.

We have seen this with the ZL1 Pump and ADM controller Just add ID-850s and the fuel pressure no longer drops.

This is because of recover time is increased between injector events.

With small injectors they Nearly can all be open at the same time.

With large injectors the injector events are shorter increasing the close time allowing the fuel pump to keep up.

Ted.
If I was to switch to the ID850's would a lot of tuning need to be done to make them work or just the Data for the injector entered?
Nitroman28 is offline   Reply With Quote
 
Reply

Thread Tools

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

Forum Jump


All times are GMT -5. The time now is 09:41 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.