Fuel pressure drop under boost.. - Page 2 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Greenhornet2 · 05-04-2020, 02:05 PM

I believe it still needs adjustment for when the aux pump kicks on to keep the pressure from going too high. It will pull less demand from the zl1 pump when the aux kicks in but it still needs to be oriented or it will try to drop pressure. I did some reading about this but i can't remember exactly how it worked. I know jannetty has used the dsx aux pump with the zl1 and fpcm pretty sure the fpcm still needs tweaking to keep the fuel pressure in range.

eLeSthree · 05-04-2020, 03:44 PM

Quote:

Originally Posted by Rons1le

Ok, how do I go about doing that?
Getting the fpcm tuned.

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$50 using HP tuners

Quote:

Originally Posted by Rons1le

Greenhornet2 thanks, Jannetty sells a pretuned one for $199 probably best and fastest option.

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Probably the best bet if you dont have HPTuners.

Quote:

Originally Posted by RupertPupkin

if you get an auxiliary pump, will your FCPM for the ZL1 pump still need to be adjusted?

Going a lil off topic but...

Yea, you'll want to increase the "High Flow" rate to 500kpa. In certain applications (e85 and boost) there is no way the ZL1 pump can maintain that pressure alone. When the aux pump kicks in, the ECM will see that fuel pressure spike/rise and try to regulate it if its still programmed to 400kpa. If its set to 500kpa, between the two pumps, it should be able to meet that demand, up until its mechanical limitations.

Make sense?

RupertPupkin · 05-04-2020, 06:28 PM

Quote:

Originally Posted by eLeSthree

$50 using HP tuners

Probably the best bet if you dont have HPTuners.

Going a lil off topic but...

Yea, you'll want to increase the "High Flow" rate to 500kpa. In certain applications (e85 and boost) there is no way the ZL1 pump can maintain that pressure alone. When the aux pump kicks in, the ECM will see that fuel pressure spike/rise and try to regulate it if its still programmed to 400kpa. If its set to 500kpa, between the two pumps, it should be able to meet that demand, up until its mechanical limitations.

Make sense?

Yup. Didn’t know that regardless with the aux pump, you’d have to adjust the FPCM From my understanding, my FPCM can be tuned by the tuner, instead of getting the FPCM that Jannety sells..?

Greenhornet2 · 05-04-2020, 06:52 PM

Quote:

Originally Posted by RupertPupkin

Yup. Didn’t know that regardless with the aux pump, you’d have to adjust the FPCM From my understanding, my FPCM can be tuned by the tuner, instead of getting the FPCM that Jannety sells..?

Yes. I know It's 1 credit from hptuners to tune it

Rons1le · 05-07-2020, 03:20 PM

Update The ZL1 programed fcpm installed and all is good. Fuel pressure never dropped below 59lbs while making 10.6lbs boost.. Thanks everyone..Although there is a very butt hurt challenger owner now..lol.

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Greenhornet2 · 05-07-2020, 06:30 PM

Excellent

eLeSthree · 05-07-2020, 06:45 PM

Nice!

Wutssup · 07-08-2020, 09:23 PM

I’m just trying to get the correct info here, I’m new to camaro. So the fuel pressure does not rise with boost? In my G/N it would.

Greenhornet2 · 07-09-2020, 10:50 AM

Quote:

Originally Posted by Wutssup

I’m just trying to get the correct info here, I’m new to camaro. So the fuel pressure does not rise with boost? In my G/N it would.

Not with the stock system.

gtstorey · 07-09-2020, 11:14 AM

Quote:

Originally Posted by Wutssup

I’m just trying to get the correct info here, I’m new to camaro. So the fuel pressure does not rise with boost? In my G/N it would.

By G/N do you mean Grand National (turbo)? The SS stock doesn't have a reason to increase pressure under boost stock since it has no need? I don't know about the ZL1.

Greenhornet2 · 07-09-2020, 02:37 PM

Quote:

Originally Posted by gtstorey

By G/N do you mean Grand National (turbo)? The SS stock doesn't have a reason to increase pressure under boost stock since it has no need? I don't know about the ZL1.

ZL1 Doesn't either.

RobZL1 · 07-09-2020, 03:10 PM

ZL1 rises to 65 psi under "high flow" conditions. Stock is 50 psi at low flow, I think 60 in the middle, and then 65.

Wutssup · 07-09-2020, 06:48 PM

Yes, I meant grand national. It would increase 1psi for every one pound of boost. So you could have 50 psi for example at idle and 65 psi under 15 psi boost. I was just wondering if the supercharged camaro did the same. Sorry didn’t mean to hijack the thread.
Thx guys

gtstorey · 07-10-2020, 07:34 AM

Quote:

Originally Posted by Wutssup

Yes, I meant grand national. It would increase 1psi for every one pound of boost. So you could have 50 psi for example at idle and 65 psi under 15 psi boost. I was just wondering if the supercharged camaro did the same. Sorry didn’t mean to hijack the thread.
Thx guys

That was likely the only way to compensate for boost pressure back and was likely done mechanically. With modern fuel injection & computers there is a lot more that can be done to compensate than just raising fuel pressure based upon boost pressure, although that is likely one of the best ways still.

05-04-2020, 02:05 PM	#15
Greenhornet2 Drives: 2011 Camaro 2SS LS3 Whipple Join Date: May 2019 Location: Connecticut Posts: 1,925	I believe it still needs adjustment for when the aux pump kicks on to keep the pressure from going too high. It will pull less demand from the zl1 pump when the aux kicks in but it still needs to be oriented or it will try to drop pressure. I did some reading about this but i can't remember exactly how it worked. I know jannetty has used the dsx aux pump with the zl1 and fpcm pretty sure the fpcm still needs tweaking to keep the fuel pressure in range. __________________ Whipple 2.9 CAI ID1050x injectors ZL1 Pump JRE FPCM JMS Voltage booster JRE Rough Idle blower cam BTR .660 springs CHE trunnion kit 1 7/8 Speed Engineering Borla Atak JRE scoop 1.5" lowering springs BMR trailing arms and toe links Cradle inserts 704WHP 603WTQ 93 octane

05-07-2020, 03:20 PM	#19
Rons1le Drives: 2015 Camaro 2SS RS 1LE AGM Join Date: Oct 2013 Location: Galion, Oh Posts: 531 View My Garage	Update The ZL1 programed fcpm installed and all is good. Fuel pressure never dropped below 59lbs while making 10.6lbs boost.. Thanks everyone..Although there is a very butt hurt challenger owner now..lol. Sent from my SM-G960U using Tapatalk __________________ 2015 2SS RS 1LE NPP/w Kooks headers, Procharged, ID1050X injectors, Katech belt tensioner, Mighty Mouse Catch Can, BMR subframe connectors, Matco driveshaft loop, AEM Wideband/Boost/Fuel gauges , Z/28 Splitter and Spoiler/w Wicker bill, Power Stop rotors and brake pads, MRR Z/28 Rep Wheels 20" w/p zeros 285 fronts and 305 rears, ZL1 addons Rock guards and Tow hook, Rear window louvers, Flags on the quarter windows and the moonroof, Billet aluminum door handles.

05-07-2020, 06:30 PM	#20
Greenhornet2 Drives: 2011 Camaro 2SS LS3 Whipple Join Date: May 2019 Location: Connecticut Posts: 1,925	Excellent __________________ Whipple 2.9 CAI ID1050x injectors ZL1 Pump JRE FPCM JMS Voltage booster JRE Rough Idle blower cam BTR .660 springs CHE trunnion kit 1 7/8 Speed Engineering Borla Atak JRE scoop 1.5" lowering springs BMR trailing arms and toe links Cradle inserts 704WHP 603WTQ 93 octane

05-07-2020, 06:45 PM	#21
eLeSthree Drives: 2011 Camaro SS 6sp Join Date: Nov 2016 Location: Drivers Seat Posts: 1,904	Nice! __________________ 2011 Camaro SS---SOLD TMS Dart 427 FED M311s, ESS Tuning G4 Blower, DSX Triple FP Assembly, DSX FF, FIC1300, Mcleod RXT 1200HD, Edlebrock Pro Flo XT 1158whp 1017wtq. 2010 CTS-V A6 - "Stock" SOLD 630whp 658wtq 2024 F-150 RCSB 5.0 4x4 waiting for tunes...

07-09-2020, 03:10 PM	#26
RobZL1 fo'shizZL1 Drives: 2017 ZL1 Join Date: Aug 2017 Location: ATL Posts: 1,281	ZL1 rises to 65 psi under "high flow" conditions. Stock is 50 psi at low flow, I think 60 in the middle, and then 65. __________________ 2017 ZL1 M6 Black \| Maggie 2650 // 103TB // Big Gulp Past Rides- 2014 ZL1 M6 Red Hot \| Tons of mods 2004 CTS-V M6 Silver \| Many mods 1995 Corvette M6 Torch Red \| A few more mods 1992 Camaro M5 White \| A few mods

07-08-2020, 09:23 PM	#22
Wutssup Drives: 2011 SS Join Date: May 2020 Location: Ontario Posts: 25	I’m just trying to get the correct info here, I’m new to camaro. So the fuel pressure does not rise with boost? In my G/N it would.

07-09-2020, 06:48 PM	#27
Wutssup Drives: 2011 SS Join Date: May 2020 Location: Ontario Posts: 25	Yes, I meant grand national. It would increase 1psi for every one pound of boost. So you could have 50 psi for example at idle and 65 psi under 15 psi boost. I was just wondering if the supercharged camaro did the same. Sorry didn’t mean to hijack the thread. Thx guys Last edited by Wutssup; 07-09-2020 at 06:51 PM. Reason: Forgot something