Fuel tuned

Rooskey · 08-10-2010, 02:01 AM

Anyone think you can gain anything by adjustiing your fuel pressure. Its worth five to ten hp on a dyno if you look at it. Especially if you own a nismo.

WarmAndSCSI · 08-10-2010, 02:13 AM

Adjusting fuel pressure will never make you a bit of power unless it was seriously too low to begin with, thus hampering proper fuel atomization at the injectors. Otherwise, you'd effectively be richening the mixture by increasing fuel pressure, which is never good for power unless you are running too lean.

Stock fuel pressure is probably around 40 psi at curb idle, so about 50 psi at WOT. Unless it's falling somewhere way outside of that, no power could possibly be gained. I suppose it's possible to lean out the mixture and gain a fraction of a hp before negatively affecting the efficiency of the engine due to poor atomization.

Jordo! · 08-10-2010, 02:40 AM

More fuel without more air will not net you more power (unless perhaps you were detonating, and the extra fuel quenches it -- that said, you're not detonating.)

And the OEM tune is pretty rich as it is...

Rooskey · 08-10-2010, 03:03 AM

So when I add intake and exhaust to my car I should keep my same fuel ratio. I do not want to add fuel pressure even in this case. If I do go lean on a dyno at least I can correct it.

Rooskey · 08-10-2010, 03:07 AM

I have built and many engine's on drag racing cars and engines. Im not trying to prove anything. I just want to know who makes a good FPR for the 370 z. Thank you for your help

WarmAndSCSI · 08-10-2010, 03:15 AM

Quote:

Originally Posted by Rooskey

So when I add intake and exhaust to my car I should keep my same fuel ratio. I do not want to add fuel pressure even in this case. If I do go lean on a dyno at least I can correct it.

Messing with your fuel pressure only serves to throw off your closed loop fuel trims. This is by far the worst way of tuning ever. Your car has electronically controlled fuel injection, which happens to be tunable electronically, please don't tune it like it has a carburetor.

Plus I'm pretty sure our fuel pressure regulator is located in-tank along with the filter and pump.

WarmAndSCSI · 08-10-2010, 03:18 AM

Quote:

Originally Posted by Rooskey

I have built and many engine's on drag racing cars and engines. Im not trying to prove anything. I just want to know who makes a good FPR for the 370 z. Thank you for your help

Not sure what you've worked on before, but if you're used to adjusting fuel mixture by messing with fuel pressure, the 370Z is going to be a whole new world...

Please refer to what I said above about our fuel system - definitely not worth modifying to the extent of adding an AFPR unless you are boosted, and heavily boosted at that.

Jordo! · 08-10-2010, 05:03 AM

Quote:

Originally Posted by Rooskey

So when I add intake and exhaust to my car I should keep my same fuel ratio. I do not want to add fuel pressure even in this case. If I do go lean on a dyno at least I can correct it.

#1, an intake and exhaust isn't going to make so great a difference that the ECU can't compensate with fuel trims -- in fact, it doesn't even appear to result in trims that are out of the "normal" range, and I've heard very few reports of driveability quirks that can be clearly traced to those bolt-ons.

Speaking of bolt-ons and AFR's, there are some dynos posted on here from Import Tuner Magazine of a 370Z with intake, intake+exahust, and both + tuning.

Interestingly enough, there is virtually no difference between the AFR's before and after the tune... in other words, you should be fine without tuning for those bolt-ons, although the tune would allow you to optimize performance, it doesn't appear to be mandatory for bolt-ons.

#2, If you really want to play with the AFR's, with or without bolt-ons, see about getting a Cobb Accessport or the Uprev Osirus ECU programmer/reflasher, and schedule some dyno time.

#3 If you were boosted, you would have serious fueling issues with the OEM set-up, and your concerns would be warranted. However, even with a blower or turbo, before going to an AFPR, you'd probably just upgrade to bigger fuel injectors. Tuning the ECU would be a must at that point as well.

hotdog · 04-19-2011, 12:38 AM

if its tuned right it should look like this at red line

Rooskey · 04-19-2011, 12:45 AM

Quote:

Originally Posted by hotdog

if its tuned right it should look like this at red line

Has anyone seen the showtime special The Whites from West Virginia with Hank the 3rd???

hotdog · 04-19-2011, 12:47 AM

Quote:

Originally Posted by Rooskey

Has anyone seen the showtime special The Whites from West Virginia with Hank the 3rd???

schrack150 · 04-19-2011, 12:52 AM

jesco ? the dancing outlaw

Rooskey · 04-19-2011, 01:28 AM

Quote:

Originally Posted by schrack150

jesco ? the dancing outlaw

Yep!! Lol!

No punt intended schrack150 one of my best friends is from Beckley, WV. Good folks

fncrow · 04-19-2011, 02:01 AM

Speaking of fuel what about E85? I've been reading on the forums about GTR guys modifying their cars to accept E85 fuel with good success. Has it been done to a 370 yet? Can it even be done?

Rooskey · 04-19-2011, 02:18 AM

Quote:

Originally Posted by fncrow

Speaking of fuel what about E85? I've been reading on the forums about GTR guys modifying their cars to accept E85 fuel with good success. Has it been done to a 370 yet? Can it even be done?

Not sure but I know the gas milage goes to crap with that stuff. Are they able to compensate with the added power? Maybe with a factory blower they can. Whats the details?

08-10-2010, 02:01 AM	#1 (permalink)
Rooskey Track Member Join Date: Jul 2010 Location: South Carolina Posts: 974 Drives: 2014 Alpha7 GTR Rep Power: 15	Fuel tuned Anyone think you can gain anything by adjustiing your fuel pressure. Its worth five to ten hp on a dyno if you look at it. Especially if you own a nismo.

08-10-2010, 02:13 AM	#2 (permalink)
WarmAndSCSI A True Z Fanatic Join Date: May 2010 Location: SLC, UT Posts: 1,671 Drives: '08 Evo X \| '10 370Z Rep Power: 17	Adjusting fuel pressure will never make you a bit of power unless it was seriously too low to begin with, thus hampering proper fuel atomization at the injectors. Otherwise, you'd effectively be richening the mixture by increasing fuel pressure, which is never good for power unless you are running too lean. Stock fuel pressure is probably around 40 psi at curb idle, so about 50 psi at WOT. Unless it's falling somewhere way outside of that, no power could possibly be gained. I suppose it's possible to lean out the mixture and gain a fraction of a hp before negatively affecting the efficiency of the engine due to poor atomization. __________________ '10 PW 370Z 7AT - wife's car - Project Raspberry Cheesecake '08 Evo X - built motor+trans \| BB-X @ 32 psi \| CH3OH \| self-built+tuned - ??? WHP '01 Galant V6 - built motor \| GT35R \| self-built+tuned - 550+ WHP (retired)

08-10-2010, 02:40 AM	#3 (permalink)
Jordo! A True Z Fanatic Join Date: May 2010 Location: nirvana Posts: 6,394 Drives: 2023 NATM Rep Power: 417	More fuel without more air will not net you more power (unless perhaps you were detonating, and the extra fuel quenches it -- that said, you're not detonating.) And the OEM tune is pretty rich as it is... __________________ Enjoy it. Destroy it.

04-19-2011, 12:52 AM	#12 (permalink)
schrack150 Track Member Join Date: Jan 2010 Location: Wheeling, West Virginia Age: 37 Posts: 590 Drives: 09 370z PW Rep Power: 16	jesco ? the dancing outlaw __________________ 2009 370z PW Base + Sport 6M 13.86@104.4 ERZ HFC, Injen, AP Exhaust...wet black powdercoated Ray's....UPrev

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08-10-2010, 03:03 AM	#4 (permalink)
Rooskey Track Member Join Date: Jul 2010 Location: South Carolina Posts: 974 Drives: 2014 Alpha7 GTR Rep Power: 15	So when I add intake and exhaust to my car I should keep my same fuel ratio. I do not want to add fuel pressure even in this case. If I do go lean on a dyno at least I can correct it.

08-10-2010, 03:07 AM	#5 (permalink)
Rooskey Track Member Join Date: Jul 2010 Location: South Carolina Posts: 974 Drives: 2014 Alpha7 GTR Rep Power: 15	I have built and many engine's on drag racing cars and engines. Im not trying to prove anything. I just want to know who makes a good FPR for the 370 z. Thank you for your help

04-19-2011, 12:38 AM	#9 (permalink)
hotdog Banned Join Date: Apr 2011 Location: where? Posts: 12 Drives: Zed Rep Power: 0	if its tuned right it should look like this at red line

04-19-2011, 02:01 AM	#14 (permalink)
fncrow Base Member Join Date: Jul 2009 Location: Miami Posts: 92 Drives: 370Z Rep Power: 15	Speaking of fuel what about E85? I've been reading on the forums about GTR guys modifying their cars to accept E85 fuel with good success. Has it been done to a 370 yet? Can it even be done?