Gas Pedal Delay

DIGItonium · 07-30-2012, 12:01 PM

I read the updated post in your thread. You're right about the gradual throttle ramping with the RPMs. It's so unnatural and feels artificially held back. That explains my boost gauge gradually getting out of vaccum and slowly or barely building boost at times. I do feel the roughness of the throttle similar to rough engagement of the clutch and not being able to keep my foot still on the pedal haha.

What's interesting is that when the car is fairly cool I can get boost to build up at half throttle and low speeds since the BOV flutters at light loads. It's pretty fun in the neighborhood. After awhile I can't get boost to build up unless I hold down the throttle and let it rev past 3-4k RPM, which is not good in the neighborhood (easy to exceed the speed limit).

I even showed my friend by punching it in 1st while turning out of the parking lot with VDC off. The car slowly ramps up, but doesn't spin out of control. His Lotus is so much better on the throttle response even after some hard driving.

This year is definitely a bad year. We're breaking records over here. The car gets so hot that when I press down on the pedal the throttle opens up, and then it hits a ceiling and refuses to do anything else.

Also, do you guys feel it's difficult to quickly rev match with this car? I usually bog on the downshifts because I end up not revving it high enough.

wstar · 07-30-2012, 03:30 PM

Quote:

Originally Posted by DIGItonium

I even showed my friend by punching it in 1st while turning out of the parking lot with VDC off. The car slowly ramps up, but doesn't spin out of control.

Yeah that's troubling. My car's NA, the breathing mods aren't ideal for very-low-end torque, and I'm on 11" wide rear rims (295 tires), and I can break the rear end loose in 1st every time if try, regardless of hot weather or runtime. I usually don't though, I like my tires to last a bit.

Edit: although I should add, it probably helps that I have a very stiff rear sway and some weight loss in the rear

IcedZ · 07-31-2012, 08:33 AM

Quote:

Originally Posted by wstar

Yeah that's troubling. My car's NA, the breathing mods aren't ideal for very-low-end torque, and I'm on 11" wide rear rims (295 tires), and I can break the rear end loose in 1st every time if try, regardless of hot weather or runtime. I usually don't though, I like my tires to last a bit.

Edit: although I should add, it probably helps that I have a very stiff rear sway and some weight loss in the rear

My Z was basically stock. After the car got hot, no way I could break out in any gear without revving to 4k RPM and dumping the clutch. And yes DIGI, rev matching was affected when I had my car.
Hopefully gonna test drive a BRZ this week =D I'm really missing a sports car (and will not buy another 370 until this issue is resolved). I really wanted to love that car.

kenny's 370z · 07-31-2012, 09:49 AM

so something is dumping too much heat in the im causing this bogging.i cant get on the car too long without stopping before i experience this bogging.there has to be one thing that is dumping too much heat into the im besides the obvious heat soak. pcv hoses are not helping for sure.i plan to remedy some of that heat with oil catch cans.i will be looking to see what else i can do to eliminate as much heat as possible.

has anyone done a egr delete or is it even possible on this engine ? that would eliminate more heat from going into the im.and does anyone have a link showing the schematics and what is what on this engine ? i would surely appreciate it !

on a side note,when i have had the bogging,i stopped,popped the hood, and immediately put my hands on the tb's and they were cool to the touch in 82 degree ambient temp.so i know the intake and tb's are not the blame.pcv hoses on the other hand were hot.what is that thing on the back of the engine towards the top that looks like a small motor ? that thing gets very hot.sorry for some of these questions.i have done alot of research on here already and these few things is all i need the answers too por favor.

edit;and my oil temps were 195-205

IcedZ · 07-31-2012, 10:11 AM

Quote:

pcv hoses on the other hand were hot.

Is it possible that the PCV valves are getting stuck open when the engine gets hot? That will cause a leaning effect, probably more pronounced at low RPM's.

wstar · 07-31-2012, 12:51 PM

What do you mean by active or passive? There are PCV check-valves screwed into both head covers, which connect to tubes that go straight to the intake manifold for vacuum sources.

Then there are unvalved lines going from elsewhere on the covers to the air intake tubes for crankcase fresh air supply, which have baffles (presumably to prevent catastrophic problems w/ intake backfires).

kenny's 370z · 07-31-2012, 01:01 PM

I pinched a pcv line today on lunch and i didnt hear any click of the pcv valve like i would on other cars when the pcv valve is operating correctly.that tells me there is an abundance of heat being sucked into the im.i am pretty sure these pcv hoses are the culprit for my bogging or hesitation after a couple of spirited runs.add hot oil mist into the equation and there you have it.i'll find out soon enough after i put some cans on.this is my next mod for sure.anything to stop a direct heat path coming from my valve cover to the im.

IcedZ · 07-31-2012, 01:24 PM

Quote:

Originally Posted by wstar

What do you mean by active or passive?

Meaning is it a normal check-valve, or are they electronically controlled (sensor + actuator hooked into the car's computer).

wstar · 08-01-2012, 12:05 AM

Quote:

Originally Posted by IcedZ

Meaning is it a normal check-valve, or are they electronically controlled (sensor + actuator hooked into the car's computer).

Oh I missed this earlier. No sensor/actuator, just check-valve.

wstar · 07-31-2012, 01:16 PM

Well, there is a proper PCV valve on those lines, assuming you're playing with the right ones (the ones that run to the pair of outlets on the front of the intake manifold). Maybe the valves have gone bad?

I do run an Al catch can way over in the battery compartment, but I wouldn't think the relatively small volume of hot PCV air would be a significant factor anyways. An actual failed PCV valve could cause all kinds of problems, though.

kenny's 370z · 07-31-2012, 01:49 PM

Quote:

Originally Posted by wstar

Well, there is a proper PCV valve on those lines, assuming you're playing with the right ones (the ones that run to the pair of outlets on the front of the intake manifold). Maybe the valves have gone bad?

I do run an Al catch can way over in the battery compartment, but I wouldn't think the relatively small volume of hot PCV air would be a significant factor anyways. An actual failed PCV valve could cause all kinds of problems, though.

yes ,the ones i checked are the ones going into the front of the manifold.im still a noob with this car so if i dont hear a click by pinching the pcv hose,how can i tell if the valves are bad ?

wstar · 07-31-2012, 03:37 PM

Good question, no idea

. They're cheap, and I'm at 30K miles. I just put in an order for a pair of them from courtesyparts because, hey, why not.

Edit: parts list from the order (2x rubber O-rings, left/right PCV valves):

2 x [11812] RUBBER PCV,VALVE - 370Z (Z34) 2009+ (11812-Z34001) = $4.92
1 x [11810PA] VALVE ASSY-CONTROL - 370Z (Z34) 2009+ (11810-Z34004) = $14.57
1 x [11810P] PCV VALVE - 370Z (Z34) 2009+ (11810-Z34003) = $14.57

robones · 07-31-2012, 04:19 PM

Well its really hard to judge why the lack of response if you start messing with the car's internals. My engine is completely stock and if I keep my revs at 3 k and slam on the accelerator, my wheels spin and i am pushed to the back of my seat. Its such an amazing feeling.. I can't and will not touch the engine because I have it warrantied up to 100 k miles 7 years.

kenny's 370z · 07-31-2012, 05:54 PM

i had the bogging issue after spirited runs around curves and such while i was stock.i have eliminated alot of whatever this issue is and when im done,i wont have this problem anymore.if i drive the car normal,i dont have a problem.but i didnt buy this car to putt around curves and keep revs under 5k

zguynate · 08-01-2012, 12:32 PM

This issue is whats keeping my 370 from being as enjoyable to drive as my 350z. Hopefully someone will be able to find a way to make the throttle response as responsive as the 350z.

07-30-2012, 12:01 PM	#1 (permalink)
DIGItonium A True Z Fanatic Join Date: Jan 2009 Location: Kansas Posts: 3,800 Drives: 09 Z34-TT 6MT Rep Power: 43	I read the updated post in your thread. You're right about the gradual throttle ramping with the RPMs. It's so unnatural and feels artificially held back. That explains my boost gauge gradually getting out of vaccum and slowly or barely building boost at times. I do feel the roughness of the throttle similar to rough engagement of the clutch and not being able to keep my foot still on the pedal haha. What's interesting is that when the car is fairly cool I can get boost to build up at half throttle and low speeds since the BOV flutters at light loads. It's pretty fun in the neighborhood. After awhile I can't get boost to build up unless I hold down the throttle and let it rev past 3-4k RPM, which is not good in the neighborhood (easy to exceed the speed limit). I even showed my friend by punching it in 1st while turning out of the parking lot with VDC off. The car slowly ramps up, but doesn't spin out of control. His Lotus is so much better on the throttle response even after some hard driving. This year is definitely a bad year. We're breaking records over here. The car gets so hot that when I press down on the pedal the throttle opens up, and then it hits a ceiling and refuses to do anything else. Also, do you guys feel it's difficult to quickly rev match with this car? I usually bog on the downshifts because I end up not revving it high enough. __________________ Last edited by DIGItonium; 07-30-2012 at 12:06 PM.

07-31-2012, 09:49 AM	#4 (permalink)
kenny's 370z Base Member Join Date: Jun 2012 Location: TN Age: 59 Posts: 243 Drives: 2012 frontier sv v6 Rep Power: 13	so something is dumping too much heat in the im causing this bogging.i cant get on the car too long without stopping before i experience this bogging.there has to be one thing that is dumping too much heat into the im besides the obvious heat soak. pcv hoses are not helping for sure.i plan to remedy some of that heat with oil catch cans.i will be looking to see what else i can do to eliminate as much heat as possible. has anyone done a egr delete or is it even possible on this engine ? that would eliminate more heat from going into the im.and does anyone have a link showing the schematics and what is what on this engine ? i would surely appreciate it ! on a side note,when i have had the bogging,i stopped,popped the hood, and immediately put my hands on the tb's and they were cool to the touch in 82 degree ambient temp.so i know the intake and tb's are not the blame.pcv hoses on the other hand were hot.what is that thing on the back of the engine towards the top that looks like a small motor ? that thing gets very hot.sorry for some of these questions.i have done alot of research on here already and these few things is all i need the answers too por favor. edit;and my oil temps were 195-205 Last edited by kenny's 370z; 07-31-2012 at 10:01 AM.

07-31-2012, 12:51 PM	#6 (permalink)
wstar A True Z Fanatic Join Date: Mar 2009 Location: Houston, TX Posts: 4,024 Drives: too slow Rep Power: 3595	What do you mean by active or passive? There are PCV check-valves screwed into both head covers, which connect to tubes that go straight to the intake manifold for vacuum sources. Then there are unvalved lines going from elsewhere on the covers to the air intake tubes for crankcase fresh air supply, which have baffles (presumably to prevent catastrophic problems w/ intake backfires). __________________ 7AT Track Car! Journal thread / Car setup details

07-31-2012, 01:16 PM	#10 (permalink)
wstar A True Z Fanatic Join Date: Mar 2009 Location: Houston, TX Posts: 4,024 Drives: too slow Rep Power: 3595	Well, there is a proper PCV valve on those lines, assuming you're playing with the right ones (the ones that run to the pair of outlets on the front of the intake manifold). Maybe the valves have gone bad? I do run an Al catch can way over in the battery compartment, but I wouldn't think the relatively small volume of hot PCV air would be a significant factor anyways. An actual failed PCV valve could cause all kinds of problems, though. __________________ 7AT Track Car! Journal thread / Car setup details

07-31-2012, 03:37 PM	#12 (permalink)
wstar A True Z Fanatic Join Date: Mar 2009 Location: Houston, TX Posts: 4,024 Drives: too slow Rep Power: 3595	Good question, no idea . They're cheap, and I'm at 30K miles. I just put in an order for a pair of them from courtesyparts because, hey, why not. Edit: parts list from the order (2x rubber O-rings, left/right PCV valves): 2 x [11812] RUBBER PCV,VALVE - 370Z (Z34) 2009+ (11812-Z34001) = $4.92 1 x [11810PA] VALVE ASSY-CONTROL - 370Z (Z34) 2009+ (11810-Z34004) = $14.57 1 x [11810P] PCV VALVE - 370Z (Z34) 2009+ (11810-Z34003) = $14.57 __________________ 7AT Track Car! Journal thread / Car setup details Last edited by wstar; 07-31-2012 at 03:44 PM.

07-31-2012, 01:01 PM	#7 (permalink)
kenny's 370z Base Member Join Date: Jun 2012 Location: TN Age: 59 Posts: 243 Drives: 2012 frontier sv v6 Rep Power: 13	I pinched a pcv line today on lunch and i didnt hear any click of the pcv valve like i would on other cars when the pcv valve is operating correctly.that tells me there is an abundance of heat being sucked into the im.i am pretty sure these pcv hoses are the culprit for my bogging or hesitation after a couple of spirited runs.add hot oil mist into the equation and there you have it.i'll find out soon enough after i put some cans on.this is my next mod for sure.anything to stop a direct heat path coming from my valve cover to the im.

07-31-2012, 04:19 PM	#13 (permalink)
robones Enthusiast Member Join Date: Mar 2011 Location: Miami Posts: 357 Drives: 2011 - Nissan 370 M6 Rep Power: 15	Well its really hard to judge why the lack of response if you start messing with the car's internals. My engine is completely stock and if I keep my revs at 3 k and slam on the accelerator, my wheels spin and i am pushed to the back of my seat. Its such an amazing feeling.. I can't and will not touch the engine because I have it warrantied up to 100 k miles 7 years.

07-31-2012, 05:54 PM	#14 (permalink)
kenny's 370z Base Member Join Date: Jun 2012 Location: TN Age: 59 Posts: 243 Drives: 2012 frontier sv v6 Rep Power: 13	i had the bogging issue after spirited runs around curves and such while i was stock.i have eliminated alot of whatever this issue is and when im done,i wont have this problem anymore.if i drive the car normal,i dont have a problem.but i didnt buy this car to putt around curves and keep revs under 5k Last edited by kenny's 370z; 07-31-2012 at 09:23 PM.

08-01-2012, 12:32 PM	#15 (permalink)
zguynate A True Z Fanatic Join Date: Jan 2012 Location: Strangeland Posts: 1,054 Drives: 09 370z Rep Power: 74	This issue is whats keeping my 370 from being as enjoyable to drive as my 350z. Hopefully someone will be able to find a way to make the throttle response as responsive as the 350z. __________________ 2009 370z touring w/sports package

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