Gas Pedal Delay

IcedZ · 12-25-2010, 12:45 AM

Quote:

Originally Posted by DIGItonium

IIRC, IcedZ is bone stock. Mine only has the pulleys and exhaust, but I already noticed the response issues prior to installing the mods. The pulleys improved it, but it did not resolve the low end power loss.

What I wonder is the difference in throttle response with the VQ35DE and the VQ37. The DE definitely has a stronger punch and a bit more aggressive tip in.

For those wondering about dyno charts, how can one graph the power band under 3k RPM? How can we get a visual of the power being cut or held back? It would be nice to get a visual on the 2.5k RPM stall or the clunky feeling (tech describes as fuel cut) as the tach revs to redline with 50-80% throttle in 3rd or 4th.

You recall correctly. The only thing "extra" I've done is put in K&N filters. I did that a while ago. I was thinking about that earlier this week while cleaning them. Maybe something as simple as that is the problem?? I was thinking about going to wal-mart or the like and picking up some Fram instead or something closer to stock. Worth a try.

wilsonp · 12-25-2010, 08:52 PM

Your filters needed cleaning already?

I have K&N as well, but I can't remember if this happened before I installed them. I wasn't that familiar with the car then.

Mine only seems to lag during turns - does it happen at stoplights going straight as well?

Junior370z · 12-25-2010, 10:20 PM

This happens to me on rare occasions. Once it even did it to me in 2nd, 3rd and 4th. Every time it happened it was between 3500 to 4000 rpms. It was always after a stop too. To try and stop it from occurring I let it rev higher before shifting. It hasn't happened after I've been doing that. It's irritating because I really don't know what causes it. At least I'm not alone on it lol!

DIGItonium · 12-26-2010, 04:54 PM

Yea, it's true you definitely need to rev beyond 3k RPM. It's hard to execute, but I tried to rev over 3k a couple of times before engaging 1st. Either that or let it rev past 3k in 1st before going into 2nd. This engine definitely lacks torque under 3k compared to the DE, but it feels artificially limited.

IcedZ · 12-26-2010, 06:51 PM

Quote:

Originally Posted by wilsonp

Your filters needed cleaning already?

I have K&N as well, but I can't remember if this happened before I installed them. I wasn't that familiar with the car then.

Mine only seems to lag during turns - does it happen at stoplights going straight as well?

I have almost 36k miles. They didn't NEED cleaning, but they were dirty. Figured it couldn't hurt to have clean filters. It seems to me that this problem didn't occur UNTIL I put K&N's in (but I did install them within a couple months). I'll hopefully replace tomorrow with cheaper, more factory like ones.

It happens at stoplights going straight. Doesn't matter what gear. I down shifted 4-3 once to pass somebody (going relatively low speed), and it just fell on its face... probably pissed the guy behind me off since I got over and didn't go immediately.

DIGItonium · 12-26-2010, 07:16 PM

Yea, another good test is getting on ramp and accelerating in 3rd with constant throttle (40-70%). You can feel the hesitation as it revs up towards redline (again, tech thinks it's fuel cutting). Why do we experience what the tech thinks is fuel cutting?

Jordo! · 12-26-2010, 08:59 PM

Quote:

Originally Posted by DIGItonium

Yea, another good test is getting on ramp and accelerating in 3rd with constant throttle (40-70%). You can feel the hesitation as it revs up towards redline (again, tech thinks it's fuel cutting). Why do we experience what the tech thinks is fuel cutting?

The factroy tune begins to cut power as you approach fuel cut for a softer bounce off of the rev limiter. You can see it on most dynos of untuned Z's pretty clearly.

It can be dialed out with tuning.

Kastley85891 · 12-26-2010, 09:12 PM

Throttle mapping can be improved for sure...ignore fuel tables in pics, not relevant for this thread.
Stock

One I revised

DIGItonium · 12-27-2010, 02:38 AM

Quote:

Originally Posted by Jordo!

The factroy tune begins to cut power as you approach fuel cut for a softer bounce off of the rev limiter. You can see it on most dynos of untuned Z's pretty clearly.

It can be dialed out with tuning.

Oh no, this is not at the rev limit. This "fuel cut" feeling can be felt as the engine revs from 2k on up regardless of how much throttle is applied. It comes and goes, though. I may try to schedule test drives with the tech this spring, and hopefully he can record or monitor this behavior.

@Kastley85891 what you're able to do there is very nice, and hopefully I can get it tuned will with the FI setup

IcedZ · 12-27-2010, 09:13 AM

Quote:

Originally Posted by Kastley85891

Throttle mapping can be improved for sure...ignore fuel tables in pics, not relevant for this thread.

Wow, impressive.

6spd · 12-27-2010, 10:11 AM

Quote:

Originally Posted by Kastley85891

Throttle mapping can be improved for sure...ignore fuel tables in pics, not relevant for this thread.
Stock

One I revised

oh wow, wish i knew how to do that!

Kastley85891 · 12-27-2010, 10:15 AM

Its not tough dude, just trial and error to get what best suits your driving style, mine might not work for everyone else... do you have an AP?

IcedZ · 12-27-2010, 11:14 AM

Quote:

Originally Posted by Kastley85891

Its not tough dude, just trial and error to get what best suits your driving style, mine might not work for everyone else... do you have an AP?

What is AP?

6spd · 12-27-2010, 11:38 AM

Quote:

Originally Posted by IcedZ

What is AP?

access port, and nope, dont have one.

IcedZ · 12-27-2010, 11:39 AM

Quote:

Originally Posted by 6spd

access port, and nope, dont have one.

OH, right. I was seriously considering one.
Would probably spend the extra and get the Osiris Tuner through Uprev though.

12-25-2010, 08:52 PM	#452 (permalink)
wilsonp A True Z Fanatic Join Date: Jul 2010 Location: Virginia Posts: 1,134 Drives: 2009 Touring Sp Nav Rep Power: 17	Your filters needed cleaning already? I have K&N as well, but I can't remember if this happened before I installed them. I wasn't that familiar with the car then. Mine only seems to lag during turns - does it happen at stoplights going straight as well? __________________ 2014 Cayman S PDK Sport Chrono White/Black Was 2009 370Z Touring Sport+Nav 7AT Metallic Black/Persimmon Was 1991 NSX Auto Black/Black

12-25-2010, 10:20 PM	#453 (permalink)
Junior370z A True Z Fanatic Join Date: Apr 2009 Location: Las Vegas Age: 50 Posts: 1,024 Drives: over the speed limit Rep Power: 293	This happens to me on rare occasions. Once it even did it to me in 2nd, 3rd and 4th. Every time it happened it was between 3500 to 4000 rpms. It was always after a stop too. To try and stop it from occurring I let it rev higher before shifting. It hasn't happened after I've been doing that. It's irritating because I really don't know what causes it. At least I'm not alone on it lol! __________________ DON'T DO IT! ( Click to show/hide ) Stillen CBECAI-U/D PulleyGround KitSwaysSetrab Oil CoolerIchiba Rear Camber KitAgility CoiloverBerk HFCTechnosquare TuneGT-R ButtonVenaci MeshSP Performance Cross Drilled/Slotted RotorsSPC Toe BoltsBomex LipMud flapsAero Jacket Type III WingSold

12-26-2010, 04:54 PM	#454 (permalink)
DIGItonium A True Z Fanatic Join Date: Jan 2009 Location: Kansas Posts: 3,800 Drives: 09 Z34-TT 6MT Rep Power: 42	Yea, it's true you definitely need to rev beyond 3k RPM. It's hard to execute, but I tried to rev over 3k a couple of times before engaging 1st. Either that or let it rev past 3k in 1st before going into 2nd. This engine definitely lacks torque under 3k compared to the DE, but it feels artificially limited. __________________

12-26-2010, 07:16 PM	#456 (permalink)
DIGItonium A True Z Fanatic Join Date: Jan 2009 Location: Kansas Posts: 3,800 Drives: 09 Z34-TT 6MT Rep Power: 42	Yea, another good test is getting on ramp and accelerating in 3rd with constant throttle (40-70%). You can feel the hesitation as it revs up towards redline (again, tech thinks it's fuel cutting). Why do we experience what the tech thinks is fuel cutting? __________________

12-26-2010, 09:12 PM	#458 (permalink)
Kastley85891 A True Z Fanatic Join Date: Nov 2009 Location: ATX 370 - Sold Posts: 1,149 Drives: 2003 Wagon Rep Power: 18	Throttle mapping can be improved for sure...ignore fuel tables in pics, not relevant for this thread. Stock One I revised __________________ Boosted V8 hunter 2850 lbs and 375WHP

12-27-2010, 10:15 AM	#462 (permalink)
Kastley85891 A True Z Fanatic Join Date: Nov 2009 Location: ATX 370 - Sold Posts: 1,149 Drives: 2003 Wagon Rep Power: 18	Its not tough dude, just trial and error to get what best suits your driving style, mine might not work for everyone else... do you have an AP? __________________ Boosted V8 hunter 2850 lbs and 375WHP

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