Slow throttle dropoff when upshifting

binto100 · 05-11-2010, 01:49 PM

Hi All.

I have 700 miles on my car and have started installing the Stillen G3 intake, CBE, oil cooler, steering fluid cooler. I can't wait to get all this behind me and get over the break-in period so I can finally open the car up a bit.

I have a throttle question I thought I'd post here for feedback b/f going to the dealer.

When I lift my foot from the throttle to upshift it sometimes takes up to a second for the rpm's to start dropping; I've never run into this on any car before. Often times the rpm's will actually momentarily and slightly increase after I've lifted my foot from the throttle and pushed in the clutch. Firstly it's rather irritating and secondly it makes for slow shifts (I'm not trying to speed shift).

My understanding is that the Z has an electronic throttle. Is it possible or likely that the throttle needs to be re-calibrated or some other adjustment is necessary?

I'm curious if this throttle phenomenon is typical for the Z or if the car needs dealer attention. I’m 54 and have driven sticks off and on since day but I’ve never experienced this before.

Thanks.

Bruce

rj45 · 05-11-2010, 04:11 PM

As I understand it, the throttle float is programmed in for emissions purposes. I guess it's slightly less polluting if the motor hangs there for a second rather than drop/regain rpm. Some brands/models have it worse than others, but most newer cars have at least some throttle float. I guess a competent tuner can adjust it out, but I don't know for sure.

kenchan · 05-11-2010, 04:37 PM

^^ yah, emissions. burn fuel completely seems like.

Nick911sc · 05-11-2010, 05:15 PM

I could be totally wrong, but I thought this was partially due to momentum of the dual mass fly wheel? Please correct me if I am.

m4a1mustang · 05-11-2010, 05:54 PM

Quote:

Originally Posted by Nick911sc

I could be totally wrong, but I thought this was partially due to momentum of the dual mass fly wheel? Please correct me if I am.

You're not wrong. It's a combination of the rotating mass of the flywheel, the lag in the electronic throttle, and emissions controls.

keioh · 05-11-2010, 06:01 PM

Could it be due to SRM turned on?

m4a1mustang · 05-11-2010, 06:15 PM

Quote:

Originally Posted by keioh

Could it be due to SRM turned on?

If there is a malfunction with the SRM system, but this really is a very common issue due to the reasons I listed in my post above. If you are accelerating quickly you actually see a rise in the RPMs after you let off the throttle simply due to the mass of the flywheel.

NCSUPACK09 · 05-11-2010, 08:39 PM

^^ m4a1mustang is right.

It also happens when the SRM is turned off BTW.

Boosted Josh · 05-11-2010, 09:44 PM

My car does it as well. I've had to adjust my driving style to accommodate it, but it still catches me off guard sometimes.

binto100 · 05-12-2010, 11:08 AM

Thanks for all the feedback, at least I know I'm no losing my mind.

Bruce

daleks · 05-12-2010, 11:20 AM

My 2007 Civic Si did the same thing. In fact, there was the exact same thread on the Civic forum with people complaining, and others replying that it was an emissions control feature.

05-11-2010, 01:49 PM	#1 (permalink)
binto100 Base Member Join Date: Apr 2010 Location: Seattle Posts: 32 Drives: 2010 370Z Anniv M6 Rep Power: 15	Slow throttle dropoff when upshifting Hi All. I have 700 miles on my car and have started installing the Stillen G3 intake, CBE, oil cooler, steering fluid cooler. I can't wait to get all this behind me and get over the break-in period so I can finally open the car up a bit. I have a throttle question I thought I'd post here for feedback b/f going to the dealer. When I lift my foot from the throttle to upshift it sometimes takes up to a second for the rpm's to start dropping; I've never run into this on any car before. Often times the rpm's will actually momentarily and slightly increase after I've lifted my foot from the throttle and pushed in the clutch. Firstly it's rather irritating and secondly it makes for slow shifts (I'm not trying to speed shift). My understanding is that the Z has an electronic throttle. Is it possible or likely that the throttle needs to be re-calibrated or some other adjustment is necessary? I'm curious if this throttle phenomenon is typical for the Z or if the car needs dealer attention. I’m 54 and have driven sticks off and on since day but I’ve never experienced this before. Thanks. Bruce __________________ Stillen G3 intake, CBE, 19 row oil cooler and power steering oil cooler. VentureShield bumper, full hood.

05-11-2010, 08:39 PM	#8 (permalink)
NCSUPACK09 Enthusiast Member Join Date: Jan 2010 Location: Somewhere Posts: 407 Drives: '10 370Z MB 6MT SP Rep Power: 15	^^ m4a1mustang is right. It also happens when the SRM is turned off BTW. __________________ 2010 Base 370z Magnetic Black 6MT SP Mods: Bone Stock

05-12-2010, 11:08 AM	#10 (permalink)
binto100 Base Member Join Date: Apr 2010 Location: Seattle Posts: 32 Drives: 2010 370Z Anniv M6 Rep Power: 15	Thanks for all the feedback, at least I know I'm no losing my mind. Bruce __________________ Stillen G3 intake, CBE, 19 row oil cooler and power steering oil cooler. VentureShield bumper, full hood.

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05-11-2010, 04:11 PM	#2 (permalink)
rj45 Base Member Join Date: Apr 2010 Location: USA Posts: 60 Drives: 40th Anniversary Z Rep Power: 15	As I understand it, the throttle float is programmed in for emissions purposes. I guess it's slightly less polluting if the motor hangs there for a second rather than drop/regain rpm. Some brands/models have it worse than others, but most newer cars have at least some throttle float. I guess a competent tuner can adjust it out, but I don't know for sure.

05-11-2010, 04:37 PM	#3 (permalink)
kenchan A True Z Fanatic Join Date: Aug 2009 Location: N/A Posts: 76,801 Drives: N/A Rep Power: 141520	^^ yah, emissions. burn fuel completely seems like.

05-11-2010, 05:15 PM	#4 (permalink)
Nick911sc A True Z Fanatic Join Date: Feb 2009 Location: Long Island, New York Posts: 1,698 Drives: 2010 Nissan GT-R Rep Power: 20	I could be totally wrong, but I thought this was partially due to momentum of the dual mass fly wheel? Please correct me if I am.

05-11-2010, 06:01 PM	#6 (permalink)
keioh Base Member Join Date: Nov 2008 Location: Calif,SF, South Bay Posts: 48 Drives: 09 370Z PG TOUR SP Rep Power: 16	Could it be due to SRM turned on?

05-11-2010, 09:44 PM	#9 (permalink)
Boosted Josh Base Member Join Date: Apr 2010 Location: Alabama Posts: 85 Drives: 09 370Z Rep Power: 15	My car does it as well. I've had to adjust my driving style to accommodate it, but it still catches me off guard sometimes.

05-12-2010, 11:20 AM	#11 (permalink)
daleks Enthusiast Member Join Date: Apr 2010 Location: St. Louis Posts: 424 Drives: 2011 Evo X MR Rep Power: 15	My 2007 Civic Si did the same thing. In fact, there was the exact same thread on the Civic forum with people complaining, and others replying that it was an emissions control feature.