Quicker Decelertaion - Toyota Yaris Forums

BrazdonW · 12-10-2009, 12:36 PM

I'm not sure if there is already a thread on this (i had no luck finding one) but when you will notice when the car is sitting still or in gear that when you rev the engine the deceleration is very slow compared to most cars. What are some step you can take to change that?

YarisSedan · 12-10-2009, 02:23 PM

I think its possible due to the drive by wire system electronic throttle. When you snap it on a conventional system the cable snaps open the butterfly and the spring quickly snaps it shut if you take your foot immediately off the gas.

On our system its controlled by a computer and electronic motor. Could be the motor can not react as quickly within a split second and gradually closes back down the butterfly.

HTM Yaris · 12-10-2009, 06:45 PM

A lightened flywheel will solve that problem , but will create others

kngrsll · 12-10-2009, 08:02 PM

Quote:

Originally Posted by HTM Yaris

A lightened flywheel will solve that problem , but will create others

like stalling when you flip it into neutral. my car does this all the time now!

why? · 12-10-2009, 08:47 PM

Quote:

Originally Posted by kngrsll

like stalling when you flip it into neutral. my car does this all the time now!

really? that stinks.

kngrsll · 12-10-2009, 09:26 PM

its not a big deal. if rolling, throw it back in gear and if stopped, just start it haha

thebarber · 12-10-2009, 11:09 PM

i had fidanza in my xrs and never had a stalling problem.....6.5lbs vs 13lb stock....so super light too

but lightweight pulleys and flywheel will help the engine rev up and down more quickly

BrazdonW · 12-10-2009, 11:29 PM

Are these the only possibilities?

Doc Zaius · 12-10-2009, 11:51 PM

Hack the signal to the throttle body?

Gideon · 12-11-2009, 12:04 AM

Actually, it would be possible to use a 1ZZ throttle body. My idle went up 200 rpms when I installed mine (and hasn't gone away), which would help.

BrazdonW · 12-11-2009, 01:16 PM

i have a corolla tb is that what you mean?
the deceleration didnt change when i swapped it.

BrazdonW · 12-11-2009, 01:17 PM

Quote:

Originally Posted by thebarber

i had fidanza in my xrs and never had a stalling problem.....6.5lbs vs 13lb stock....so super light too

but lightweight pulleys and flywheel will help the engine rev up and down more quickly

maybe i should do more pulleys?
i have the lightweight crank pulley
would changing the others really help?

kngrsll · 12-12-2009, 10:17 PM

why do you want to make the engine stop spinning faster??

the only reason i can think of would be because that means it spins more easily while accelerating? thats kind of a backwords way to look at an improvement in throttle response though.

to improve throttle response, in general there are two things you can do. lighten the parts that rotate (ie pulleys, flywheel, remove things like AC) or improve the flow (individual throttle bodies, header). i think timing has a small influence, but its probably minimal.

so if you improve throttle response, you will improve your engine slowing down thing, also increasing your ability to stall the car lol

thepoche · 12-13-2009, 12:49 PM

Quote:

Originally Posted by kngrsll

why do you want to make the engine stop spinning faster??

More engine brake would help with throttle steering but I don't know if thats what BrazdonW had in mind.

BrazdonW · 12-13-2009, 12:56 PM

It is more of preference thing than it is a performance thing
i like when it snaps back fast because it is what i'm used to
the other cars i have owned have all snapped back much quicker
and its not as if every car i have owned has been a performance car (geo metro, dodge neon, vw gti mkII)
as an econo car i know it will have some quirks but this is just one i don't like
id like to fix it somehow :)

jonismyname · 12-28-2009, 10:08 PM

hmm. friction brake on the serp belt? if anyone (other than ctscott, he's busy making yargauges!) has the ability to read the signal to the solenoid that controls the throttle body it coud at least be confirmed it's a bastard child of fancy programming and our econobox.

another option is following in garms footsteps---fancy gas pedals and cable system!

standalone ecu?

i'd say it's in the software...

MUSKOKA800 · 12-30-2009, 02:17 PM

I noticed this back in the day when emission controlled vehicles became the normal and was told that a slower/controlled RPM drop reduced pollution. My guess is that todays cars rev down slowly for the same reason.

cali yaris · 12-30-2009, 02:22 PM

No problem at all with stalling and a lightweight flywheel here. (and that includes before I added FI). Don't let these guys warn you off of that idea. Excellent way to open up throttle response, both directions.

12-10-2009, 12:36 PM	#1
BrazdonW What kind of car is that? View User's Garage Drives: Yaris 3d liftback Join Date: Jun 2007 Location: Columbia, MD Posts: 571	Quicker Decelertaion I'm not sure if there is already a thread on this (i had no luck finding one) but when you will notice when the car is sitting still or in gear that when you rev the engine the deceleration is very slow compared to most cars. What are some step you can take to change that? __________________

12-10-2009, 02:23 PM	#2
YarisSedan Drives: 08 Yaris Sedan Join Date: Oct 2008 Location: California - Bay Area Posts: 2,773	I think its possible due to the drive by wire system electronic throttle. When you snap it on a conventional system the cable snaps open the butterfly and the spring quickly snaps it shut if you take your foot immediately off the gas. On our system its controlled by a computer and electronic motor. Could be the motor can not react as quickly within a split second and gradually closes back down the butterfly. __________________ http://www.cardomain.com/ride/3210549

12-10-2009, 06:45 PM	#3
HTM Yaris resident senior View User's Garage Drives: 07 Yaris Join Date: Jan 2007 Location: south Carolina Posts: 814	A lightened flywheel will solve that problem , but will create others __________________

12-10-2009, 09:26 PM	#6
kngrsll Apexing Egg!! Drives: 07 Toyota Yaris white hatch Join Date: Oct 2006 Location: Spartanburg, SC Posts: 872	its not a big deal. if rolling, throw it back in gear and if stopped, just start it haha __________________ HighTach Motorsports 2007 Toyota Yaris-ARGH!! Mods: Tokico HTS, 6.6 kg F, 6.1 kg R custom springs, 23 mm RSB, 2-way TRD LSD, 15x7 +25 Team Dynamic wheels, 195/55/15 Dunlop Star Specs, Cobra Suzuka S

12-10-2009, 11:09 PM	#7
thebarber daily driver View User's Garage Drives: the #wrecho Join Date: Jun 2006 Location: Grand Rapids, MI Posts: 5,877	i had fidanza in my xrs and never had a stalling problem.....6.5lbs vs 13lb stock....so super light too but lightweight pulleys and flywheel will help the engine rev up and down more quickly __________________

12-10-2009, 11:29 PM	#8
BrazdonW What kind of car is that? View User's Garage Drives: Yaris 3d liftback Join Date: Jun 2007 Location: Columbia, MD Posts: 571	Are these the only possibilities? __________________

12-10-2009, 11:51 PM	#9
Doc Zaius Lurker supreme! View User's Garage Drives: old and boosted! Join Date: Nov 2006 Location: Ottawa, ON, Canada Posts: 792	Hack the signal to the throttle body? __________________ 2006 Red Blitzed RS 5-door

12-11-2009, 12:04 AM	#10
Gideon ★weeaboo★ View User's Garage Drives: 2008 Bayou LB Join Date: Oct 2008 Location: Sunnyvale, CA Posts: 661	Actually, it would be possible to use a 1ZZ throttle body. My idle went up 200 rpms when I installed mine (and hasn't gone away), which would help.

12-11-2009, 01:16 PM	#11
BrazdonW What kind of car is that? View User's Garage Drives: Yaris 3d liftback Join Date: Jun 2007 Location: Columbia, MD Posts: 571	i have a corolla tb is that what you mean? the deceleration didnt change when i swapped it. __________________

12-12-2009, 10:17 PM	#13
kngrsll Apexing Egg!! Drives: 07 Toyota Yaris white hatch Join Date: Oct 2006 Location: Spartanburg, SC Posts: 872	why do you want to make the engine stop spinning faster?? the only reason i can think of would be because that means it spins more easily while accelerating? thats kind of a backwords way to look at an improvement in throttle response though. to improve throttle response, in general there are two things you can do. lighten the parts that rotate (ie pulleys, flywheel, remove things like AC) or improve the flow (individual throttle bodies, header). i think timing has a small influence, but its probably minimal. so if you improve throttle response, you will improve your engine slowing down thing, also increasing your ability to stall the car lol __________________ HighTach Motorsports 2007 Toyota Yaris-ARGH!! Mods: Tokico HTS, 6.6 kg F, 6.1 kg R custom springs, 23 mm RSB, 2-way TRD LSD, 15x7 +25 Team Dynamic wheels, 195/55/15 Dunlop Star Specs, Cobra Suzuka S

12-13-2009, 12:56 PM	#15
BrazdonW What kind of car is that? View User's Garage Drives: Yaris 3d liftback Join Date: Jun 2007 Location: Columbia, MD Posts: 571	It is more of preference thing than it is a performance thing i like when it snaps back fast because it is what i'm used to the other cars i have owned have all snapped back much quicker and its not as if every car i have owned has been a performance car (geo metro, dodge neon, vw gti mkII) as an econo car i know it will have some quirks but this is just one i don't like id like to fix it somehow :) __________________

12-28-2009, 10:08 PM	#16
jonismyname Drives: 08 liftback 5spd Join Date: Oct 2008 Location: adirondacks, ny Posts: 220	hmm. friction brake on the serp belt? if anyone (other than ctscott, he's busy making yargauges!) has the ability to read the signal to the solenoid that controls the throttle body it coud at least be confirmed it's a bastard child of fancy programming and our econobox. another option is following in garms footsteps---fancy gas pedals and cable system! standalone ecu? i'd say it's in the software...

12-30-2009, 02:17 PM	#17
MUSKOKA800 Drives: '08 Yaris Sedan, Aero Package Join Date: Oct 2008 Location: Burlington, Ontario, Canada Posts: 1,720	I noticed this back in the day when emission controlled vehicles became the normal and was told that a slower/controlled RPM drop reduced pollution. My guess is that todays cars rev down slowly for the same reason. __________________ TRD Upgrades: 18" Wheels wrapped in 215/35/18 PZero's, Sportivo Shocks/Struts, Lowering Springs, Swaybar, Axle-Back Exhaust, Oil Cap, Rad Cap, Signage. Aftermarket Goodies: Piggies SS, K&N Drop-In, Blitz S/C, DC Header, NST Pulley) Toyota Options/Accessories: Sport Pedal Covers, Sport Shift Knob, Ipod Interface, Summer Mats, Winter Mats, Cruise Control, Auto-Dim Mirror, Echo steelies with winter boots.

12-30-2009, 02:22 PM	#18
cali yaris ULTIMATE View User's Garage Drives: 07 Yaris Turbo Join Date: May 2007 Location: Canoga Park, CA Posts: 14,859	No problem at all with stalling and a lightweight flywheel here. (and that includes before I added FI). Don't let these guys warn you off of that idea. Excellent way to open up throttle response, both directions. __________________ Micro Image forums, online store and shop are now closed. It was a great eight year run, but it was time to focus on other things. I'm still selling parts on eBay under micro*image seller ID and customers can still make requests for anything specific.

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