Tuning transient throttle enrichment on aftermarket ECU

[RyleyMA61]

Can everyone share their experiences, tips etc?

I've got a Haltech E11v2 on the Toyota 7MGTE, and am having trouble getting a lean spike out of the AFRs when you open the throttle very lightly (3-7% and hold it) on gearchanges and slowly revving the car up etc.

Any ideas, and, would AFRs of 16-17:1 do any damage to the car if it is barely under load at all?

Driving around and then nailing the throttle is fine, enriches properly and runs safe AFRs, just super lightl loads.

Thanks all, want to hear your stories!

[oldcorollas]

only a problem if it causes hesitation.
on MS you can tune the enrichment on throttle movement in diffrent parts of the map to eliminate the hesitations, or, you can richen up those areas which are onyl ever used in the transition.

but if it still smooth, the lean AFR will not usually cause issues

[MWP]

I wouldnt worry about it.
16:1 AFR at those small loads wont harm anything.

Its mashing the pedal from light cruise where you need to really worry about lean AFRs and TPS-enrich settings.

[oldcorollas]

yup, and about tuning out stumbles on transition.. if it isn't stumbling (ie,lean or rich misfire).. all good.

[RyleyMA61]

thanks guys good to know. i thought that was the case but would hate to blow something . will probably richen up a few bits too that won't get used otherwise

[JZA70 R]

am having trouble getting a lean spike out of the AFRs when you open the throttle very lightly

what kind of spike? ...for a split second or a sustained spike, if theres such a thing?

A spike for a split second could be a missfire...

and, would AFRs of 16-17:1 do any damage to the car if it is barely under load at all?

No. I cruise and idle @ 16-17 AFR


Todd

[RyleyMA61]

yeah, it's not misfiring, just a split second spike when the initial rush of air comes in and the ecu is too slow (enrichment is done by % throttle / 10mS period- sucks the wang)

there is a misfire at one point but i might just richen it up to counter it, fuckit. i'd rather it drive like a standard ecu car than get a wee bit better economy.

thanks todd, read your tuning thread lots, good info, very inspiring.

[JZA70 R]

Thanks mate. Unfortunately you cant smooth out misfires with more fuel as it doesnt matter how much fuel you add, its not going to ignite. No ignition no burn no gas therefore the o2 sensor wont pick anything up except for a pocket of air which will read full lean.

In regards to enrichment, are you sure the e11 is only correcting in 10ms increments? that doesnt sound right are you sure thats not the refresh rate of the reading in the software?

[VA61DETT]

Ryley, Sorry to hijack..

-JZA70 R

What trick do you use to Idle @ 16+ AFR??
My bloody VG shits itself @ >12afr & it bugs me.. alot....

-A

[JP]

I've found that modifying the injector timing allows the fuel to atomise better and let you run leaner at idle without it stumbling etc.

basically get the engine idling at a steady rpm with a stable injection rate, then change the injection timing until the mixture is the richest. Then you mod the fuel map to take excess fuel out.

[JZA70 R]

no trick, every engine is different and how you've set it up will play a large role in how it behaves at different air fuel ratio's.

i played with mixtures a lot while tuning, found the limits at all different points of load, rpm ect and it just so happens that it was happy to idle at 16:1. The car would start to stumble at > 16:5 and during cruise would surge.

If you jump to 50 seconds in this vid, you can see and hear it idle at 16

http://www.youtube.com/watch?v=fAdAfqzRD0A

Todd

[VA61DETT]

-JZA70 R

That sounds fantastic & rock solid too.
I swear there must be something my car hates about the MT ecu... I had rock solid Idle on the 20 year old LINK unit... But not sure on the AFR back then.

Cheers for the clip.
-A

[TurboRA28]

I can get away with around 15:1 idle on the 1mz..
Maybe we should start a tuning discussion thread as this is all pretty interesting stuff for those of us who like to tune own cars..

[pandaah]

yeh that sounds like a good idea, as id let to get into it myself too as im sure many other people would..

how are you guys tuning by yourself btw?.. obviously road testing but how are you starting off from base maps etc?, and what software and computers are you using....

because pending my 1jz install in my z20 i may buy a certain computer if i know i can tune it myself..

thanks guys

[MWP]

Good idea, someone start a fuel/ignition tuning thread

Im running a Microtech LT10s and Innovate Motorosports LC-1 WB02 kit.
The MT ECU works, but its a piece of shit!
I would never recommend anyone install one for street use. Is OK for a track/drag car though.

If i were going to buy a new ECU, it would be a Wolf V4X or V500.
Very very powerful ECU's and awesome PC/Laptop tuning software.

[pandaah]

i think a mod should change the title of this thread as this will do... riverz? lol

ive always wondered about wolfs, i dont know much about them but some people say there very powerful ecu's, other people say there shit but ive always wondered if thats cos they dont know how to use them properly

[JZA70 R]

lol welcome to 2008 guys...

The Tuning Talk Thread - Forced Induction EFI & JZ Tuning.

[RyleyMA61]

hahah yeah i am suprised how many people haven't chimed in there!

re: misfire, sorry i meant that a misfire caused by a lean spike.

ie i was getting missing/stumbling due to leaning out when taking off from a standstill (throttle at constant position, bring clutch out to vary load)

making it run richer in these load points has solved the issue. got it driving very well now except the initial 16-18:1 AFR lean spike as you open the throttle (light) and about 14 (heavy)

the enrichment is done quicker, but the throttle scaling for defining map points is in "% throttle / 10mS" which makes it hard to get the really tiny inputs sorted without it enriching on just TPS noise. ie, these spikes occur at around 0.16%/10mS.... which is below the 0.5% deadband on the tps enrichment settings. lowering the deadband triggers enrichment events on the jittery signal though

so it's a compromise between annoying drivability and slightly lean mix for a split second on gearchanges at this stage.... apparently it can be fixed but at this stage it's still out of my league

[RyleyMA61]

and fuck me that launch control is good man! video rocks!

[thechuckster]

what is your timing doing as you open the throttle/take off? are you doing any accel enrichment based on MAP changes or just TPS position change rate?

and what size is the throttle and volume of plenum? If the throttle is too large, you end up with a stumble when taking off the line, e.g.:
- first movement of throttle changes MAP and combined with TPS change provides adequate accel enrichment
- a further movement of the throttle doesn't trigger enough change in MAP and the small TPS movement doesn't trigger enough fuel enrichment
- motor then stumbles
- greater TPS movement and change in MAP (as you give motor a bootful of the loud pedal) pushes you out of low load/low rpm region of your fuel/spark maps and combined with the TPS-driven enrichment you get more fuel and a subsequent increase in RPM

Low air speeds (as found at low rpms with big throttles) and minimal changes in MAP make for challenging acceleration tuning.


note: are you using TPS-only driven acceleration enrichment? that's not an ideal (at all) method for turbo engines. You need an approach that combines MAP and TPS changes for acceleration enrichment otherwise you will get lean events during boost.