GR Yaris Inconsistent Boost

[Onehp]

Is a servo wastegate possible without going to an aftermarket ECU?

Never say never, but near impossible as completely different control strategy. Would need to dismount and modify turbo for one as the vacuum actuator is integrated in the turbo.

 

[JJ.King]

I managed to take the car for a little squirt in the back roads tonight on “private land” and found super interesting results using guesstimate. I basically recorded the boost gauge while WOT and slowed down frame by frame to see what rpm I was at before boost came on. Don’t mind sharing video if it brings any insight



When WOT in 3rd from 1750rpm, I see the orange dial hit 1 bar at 4000rpm and continues to climb to what seems like 1.2bar and holds that until redline.

1st run WOT in 2nd from 1500rpm - I see the orange dial hit 1 bar at 3100rpm. It only changes to 1.1-1.2bar after it’s hit 5250rpm

2nd run WOT in 2nd from 2100rpm - I don’t see the orange dial hit 1 bar until it’s at 5550rpm (this is what I experience but usually worse as I never see the orange dial/never hit 1bar )

3rd run WOT in 2nd from 1750-1950rpm - I see orange dial hit 1 bar at 3100rpm. I don’t hit 1.2 bar until around 5100rpm.

Unofficial as I didn’t record this, but as I was going home and did another second gear run, it felt ridiculous. I think from memory I hit 1bar at 3000rpm and hit 1.2bar at 4000rpm and that was the fastest it’s felt all night (+ fastest it’s felt in weeks)



As you can see, 1st and 3rd run in 2nd gear were the best and the first time in a long time I’ve seen and felt the ‘boost’ kick in. Especially the run on the way back home.

I didn’t even try first gear as the few times I did I still had the issue of it only going to 0.8bar. I’ve also noticed 9.5/10 times if I shift from 1st to 2nd WOT I don’t see peak boost of 1.1-1.2bar. Only when I’m already in 2nd gear at a low rpm will I feel boost it seems, but this was just one night of ‘testing’.
Wouldn’t know how to present these findings to Toyota though

 

[nikoel]

I caved in and followed the advice of a mad man by the handle Toni (on the other forum but probably is on here too)
I solved my issue by running an E85 RON98 Blend. At the moment around E20ish but will test with E25ish and then E30ish

Emphasis on the ish rather than the number. But math checks out via this calculator https://www.tuneplusinc.com/pages/tuning-tools#

 

[Onehp]

I caved in and followed the advice of a mad man by the handle Toni (on the other forum but probably is on here too)
I solved my issue by running an E85 RON98 Blend. At the moment around E20ish but will test with E25ish and then E30ish

Emphasis on the ish rather than the number. But math checks out via this calculator https://www.tuneplusinc.com/pages/tuning-tools#

Running blends too sometimes, still happened sometimes but possibly less often, hard to tell

 

[Michael Knight]

Ecu varies boost quite a bit depending on various reasons. I think its normal unless you have severe boost drop etc.

 

[nikoel]

Running blends too sometimes, still happened sometimes but possibly less often, hard to tell

I logged the timing and knock and the values are certainly better with E## - higher RON

I think there are two camps

One who says there is inconsistency of boost due to ECU programming

Second who agrees and says that their inconsistencies and reductions are much higher than normal. Eg not even reaching into the yellow range of boost etc…

When it used to happen to me, I didn’t need no instruments to tell me that the power was way down

 

[Ecsrobin]

I managed to take the car for a little squirt in the back roads tonight on “private land” and found super interesting results using guesstimate. I basically recorded the boost gauge while WOT and slowed down frame by frame to see what rpm I was at before boost came on. Don’t mind sharing video if it brings any insight



When WOT in 3rd from 1750rpm, I see the orange dial hit 1 bar at 4000rpm and continues to climb to what seems like 1.2bar and holds that until redline.

1st run WOT in 2nd from 1500rpm - I see the orange dial hit 1 bar at 3100rpm. It only changes to 1.1-1.2bar after it’s hit 5250rpm

2nd run WOT in 2nd from 2100rpm - I don’t see the orange dial hit 1 bar until it’s at 5550rpm (this is what I experience but usually worse as I never see the orange dial/never hit 1bar )

3rd run WOT in 2nd from 1750-1950rpm - I see orange dial hit 1 bar at 3100rpm. I don’t hit 1.2 bar until around 5100rpm.

Unofficial as I didn’t record this, but as I was going home and did another second gear run, it felt ridiculous. I think from memory I hit 1bar at 3000rpm and hit 1.2bar at 4000rpm and that was the fastest it’s felt all night (+ fastest it’s felt in weeks)



As you can see, 1st and 3rd run in 2nd gear were the best and the first time in a long time I’ve seen and felt the ‘boost’ kick in. Especially the run on the way back home.

I didn’t even try first gear as the few times I did I still had the issue of it only going to 0.8bar. I’ve also noticed 9.5/10 times if I shift from 1st to 2nd WOT I don’t see peak boost of 1.1-1.2bar. Only when I’m already in 2nd gear at a low rpm will I feel boost it seems, but this was just one night of ‘testing’.
Wouldn’t know how to present these findings to Toyota though

What modes are you running in? Track, Sport, Normal. Standard, Expert, Expert+?

 

[JJ.King]

Ecu varies boost quite a bit depending on various reasons. I think its normal unless you have severe boost drop etc.

in one of my videos you can see the boost gauge actually dropping off as rpm is climbing…

 

[JJ.King]

I did a few more tests a few nights ago, and got them all on video. Most noticeable was I did a 2nd gear pull in normal mode (ambient temp 9.3 degrees Celsius) and boost kicked in at 3,000rpm and held until redline.

In another video I was in sport mode starting from 1st gear to 3rd gear. I don’t hit boost in first gear until 6,100rpm… in sport mode?!? Comparing to what I said above, normal mode came on faster and better. (Ambient temp was 9 degrees Celsius)

Then I did another run, where I downshifted from 4th to 2nd and WOT. This is the video where you can see the boost guage needle is dropping while climbing rpm. (Ambient temp 8 degrees Celsius).


It’s crazy, I’ve had new fuel since initial issues begun, went with Ampol which is Toyotas sister company and what fuel they recommend here in Victoria. Ambient temps were perfect, did all these runs with 4-6 min rests between runs to avoid any heat soaking. Same stretch of road. Everything was in perfect condition yet this issue is so inconsistent where sometimes I get boost early (rarely happens) other times boost comes on at 6,000rpm and other times I won’t even hit (and as I’ve recently discovered, in some cases boost looks like it’ll actually drop)

 

[JJ.King]

What modes are you running in? Track, Sport, Normal. Standard, Expert, Expert+?

Trying everything, normal mode is my usual method of testing as I’m driving in that mode most of the time.

I know sport changes some timing and is suppose to come in faster or boost slightly harder, but if you read above what I just wrote, sport mode did so much worse than just normal mode in my testing

 

[JJ.King]

I caved in and followed the advice of a mad man by the handle Toni (on the other forum but probably is on here too)
I solved my issue by running an E85 RON98 Blend. At the moment around E20ish but will test with E25ish and then E30ish

Emphasis on the ish rather than the number. But math checks out via this calculator https://www.tuneplusinc.com/pages/tuning-tools#

Only reason I haven’t tuned for Ethonal blend yet is because I want to tune the car properly, either once ecutek has cracked the DME or go with motec.

Bear with me but this is how it was explained to me by a mechanic/tuner.

If the car is suppose to make 2 (using this as point of reference for power), but is now only making 1 - something that’s causing that problem needs to be looked into. If you get a piggyback it’s going to trick the car into thinking it has 0, so the car is going to push an additional 2 to make up for the power. On a normal working car, you’d now theoretically have 4, but because your car has issues and dropped down to a 1, you’re now only getting 3. 3 is still better than 2(OEM power) and most people probably will say ‘yup piggyback or octane booster fixed the problem’ , but in reality you haven’t sorted out the problem.

I’m saying that, if you’re at a 1 in power and get up to 3 all of a sudden, yes you’re probably going to think everything is sorted with the car.


This is why I haven’t added octane boosters or just added a piggyback yet. I want to sort out the main issue as it’s like a Band-Aid solution. The problem is still there and you’re not doing yourself any favours.


It was explained to me in this way and it made sense to me, but I’m not too sure if anyone else follows? I’m still pursuing the dealership and trying to get this sorted under warranty. Will keep updating as I go.

 

[Michael Knight]

in one of my videos you can see the boost gauge actually dropping off as rpm is climbing…

that's normal, car has hardly 1bar boost at redline in certain conditions.

 

[nikoel]

Good luck buh' - You will be the first

My prediction. They will keep taking your car, doing their 40km'h single runs and charging you 200 kangaroos every time you go there and then telling you how there is nothing wrong with it

Andrew from Motiv replied to my query himself and said that his has never seen an ECU that has been this inconsistent before

For the record I have not tuned for Ethanol either. The stock ECU handles my mix just fine

I would love to go the route of ECUTEK sometime, but I am in Brisbane and will be a downright lab rat, which I am not keen on

Biggest increase with Ethanol that I have observed is the down low torque - Knock Feedback value is back up to 24-26 btw

 

[Ecsrobin]

Trying everything, normal mode is my usual method of testing as I’m driving in that mode most of the time.

I know sport changes some timing and is suppose to come in faster or boost slightly harder, but if you read above what I just wrote, sport mode did so much worse than just normal mode in my testing

You haven’t mentioned if using expert or expert+. If I was a betting man going into expert or expert+ the problem might disappear.

 

[SckSqzBngBlo]

Assuming everyone drives with AC off like me? Besides my 5min per week as per manual, i find it saps too much power like every other car.

 

[nikoel]

Assuming everyone drives with AC off like me? Besides my 5min per week as per manual, i find it saps too much power like every other car.

Location: Australia
No AC...



Are you in the pademelon country or perhaps somewhere around Mawson Station?
Have you done something so horrendously bad that you're trying to climatise for the afterlife?

 

[Duke]

Assuming everyone drives with AC off like me? Besides my 5min per week as per manual, i find it saps too much power like every other car.

No, that would be daft. Why would you drive with it switched off?

The GR will be like any other decent car since the late 1990s and disengage the compressor at WOT, meaning you can drive around in lovely cool air all the time and still get full engine power any time you actually need it. Plus you won't get any issues with bacterial build-up, smells, or seals drying out etc.

Even if it didn't disengage it can only sap about 1-2% of engine power at most, and unless you live your life one quarter mile at a time that's just not going to make any tangible difference.

Turning it off in my company Civic in mid-90s Qatar though? Absolutely, that was like a 'VTEC Yo!' event but then the thing only had about 100hp on a good day and it was inevitably ~40°C outside so the compressor duty cycle would be approaching 100%

 

[Sam]

My AC is on all the time...

 

[Michael Knight]

Have you noticed inconsitent power with AC? or maybe should open another thread for that...

 

[Sam]

Have you noticed inconsitent power with AC? or maybe should open another thread for that...

I pipe cold air from the AC into the intake to counteract the powerloss.