GR Yaris Inconsistent Boost

[Onehp]

Even though throttle reduction is just part of the software I have found that for me, for whatever reason, this has almost completely eliminated the inconsistency. No idea how it's doing it but it works. Boost is now instantaneous in 6th gear too. Couldn't believe the difference it made once I installed it.

Toyota Yaris GR Inlet Duct | FMINLD1 | Forge Motorsport | FMINLD1 | Forge Motorsport

Toyota Yaris GR Inlet Duct designed to add an aesthetically pleasing carbon fibre part to your engines bay, keeping temperatures down during spirited driving.

www.forgemotorsport.co.uk

I've noticed less heat soak and less rubber band feeling on the throttle that otherwise would start at even moderate summer temps and any driving involving stops and revs above 4k rpm. Should be a similar effect for any aftermarket intake that functionally is an actual cold air intake.
If there is anything else at play other then lower temps, I don't know, but who knows what kind of corrections are happening in the ecu due to IAT...

 

[Tralien]

I've noticed less heat soak and less rubber band feeling on the throttle that otherwise would start at even moderate summer temps and any driving involving stops and revs above 4k rpm. Should be a similar effect for any aftermarket intake that functionally is an actual cold air intake.
If there is anything else at play other then lower temps, I don't know, but who knows what kind of corrections are happening in the ecu due to IAT...

the forge inlet does not eliminate inconsistent boost / throttle reduction in my car.
But it looks like you can eliminate when dyno-tuning the car with cracked stock ecu.

I see no reason too why boost should be cut at around 1,3 bar what I can see sometimes in 6th gear.

 

[Benj]

the forge inlet does not eliminate inconsistent boost / throttle reduction in my car.
But it looks like you can eliminate when dyno-tuning the car with cracked stock ecu.

I see no reason too why boost should be cut at around 1,3 bar what I can see sometimes in 6th gear.

Yeah it doesn't make any sense to me that it would make a difference. Thought it would just be worth mentioning as there may be some others that find benefit. Although this did help in my case the only way of properly eliminating this is with a "tune".

 

[Onehp]

Remap. Yeah, but still a lot of developments now, this throttle control isn't out just yet.
ECU is complex and having it work on the dyno isn't the same as great driveability in all possible road conditions and temps, as long as xx tables are unidentified what they do... Some of the big tuners aren't offering remaps yet for a reason?

See where it goes as I like understanding of what is done/happening...

 

[Funky]

Quick way to test power output TC on vs off is to be aggressive with the throttle in second once settled in a long bend like a roundabout.

TC off (expert mode, not off off) you can feel it work to limit yaw angle a little, but give plenty power.

TC off off it'll take a bit more angle and sometimes need steering input to control.

TC on it's very obvious that it's not giving full throttle, and sometimes feels like there's something far wrong as you don't accelerate anywhere near as fast as expected.
This has all been on dry, relatively warm roads (>10 degrees). Looking forward to playing more as the roads get colder here. Wet hasn't made a huge difference as yet!

 

[Benj]

Remap. Yeah, but still a lot of developments now, this throttle control isn't out just yet.
ECU is complex and having it work on the dyno isn't the same as great driveability in all possible road conditions and temps, as long as xx tables are unidentified what they do... Some of the big tuners aren't offering remaps yet for a reason?

See where it goes as I like understanding of what is done/happening...

Good point. Personally I'll be leaving the ECU stock. More than happy with the way it's behaving for me after fitting the Forge inlet duct.

 

[Benj]

Quick way to test power output TC on vs off is to be aggressive with the throttle in second once settled in a long bend like a roundabout.

TC off (expert mode, not off off) you can feel it work to limit yaw angle a little, but give plenty power.

TC off off it'll take a bit more angle and sometimes need steering input to control.

TC on it's very obvious that it's not giving full throttle, and sometimes feels like there's something far wrong as you don't accelerate anywhere near as fast as expected.
This has all been on dry, relatively warm roads (>10 degrees). Looking forward to playing more as the roads get colder here. Wet hasn't made a huge difference as yet!

TC is the first thing I turn off when I jump in the car. I can't even remember what it's like with it on.

 

[Tralien]

TC is the first thing I turn off when I jump in the car. I can't even remember what it's like with it on.

need to test that too.....how can I turn it off?

 

[Duke]

Press and hold the middle button for a few seconds.

 

[Sekred]

Remap. Yeah, but still a lot of developments now, this throttle control isn't out just yet.
ECU is complex and having it work on the dyno isn't the same as great driveability in all possible road conditions and temps, as long as xx tables are unidentified what they do... Some of the big tuners aren't offering remaps yet for a reason?

See where it goes as I like understanding of what is done/happening...

Maybe you can just Fit a cable operated throttle body on it and stick the electronic shit in a sealed plastic bad and cable tie it to the engine somewhere or am I serious .

 

[Onehp]

Maybe you can just Fit a cable operated throttle body on it and stick the electronic shit in a sealed plastic bad and cable tie it to the engine somewhere or am I serious .

Well on a serious note, on a modern turbo car the amount of 'go' is regulated by the manifold boost pressure and timing. The former regulated by the wastegate and throttle. All three perform a complex 'dance' with each other to control the torque and thus power (= torque x revs). Each of these three is controlled by a number of parameter tables that are intelinked with each other and lots of other parameters. I admire those that try to crack this.... If only it were as simple as a physical throttle cable...

We'll see what the future brings, until then I'm happy with my stock map+ecu and very subtle boost modification with my own boost add table in a box...

 

[Sekred]

I am only joking of course. The throttle closing and plenty of other car make use this method to control torque is very obvious on the GR when all the nanny controls are still switch on.
Pity Toyota (need to ?) use Denso. Now if we had Bosch components things would be easier.
I have very little faith in any of the Tuners playing with the ECU on this vehicle at the moment.

 

[Onehp]

Yes I know you were joking but I hear/read quite some confusion about the throttle and its function, that's why I try to clarify some more. Throttle closing a bit isn't necessarily a problem even if your right pedal is to the metal...

 

[Tralien]

seems like motec and syvecs did a better job on this side....or they just dont include the maps that are still unknown in the oem ecu.

 

[Onehp]

seems like motec and syvecs did a better job on this side....or they just dont include the maps that are still unknown in the oem ecu.

They take the same sensors and outputs but have their own control logic entirely. Great hardware, however for a good driveability year round probably needs many hours of mapping for your specific car also.

Maybe one day I go there (specifically, it will maybe be 'worth' it for me if there is a future for E85 where I live, new government now, no idea where they will go...).

 

[Sturesmyg]

Hate to bring this up again… read all the treads both here and at the other forum and no one has asked this questing. Maybe because it’s incredibly dumb. By here goes:

After getting the Forge box + inlet and a resonated catback I also experience lack of and/or inconsistent boost. The car feels slower to me, but has it had a drop in HP?

Is there an actual decrease in overall power from my mods as a result of this software bug or whatever it turns out to be.

 

[GRandemakina]

Hate to bring this up again… read all the treads both here and at the other forum and no one has asked this questing. Maybe because it’s incredibly dumb. By here goes:

After getting the Forge box + inlet and a resonated catback I also experience lack of and/or inconsistent boost. The car feels slower to me, but has it had a drop in HP?

Is there an actual decrease in overall power from my mods as a result of this software bug or whatever it turns out to be.

Lacking better ideas, I suspect that your issue may be related to the Forge top box... if that's the case that the MAF tubing is bigger diameter (than OEM) this usually impacts the engine management - probably leaning out (TBC).
As an example, I recall that Tegiwa made a comparison of CAI's... where the one of the cheapest (better bang/buck) was one with (seamed to me at least) smaller MAF diameter tube - which may trigger the ECU to inject further fuel to compensate the higher air mass readings, getting better performance figures as result!
Take my thoughts with a pinch of salt... but I would start by measuring the MAF tube of both OEM and Forge filter top box...
Lykke til

 

[Sekred]

I monitor the boost pressure of vehicle regularly every time I drive it. I am talking about peak boost pressure at WOT. I have a E-Boost 2 mounted on the A pillar.
The E- Boost 2 in not controlling the wastegate actuator at the moment and just acts like an expensive boost gauge. One thing it does do is record and save peak boost pressure and this cycles with the ignition.
I see anything from 19.5psi to 22.5psi with not real change in conditions or the way I drive, WOT 4th gear or higher. The longer you can hold the throttle wide open the higher the boost seems to creep higher to a point before it starts to fall away towards the red line.
It makes no real sense and its not logical to my way of thinking. I have owned around 4 turbo vehicles and the GR has the most inconsistent peak boost pressure. I do expect some inconsistency but not 3psi.
There is a definite boost reduction in 2nd and 3rd gear, maybe around 1.5psi but that is not unusual and its just the factory mapping controlling engine torque in the lower gears.

 

[Onehp]

Hate to bring this up again… read all the treads both here and at the other forum and no one has asked this questing. Maybe because it’s incredibly dumb. By here goes:

After getting the Forge box + inlet and a resonated catback I also experience lack of and/or inconsistent boost. The car feels slower to me, but has it had a drop in HP?

Is there an actual decrease in overall power from my mods as a result of this software bug or whatever it turns out to be.

If it feels slower and boost gauge is lower, it is slower.

This fault we talk about in this thread is intermittent. You could try a ecu reset by taking off the negative from the battery and let it sit for 20min then reconnect. Then ECU will relearn and maybe accept the new MAF readings which the Forge top box changes with a new diameter at thr sensor as documented on their site - too bad you didn't ask before as I was sceptical as soon as I read about that as it causes a mismatch in AFR control strategy between MAF and Lamnda sensor inputs.

If the fault is there all the time, I would run down all the grey vaccum tubing and make sure it doesn't leak anywhere, maybe it got pinched or punctured somewhere during install. If outside air can finds it way into the system just a bit, the wastegate will be fysically impossible to fully close and thus not be able to create full boost. As said if this is the case, this issue will be there all the time.

Hope you can solve it!

 

[Onehp]

I monitor the boost pressure of vehicle regularly every time I drive it. I am talking about peak boost pressure at WOT. I have a E-Boost 2 mounted on the A pillar.
The E- Boost 2 in not controlling the wastegate actuator at the moment and just acts like an expensive boost gauge. One thing it does do is record and save peak boost pressure and this cycles with the ignition.
I see anything from 19.5psi to 22.5psi with not real change in conditions or the way I drive, WOT 4th gear or higher. The longer you can hold the throttle wide open the higher the boost seems to creep higher to a point before it starts to fall away towards the red line.
It makes no real sense and its not logical to my way of thinking. I have owned around 4 turbo vehicles and the GR has the most inconsistent peak boost pressure. I do expect some inconsistency but not 3psi.
There is a definite boost reduction in 2nd and 3rd gear, maybe around 1.5psi but that is not unusual and its just the factory mapping controlling engine torque in the lower gears.

Boost isn't very stable on this car, varies 1psi easily between subsequent pulls, and up to 3 psi possible as temperatures vary during a drive (2psi temp + 1 psi general variance). I log almost every performance drive as it's dead easy with JB4.