GR86 Overly sensitive throttle mapping - Solution found :-)

[SJR202]

Hi - grab a cuppa...

So a side subject of 'Jerky acceleration when cold?' which might help those who like me feel the throttle is too sensitive and aggressive in many situations. For me it is a bit of a pain when driving in traffic or slow situations and a jaunt across Wales showed it up in my opinion that it really lacked the tactile mid corner adjustability that you really want from a sports car, especially if like me you were driving in the wet and cold!
Long story short its been a bug bear of mine since day 1 and has caused me to contemplate selling the 86 many times as it just wasnt that enjoyable for me.

By chance I came across Race Chips and specifically this throttle mapping product https://racechipuk.co.uk/racechip-xlr5-controller-toyota-gr-86-zn8-from-2021-2-4-234-hp-172-kw/
So I thought I'd take a punt and see what happens after chatting to the company, while the aim of this throttle controller is to sharpen throttle response and give a more sporty feel, it also said it could reduce the sensitivity by using the 'eco / eco+' mode...

Long story short, took about 2 mins to disconnect the factory throttle link and insert this XLR5 controller. Then about 5-10 mins to set it up via the app, basically you map the minimum and maximum throttle position and the XLR can then use that range to amend/adapt the throttle according to the setting you set.

It defaults to 'sport' so I set sport to the 'eco+' level which is the most docile throttle setting and after trying it with eco+, eco and sport settled on eco+ as my default. The throttle now opens gently and progressively, you can hold specific revs and ease acceleration out of a corner without the factory 'on / off' feel.

I also took the car for a service a few days later and removed it in seconds, no problems were thrown up from the service so as per the company claim, once removed its not traceable.

I took the car for a 'test drive' once installed and for the first time in over 2 years kept looking for more roads to drive rather than just getting frustrated and going home! Its smoother overall too in delivery, I wouldnt say it is as good as a Porsche throttle but I would recommend it if you feel the 86 throttle pedal is too sensitive or not adjustable enough.
I did also get the 'controller' which didnt work so I sent it back, I dont actually think you need it unless you want to change the set up while driving and not use the app.

 

[Sonic]

I also took the car for a service a few days later and removed it in seconds, no problems were thrown up from the service so as per the company claim, once removed its not traceable.

I like the look of that.
How is it powered and mounted? That is, do you have to splice it into a 12v line from the fusebox? Is the unit mounted by velcro (or similar) on any flat surface in the footwell?

 

[SJR202]

I like the look of that.
How is it powered and mounted? That is, do you have to splice it into a 12v line from the fusebox? Is the unit mounted by velcro (or similar) on any flat surface in the footwell?

It takes power from the car, the XLR plugs into the same factory connectors / pin from car to throttle so it must take the feed from that.

Mounting you have a few options, it comes with cable ties and double sticky Velcro, I have cable tied the excessive wire away from the pedals up above the pedal box and then mounted the 'box' behind the carpet on the driver footwell just behind the front wheel, all seems quite secure there.

Honestly when it comes to electrics, if it doesnt plug and play I dont even bother

 

[sim61]

Interesting...

 

[ZN8]

Interesting...

It is, I didn't find that the Pedal Commander was worth it, wonder if this is better. Clutch spring was the winner for me.

 

[Conscript]

<Strokes chin>
Always a bit dubious of these products, as it seems to my completely unqualified eye that all they're doing is intercepting the throttle pedal voltage - so while they can make the pedal feel lazier or more sensitive, I'm not sure they can do anything about the actual throttle curve. I tried the Pedal Commander and it didn't make things much better - in fact the best thing about it was that it made the throttle more sensitive to a quick input, but that wasn't worth £200.

However...

Then about 5-10 mins to set it up via the app, basically you map the minimum and maximum throttle position and the XLR can then use that range to amend/adapt the throttle according to the setting you set.

...does this mean that the pedal is actually responsive for it's full range of motion? No more hitting 100% throttle open when the pedal is only 60% down?

 

[ZN8]

I'm not sure they can do anything about the actual throttle curve.

It can, but and it is a big but, it can only influence the throttle position sensor, it has limited capacity to alter the throttle map, there is alot more going on to change throttle response than just tweaking the output of a single sensor. That in itself isn't directly proportional to what happens to the throttle butterfly, fuel, timing etc.

 

[Conscript]

It can, but and it is a big but, it can only influence the throttle position sensor, it has limited capacity to alter the throttle map, there is alot more going on to change throttle response than just tweaking the output of a single sensor. That in itself isn't directly proportional to what happens to the throttle butterfly, fuel, timing etc.

Yeah, that's my worry, it seems there's a lot more going on that just "how hard is the throttle being pushed".

However, if this thing is able to do something about the seemingly artificially shortened travel of the throttle pedal, I would be interested, as it feels to me like that is actually the majority of the problem - all the throttle control feels like its only happening in the top half of the pedal travel. If you can make the car recognise more of the pedal travel, then it should feel more linear and easier to manipulate as a consequence.

Might be talking bobbins. Hopefully you get what I'm on about

 

[Itcaptainslow]

Interesting development - thanks for posting!

 

[airwolf]

I am using a device called SprintBooster v3 and I am happy with it. I used SprintBooster v2 and v3 in my previous Alfa Romeo for almost 15 years in total, and recommended this throttle controller, or similar products by Pedalbox or Blitz, to 14 friends/customers in total through the years, from VW Polo to Maserati Levante, both with manual and automatic transmissions.

With all of these controllers there will be a hard job to find the right mode to use (in comparision to other cars with more "normal", not so steep and jerky throttle response like in a GR86). From all available 36 (sub)modes in SprintBooster v3, I can use 3~4 only. The best is Green-3 ('softer' green Sport mode with submode 3 on display) and the transmission switch selected in the also 'softer' Automatic position. This gives the most linear throttle reaction characteristics for spirited driving. Green-2 is good for city/MPG/cold start driving. Green-4 for track. From the sharper Red (Race) mode, I can use only the softest/slowest 1 submode, otherwise I get jerky reactions from engine.

I bought this controller in Austria (but is available also in many other countries): https://www.fosab.com/index.php?cat=engine_detail&id=28954 Controller and wire is tiny, I have fitted it near the steering wheel (with the attached 3M tape), so I can change the submode anytime with my right middle finger, with hands still on the steering wheel.

In conjunction with a softer clutch pedal spring, adapted height of all pedals and widened brake and throttle pedal (over)cover, there is now a satisfactory use of manual gear change, launch from start, and heel & toe technique.
Further improvement of a more 'mechanic' feel of gear change got by STI transmission mount, and yet more quick responding throttle response by install of the rearmost differential bushing inserts (Cusco or Whiteline) and reducing the engine movement by fitting of the stiff armed silicone post MAF hose/tube (by e.g.GrimmSpeed, Apexi, Greddy, or aFe Power). Sportive air filter panel insert (dry GrimmSpeed or Blitz, or oiled BMC or K&N) is also helping to get more lively reactions from engine.

 

[GaryG]

Sounds interesting but an Ecutek remap isn’t much more and should 100% solve the issue….granted, factory warranty would be affected.

 

[Conscript]

...does this mean that the pedal is actually responsive for it's full range of motion? No more hitting 100% throttle open when the pedal is only 60% down?

@SJR202 as well as the above, another quick question if you've tested it...does this fix the throttle sometimes not even registering a quick input?
If you're sitting at idle in neutral, and you just jab the accelerator really quickly, the engine doesn't respond at all. Pretty sure that this didn't happen when I had the Pedal Commander. Does it happen with the XLR5?

 

[kalniel]

Yeah, that's my worry, it seems there's a lot more going on that just "how hard is the throttle being pushed".

However, if this thing is able to do something about the seemingly artificially shortened travel of the throttle pedal, I would be interested, as it feels to me like that is actually the majority of the problem - all the throttle control feels like its only happening in the top half of the pedal travel. If you can make the car recognise more of the pedal travel, then it should feel more linear and easier to manipulate as a consequence.

Might be talking bobbins. Hopefully you get what I'm on about

My thoughts exactly. If the car can actually report throttle position beyond the current 50% or so of range and this tool can use that range then fantastic. If it's just altering the curve within the same range then I can see some benefit, but not as much.

 

[jb1750]

@SJR202 as well as the above, another quick question if you've tested it...does this fix the throttle sometimes not even registering a quick input?
If you're sitting at idle in neutral, and you just jab the accelerator really quickly, the engine doesn't respond at all. Pretty sure that this didn't happen when I had the Pedal Commander. Does it happen with the XLR5?

I’d say it’s this that catches me out the most. I’ve gotten pretty comfortable with the aggressive map at this point (just a case of muscle memory I guess), but it’s the numb response to a throttle blip that continues to frustrate

 

[benzz280]

isnt this something that can be tested out using an OBD2 scanner by looking at the TPS graph? I have a trial scheduled on monday for it and hope I can measure and compare the TPS graph before & after. Thoughts?

 

[Conscript]

@SJR202 how are you getting on with the XLR5? You can't just casually start a thread claiming you've solved one of the cars most annoying issues and then just disappear....unless it's so good that you've been driving non-stop since then

 

[benzz280]

after trying the XLR5 using the OP's setting, my impression is that the kit just dull the throttle response to make it easier to drive on busy traffic at low rpm. At high rpm range I couldnt prove the kit made the last few inches of the throttle pedal alive (vs stock). I didnt feel the car pulling anymore at the last few inches of pedal travel which to me didnt made any difference there, hence I ended up not getting it. Although some may find other features the kit offers useful such as Valet mode (restrict how much throttle is available) and the anti theft mode (kill the throttle completely).

 

[SJR202]

@SJR202 how are you getting on with the XLR5? You can't just casually start a thread claiming you've solved one of the cars most annoying issues and then just disappear....unless it's so good that you've been driving non-stop since then

Hi Conscript, that did cross my mind, I dropped this post and then didnt visit the forum for the longest period in 3 years!!

So I've had it just over a month and for me it cures the main issue that I experienced and led me to the verge of selling the car, the throttle mapping/responsiveness just irritated me and with 12k miles on the car its not like I havent got used to it, I just hated it.

The controller for me is set to the least aggressive setting all the time, I have found that natural to daily driving and able to adjust acceleration incrementally mid bend or on slippy surfaces/junctions etc. I have even done a 12 car rally in the car on damp slippy country lanes and didnt have much traction control flashing at all as I could 'feel' as the car was starting to lose traction I could amend my inputs.

Is it the perfect solution to everyone, probably not, it depends what you're looking for, but to me its how it should have been out of the factory and all the better for it.

A note that @benzz280 raised, yes that is a reasonable account of how it works which is for me exactly what was needed for commuting, traffic and cold engine. In the most 'economical'/sedate setting it does dull or relax the throttle responsiveness, so initial travel of the accelerator/acceleration is much more gentle and controllable than stock. Knock it up a setting (from E+ to E) then it is much sportier in response, not as aggressive as stock or short in its response but I contemplated using this setting day to day but found on fast bends the most 'relaxed' setting the best for me.

As for the 0-100% travel affecting acceleration, no I dont think it quite does that, what I felt was in stock form, c30% of the throttle was 100% open which I hated, its more to me now with the XLR5 80% of throttle is 100% open, so the final 1-2cm of travel makes no discernable difference to the throttle but up to that point it makes a substantial difference to me.

Additionally it is easy to fit/remove and change settings and seems untraceable via the service reports (mine was removed for service) then it does the job.

The clutch spring is something which is still tempting me to change to have that smoother and progressive release of the clutch but 'solving' the throttle mapping/responsiveness was key for me.
The 'rev hang' is also something which frustrates in day to day driving but I understand there isnt anything which can be done about that without hacking into ECU etc and programming it out.

 

[Conscript]

As for the 0-100% travel affecting acceleration, no I dont think it quite does that, what I felt was in stock form, c30% of the throttle was 100% open which I hated, its more to me now with the XLR5 80% of throttle is 100% open, so the final 1-2cm of travel makes no discernable difference to the throttle but up to that point it makes a substantial difference to me.

Cool...so it does at least feel like it's making use of more of the pedal travel?

I am tempted if that's the case. I wonder if they are open to a trial period. It's a lot of money, which I would be fine with if there was a guaranteed improvement, but if it's like the Pedal Commander where it just felt 'different' rather than 'better', I'm not sure I'd want to swallow the cost.

 

[SJR202]

Cool...so it does at least feel like it's making use of more of the pedal travel?

I am tempted if that's the case. I wonder if they are open to a trial period. It's a lot of money, which I would be fine with if there was a guaranteed improvement, but if it's like the Pedal Commander where it just felt 'different' rather than 'better', I'm not sure I'd want to swallow the cost.

Yes it makes use of a lot more of the pedal travel and therefore removes 90% of that 'on/off' feel that it can give. Double check but I am pretty sure they'll accept returns within 14 days if not happy with the product, it would have to go back to Germany but for the cost of some airmail it sounds like its worth a try.
If you're in the Surrey area (Woking) give me a shout as you're welcome to take a look before buying, on that note, they have regular sales so I saved quite a bit. I paid £150 for the XLR5 and £50 for the bluetooth controller, to be honest unless you want to change the settings on a regular basis then the app works well enough and I think it comes with an analogue wired controller as standard. For me I havent even paired the bluetooth controller as dont have a need for it.