The Toyota GR Yaris gave the whole team a lift at the end of the year and we can’t think of a more anticipated car.  From the very first reviews it was clear this was something special and having cut our teeth with Subarus and Evos we had couldn’t wait to receive our cars. 

 

We decided to get a second Yaris to speed up our development work as it was extremely useful with the Focus RS testing and we were keen to get started straightaway.  Having two cars means we can back to back test subtly different specs for the engine and chassis, invaluable when trying to decide on an exhaust note or a preferred suspension settings.


So far we have a number of parts in development and hope to release the first components in Jan/Feb.   We have our own exhaust being produced now with both a Catalyst back system and later OPF removal options.  We have a bolt in cage being designed, intake system currently in the CAD stages, our own tuning box setup on the dyno, larger intercooler, revised chassis bushes, suspension spring kit and most importantly replacement seats and lowering options being tested.

Our biggest change to the car comes from our new suspension kit and handling setup.   Once the initial novelty of this amazing car begins to wear off you are aware of the unforgiving ride which over longer journeys can become tiresome.  It also sits very high with large gaps in the arches.


We have a great relationship with leading British suspension manufacturer Nitron who produce some stunning kits for high-end sports cars and motorsport.  Their location is relatively close to us and we know their Senior Application Engineer extremely well (we have been playing football together each week for 15 years) so they make a great partner to work with.  Our first GR Yaris arrived on the Friday and by the Monday morning it was on the ramp in Nitron’s HQ.
 


The initial target was to improve the ride quality without sacrificing the character or fantastic handling traits the Yaris has.  The first weekend of driving on the local roads we know so well proved that its agile and exciting chassis was great fun but for us it felt like the chassis could use a broader range.  Simply adding a higher quality damper setup will start this process but it needs fine tuning and time behind the wheel to make something special and worthy of the rest of the chassis.

 

Whilst our first White Yaris was away our 2nd Black Yaris arrived and interestingly this car felt even sharper so it was clear that the dealers were supplying these with a wide tolerance in the wheel alignment setup.  These figures were recorded on our Hunter wheel alignment machine for future reference.  We have our preferred starting settings for our fast road setup of a 4wd chassis and interestingly the Black Yaris was not far off this out of the box, the White Yaris less so.


With the White Yaris away at Nitron we turned our attention to tuning the engine of the Black Yaris.   Having already contacted our usual partners for ECU access it’s wasn’t looking promising.   Ecutek visited the workshop and although they could communicate with the Denso ECU it possesses a whole new protocol and would need substantial time spent reverse engineering the code to allow access.  ECU OBD tuning will be some time off.   We were also contacted by UK ECU manufacturers Syvecs, who have already reversed engineered the GR’s CANbus system but were trying to find a source for the ECU connectors to allow their powerful replacement ECUs’ to become plug & play.


In the meantime we started investigating the use of a simple tuning box that would allow us to lift the boost slightly and provide a worthwhile increase while we wait for the more advanced options to become available.   The initial tests worked well and we were able to achieve 300 bhp but the Tuning Box calibration needs some work to make it smoother on the road and make the power more consistent.  The other benefit is that it can quickly be unplugged if required.




The chassis of the YR Yaris is focused and impressive with its solid mounts, wide track and huge wheel articulation.  When the White Yaris returned from Nitron we were thrilled with the initial setup and we could begin the process of adjusting the damping.  When we’d settled on a final setting for these initial prototypes there was a much improved ride and a nice balance between the front and rear of the car but it was clear we needed to adjust springs.  Curtis from Nitron arrived with a number of different spring weight options to try so the process started all over again.


We could then all head back out and compare the new setup to the original car.  This was very satisfying as not only was the ride quality significantly improved but the lower ride height brought noticeable improvements to composure and response from the chassis.   There was plenty more to come however.  



The white car has returned to Nitron where they are making further valving changes based on our testing and will now produce a 3-way version of the suspension kit.  This will give us even more adjustment to fine tune our chassis setup which can ultimately be applied to the more cost effective 2-way kit.


Follow the development of our GR Yaris upgrades on our social media channels.  We can’t wait to see where this great car will take us.
 

 






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