A90 Supra Testing and Tuning
Oh the A90 Supra... is it even really a Supra or is it a BMW in Supra clothing? We're not sure but, we do know one thing now... the B58 engine (even the special variant here in in the first year of the new MK5 Supra) is a potent beast of an engine and has a lot of available power that can be unlocked with a re-calibration of the ECU. We held out and waited waited for our friends at EcuTek Technologies to finish their software suite for this platform and then we jumped into the Beta testing as soon as it was available.
Our main test subject has been the FTSpeed Supra (above left) they've kindly loaned us for some tuning development. It is fitted with an aftermarket catback exhaust but retains all other stock exhaust/intake components so it has been a good car to test. We've also been able to do some testing with a 100% stock Supra (above right) which is still fitted with the OEM catback. More on that below. The first order of business with the FTSpeed Supra was some test driving, a thorough analysis of the OEM tuning approach and of course, laying down some baseline runs for reference. As you can see from the graph below (red), the OEM tune is no slouch. It puts down 336 whp and 380 torque to the wheels, pretty much matching the OEM horsepower rating, typically considered to be at the crank. It runs a very conservative boost level and a surprisingly lean fueling strategy which the direct injection lets it generally get away with. It makes nice power but favors fuel efficiency (even at high loads) over performance, smoothness and knock resistance. With this understood, we went to work on our own mapping. We brought the boost levels up everywhere while remapping to a fueling curve that favors power, smoothness and knock resistance which is important with the higher boost. We of course remapped all other important aspects of the tune with regard to the higher power and gave it pretty much all the boost the stock turbo has to give just to understand the limits. The result of this testing is blue graph below. An incredible jump in power and torque everywhere with new peak figures of 446 whp and 542 torque using 93oct fuel.
The next thing we started testing was blending in some ethanol. Given how limited we already are on the fuel system with this car, we stuck to an E40 mixture or about half gas and half E85. Right away we found some fuel limits at low rpm, high fuel demand and had to pull back the boost there to handle it but after some adjustments, we were able to make more torque and more power everywhere while staying safely the under the limits of the fuel system. We still have a bit more testing to do on E40 but we finished that particular tuning session sitting at 465 whp / 560 torque which is graphed below.
Using the data we've collected from the dyno testing and a good amount of real-world testing or our calibration, we've completed a Stage 1 tune file we are excited about and ready to share with customers (graphed below). Boost and other aspects of the tune were pulled back to a more conservative mapping to ensure longevity for a customer car application and to ensure this tune will work well in all environments and with all fuel types. The final figures from this mapping on the FTSpeed car were 427 whp and 500 torque which is still an incredible jump above the stock figures. Customers will of course be able to ask for our higher boost mapping at their discretion but we like to be transparent about things and offer something for everyone and ranging from mild to more wild.
Additionally, one of our good customers just so happened to have a new Supra and the idea of adding a bunch of power was appealing so we were able test our Stage 1 tune file with a completely stock car, including the catback still being stock. Interestingly, the catback on the FTSpeed car is freeing up some power which we can see in the data and on the dyno graphs, but the completely stock car still put down a really impressive 415 whp and 495 torque with our Stage 1 mapping (graphed below).
Next up we will start testing with hard parts added including turbo-back exhaust changes and inlet side changes to see what kind power that unlocks and get the calibration done for those things. We also have more testing and development to do with ethanol fuel blends to understand the limits and see what power is left with an E40 mixture on our Stage 1 car so stay tuned for those updates. For now, it is safe to say these cars are underrated out of the box and really wake up with a simple re-tune. Equally impressive to the power gains on these cars is Ecutek's progress with this platform in such a short time. They've made working with this car a treat compared to other options and they've allowed us to make very quick progress with our testing and calibration. We're very excited to see what's to come with this platform and continue working with it. Thanks for reading up and email us if you have any questions. Posted below is a final picture comparing all the graphs from this post.