Design
The GR86 is already a highly entertaining back to basics sports car which is a huge amount of fun to drive. The engine has a good torque curve and the rpm’s build progressively to the red line. However, it does lack something and this is evident from just hearing the engine under normal driving and looking under the engine bay. The intake sound is mostly artificial being driven into the car by the speakers and it is very small with a series of Helmoltz resonators which quieten the induction sound.
There is also a distinct hesitation at the lower rpm’s (not the mild torque dip).Our aim was to vastly improve the intake with a full redesign to give faster throttle response, improved torque under both partial load and full load and most of all more induction sound. The Toyota GR86 is the least powerful car we have ever developed an intake system for but it’s been the most rewarding.
DEVELOPMENT PROCESS
During the development process we created multiple prototypes. The initial prototype used a straight venturi tube feeding into a large airbox which took it’s air from the stock OEM area with an enlarged area with an additional air feed on the opposite side which is very small.The idea was that the additional air feed would help in increasing available airflow. However this design failed to give the desired results both on the dyno testing and on the road with no difference in power. Drivability was compromised with an additional torque dip in the higher midrange. CFD analysis showed vast amounts of turbulence in front of the air filter.
In order to keep the airflow smooth and uniform the direct approach was taken with the same path with the single feed but with the following major changes:
1 – Double the cross sectional area of the front inlet feed giving more a more than adequate increase on available air for the FA24
2 – Extend the snorkel towards the front and incorporate a bell mouth to smooth the air flow
3 – use a significantly larger air filter housing and the largest possible venturi inlet tube.
After some iterations this method gave the best air flow under CFD analysis showing less turbulence than the OEM system with vastly increased airflow.
The results on both the dyno (see below) and road driving were excellent. Vastly improved throttle response, low end torque response improvements with all of the hesitation now absent. At mid-higher rpm heavy load driving a clear gain in performance noticed. Under normal but spirited driving the engine feels even more eager to accelerate in the 2000-4000rpm range required with more torque.
1st Prototype
Final Design
Air Feed Comparison
Infinity vs OEM
High Flow Air Filters & Intake Temperatures
Our bespoke short stack high surface area filter larger than any cone filter design currently on offer on the market with a huge opening of 170mm (6 3/4") and is designed to take full advantage of the intake tubes by altering the direction of the airflow towards the outer walls. By placing the air filters in front of the inlet tube we achieve the largest velocity stack.
PERFORMANCE TESTING
Dyno tests were performed under strict controlled conditions on an independent Maha MSR500 dynamometer in order to show a true and realistic result.
The stock car made almost exactly what the manufacturer quotes with 228 BHP and 179 lb.ft torque with a perfect power curve.
After fitting our intake system the peak power went to 239BHP and 184 lb.ft torque.
A significant and clear gains of 11 BHP and 5 lb.ft torque peak.
From 2000-3000rpm a torque increase of 10 lb.ft was gained which is a significant gain.
From 6000rpm onwards the FA24 engine gains significant HP and torque to the red line.
Run down losses remains identical between the two tests as did the ambient temperature.
Both sets of tests were carried out with identical starting oil and coolant temperatures.Dyno Line Key:
Solid Blue line / Dotted Blue Line – WHEEL HPSolid Green Line / Dotted Green Line – Drivetrain LossSolid Red Line / Dotted Red Line – Flywheel Calculated HP (wheel + loss)Solid Yellow Line / Dotted Yellow Line – Flywheel Calculated Torque
Driven Media Test
Driven Media have independently tested the GR86 intake on their in house modified car and had the most positive results from any intake to date.
Tegiwa Dyno and Road Test
Tegiwa, known for the dyno shoot outs, test our car before and after the intake. Road tests and air intake temperature testing.
What is in the Box
1 x Venturi Inlet Tube
1 x Air Filter Housing / Inlet Duct
1 X Snorkel
1 x Bespoke Infinity Design Air Filter
1 x Black metal clamp
1 x Silicone Joiner with Clamps
