Two Silhouettes Beyond the Crest

What would happen if a JAF GT300 car and a TA1 contender shared the track at Mosport?

Our “What if…” series moves to another continent, following comparisons of aerodynamic wakes at the Hungaroring and Thruxton, and the elevation profiles of Knockhill and Sugo.

While Super GT’s organisers are still dreaming of taking GT500 to Le Mans, we have no hesitation in sending a JAF GT300 silhouette out against a NASCAR-like TA1 monster at Canada’s Mosport. Ahead of them sits an LMP2 prototype, providing a rather elusive target. What would a one-lap qualifying sprint, with a rolling start, produce?

The short answer: LMP2 wins without much suspense. The Japanese GT300 silhouette most likely finishes second. The TA car is fastest during certain acceleration phases, but not over the lap. The exception is apr’s heavy hybrid Lexus: TA could fight that car on something approaching equal terms, whereas the light, aerodynamically efficient Subaru should pull away.

Assume a dry track, equally capable drivers, fresh tyres and each car in its normal specification. There is, for obvious reasons, no Mosport-specific Balance of Performance for GT300, so its lap time must remain an estimate.

Car	Principal weapon	Principal limitation
ORECA 07 LMP2	Low mass, effective floor and diffuser, braking and mid-corner speed	Sensitivity to dirty air
JAF GT300	Sophisticated aerodynamics, bespoke Japanese tyres, greater suspension compliance	Less power than TA; performance strongly dependent on BoP and tyre supplier
TA	Around 850 bhp, acceleration and top speed	High mass, basic aerodynamics, live rear axle, no ABS or traction control

Turn 1: TA is still in the picture

On the run to the first corner, the TA car makes a persuasive opening statement. It has around 850 bhp - considerably more than an LMP2, and more still than a GT300 silhouette constrained by BoP. From a rolling start, the American car could remain alongside the prototype and would almost certainly be travelling faster than the GT300 over the final metres of the straight.

Those metres gained must then be handed back almost immediately. The LMP2 is lighter, lower and carries far more aerodynamic load. It brakes later and can begin committing to the corner sooner. The GT300 occupies the middle ground: its body still produces substantial drag, but its splitter, floor, diffuser and large rear wing allow braking and cornering to overlap much more confidently than in the TA car.

The TA driver must shed the heavy car’s kinetic energy, establish load on the front axle and ask it to turn. Without ABS, locking the inside front is all too easy; too much rearward brake bias can turn corner entry into an impromptu variety performance.

Turn 2 settles much of the argument

This is where it becomes clear why 550 bhp can sometimes be faster than 850. Aerodynamic load rises approximately with the square of speed, a relationship the LMP2 helpfully demonstrates. The faster it enters the long second corner, the harder it is pressed into the road. Downforce allows it to retain speed, and retained speed sustains more downforce. Tyres and drag impose limits, of course, but the prototype reaches those limits much later than the others.

The TA car enjoys little of this reinforcing effect. Its grip depends mainly on the load supplied by its weight and the performance of its tyres. As the road falls away and vertical load changes, the live rear axle also couples the movements of the rear wheels. The driver must lift because the available power cannot usefully be applied.

The GT300 approaches Turn 2 more like the LMP2, though at a lower speed. It has sophisticated aerodynamics and tyres developed in the competitive environment of Japan’s tyre war.

The Subaru BRZ would be particularly convincing here: a compact silhouette, a relatively short wheelbase and traditionally strong agility. For 2026, it also received a new three-litre twin-turbo flat-six in place of the old EJ20. Subaru explicitly connects the new engine with further development of the car’s cornering strengths, as well as its power output.

Through Turns 3 and 4: the prototype disappears

Through Turn 3, and especially Turn 4, the LMP2 benchmark begins opening the gap rapidly. These corners demand a car comfortable with the combination of high speed, roll and changing elevation. The prototype has the stiffest platform, a low centre of gravity and the most effective floor.

The GT300 loses ground but remains composed. Its body is taller, its mass greater and its aerodynamic efficiency lower, yet its suspension allows each rear wheel to follow the road independently.

In the TA car, movement at one rear wheel continues to influence the other. Under acceleration on a smooth surface, that arrangement can still be made to work to its advantage. In a fast corner over changing terrain, the axle can unload the inside tyre just as the driver begins returning to the throttle. The engine is ready. The rest of the car is still considering the matter.

It is between Turn 1 and the braking zone for Moss Corner that the LMP2 would earn most of its roughly six-second advantage over TA1.

Moss Corner: TA’s moment of glory

Through the slow Turns 5A and 5B, the LMP2’s aerodynamic advantage shrinks sharply. Downforce has fallen with speed, bringing mechanical grip, differential behaviour and engine delivery to the foreground.

The prototype still brakes later: it is lighter and controls each wheel’s movement more effectively. But the difference narrows. The GT300 needs to rotate well into the first part of the sequence and manage the load transfer carefully before the exit.

Here, the two Japanese silhouettes would reveal different characters. The Subaru changes direction more readily and points towards the exit sooner. The hybrid apr Lexus LC500h GT has an enormous wheelbase by GT300 standards - 2,870 mm - and considerably more mass. That long wheelbase assists stability in fast corners but makes the car less eager to rotate through a tight sequence. Electric drive recovers some of the loss on exit, although it cannot repeal the effect of the longer wheelbase on negotiating slow corners.

The TA car brakes earliest, but after the apex it can finally produce its credentials. If the rear tyres are evenly loaded, the differential is correctly set and the driver does not summon all 850 horses with one movement, it fires uphill at considerable speed.

Over the first few metres, it may recover a substantial part of its loss to the GT300. It recovers much less against the LMP2: the prototype has passed the apex sooner, unwound the steering sooner and begun accelerating with a speed advantage already in hand.

The Andretti Straight: horsepower meets initial conditions

On the longest straight, TA could record the highest speed - particularly with gearing suited to Mosport, provided the engine does not reach the limiter before Turn 8.

But the speed attained at the end of a straight depends on the speed at the beginning of it, as well as the available power. The LMP2 leaves Moss Corner sooner, lighter and faster. The TA car may accelerate harder, but it first has to recover several dozen metres lost through the preceding corners.

Against the GT300, the situation is different. The American car would close noticeably and could mount an attack. The heavy Lexus is particularly vulnerable: its aerodynamic drag and lower power-to-weight ratio would give TA a chance to get ahead before the braking zone.

The Subaru would be a more difficult target. It exits Moss Corner better, and sophisticated aerodynamics need not mean enormous drag. Even so, TA would be a serious threat alongside it on the straight, potentially using side-drafting to help complete the pass.

The American car’s principal difficulty is that the straight eventually ends.

Turn 8: hand back the winnings

Before Turn 8, the LMP2 brakes later, sheds less speed and almost immediately returns to substantial aerodynamic load. Through the final sequence of Turns 8-10, the prototype pulls another few car lengths clear.

The GT300 can also keep the throttle open longer and carry the car through the changes of direction in one flowing movement. The Subaru should be particularly effective here. The long Lexus responds more calmly to a fast corner but is slower to change direction between Turns 9 and 10.

The TA driver must shed more speed and then send the heavy body through two changes of direction. Its basic rear wing helps, but it lacks an effective underfloor comparable with the prototype’s. The axle couples the rear wheels, and without traction control the driver must wait until the car has genuinely finished turning before applying full power.

What would the stopwatch say?

We have two firm reference points:

• The current TA1 qualifying record: 1:13.613.
• The 2026 LMP2 pole time: 1:07.904.

The measured gap between the classes is therefore already 5.709 seconds, or roughly eight per cent of a lap.

There are, naturally, no direct GT300 data. A contemporary GT3 provides a slower reference point: the 2025 GTD Pro pole at Mosport was 1:15.046. A Japanese GT300 silhouette has greater design freedom and - for the time being - bespoke tyres, so it should be appreciably faster than a conventional GT3.

An approximate projected range would look like this:

Car	Estimated lap time
ORECA 07 LMP2	1:07.0–1:08.0
Subaru BRZ GT300	1:11.5–1:12.8
apr Lexus LC500h GT	1:12.8–1:14.0
TA1	Approximately 1:13.5–1:14.5

With the Subaru, the likely order is clear: LMP2–GT300–TA. With the Lexus, the final two positions could reverse. On a suitable soft Japanese tyre, the LC500h would beat TA; with an unfavourable BoP, additional mass or difficulty bringing its tyres up to temperature, the American car could finish ahead.

And over a race?

The LMP2 gradually disappears into the distance. Over 41 laps, the qualifying gap would theoretically give it almost four minutes over TA. Allowing for race pace, overtaking and lapped traffic, the projected margin is approximately two laps over a quick GT300 and around three over TA.

The GT300 - TA contest would be much livelier than the lap-time table suggests. The Japanese car is faster through the corners, but it still has to pass. Trapped behind TA, it would lose some front downforce through Turn 2, whereas the TA car is relatively insensitive to another car’s aerodynamic wake. The American machine then deploys its 850 bhp uphill, pushing the next passing opportunity back towards Turn 8.

TA could therefore keep a faster GT300 behind for quite some time. But its rear tyres and brakes work hard, and the driver must personally meter out the surplus power. As the race progresses, the exit from Moss Corner becomes less emphatic, giving the GT300 an opportunity under braking.

The most likely finishing order would be:

1. LMP2: a decisive victory. Mosport makes almost ideal use of its aerodynamics and low mass.
2. Subaru BRZ GT300: a comfortable second, approximately two laps down.
3. TA1: another 30–60 seconds behind, but with the highest straight-line speed and the most spectacular resistance to being overtaken.

Replace the Subaru with apr’s heavy hybrid Lexus, and the fight for second becomes closer still. GT300 finds its speed in the chassis, TA in the engine, and Mosport gives each just enough suitable road to keep making its case to the other.