This weekend’s British Touring Automobile Championship season-opener at Donington Park heralds the primary race for a stronger hybrid enhance system that delivers twice the ability in comparison with final yr.
BTCC sequence organiser TOCA launched the spec 48V hybrid-electric system in 2022. The Cosworth spec unit changed success ballast, which noticed probably the most profitable drivers get handed extra weight to gradual them down in races and stability out the sphere. An analogous sliding scale method has been used after the change to hybrids, whereby extra profitable drivers are given fewer laps on which they’ll deploy energy from the motor generator unit (MGU).
BTCC groups and viewers quickly obtained accustomed to the brand new expertise, which was a world-first in touring vehicles. Nevertheless, they quickly recognised that it tended to supply lengthy trains of vehicles with out a lot overtaking. In response, the BTCC has elevated turbo enhance strain by 200mb and factored that into the hybrid system enhance. That is designed to extend the distinction (or delta) between a automobile that’s utilizing hybrid enhance and one which isn’t. The change, which doesn’t add to the MGU’s output, equates to a doubling of the ability {that a} driver has after they push the enhance button, from 30bhp to 60bhp.
The BTCC has been frequently reviewing its hybrid deployment guidelines for the reason that expertise was launched. Final yr, it added a minimal pace at which drivers may use the enhance, with those that have been larger within the championship standings (relevant to Race 1) or coming off the again of a robust previous race (Races 2 and three) each getting the next threshold. Decrease-ranked drivers obtained a decrease threshold, that means they might assault sooner out of corners.
However now, drivers could have double the quantity of enhance obtainable. How will it have an effect on the racing? Alliance Racing Ford engineer Tony Carrozza, who gained the 2023 BTCC title working with driver Ashley Sutton, reckons it can have a noticeable affect.
‘A part of the principles that modified for final yr was, vehicles exterior the highest 10 didn’t have it for each lap,’ he tells Racecar Engineering. ‘The earlier yr, there was this hybrid prepare the place the entire vehicles have been pushing hybrid on the similar level. It didn’t make a delta to the racing.
‘The most important distinction this yr is the overlap that you may get between somebody not deploying versus somebody deploying. Down the start-finish straight at Donington, there’s a 16-metre delta. Automobiles are usually 4.4 to five metres lengthy. That’s 4 automobile lengths. Should you come off the chicane on the bumper of the automobile in entrance, you’ve obtained sufficient deployment to get alongside, pull in entrance and have a automobile size within the braking zone, which is important.
‘The sheer overlap is the highly effective bit. We additionally ran [simulations] for Silverstone which is probably the most highly effective circuit for the hybrid. It was 28 metres down the again straight the place you’re pushing [the hybrid boost button] for 8-9 seconds. The 28-metre overlap is sufficient to do two or three vehicles.’
Alliance sampled the elevated turbo enhance throughout a Goodyear tyre take a look at at Donington final yr, making it one of many first groups to check out the replace. Against this, the West Surrey Racing BMW squad, for instance, solely used the 2024 ranges of enhance for the primary time on the second of three pre-season exams in April.
‘We all know that 200mb is about 30bhp,’ says Carrozza. ‘I ran a load of lap time simulations to work out the optimum deployment zones. It’s very simple to dump all of it down one straight, however over the course of the lap you’ve obtained to set off it slowly. Final yr, at Donington, we have been 0.45s [quicker] per lap. This yr, it’s simply over 0.7s per lap. It’s fairly a considerable delta. Manufacturers Hatch Indy was solely 0.55s [quicker].’
On condition that he gained final yr’s BTCC title, Sutton usually obtained the quick finish of the stick when it got here to hybrid deployment allocations. Including to the problem was the introduction of minimal hybrid deployment speeds, and fewer laps obtainable to deploy. For instance, factors chief Sutton had 5 laps on which he may enhance in Race 1 at Silverstone final yr, in contrast with 9 enhance laps for factors chief Colin Turkington on the similar spherical in 2022. Nonetheless, Alliance considered a approach to offset that distinction.
‘Ash wouldn’t push hybrid on the lap when the individual in entrance was pushing hybrid,’ Carrozza explains. ‘He would simply wait till I’d given him the go-ahead that whoever he was combating towards wasn’t pushing. There was his likelihood to get the overlap.
‘You nearly waste the hybrid if you happen to’re utilizing it when the individual in entrance is utilizing it, since you simply negate the delta. Should you’re in a quicker automobile, you may make up a few of that lap time in one other approach. You don’t should be pushing the hybrid button.’
The variety of hybrid enhance laps that every driver will get is unchanged for this yr, however the energy can be larger. Subsequently, count on to see extra drivers making overtakes when they’re boosting towards a driver who isn’t. The situation shouldn’t be any completely different to final yr when two drivers are on the enhance, though Carrozza and different engineers are continuously on the radio informing their drivers about when rivals are pushing the button to get that all-important delta down a straight.
The uprated enhance isn’t solely set to have an effect on acceleration out of corners: Carrozza anticipates that it’s going to improve braking distances by between 5 and 10 metres.
‘The one that is on the hybrid is braking barely earlier,’ he says. ‘I believe there can be some fascinating racing. There’ll in all probability be some huge closing speeds.’
The BTCC’s transfer to hybrids in 2022 resulted in a set minimal weight being launched in 2022. That is 1355kg for rear-wheel-drive vehicles and 1325kg for front-wheel-drive. Having obtained used to adapting to success ballast for a number of years, BTCC engineers can now get a clearer image of automobile arrange.
‘Each session the automobile stability was altering, as a result of nearly each time you went out, you needed to change the ballast,’ Carrozza recollects. ‘We might go into a gathering main the championship, so we might have 75kg in qualifying for Race 1. We’d nearly by no means win Race 1 as a result of we’d qualify sixth or seventh. You then take ballast out for Race 2 and also you’d win quite a bit. You then’d have ballast on for Race 3 with reverse grid, so that you’re in the midst of the pack with all of the ballast on.
‘Usually, you have been altering the automobile continuously over the weekend. Now, we’ve a set base weight. You may actually house in on a arrange that’s actually crisp for that weekend and know that the one adjustments are going to be monitor circumstances, which is kind of good.’
This weekend’s Donington season-opener would be the first time the elevated hybrid enhance is deployed in anger, though it might take a couple of rounds for its effectiveness to turn into clear. For example, will a automobile that has fewer 60bhp hybrid system energy deployments be as hamstrung as a automobile that carried the utmost 75kg additional weight throughout the success ballast period? They may, not less than, be extra pegged again in comparison with final yr. The early indicators are that the elevated enhance ought to present extra overtakes and fewer predictable racing which has been a trademark of the BTCC for thus lengthy.
‘The yr that stands out for me is 2018, whenever you had 17 completely different winners,’ says Carrozza. ‘Colin [Turkington] gained the championship and gained just one race. That’s what you’re going to get this yr, I believe.’