Last year, Stuart Bowling took a closer look at the inner workings of the BMW M4 GT3. In his technical analysis, he delved into the car’s engineering. Back then, only a handful of people knew how the car actually drives. Now that the car has been fully homologated and is deployed across the globe, we put the question to Walkenhorst Motorsport BMW M4 GT3 driver Christian Krognes: what is it like to race the BMW M4 GT3 and unlock its speed?
Right from the get-go, the new BMW M4 GT3 seemed like a winner, underlined by two wins at the Nürburgring so far. Krognes’ contribution to the car’s success is a pole position at the ADAC 24h Nürburgring Qualifiers and a podium finish in the VLN Nürburgring Endurance Series’ (NLS) NLS3.
“It’s really very different from the M6,” the Norwegian says, in comparison to the previous BMW M6 GT3.
“I was kind of expecting the car to be similar in many ways because physically it is kind of the same in measurement. But it is a lot more pointy, and it is also, let’s say, more gentleman friendly I think. It’s easier to just to jump into it and get a feel for it.”
The first races at the Nordschleife were mostly based around setting up the car, getting to learn its behaviour under racing conditions and finding its sweet spot.
“Now, we’re kind of exploring different set-up options. When you are really on the edge, it behaves differently driving at 90 percent to say at 100 percent. We tried a lot of different sets of angles and directions during these two days [at NLS] and I think we have found something, but it is still some way to go I think until we really have it dialled in.
“It’s not so much about lap time, it’s more about drivability. I think we went through three to four different set-ups – completely different – and they all delivered the same lap time, but one of the set-ups was a lot easier to drive, let’s say.
“So, while it’s kind of keeping hold of the high-speed stuff, you need to be able to depend on the rear in the high-speed stuff, so keeping this in check is key. But then also to get rotation at low-speed is tricky in some ways because the rotation at low-speed also affects the rotation at high-speed. So if you go too far on the rotation at low-speed, you get a tricky car in high-speed.
“There are a lot of carry-over values that are difficult to plan for, it’s very hard to judge ‘if you do this change…’
“I think we’ve found a good way now in between, but then to maximise to both high-speed and low-speed will be kind of the next step. We’re not far off but let’s see if we can unlock something later on.”
One of the BMW M6 GT3’s big points of criticism was its lack of low-speed corner performance. Has this issue been addressed with the M4?
“Yeah, especially in mechanical grip – combined traction when you’re on throttle and turning at the same time was difficult with the M6. That’s a good step in the M4, which again makes it easy to jump into it and get a good feel for it.
“You feel a lot more secure in low-speed especially when you’re trying to accelerate and exit a corner. That’s a nice thing, but you get used to it so quickly that it is actually nicer, and then you find all the other areas you want to improve on so I guess all cars have their strengths and weaknesses. Even though the M4 is a very strong car, it still has some way to go to really fine tune it.
“The M6 was developed over six years and I think we really found the sweet spot in the end and it will take some time with the M4. I don’t know if we will be able to really squeeze more time out of it, but I hope we can make it easier to drive.
“We already have a pretty good picture of where we are set-up wise, but still things to explore and that’s kind of the nice thing. With the M6, we always knew that if we do this click here on the damper, we know exactly what’s going to happen, you know? Now, it’s kind of an open playing field. Also, for the drivers, it’s a new challenge and I like it.”
While the M4 is BMW M Motorsport’s third GT3, it is yet again a new model. This makes the M4 an almost unrecognisable machine at the hands of a driver, Krognes says.
“I was expecting to recognise the car a bit but no, not really at all. It’s really new to get into and I was really excited about this when I drove NLS1, because it just felt so different and it is like re-discovering the track a bit.
“They’ve done improvements in damping as well, the new damping system from KW, and this reacts so differently to the kerbs, to bumps, which is key around here. It opened up some new windows of performance that we’re trying to extract, but yeah we need to finish the set-up first to really get there.”
Another major improvement has been in the electronics department by Bosch, where the traction control has made big strides. However, with Nürburgring rules stipulating lower engine power and allowing for the almost unlimited development and the deployment of grippy tyres, this advantage cannot be fully exploited in the Eifel.
“It’s different, I mean you have to take into account that the tyres in this championship in general combined with – I don’t want to say, low power, but it is less power than in GT World Challenge for instance – there is really a lot of grip, so traction control doesn’t really interfere here as much as in other championships with let’s say cup tyres.
“But still, it’s a nice step. We never had a lot of intrusion from the TC anyway, of course a little bit helps, but it is nicer and it is less intrusive when it kicks in. Small steps here and there, but I don’t know if it really makes a lot of difference here. I can imagine it makes a lot of difference in other championships.”
Over the years, Krognes, together with Walkenhorst, has had successes at both the Nürburgring and elsewhere – most notably winning the 2018 24 Hours of Spa – but have yet to taste the champagne at the 24 Hours of the Nürburgring. With the BMW M4 GT3 looking like a true contender, that might change this weekend.
“I hope so! There’s still some ways to go. I expect the other manufacturers to be very quick come the 24, so it’s hard to judge from today where we really are. I mean, it’s nice to see three BMWs on the podium [at NLS3] but it doesn’t mean very much in the grand scheme of things.
“I just know that Mercedes will be there, Audi will be there, Lamborghini will be there, so then hopefully we have an answer to that as well. But I think we have a good package, the Yokohama is a new front tyre which we worked on during the winter, and it seems to work out pretty well.
“The tyre stuff is also part of the set-up work that we do, and they’ve done a good job. We have a good base, so I think pace-wise, we have the pace to be there with the top teams but getting the whole package together with no incidents, like at NLS3 we had a completely trouble-free race but we still ended up one minute and 50 seconds behind. We can see that there is still something to gain there overall.”
One of the big questions for this weekend is centred around the weather. Everyone will be looking up, wondering if, when, where and how much it’s going to rain. Will Walkenhorst’s Yokohama tyres be up to the task? Krognes believe they are.
“That’s also a question mark at this point. I mean, the tyre really performed well in 2020, it was really a bottleneck for us, the rain, before 2020. We did a lot of work and since then we’ve never really tested it [in the race] so I don’t know where we are in the rain.
“I’m hopefully that we can also, you know, if we lose 10 or 20 seconds a lap in the rain then you are out of the race contention – at least in terms of the top three. So, you need to have a tyre that can hold on and be on pace. But 2020 showed that we can do that, so there’s no reason we shouldn’t be able to do it this year.”
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