McLaren MCL33

[M840TR]

[M840TR]

Front wing detail.





Cape duct

[testing]

With the Honda engine McLaren struggled on high speed tracks like Monza and fast high downforce tracks like Suzuka. But often they were best of the rest at slow tracks where engine power is less crucial. This year however the Mclaren is not as competitive on slow tracks. In Canada they reported that they struggle in low speed corners and lose top-speed by running more wing to try to compensate for this.
The low speed speed issues seem kinda obvious when watching the onboards: the car is sprung rock hard. I think they don't run the suspension as soft as they would like to because the car loses too much downforce when the car starts to roll in the corners. Somehow the sealing of the floor got messed up during the redesign of the rear of the car, or the car lost performance after the latest ban on trick suspensions.

[M840TR]

[charliesmithhd]

With the Honda engine McLaren struggled on high speed tracks like Monza and fast high downforce tracks like Suzuka. But often they were best of the rest at slow tracks where engine power is less crucial. This year however the Mclaren is not as competitive on slow tracks. In Canada they reported that they struggle in low speed corners and lose top-speed by running more wing to try to compensate for this.
The low speed speed issues seem kinda obvious when watching the onboards: the car is sprung rock hard. I think they don't run the suspension as soft as they would like to because the car loses too much downforce when the car starts to roll in the corners. Somehow the sealing of the floor got messed up during the redesign of the rear of the car, or the car lost performance after the latest ban on trick suspensions.

Could a hard rear suspension cause them go be slow on straights as the car keeps it's high rake rather than goes more flat

[mwillems]

With the Honda engine McLaren struggled on high speed tracks like Monza and fast high downforce tracks like Suzuka. But often they were best of the rest at slow tracks where engine power is less crucial. This year however the Mclaren is not as competitive on slow tracks. In Canada they reported that they struggle in low speed corners and lose top-speed by running more wing to try to compensate for this.
The low speed speed issues seem kinda obvious when watching the onboards: the car is sprung rock hard. I think they don't run the suspension as soft as they would like to because the car loses too much downforce when the car starts to roll in the corners. Somehow the sealing of the floor got messed up during the redesign of the rear of the car, or the car lost performance after the latest ban on trick suspensions.

Could a hard rear suspension cause them go be slow on straights as the car keeps it's high rake rather than goes more flat

Interesting thought. It's as hard as nails today, you can see the car really bouncing around.

[charliesmithhd]

With the Honda engine McLaren struggled on high speed tracks like Monza and fast high downforce tracks like Suzuka. But often they were best of the rest at slow tracks where engine power is less crucial. This year however the Mclaren is not as competitive on slow tracks. In Canada they reported that they struggle in low speed corners and lose top-speed by running more wing to try to compensate for this.
The low speed speed issues seem kinda obvious when watching the onboards: the car is sprung rock hard. I think they don't run the suspension as soft as they would like to because the car loses too much downforce when the car starts to roll in the corners. Somehow the sealing of the floor got messed up during the redesign of the rear of the car, or the car lost performance after the latest ban on trick suspensions.

Could a hard rear suspension cause them go be slow on straights as the car keeps it's high rake rather than goes more flat

Interesting thought. It's as hard as nails today, you can see the car really bouncing around.

PDR was saying how soft the force India's suspension was and they're looking quite handy

[Edax]

With the Honda engine McLaren struggled on high speed tracks like Monza and fast high downforce tracks like Suzuka. But often they were best of the rest at slow tracks where engine power is less crucial. This year however the Mclaren is not as competitive on slow tracks. In Canada they reported that they struggle in low speed corners and lose top-speed by running more wing to try to compensate for this.
The low speed speed issues seem kinda obvious when watching the onboards: the car is sprung rock hard. I think they don't run the suspension as soft as they would like to because the car loses too much downforce when the car starts to roll in the corners. Somehow the sealing of the floor got messed up during the redesign of the rear of the car, or the car lost performance after the latest ban on trick suspensions.

Could a hard rear suspension cause them go be slow on straights as the car keeps it's high rake rather than goes more flat

Interesting thought. It's as hard as nails today, you can see the car really bouncing around.

That has been a characteristic of the McLaren cars since the 90’s. Drivers have always said that it is the roughest ride our there by far.

But I wonder whether that philosophy is not biting them now. With the shift to underbody aero I think suspension is getting more important. Especially with the tire pressure restricitions. Mercedes has put a lot of resources on developing their suspension. The evidence is there. It is sometimes looking at completely different cars, both compliant and stiff in different phases of the corner. I have some suspicion they even allow some chassis twist to allow the rear end to roll while keeping the FW level.

The mclaren on the other hand just looks extremely stiff and non compliant. Especially on bumpy tracks. The front end bounces around in the braking zone and on exit the rear just skittles along finding no traction.

[M840TR]

Flo-viz testing on new diffuser.

[Thunder]

Some posts have been moved to the Team Thread as they are mor fitting over there.

[mwillems]

Could a hard rear suspension cause them go be slow on straights as the car keeps it's high rake rather than goes more flat

Interesting thought. It's as hard as nails today, you can see the car really bouncing around.

That has been a characteristic of the McLaren cars since the 90’s. Drivers have always said that it is the roughest ride our there by far.

But I wonder whether that philosophy is not biting them now. With the shift to underbody aero I think suspension is getting more important. Especially with the tire pressure restricitions. Mercedes has put a lot of resources on developing their suspension. The evidence is there. It is sometimes looking at completely different cars, both compliant and stiff in different phases of the corner. I have some suspicion they even allow some chassis twist to allow the rear end to roll while keeping the FW level.

The mclaren on the other hand just looks extremely stiff and non compliant. Especially on bumpy tracks. The front end bounces around in the braking zone and on exit the rear just skittles along finding no traction.

Yes I agree. I have been saying this for a while now. I am not a technical guy but there is too much information out there to suggest that the issue isn't just aero. After Mclaren said their issue was wind tunnel correlation, a Mclaren engineer stated on twitter that it "wasn't exactly correlation", which led me to suggest car behaviour was affecting aero, without gaining much traction (forgive the pun). I had not thought at all about the car needing to bottom out on straights in order to reduce drag (Good shout).

Canada was another track where the suspension was very stiff in comparison to other teams.
Mclaren stated their issue was traction out of low speed corners and said they had to run more downforce, but telemetry posted in these forums showed the car performing fine in these corners at Canada, but very slow on the straights. Pictures also showed them to be running a reasonably skinny wing, in line with other competitors... so downforce was not being piled on to the rear wing to compensate or fix the low speed traction. So where was the higher downforce compromise? To keep a hard suspension, stopping the car from bottoming out in the corners and keeping the diffuser working, it does seem like they are running very very stiff.
Given the fact it is a high rake car who's philosophy is to sink on the straights to reduce drag, this would explain the "draggy aero".

I also read that Mclarens 2019 car is not going to include this new suspension, but that is anecdotal at the moment. I'm probably going to get shot down as I've been harping about this for a couple of months now, but I am really convinced that the cars behaviour against the tarmac is the reason why the car can not be developed further or fixed. I would add also, that in 2016 when the suspension was rubbish and the centre of many issues, we didn't learn this to be the case until 2017, it was all put to the engine.

[mclaren111]

Old McLaren trick of running very stiff suspension when the car is bad.

Last year was much better and they were so stable under braking (2nd to RB only), which points to a good suspension to me.

Complete rework/redisgn required for 2019......

[charliesmithhd]

Interesting thought. It's as hard as nails today, you can see the car really bouncing around.

That has been a characteristic of the McLaren cars since the 90’s. Drivers have always said that it is the roughest ride our there by far.

But I wonder whether that philosophy is not biting them now. With the shift to underbody aero I think suspension is getting more important. Especially with the tire pressure restricitions. Mercedes has put a lot of resources on developing their suspension. The evidence is there. It is sometimes looking at completely different cars, both compliant and stiff in different phases of the corner. I have some suspicion they even allow some chassis twist to allow the rear end to roll while keeping the FW level.

The mclaren on the other hand just looks extremely stiff and non compliant. Especially on bumpy tracks. The front end bounces around in the braking zone and on exit the rear just skittles along finding no traction.

Yes I agree. I have been saying this for a while now. I am not a technical guy but there is too much information out there to suggest that the issue isn't just aero. After Mclaren said their issue was wind tunnel correlation, a Mclaren engineer stated on twitter that it "wasn't exactly correlation", which led me to suggest car behaviour was affecting aero, without gaining much traction (forgive the pun). I had not thought at all about the car needing to bottom out on straights in order to reduce drag (Good shout).

Canada was another track where the suspension was very stiff in comparison to other teams.
Mclaren stated their issue was traction out of low speed corners and said they had to run more downforce, but telemetry posted in these forums showed the car performing fine in these corners at Canada, but very slow on the straights. Pictures also showed them to be running a reasonably skinny wing, in line with other competitors... so downforce was not being piled on to the rear wing to compensate or fix the low speed traction. So where was the higher downforce compromise? To keep a hard suspension, stopping the car from bottoming out in the corners and keeping the diffuser working, it does seem like they are running very very stiff.
Given the fact it is a high rake car who's philosophy is to sink on the straights to reduce drag, this would explain the "draggy aero".

I also read that Mclarens 2019 car is not going to include this new suspension, but that is anecdotal at the moment. I'm probably going to get shot down as I've been harping about this for a couple of months now, but I am really convinced that the cars behaviour against the tarmac is the reason why the car can not be developed further or fixed. I would add also, that in 2016 when the suspension was rubbish and the centre of many issues, we didn't learn this to be the case until 2017, it was all put to the engine.

So what is stopping them softening the suspension?

[DiogoBrand]

So what is stopping them softening the suspension?

I'd guess unstable aero. Maybe the front wing or the floor stalling with the suspension movement.

[mclaren111]

Good picture of low downforce RW.