Red Bull RB20

[djones]

redbull changed its brake supplier these year wonder max problems are related to these change

I don’t know if it is related.

But why on earth would you make such a big change though when what you had before worked well and was reliable.

[venkyhere]

Any update about what was the real problem with Max's car ? 'rubbing brakes' related, but vendor related or re-assembly (FP1) related ? Also, has this any similarity with LeClerc's issue in Bahrain ?

[Henk_v]

Given the violent RUD of the assembly, they may never know for sure. There have been complaints about leaves. A tear off seems unlikely.

As max said in the interview the temperature did not come down, loss of cooling air might not be the cause. Even without airflow, som cooling must take place.

[Vanja #66]

Brake was stuck after the WU lap, it can happen. Wouldn't consider it a supplier design flaw

https://www.racefans.net/2024/03/24/ver ... ding-fire/

[Farnborough]

Looks like compression of pads to disc in constant situation rather than lacking cooling, reaches much higher temp that way.

Unsure if they use dry coupling in lines on this to each caliper, can have a "one way" valve effect if fault present.

Sighting / formation lap likely to be max regeneration and low disc usage for rear, which may not bring fault to observable prominence coming to grid.

[Stu]

Pace, tyre deg, etc. belongs in the race thread (or, maybe, the team thread).

Several off-topic posts deleted.

[Stu]

Looks like compression of pads to disc in constant situation rather than lacking cooling, reaches much higher temp that way.

Unsure if they use dry coupling in lines on this to each caliper, can have a "one way" valve effect if fault present.

Sighting / formation lap likely to be max regeneration and low disc usage for rear, which may not bring fault to observable prominence coming to grid.

I’m wondering whether this is a BBW issue?

[venkyhere]

Looks like compression of pads to disc in constant situation rather than lacking cooling, reaches much higher temp that way.

Unsure if they use dry coupling in lines on this to each caliper, can have a "one way" valve effect if fault present.

Sighting / formation lap likely to be max regeneration and low disc usage for rear, which may not bring fault to observable prominence coming to grid.

I’m wondering whether this is a BBW issue?

Pardon my ignorance, doesn't BBW in an F1 car refer to the regen braking/ battery recharge 'assist' provided by the KERS/MGU-K ? My understanding is that brakes are purely hydraulic, just like in road cars without an ABS unit - purely connected to the pedals via master & slave cylinders, thus providing 'feel'.

[Farnborough]

Looks like compression of pads to disc in constant situation rather than lacking cooling, reaches much higher temp that way.

Unsure if they use dry coupling in lines on this to each caliper, can have a "one way" valve effect if fault present.

Sighting / formation lap likely to be max regeneration and low disc usage for rear, which may not bring fault to observable prominence coming to grid.

I’m wondering whether this is a BBW issue?

Pardon my ignorance, doesn't BBW in an F1 car refer to the regen braking/ battery recharge 'assist' provided by the KERS/MGU-K ? My understanding is that brakes are purely hydraulic, just like in road cars without an ABS unit - purely connected to the pedals via master & slave cylinders, thus providing 'feel'.

Yes, in that all calipers (sweeping statement alert) are such that operation by hydraulic fluid is there to enact brake command.
No in that the BBW systems though, interupt the rear line by interpretation of the intended line pressure to assimilate "virtual" brake retardation through regen system (enacted to wheels by transmission only) UNTIL the retardation cannot be completely supported by this system, at which point it starts lifting the line pressure to rear calipers in then blending axle retardation into and toward disc friction, proportion of this according to software and hardware interaction.

In effect, rear calipers v-lightly used IF electrical recovery can suffice. This has mandated "backup" from rules to have bypass hydraulic direct to caliper in the event of recognised fault/failure of BBW control and modulation, I believe.

Common though, and pertinent to IF its a BBW problem, the rear line to calipers appears to be common, then split to each to give no control across the axle as demanded by rules, so no "steering" ability by any manipulation. This suggests one caliper or line was compromised after that division to give the one wheel fault we saw.

Hence my suspicion that there was impairment of the hydraulic line in that particular location.

It looked like it really got going after the big braking stop first time through corner one approached at full speed end of lap,one, then giving a steering bias on application thereafter, and probably as the bleed from recovery to friction ramps up at the end of braking phase into each corner.

[venkyhere]

I’m wondering whether this is a BBW issue?

Pardon my ignorance, doesn't BBW in an F1 car refer to the regen braking/ battery recharge 'assist' provided by the KERS/MGU-K ? My understanding is that brakes are purely hydraulic, just like in road cars without an ABS unit - purely connected to the pedals via master & slave cylinders, thus providing 'feel'.

Yes, in that all calipers (sweeping statement alert) are such that operation by hydraulic fluid is there to enact brake command.
No in that the BBW systems though, interupt the rear line by interpretation of the intended line pressure to assimilate "virtual" brake retardation through regen system (enacted to wheels by transmission only) UNTIL the retardation cannot be completely supported by this system, at which point it starts lifting the line pressure to rear calipers in then blending axle retardation into and toward disc friction, proportion of this according to software and hardware interaction.

In effect, rear calipers v-lightly used IF electrical recovery can suffice. This has mandated "backup" from rules to have bypass hydraulic direct to caliper in the event of recognised fault/failure of BBW control and modulation, I believe.

Common though, and pertinent to IF its a BBW problem, the rear line to calipers appears to be common, then split to each to give no control across the axle as demanded by rules, so no "steering" ability by any manipulation. This suggests one caliper or line was compromised after that division to give the one wheel fault we saw.

Hence my suspicion that there was impairment of the hydraulic line in that particular location.

It looked like it really got going after the big braking stop first time through corner one approached at full speed end of lap,one, then giving a steering bias on application thereafter, and probably as the bleed from recovery to friction ramps up at the end of braking phase into each corner.

What I am able to interpret is -

Architecture wise, BBW is similar to the ABS module in road cars, it's a man-in-the-middle agent between the hydraulic line from the pedal and the lines to the wheels. Just like ABS module, this too has a failsafe bypass in parallel to the module, where pedal action directly reaches the wheels. Function wise, unlike the task of a road car ABS module manipulating hydraulic pressure like a binary switch (on-off-on-off whenever it needs to interfere) to the four individual brake calipers, here the task is like a dimmer switch that is common to both wheels of the rear axle,a nd the dimmer switch is called into action all the time. The left-right split on each axle is purely mechanical, there is no proportioning valve for left v/s right. There is only front v/s back proportioning.

[Farnborough]

Although there's obvious commonality with a brake system for most vehicles, feel there's need to disassociate this with ABS typical system, one that's reactive to wheel speed events.

This in RB 20 (mirrored across all chassis) is primarily led by algorithm determination to maximise recovery of energy by using the MGUK facility to generate high proportion of braking torque, only blending more effort through hydraulic caliper route when the capacity within recovery tapers to below braking demand.

This illustrated by the down sized disc and caliper equipment that effectively provides secondary "top up" torque, but would be completely overwhelmed if used as primary.

Agree that NO modulation of split across the axle (at either end) is the normal arrangement. Indicating that BBW control of that single line out to rear was not the culprit.

Fault seems to exist in the discreet line, after split, out to right rear caliper.

[venkyhere]

Although there's obvious commonality with a brake system for most vehicles, feel there's need to disassociate this with ABS typical system, one that's reactive to wheel speed events.

This in RB 20 (mirrored across all chassis) is primarily led by algorithm determination to maximise recovery of energy by using the MGUK facility to generate high proportion of braking torque, only blending more effort through hydraulic caliper route when the capacity within recovery tapers to below braking demand.

This illustrated by the down sized disc and caliper equipment that effectively provides secondary "top up" torque, but would be completely overwhelmed if used as primary.

Agree that NO modulation of split across the axle (at either end) is the normal arrangement. Indicating that BBW control of that single line out to rear was not the culprit.

Fault seems to exist in the discreet line, after split, out to right rear caliper.

Right. The intention behind my comparison with road car ABS module was not in terms of functionality, but only in terms of architecture - BBW is like a man-in-the-middle-who-manipuiates-hydraulic-pressure, where driver pedal input, after getting proportioned front v/s back according to his brake-bias setting, the pressure to the rear axle is 'translated' to a different value, according to 'how much' of total "rear braking energy" needs to be shared between electrical loading v/s friction loading. Hope I understood the gist of what you are trying to convey.
And yes, the problem that Max had is pointing to some fault with the hydraulic line OR the caliper mechanism that went to the right rear wheel, and doesn't look like an issue with BBW itself.

[Henk_v]

(Knowing I tread on thin ice here, as it is not 100% technical)

I just read the news on Motorsport.com that Perez lost 20 points of downforce due to a tear-off that got lodged in his floor.

Though I am interested to know where that was, I just want to remark that RedBull NEEDS to have e technical explanation for the seemingly loss of dominance and therefore I think we should take the coverage with a pinch of salt.

Red Bull simply can't lose dominance right now. The media will eat them up linking it to the Horner saga.

[Cassius]

(Knowing I tread on thin ice here, as it is not 100% technical)

I just read the news on Motorsport.com that Perez lost 20 points of downforce due to a tear-off that got lodged in his floor.

Though I am interested to know where that was, I just want to remark that RedBull NEEDS to have e technical explanation for the seemingly loss of dominance and therefore I think we should take the coverage with a pinch of salt.

Red Bull simply can't lose dominance right now. The media will eat them up linking it to the Horner saga.

Another conspiracy theory. Horner making this up to prove they are still dominant?
Jeez, come on guys. I was expecting more from this forum.

Perez had the worst deg of any drivers. It was likely due to setup choices and the loss in df.

Overall RB still has the best car, although Ferrari is closing the gap and will have the best car in certain races this year.
Let's see what Suzuka will bring in terms of upgrades. Both RB20 and SF24 will get new bits.

[taperoo2k]

Scarbs has a bit more info on what the issue might have been with the rear brake.
https://x.com/ScarbsTech/status/1772389 ... 21315?s=20