[Tech Issue] Odd Engine Note Changes from On-Board Shots

[shiny side up!]

I haven't seen any discussion of this, if I have missed it and it is another thread I apologize!

Has anyone noticed the engine note skipping around quite a bit in the on-board shots? At first I thought it was miss-shifts - and during the qualifying telecast, one of the SPEED commentators also noted it when on board with someone in Q3...

But in retrospect I think what I was hearing is the effect of KERS - when it kicks in, it sounds almost as if the driver downchanged at the wrong time (instant rev climb), and when it cuts out it sounds as if the driver upchanged at the wrong time (instant rev drop).

That also got me wondering about how the teams might change their gearing strategy to incorporate KERS. Clearly, the car's top speed in 7th gear would change drastically with 80bhp more - but according to Matchett on SPEED the drivers have been instructed by the teams to use a little bit of KERS spread around the track instead of all in one shot down the main straight - which would indicate that KERS is used in different gears around the track.

Anyway, interesting stuff - looking forward to the race to see how it plays out!

[cmifsud]

Hi, yes I noticed what you say as well. Originally I thought it was a problem with the audio sync from FOM TV because our local broadcasters sound was fine. But to confuse things though, I'm pretty sure I heard the sound from a Red Bull as well, which isn't running KERS ATM.

[gttouring]

i heard this best with the Rubens onboard video
what is going on?
it kinda sounds like it skipped or was running a double gear,
it was clearly before the limiter...
and woohoo good job BrawnGP!

[Pingguest]

Originally Posted by gttouring

i heard this best with the Rubens onboard video
what is going on?
it kinda sounds like it skipped or was running a double gear,
it was clearly before the limiter...
and woohoo good job BrawnGP!

Indeed, and as far as I know Brawn isn't using KERS.

[Marbot]

Probably has more to do with not locking the rear wheels under braking and not spinning the wheels coming out of corners than anything else.

[Pingguest]

Originally Posted by Marbot

Probably has more to do with not locking the rear wheels under braking and not spinning the wheels coming out of corners than anything else.

I thought that making the rear wheels not locking under braking was banned from last year.

[Marbot]

Originally Posted by Pingguest

I thought that making the rear wings not locking under braking was banned from last year.

Only Toyota seem to have a problem with "rear wings not locking".

Apparently the drivers can use the gears to prevent the wheels from locking up and from spinning.

[Glen]

Originally Posted by shiny side up!

Clearly, the car's top speed in 7th gear would change drastically with 80bhp more

Top speed can't alter at all - the car will already be geared to go to or bery near the rev limiter in top gear, so additional bhp won't enable them to rev any higher than that.

[shiny side up!]

Yes, I suppose that what I heard could have been the drivers upshifting early to limit wheelspin - an age-old driving tool. However, what seemed different is that the revs would also increase quickly at times (opposite of short-shifting) - but perhaps with how quick the boxes can change nowadays it would be possible to shortpshift to cut wheelspin and then downchange a gear once you're out of danger to keep from bogging the engine?

[Canberra>karter]

Originally Posted by Marbot

Probably has more to do with not locking the rear wheels under braking and not spinning the wheels coming out of corners than anything else.

Nope it was definetly down the straights well after exit and not anywhere near a braking zone. It was usually after turn 12 at Hill. It sounded like they went for another gear but only grabbed the same one. Very odd as I've not heard it ever at Melbourne (or anywhere else), I could not work out what it was and presume it must be a broadcast glitch.

[djinvicta]

Originally Posted by Marbot

Probably has more to do with not locking the rear wheels under braking and not spinning the wheels coming out of corners than anything else.

Errrr.. you mean a form of traction control??

[Marbot]

Originally Posted by djinvicta

Errrr.. you mean a form of traction control??

Yes,it's called 'skill'.

[calibrax]

How would KERS affect the engine revs? Surely KERS works on the drivetrain and not directly on the engine?

[Pingguest]

Originally Posted by Marbot

Only Toyota seem to have a problem with "rear wings not locking".

Apparently the drivers can use the gears to prevent the wheels from locking up and from spinning.

I don't really understand how. As a driver shifts down the rev-limiter kicks, causing in the rear wheels to lock up.

[shiny side up!]

Short-shifting, or upshifting before you typically would, allows a driver to mitigate wheel spin (usually out of a slow corner) due to the lower torque multiplication of a higher gear. This is certainly nothing new to F1 or most other forms of racing, although it is of no use if you have traction control. Short-shifting is also used in some circumstances as a way to reduce fuel consumption due to the engine using lower revs.

[Sodemo]

I put it down to sound problems, we lost picture at one point and the post race interview sound wasn't synced.

[shiny side up!]

Originally Posted by calibrax

How would KERS affect the engine revs? Surely KERS works on the drivetrain and not directly on the engine?

I don't know the nitty-gritty detail of how the KERS is integrated into the drivetrain, but in order to have the KERS act in an additive way to the engine output, both would have to be linked to the diff (or whatever bit of running gear) at the same time - so if KERS kicks in and helps the engine propel the car with more force, the engine would rev quicker through a given gear than it would otherwise do without the KERS, as the force required to move the car remains the same but the force available to do the moving is increased.

[the.cosmic.pope]

It was just the signal being shake. Remember quite a bit of Albert Park has tree coverage, and the signal goes to a helicopter before being sent back down to the broadcasting base in the circuit.

We were also onboard with Kimi and seen the KERS button being used (and the FOMs pretty graphic), and there was no difference in the engine sound.

[GTRMagic]

Originally Posted by Sodemo

I put it down to sound problems, we lost picture at one point and the post race interview sound wasn't synced.

I dont think this is the case. I watched the onboards on the Brawns, on the Red Bulls on the McLarens... and they were all doing it.

Seemed strange.

Its kinda like a shift from 5-6 then a short burst to 7... but its more like a hiccup... that it was on so many cars seems to suggest its planned that way.. but it was on straights mostly, in the higher gears, approaching vMax...

[ScotsBrutesFan]

Originally Posted by the.cosmic.pope

It was just the signal being shake. Remember quite a bit of Albert Park has tree coverage, and the signal goes to a helicopter before being sent back down to the broadcasting base in the circuit.

They don't do it by helicopter these days.

There are a number of recievers around the circuit that pick up the signals from the cars. These are then sent back to the TV compound by (I think) fibre optic.

This is the reason why in recent years the on-boards have been break up free especially when passing under bridges and allows the live on-board views through the tunnel at Monaco.

[scoobiesnoop]

I sounds as though it is KERS because Kers lasts for about 6 secs and that is how long (approx) it takes out of the last corner to the finish line (where the sound usually seems to occur). However if the non-KERS runners also have the engine note anomily then it can't be KERS. It sounded to me like the top gear was not set right. I'm not hugely technical but I've noticed on video games if you don't set the gear ratio's right, sometimes 7th gear will 'pop' back down to 6th momentarily and then back to 7th for the remainder of the straight. Just a thought.

[runshaw]

Originally Posted by shiny side up!

Clearly, the car's top speed in 7th gear would change drastically with 80bhp more

No it wouldn't.

[calibrax]

Originally Posted by shiny side up!

I don't know the nitty-gritty detail of how the KERS is integrated into the drivetrain, but in order to have the KERS act in an additive way to the engine output, both would have to be linked to the diff (or whatever bit of running gear) at the same time - so if KERS kicks in and helps the engine propel the car with more force, the engine would rev quicker through a given gear than it would otherwise do without the KERS, as the force required to move the car remains the same but the force available to do the moving is increased.

No, that doesn't follow, otherwise the engine could exceed the 18k rev limit when on KERS... it must work by somehow increasing the speeds within the transmission, perhaps with a separate clutch-type mechanism to avoid increasing the speed of the engine.

Best metaphor I can think of to explain what I mean it is if you roll a hula hoop down a hill using gravity, and then run alongside it and hit it forwards with a stick (we've all done it haven't we?), then the hoop's speed will increase, but by doing that you haven't changed the amount of gravity on the hoop (you and the stick representing KERS, the hoop representing the car, and gravity representing the RPM)

[the.cosmic.pope]

Originally Posted by ScotsBrutesFan

They don't do it by helicopter these days.

There are a number of recievers around the circuit that pick up the signals from the cars. These are then sent back to the TV compound by (I think) fibre optic.

This is the reason why in recent years the on-boards have been break up free especially when passing under bridges and allows the live on-board views through the tunnel at Monaco.

The onboards were breaking up in the heavy tree cover at the end of S1 and the bridge at the end of S3 though?

[fourWheelDrift]

The extra power is a result of increasing the torque in the drive train and so to the rear wheels. As long as the wheels are not spinning the engine reves are determined by the road speed and which gear is engaged. Of course if the extra power is doing anything the road speed and therefor engine speed will rise more rapidly under accelleration but the engine speed cannot change instantaneously just because KERS kicks in unless the wheels spin.