F1technical.net

Hi,

I was under the impression the strange changes in revs you hear down the straights are to do with the KERS system.

However the Brawn also does it. It's not like they are changing an engine map as the revs go crazy.

So is it KERS or something else?

I'm pretty sure it's a tv glitch as the rev changes never coincide with the KERS usage graphics, and as you say, it happened when onboard with a Brawn GP car.

I have however noticed they do usually coincide with the driver pressing something on the steering wheel.

With the onboards of the McLaren's, it almost seemed like they had an extra-long top gear to make use of the extra KERS power without exceeding max revs, or compromising their non-KERS top speed.

i.e.
KERS discharge starts > change up > KERS discharge stops > change down

If this is the case, they must be compromising their overall gearing, with longer ratios.
Plus, it wouldn't explain it with the Brawn. So who knows...?

No, really. Who does know?

The world feed's getting a bit crap if from 1 year to the next, they've introduced some weird sound interference at strategic points around the tracks. So I'm guessing either the sound's correct, or something electrical on the cars is causing the blip.

TV glitch

Possibly a European strain of what in North America is called ...Dubb's Disease.
This is what afflicts TV personalities and causes their mouths to move and the sound to come out with a delay. Usually only a minor case will result in a 500 ms delay but some severe cases result in an off-set of up to two seconds.

I've just come over from another forum to find an answer to this exact "phenomenon". I'm having a hard time believing the audio/video theory since it only happens during certain times (usually in a higher/ top gear).
It has been mentioned that Brawn has a system where the cars are momentarily allowed 500-1000rpms. This is one possible explaination, but really nothing definite.
Wonderin if an e-mail to the Speed guys is in order?

I just do not see how KERS can be practical when the engine is near peak RPM. KERS does not posess enough power to drag the engine past it's limited RPM.
It's present application is for acceleration, getting a good launch out of corners. Not at the end of a straight.

DaveKillens wrote:I just do not see how KERS can be practical when the engine is near peak RPM. KERS does not posess enough power to drag the engine past it's limited RPM.
It's present application is for acceleration, getting a good launch out of corners. Not at the end of a straight.

This is intriguing. If I understand you, you are saying that KERS can increase acceleration (say 100 - 140 MPH time), but not absolute top speed?

We all know that the mathematically calculated speed a car could achieve -- with, for example a 1:1 (!) final drive -- is not possible in the real world. I suppose KERS could increase a car's top speed if the gearbox had a gear to be used only with KERS. Without KERS, the engine would not have enough power to take advantage of this "high speed" gear, but could gain an advantage by using KERS in conjunction with that gear. I am probably not stating this with technical rectitude, but I'm counting on the intelligence of our posters to educate me on this point. . . .

donskar wrote:This is intriguing. If I understand you, you are saying that KERS can increase acceleration (say 100 - 140 MPH time), but not absolute top speed?

Ofcourse it can, but the gain from extra top speed won't be as high as the gain from quicker acceleration at the beginning of that same straight.

I'm still choked that we don't know.

TV Glitch means nothing unfortunately. A glitch to me is a one time event, not a consistent thing that happens on straights in Formula 1 car on board views.

It happens at each race, and all around the world on different networks, so it must be at the source, or at the satellite that relays the signal from the tracks.

So... this would mean that it is the equipment they use to broadcast the race. Now i doubt a professional trailer style mobile television studio would have a 'glitch' like that in their equipment.

So that leaves the camera in the car, and it's radio.

Based on this, I have a guess.

If there is a receiver on two points of the straight, which makes sense as it is the longest part of each track, it might be the car getting out of range of one receiver on the beginning of the straight, and entering the range of another at the end.

Maybe, just maybe, during the rerouting of the cars signal to the new receiver, there might be a buffer that has filled and needs to be unloaded, causing the time compression.

I make many assumptions in my idea, as I have no idea if there are multiple receivers or not, or just weird --- with the car we don't get.

watch this
http://www.youtube.com/watch?v=evN-K2vSPCM
while the KERS on, the loading of engine will be lesser, so the ECU will inject lesser fuel. while the KERS off, the ECU can't response immediately. so the engine speed will drop down little bit, in a mile second, the fuel supply back to the normal level, so we can hear that the engine drop down little bit & go up back while the KERS shut down. But this sound will also appear while the drive change the air-fuel raito.

Again, Brawn cars make the same noise, without KERS.

Still unexplained.

i wonder if its the adjustable front wing they are changing, and the resulting drain on the engine as the actuators move the wing. once the wing has moved, the engine returns to its normal noise.

Welcome to the site ian!

The actuators are electrical and will get their power from the battery that is charged by the engines alternator.

This that the energy needed to move the flaps does come from the motor, just indirectly.