McLaren MP4-26 Mercedes

[imightbewrong]

Scarbs: McLaren Roll Hoop and Cooling Arrangement

He seems to have missed the split side pod intake though..

Those little inlets are for cooling the electronics and hydraulics within the sidepods. Most teams have inlets positioned just inside the main sidepod inlet.

Thanks mate!

[speedsense]

Rumours swirled around that Jerez test that the car is very sensitive to changes in wind direction with some of the heavy winds there, and hence probably air direction in yaw as well. Why am I not surprised? If that's the case then they've got their work cut out and have more to worry about than exhausts.

The comments by Mclaren were that the data collection was being effected by the crosswinds.
IMHO, having done a lot of testing with pitot tubes, getting a correct airspeed number is highly difficult as air (from crosswinds) entering the pitot at an angle is corrupted by turbulence, so the airspeed number goes into flux. Even the body taps are effected by this, so the aero testing goes into question when changes are made to bodywork.
Not knowing if the top speed gain/loss is "true" and imbalances in what should be seen at the aero taps, throws a literal wrench into the results and conclusions become too difficult to conclude anything, aero wise and even mechanical wise. The performance of changes can't be tracked accurately.
The data is crossed to the weatherstation, normally located in the pit area, which I would expect is tracking wind direction, wind speed BUT is difficult to correlate to the cars position on the track and the distance away from the weather station as reliable, especially if the wind is shifting, swirling on track etc.

I find nothing untrue about Mclaren's statements.

[Just_a_fan]

@speedsense

There you go bringing facts to one of Seg's diatribes about how McLaren can't see the obvious that he can see from a few internet pictures.

[N12ck]

I think they have kept a similar layout of the exhausts as in 2010 better hidden though, as when listening to the car at the end it makes that nice humming deep noise only their EBD made as they approach a corner after a straight, listen http://www.youtube.com/watch?v=KUCHVZEK7FU

I may be completely wrong but listen to the MP4-25 as it approaches a corner after a straight and compare

[speedsense]

@speedsense

There you go bringing facts to one of Seg's diatribes about how McLaren can't see the obvious that he can see from a few internet pictures.

...there's an old addage in data collection..."put garbage in, you get garbage out"... I guess the same can be applied to rumors

[myurr]

No no no.... but compression points... distruption... interruptions... YAW!!!!

OK, my post was a bit tongue in cheek, but it was does raise a question. In what way is the trough in the 26 different to the fin on the 22 & 23?

Both have air flowing along a U shaped trough that is subject to cross winds over the top. I imagine there is a difference in the creating that channel with a knife on the 22 rather bludgeoning with the upstand of the sidepod this year.

I was really trying to focus on yaw and cross winds.

Ditto with the tongue in cheek bit

I don't think there's any issues with side winds (that overall will be slow compared to the speed of the car unless we're in a full hurricane situation) and yaw angles are likely to be too small to be a problem. The side area of this car is no worse than other cars have been in the past, so the only way they could have a problem is if the car is so sideways that they aren't getting enough airflow down the U channels, in which case the cars is probably already heading towards a crash.

[/armchair analysis]

[AbbaleRacing77]

Rumours swirled around that Jerez test that the car is very sensitive to changes in wind direction with some of the heavy winds there, and hence probably air direction in yaw as well. Why am I not surprised? If that's the case then they've got their work cut out and have more to worry about than exhausts.

....

You honestly think that the f duct ruined Mclarens season?

I'm gonna use my analytical skills to prove you wrong.

First of all you obviously believed in your fantasy land mind that mclaren has a total of 25 employees who are also crew members that have never built f1 cars. Infact these guys build new aero devices out of cardboard between pitstps and then duct tape them to the car. Infact all the data collected and testing they did last year was only for the fduct. Ron dennis called them up and said he wanted 500 employees working on the f duct and with strict instructions to not work on anything else. The cardboard is why they aren't getting results out of there new aero devices! I figured it out!

Reality.... Maybe 10 employees total worked on the f duct and it was ready before the beginning of the season. Oh yea what do you think mclaren was doing when everyone else was working to copy the fduct? Oh yea they were busy developing new wings, floors and diffusors and new engine maps. Not to mention the fduct was probably the best development of 2010 that almost every team copied and spent time developing it so obviously time well spent

Mclaren won races and I gues the reason why they were leading the championship for the first half of the season was because they spent too much time on the fduct. (sarcasm)

You mentioned that you proved everyone wrong and that there was silence in the room. I'm interested what do you think that you proved? Because I don't think anyone knows what your talking about

You need to think before you speak and if you have an opinion give some legitimate evidence to prove your point. Otherwise I'm just gonna continue to read your posts solely to have a good laugh because your posts are not intelligent, theyre just assumptions made from inexperience and hopes and dream

[ell66]

I think they have kept a similar layout of the exhausts as in 2010 better hidden though, as when listening to the car at the end it makes that nice humming deep noise only their EBD made as they approach a corner after a straight, listen http://www.youtube.com/watch?v=KUCHVZEK7FU

I may be completely wrong but listen to the MP4-25 as it approaches a corner after a straight and compare

just because the retarded ignition sounds similar, doesnt mean the layout is in any way the same.

[Giblet]

Considering half the noise we hear is from the intake anyways, it's hard to tell just off of sound where they come from.

[Chalke]

I think they have kept a similar layout of the exhausts as in 2010 better hidden though, as when listening to the car at the end it makes that nice humming deep noise only their EBD made as they approach a corner after a straight, listen http://www.youtube.com/watch?v=KUCHVZEK7FU

I may be completely wrong but listen to the MP4-25 as it approaches a corner after a straight and compare

just because the retarded ignition sounds similar, doesnt mean the layout is in any way the same.

I agree, although the raspy exhaust note arrived around the same time as Mclaren's EBD last year I haven't seen anything that explains why the layout causes the noise as opposed to the engine map they use.

Incidentally in that video I think they may be be running a relatively conventional exhaust setup, as at around 1:44 at the exit of the left-hander there is a pop from the exhaust that coincides with a flash from next to the gearbox, perhaps flames from the exhaust. Either that or it's a coincidental glint of sun from the chassis. Having said that it's clear that Mclaren are testing multiple EBD setups, so likely will use one of their more radical systems come Bahrain.

If I were to speculate on the Mclaren's rasp (and i'm going to ) - I remember rumours that last year RB could only run during Q3 with a retarded ignition to blow the diffuser, contributing to their exceptional Q3 pace relative to race pace. Running for long periods in this map would cause inevitable overheating problems. This brings my mind to a soaked Nurburgring a few years ago (2007?) where Hamilton in the Mclaren slid off at turn one, but after being craned out of the way for safety, was able to drive away and continue the race. There was shock that the engine or exhaust hadn't cooked itself during the time stationary. He was able to do this because he could select an ignition map that (if memory serves) only fired 4 cylinders to keep the engine running without overheating.

If you apply that logic to blowing the diffuser, could it be possible that Mclaren have maps that, when off the throttle, retard the ignition and only fire limited cylinders, keeping some of the blown effect and aiding stability, while not producing enough heat in the system to cause problems?

Though I claim to be no design or engineering genius and may have this completely wrong, wouldn't this explain that raspy, misfiring engine note while off-throttle, and still allow them to benefit from a partially EBD even off throttle to aid stability all race long?

[forty-two]

Hi Chalke, I notice that you're new here, so on behalf of everyone I'd like to say welcome and sorry I missed your 1st and 2nd posts!

I agree, although the raspy exhaust note arrived around the same time as Mclaren's EBD last year I haven't seen anything that explains why the layout causes the noise as opposed to the engine map they use.

Agreed, but surely the engine map would be selected (or more accurately designed) to work well with a given exhaust layout. What I'm saying basically is that perhaps the two go hand-in-hand?

Incidentally in that video I think they may be be running a relatively conventional exhaust setup, as at around 1:44 at the exit of the left-hander there is a pop from the exhaust that coincides with a flash from next to the gearbox, perhaps flames from the exhaust. Either that or it's a coincidental glint of sun from the chassis.

It's members who notice stuff like this that makes me glad to be a member of this forum. Especially when they cavaeat their observations with comments like "either that or...".

This brings my mind to a soaked Nurburgring a few years ago (2007?) where Hamilton in the Mclaren slid off at turn one, but after being craned out of the way for safety, was able to drive away and continue the race. There was shock that the engine or exhaust hadn't cooked itself during the time stationary. He was able to do this because he could select an ignition map that (if memory serves) only fired 4 cylinders to keep the engine running without overheating.

I too remember speculation that that COULD have been the case, but I also remember thinking, hang on, perhaps it's at least in part a result of low air temperature and hissing rain

If I were to speculate on the Mclaren's rasp (and i'm going to ) - I remember rumours that last year RB could only run during Q3 with a retarded ignition to blow the diffuser, contributing to their exceptional Q3 pace relative to race pace. Running for long periods in this map would cause inevitable overheating problems.

After their "Spark plug" issue in Bahrain last year, I think that the consensus at the time was that the supposed overheating concern was as much to do with the engine and exhaust pipe itself as parts downstream of it, but I guess that it could also apply downstream.

If you apply that logic to blowing the diffuser, could it be possible that Mclaren have maps that, when off the throttle, retard the ignition and only fire limited cylinders, keeping some of the blown effect and aiding stability, while not producing enough heat in the system to cause problems?

This was discussed here last year viewtopic.php?f=4&t=8702 and if I remember correctly the consensus there was that a map like this would only serve to push MORE heat downstream into the exhaust pipe itself, as doing so would be achieved by timing the spark such that ignition took place as the fuel/air mix was being pumped out of the cylinder (hence the "retarded" monicker). As for running on fewer cylinders, I think this was also discounted by a number of esteemed members, although I confess I don't fully remember the reasons why.

Keep up the good work!

[Chalke]

@ forty-two

Thanks for the warm welcome

I feared I'd missed the boat on the Mclaren 'rasp' debate but my (apparently half-arsed) search didn't come up with much. Thanks for the link, it looks like an interesting read.

[timd]

I think they have kept a similar layout of the exhausts as in 2010 better hidden though, as when listening to the car at the end it makes that nice humming deep noise only their EBD made as they approach a corner after a straight, listen http://www.youtube.com/watch?v=KUCHVZEK7FU

I may be completely wrong but listen to the MP4-25 as it approaches a corner after a straight and compare

I dont hear any EBD overrun(retarded map / whatever you call it) on that clip. Just the usual small amounts on lift off.

On the camera angle of the S bends after straight you do hear a click of overun in the middle of the S but i think thats them lifting the throttle just to set the car up for the longer exit right corner.

[clarkiesyeah]

I think they have kept a similar layout of the exhausts as in 2010 better hidden though, as when listening to the car at the end it makes that nice humming deep noise only their EBD made as they approach a corner after a straight, listen http://www.youtube.com/watch?v=KUCHVZEK7FU

I may be completely wrong but listen to the MP4-25 as it approaches a corner after a straight and compare

Just looking at that vid it seems like the macca is quite quick through the slower right left right, at the end of the straight. It appears to clear the corners quicker than the ferrari. (not very accurate as im pausing the vid on entry to the corner and then on exit, subtracting one from the other)

[clarkiesyeah]

Here's a pic of the MP4-22 (2007) car with fins on the side pods. The 23 car had similar fins and that won the WDC in 08 ...

I see what you're saying. Here's a clearer view of those fins on the 22. So do you think they are trying to replicate this principle with their sidepod design this year?