Exhaust blown diffusers and FIA restrictions/ban

[hardingfv32]

Any data on how deep the trail breaking might extend braking for a F1 car?

In slow corners, after brake completion, do you think the F1 cars coast for an amount time before they are back on the throttle?

Brian

[godlameroso]

Depends on the type of corner, for example the final three turns in Istanbul Park would be an example of trail braking and long slow corners with lots of off throttle. Or turns one and two in China, is an example of drivers using trail braking and off throttle. Also a couple of corners in Singapore require a few seconds off throttle. Also the fagnes chicane in Spa, and the end of the second sector and beginning of the third sector in Korea. What about first corner, the last right hander in the esses, the degner curves and spoon curve in Suzuka.

In Valencia you have the 90 degree turns after turn 1, the turns entering and leaving the bridge, the series of curves after the long back straight, and the final braking zone.

I won't claim to have any detailed data, but there are a good number of medium speed corners where you go off throttle for a second at least. In Silverstone, the maggots beckets complex require some off throttle action especially with a full tank. The right hander after hangar straight also require some off throttle and trail braking.

These are corners where we will see the ban make the biggest difference, I suppose Ferrari will be fast there if they can marginally improve their aero because they have the best mechanical grip as of Canada.

[hardingfv32]

It is my opinion that you are completely wrong. Once off the brakes then back on the throttle. Not necessarily 100% throttle, but no coasting. This is no matter how slow the turn. Once back on the throttle the off throttle mapping is not relevant.

Brian

[godlameroso]

[youtube]http://www.youtube.com/watch?v=Fav773EU ... 8B4BBBDB5C[/youtube]

The RB7 was the fastest car here, and look at all the coasting and trail braking

He coasts at 0:08, at 0:19, briefly @ 0:22, massive lift at the next corner, trail braking followed by a small lift @ 0:35, and a some coasting in sector 3.

Now you can tell me with a straight face that I'm wrong and all F1 drivers never coast their cars even for a little bit?

[youtube]http://www.youtube.com/watch?v=GVI4QAfz ... re=related[/youtube]

Lookie here first corner trail braking and coasting, and around two seconds of coasting going into the left hander right after, this was pole lap so they weren't heavy.

[hardingfv32]

No, very good data.

The sound of the off throttle mapping is not very apparent to me.

Also a lot of time is spent downshifting in the brake zones. I know the shifts are very fast, but would they be done while in the off throttle mapping mode? How would the ECU know that the throttle is open for a downshift or for blowing?

How is the engine controlled during the automated down shifts? Throttle motion only?

Brian

[DaveW]

For what it's worth, I suspect that the blown diffuser has proved to provide a performance advantage with or without engine mapping to maintain throttle-off downforce. The latter would be expected to improve low speed cornering performance & to make vehicle handling more consistent, but I don't think the change in mapping rule for Silverstone will introduce anything new to drivers. This is because "aggressive" engine mapping increases fuel consumption & probably has a significant effect on engine life and is, as a consequence, currently used only sparingly during a race.

Sticking my neck out, I guess the new "rule" (interpretation) will mean startling Q3 lap times will no longer feature, & races will become (even) more processional (I wonder if engine mapping played a part in JB's "rags to riches" drive in Canada).

[BreezyRacer]

"The only new thing is trying to move weight lower and back in the chassis in the diffuser box itself."

1) Weight distribution is prescribed by the rules for qualifying. So no moving weight to the rear.

2) Fact: Everything is as low as the overall design will allow from day one.

The rest of your recommendation sound good for a club racer, not an F1 car.

"ad more low speed rebound to the rear, though this is a touchy thing to get right without unloading the tires."

You think it is very hard to dial in the shocks on a 7-8 Poster Test System?

Brian

Brian
As my post said they are already maxing out these things, it's just that they may adjust them more towards controlling the rear under braking, rather than pure cornering performance, for example. It's not a question of how hard it is to adjust these things, it's a question of what the goals are.

As for the weight, the distribution is fixed however there is a great difference between weight before the rear axle and weight past the rear axle. It should help to keep the rear from raising under braking and BTW, it actually allows you a bit more in ballast options up front too, as it actually reduces weight off the front end, which you tune by placing more weight towards the front. Could be a kind of trick for moving weight around, but again, it's not how hard it is to do these things, it's what the goals are.

One last thing .. I seem to have missed your list, please show it oh wise one.

[hardingfv32]

1) "As for the weight, the distribution is fixed however there is a great difference between weight before the rear axle and weight past the rear axle."

The formula for weight transfer does not have a variable for location. So for weight transfer, the car does not care if the weight is on the ends or in the center, assuming a fix CG distribution.

2) It is my belief that the teams are losing a downforce generating mechanism that cannot be replaced or compensated for. There could be some compromises made to the aero system to best accommodate the loss, but I have no ideas. I view the discussion as a way to help me see things in a better or different light.

Brian

[raymondu999]

While we're on the topic of who will lose the most from this blown diffuser ban. Could it be that in the races McLaren is blowing the diffuser, but not Red Bull? Could help to explain how they make up a good chunk of their race pace deficit in the race as well. I remember in Spa 2010 weren't they like the first to be able to do it in the races as well?

[munudeges]

In reality I'm expecting it to make very little difference. I believe that there's also a bit of smoke and mirrors going on where some teams are trying to make it look like the Cosworth powered teams are the ones complaining when in fact teams behind Red Bull would like to see it banned as well. Witness Ferrari's talk of a 'second championship', which basically they're just hoping for. It's all very Machiavellian.

You can visibly see how uncomfortable engineers in other teams have been with getting this working though. The heat proofing materials required and managing temperatures have been difficult enough but the real brick wall is modelling the exhaust gases and vortices off the back of the car and understanding what's happening. That's where Red Bull are well ahead and it's probably going to take other teams years to catch up. It's just well out of their 'comfort zone' and it's not something they really wanted to do anyway.

Into next year the cars are just going to be put back to where they were in 2009 really and I don't see it changing the pecking order. If you have a better understanding of the vortices created at the back of the car, with or without exhausts thrown into the mix, then you're still going to have a sizeable advantage.

[munudeges]

Renault FEE, was it ever successful?

Good idea but needed more development. By virtue of the fact that their exhausts are much further away from the diffuser and the back of the car Renault needed to make sure that their exhaust gas stream was predictable and consistent. Too difficult to control and understand in my opinion.

[ianwit]

In race mode the off throttle EBD has to be a compromise between Fuel consumption and weight but in Quali this is not an issue as they can burn as much fuel as they like. The theory is that the Renault engine is easier to optimise for off throttle blowing and it can do it much more aggressively. I think everyone is guessing and Silverstone can't come fast enough.

[ianwit]

THIS weekend has now become interesting.

http://www.autosport.com/news/report.php/id/92494?

[horse]

Wow, McLaren must have a much better chance of a pole now. RedBull still have quali DRS advantage, mind.

[imightbewrong]

Wow, McLaren must have a much better chance of a pole now. RedBull still have quali DRS advantage, mind.

What is this advantage? If you are speaking about them being able to open it earlier, then it might not be true. If they loose a bunch of downforce due to the new engine maps then they might not be able to open it earlier than the other teams. We'll just have to wait and see.