The relative benefits of a pull rod suspension

[SiLo]

Interesting stuff there, the RB crash structure at the rear was certainly very bent. Surely this would of negated the effect of it? Unless it was a crumple zone of course.

It will be interesting to see just how many teams have pull-rod suspension, and if Mclaren stick with the single heave spring operation, which apparently aided traction, but to me actually seemed to reduce it.

[Blackout]

The low CoG is just one of the pull-rod architecture's advantages but the aero advantages it provides are obviously the most important... Just look at how the beam wing is exposed. The air flow above the rear end is much cleaner.

[Blackout]

Why would Red Bull's crash structure shape be illegal next year?

Not doubting, just interested to know.

Not really illegal... If I understand it correctly, the new rules will limit the angle of the crash structure. But these will remain steeper than in 2008 and non RBR cars in 2009.

[ringo]

On the other hand you are just preventing flow over the diffuser, so on that part there is nothing gained nor lost.

For next year, when Red Bulls crash box shape wont be legal anymore, an Pull Rod would make less sense, as you are having the space higher upwards due to the more regulated space, but you place it lower limiting flow over the diffuser.

How do 2 skinny rods prevent flow over the diffuser?


Look how clean this is (green lines):

nothing blocking the diffuser, and very good flow to diffuser. No pesky suspension parts in the way.

Side pods/engine cover don't have to cover suspension parts, so they can terminate much earlier.

compare to this:

1/3 of the beam wing blocked from high speed flow. Sidepods also need to be shaped to condition flow over these parts as well.

Mcalren will be ignorant not to try push rod suspension on the interim car at least. Worst that there a no more DDD, where under car space is a priority.

[Just_a_fan]

Look how clean this is (green lines):

nothing blocking the diffuser, and very good flow to diffuser. No pesky suspension parts in the way.

Side pods/engine cover don't have to cover suspension parts, so they can terminate much earlier.

Another way to look at it - take the current high nose, turn it over and turn it round to face the rear. The result looks similar to the RB's low rear end. The RB was designed to maximise flow out of the back of the car (just as the high nose maximises flow in that area) via the aerofoil sections of the beam wing. This meant that the diffuser was 'driven' more than is possible with the 'choked' traditional pushrod systems e.g. the MP4-25. The beam wing is key in driving the diffuser - especially with the higher main planes of the current regs.

The ability to drive the diffuser was crucial, IMHO, to the RB's success. That they also managed to get the front wing to balance it (by fair means or foul) was the icing on the cake.

A typically well thought out Newey design really.

[raymondu999]

BTW, if McLaren are indeed using the old MP4-25 as an interim for the firs test, how will they cope with the fact that the diffuser will have to be blocked off? Or will they just simulate the lower levels of downforce? Kinda like what they did with the MP4-24

[PlatinumZealot]

Do the technical regulations have to be adhered to in winter testing? Just wondering...

[spinmastermic]

Do the technical regulations have to be adhered to in winter testing? Just wondering...

Just the safety regs

[Formula None]

On the other hand you are just preventing flow over the diffuser, so on that part there is nothing gained nor lost.

For next year, when Red Bulls crash box shape wont be legal anymore, an Pull Rod would make less sense, as you are having the space higher upwards due to the more regulated space, but you place it lower limiting flow over the diffuser.

Keep in mind that a push or pull rod will exist in between the wishbones, which lie at or above the wheel centerline. All of which is about 130mm above the maximum height of the single diffuser (125mm from reference plane), based on a 660mm dia wheel and depending on ride height.

So, as was said the pullrod is more for the benefit of the beam wing, since all of the suspension arms lie in an area ahead of it, not the diffuser.

Look how clean this is (green lines):

nothing blocking the diffuser, and very good flow to diffuser. No pesky suspension parts in the way.

Side pods/engine cover don't have to cover suspension parts, so they can terminate much earlier.

compare to this:

1/3 of the beam wing blocked from high speed flow. Sidepods also need to be shaped to condition flow over these parts as well.

B-but... Frozen honey! Erm... Flexible things! Ehm... Turbo Encabulator!

[raymondu999]

Do the technical regulations have to be adhered to in winter testing? Just wondering...

Don't think so. If you remember, the MP4-24 was first tested using the MP4-23's rear wing. It was actually quite quick with that wing... then they bolted on the MP4-24's own wing and it became hideously off the pace. Again.

[Donuts]

Do the technical regulations have to be adhered to in winter testing? Just wondering...

Don't think so. If you remember, the MP4-24 was first tested using the MP4-23's rear wing. It was actually quite quick with that wing... then they bolted on the MP4-24's own wing and it became hideously off the pace. Again.

Same question was asked to James Allen a couple of days ago, he said: No. From what I understand, several teams will be running b-specs of '10 cars. McLaren's strategy is to run an updated aero package without having to spend to much time in the garage(they'll be doing that later) hence having as much track time as possible to test the Pirelli's. Is this a good idea? It could be, but what if there will not be enought time later to solve reliability issues? Dooh!

[raymondu999]

I'd be more concerned about getting real, live performance data on track for the 2011 cars rather than reliability, but I guess there is some truth to the fact that they wanted a known base for which to gather tyre data and then make a comparable model. They did that in Abu Dhabi with Paffett, but the tyres would've gone through quite a few changes since. Also Lewis and Jenson wouldn't have experienced the Pirellis on track yet.

[myurr]

Mcalren will be ignorant not to try push rod suspension on the interim car at least. Worst that there a no more DDD, where under car space is a priority.

None of the teams in the pitlane are ignorant, and if they don't try the push rod suspension then they'll have many reasons for doing so. The aero on an F1 car is incredibly complex with many subtle effects that make eyeball comparisons of limited value.

My understanding was that McLaren optimised for airflow under the car and overall efficiency, Red Bull for over car airflow and downforce at the cost of efficiency and drag. Throughout the year McLaren were piling on the downforce and drag whereas Red Bull were trying to find ways to increase the efficiency and lessen the drag of their solution whilst keeping the down force.

Hence when everything was set up and working perfectly the McLaren was able to challenge the Red Bull, but because they relied so much on the diffuser their car was relatively pitch sensitive, requiring an overly stiff set up and giving them big problems on bumpy tracks.

[raymondu999]

Mcalren will be ignorant not to try push rod suspension on the interim car at least. Worst that there a no more DDD, where under car space is a priority.

None of the teams in the pitlane are ignorant, and if they don't try the push rod suspension then they'll have many reasons for doing so. The aero on an F1 car is incredibly complex with many subtle effects that make eyeball comparisons of limited value.

My understanding was that McLaren optimised for airflow under the car and overall efficiency, Red Bull for over car airflow and downforce at the cost of efficiency and drag. Throughout the year McLaren were piling on the downforce and drag whereas Red Bull were trying to find ways to increase the efficiency and lessen the drag of their solution whilst keeping the down force.

Hence when everything was set up and working perfectly the McLaren was able to challenge the Red Bull, but because they relied so much on the diffuser their car was relatively pitch sensitive, requiring an overly stiff set up and giving them big problems on bumpy tracks.

Do you blokes mean they should try "pull" rod rather than "push" rod?

[Just_a_fan]

BTW, if McLaren are indeed using the old MP4-25 as an interim for the firs test, how will they cope with the fact that the diffuser will have to be blocked off? Or will they just simulate the lower levels of downforce? Kinda like what they did with the MP4-24

The diffuser is part of the floor 'panel' and thus can easily be modified just by putting a different floor on the car. No need to simulate anything.

Indeed, due to lack of money, Minardi, for example, used to run two part floors so that the rear could be altered without having to create a whole new (and thus more expensive) floor.