The relative benefits of a pull rod suspension

[ringo]

myurr,
There is an unused gap i believe. I have not seen inside an F1 gearbox bell housing, but going off of the resident Honda F1 car's gearbox, there seems to be some space in the housing.
The Rb6 is a pretty short car, and whatever increase in length in the gear box area is sure better than an increase in height.
The 2009 cars have the room to place the suspension in the housing, remember we had smaller fuel tanks then.
The cars are as long as they have to be. The gearbox is half the chassis. There is no limit to the car's length.
To be sure about an increase in length we need to see the RB6 suspension. No one has seen it as yet.

[Ciro Pabón]

Thanks, Dave. Scarbs expresses the crux of issue better, no a-arms in his explanation... He says, talking about how the new high noses have changed the car (noses that have an aerodynamic advantage that cancels the higher CoG disadvantages of push rod):

Now the front of the chassis is raised too high for a pull rod to work, the angle from the upper wishbone to the chassis is nearly horizontal. This geometry meaning that almost no movement of the pull rod will occur as the suspension moves. Making the set up structurally inefficient.

Well, if that's not clear enough, I don't know what else to add.

I would like to say that the "hype" mentioned in previous posts only exists in the minds of journalists and forum members. Although some people thinks that compromises are a sign of weakness (apparently, at least from the previous talk I see) and that engineers are miserable people that refuses to see what it's, oh, so clear in retrospective, I quote:

“For everything you have missed, you have gained something else, and for everything you gain, you lose something else.” -- Ralph W. Emerson -- (yeah, duh, but...)

Finally, I bet one bottle of rum to this: the car that wins the championship will have something different from what you read in the newspapers and the Net. After all, if it appears in the papers, then why would make a difference? Is the unexpected, the brilliance (again, seen in retrospective) what makes champions.

In this time and moment we do NOT know if GM, for example, will rebound from its misery. I still remember when Toyotas were cheap, ugly cars that nobody wanted. People used to mock the lack of inspiration and low quality of those cars, remember?

First Toyota Corolla: incomprehensible back then. Why, oh, why? What's with the mirrors? I'm not even talking about the valves, for the love of Pete. From that piece of junk, slightly better than a Yugo, a global empire was made. I just post it so people that now is gaga with Japanese cars get a grip on perspective


I think people that mocked Toyota back then, or mock american designers today, do that to compensate for their short, less than satisfying lives. So, if you are going to criticize american designers now that they are in a bad situation, do it gently. As Garfield says: may your words be sweet, in case you have to swallow them.

[Ciro Pabón]

Oops.

[Formula None]

-Achieve 2500 posts in 2 years.
-Make quality posts.

Ringo had to choose one of the above.

[ringo]

-Achieve 2500 posts in 2 years.
-Make quality posts.

Ringo had to choose one of the above.

Yes lead by example noble Formula None =D> my post count is very relevant to pull rod suspension.


@ Ciro, I am not disrespecting american cars or engineers. I was just giving an example of the importance of adapting and being aware of what is happening on the outside. SWOT analysis if you will.
GM will rebound, but this is dependent on how well they copy or innovate. Copying being the faster route. I wont buy any of their cars, they're too big, but they seem to be looking better since the restructuring.

Compromise is not a sign of weakness, it depends on the context. Given the choice i would rather not have to make compromises. Compromise in itself is acceptance of a weakness.Now given the choice, knowingly and unnecessarily choosing compromise is brash and reckless.

About the front pullrod. I am aware of the issue with the use of pullrod, we discussed that before somewhere else IIRC. We are clear on the high nose requiring the push rod; for sure.

The rear of the car is the focus, the title doesn't really specify but the discussion started with the rear suspension of the mp4 26.

This is just like the exhaust blown diffuser thread.
Things are more straight forward than they seem, but some refuse to accept it.
It makes F1 less wondrous and interesting.

[myurr]

Ringo, I suggest you read that link to scarbs post. He goes through a lot of detail in the relative benefits of each, with diagrams showing how each suspension design is packaged in and around the gear box. He also states that the teams evaluated pull rod in 2010 but dismissed it because they needed the space for the DDD, and quotes Newey as saying that pull rod wasn't obvious for 2010 but they stuck with it as they didn't want to redesign the back end of the car when they had a proven pull rod design they could try and work around.

He also concludes that for next year all the teams will evaluate it again, but:

There’s no one answer to which is best, you look at your design requirements and pick which solution works, best. Next year the best car is not necessarily going to be the one with Pullrod rear suspension.

[raymondu999]

Here is said article: http://scarbsf1.wordpress.com/2010/10/1 ... odynamics/

[Tim.Wright]

Things are more straight forward than they seem, but some refuse to accept it.
It makes F1 less wondrous and interesting.

I had given up on this argument, but really, statements like this prove you are either pretty ignorant are have done no major design work in your life.

What exactly is your background?

Tim

[ringo]

Believe what you want. I'm a mechanical engineer. 3rd world one at that.
when you have a lack of resources, reverse engineering/copying is your friend.

raymond you are repeating what i've said many times about the DDD.

I'm starting to feel like white blue here, attacked at all angles.

Everyone should calm down, take a breather, and wait until the cars are released.

[myurr]

and wait until the cars are released.

But what will that prove? We're all agreeing that there's a good chance that most if not all the cars will have pull rod suspension this year - where we're disagreeing with you is with that it's a no brainer to the point of being a necessity. With the rules as they are it probably will make sense to most teams to run the pull rod this year, plus there will definitely be a bit of a herd mentality among some to copy what Red Bull are doing. But what you seem to find so hard to even contemplate is that a push rod car could win this year if one of the teams goes that route and does a better overall job than everyone else.

[ringo]

I said this on page 8:

A push rod can still win the championship, but it will have to compensate for it's disadvantage to the pullrod in other areas.

[myurr]

Your full quote was actually as follows, where it's not as tempered as your selected text:

A push rod can still win the championship, but it will have to compensate for it's disadvantage to the pullrod in other areas. There is no reason to add this extra effort to prove a point with a lesser layout, it's better to copy what wins and save time and money for other areas of development.

The rest of that post also went on about how there was no disadvantage to pull rod AT ALL.

Also from page 8...

If the winning car has it, copy it with no second thoughts. Don't think about it just copy it, you wont regret it.

And then this beauty:

Evidently the engineers never considered it seriously before 2010, you have no proof that they did. I have proof that they didn't; you can't seriously consider something advantageous then toss it away.

None of those statements is tempered with reality or consistent with the view that a push rod suspension car can win this year. The reality is that the push rod has different packaging requirements to the pull rod, and that it's entirely feasible that these packaging requirements cause a compromise elsewhere on the car that more than overshadow the perceived benefits of the pull rod.

If McLaren, Ferrari or even Red Bull launch a car with push rod suspension would you criticise them as being stupid and write off their chances?

[ringo]

What does temperament have to do with the facts? This is not about me being right or wrong.

If push rod has a performance advantage tell me. I've been asking for it for pages.

When you say this now:

The reality is that the push rod has different packaging requirements to the pull rod, and that it's entirely feasible that these packaging requirements cause a compromise elsewhere on the car that more than overshadow the perceived benefits of the pull rod.

It's not saying anything at all to someone who has no clue about the topic. Be specific when you talk about "advantages" and "packaging requirements" and "compromises".

What are they? Land the finishing blow with specifics. Why make it seem so complicated that you dare not touch it?

I said this:

pullrod rear suspension :
[*]lower centre of gravity
[*]lighter rod and gearbox casing thinner at the top.
[*] lower radius of gyration, suspension masses closer to the centre of the car being in the bell housing.
[*]aerodynamic benefit, cleaner flow to beam wing and tighter rear end.
[*]cooling benefits since the rockers and spring aren't in the path of cooling exhuast.
[*] slightly stronger upper A arms required.
[*] depending on how much room is in the bellhousing, gearbox may be set back a few cm( We still haven't seen the rb6 suspension to make that judgement.
[*]Occupies space under the car in the case of a double diffuser.
[*] relative R&D costs of transition from push rod???

Now you do the same with the push rod. That's all i was asking. I don't care for personality or temperament. You can curse while you're doing it, just list the facts without dodging the issue.

[Jersey Tom]

If push rod has a performance advantage tell me. I've been asking for it for pages.

And has been said many times, it is contingent on the system it's in. It doesn't just exist by itself!

Might as well be asking something as silly as, "Which metal is better... aluminum or steel?" Or even adding, "What metal is better for an upright, aluminum or steel?" There's no answer by itself! Depends on a heap of other things.

[myurr]

Further to Jersey Tom's reply, to temper something is to moderate it or apply caveats. In this instance it wasn't a reference to anyones temperament etc.