The relative benefits of a pull rod suspension

[PlatinumZealot]

It seems we have some people here that could do what took Nikolas Tombazis years to do in a mere day!.

NOBODY saw that Ferrari setup coming! I think it's dishonest for people to say they expected it.

I was somewhat satisfied to see Tombazis admit there are/were inherent weaknesses of the push-rod. It would be interesting to see why he didn't go with the pull-rod though.

"We evaluated different suspension configurations, and also pull-rod suspension like the one Red Bull introduced," he explained at the launch of the new Ferrari F150 on Friday.

"There are different possibilities - one is for aero volumes and we have found a way, which is not so visible on the car right now, to reduce the volume of the push rod suspension in an extreme way.

"That means we could reduce the rear volume, so our version is far more compact compared to the previous ones. We believe we have reached a similar level of packaging to the other ones."

[bettonracing]

...
I was somewhat satisfied to see Tombazis admit there are/were inherent weaknesses of the push-rod. It would be interesting to see why he didn't go with the pull-rod though.
...

That stood out to me too. I'm given the impression they went beyond the call of duty to not use the pullrod - indicating a potential weakness (of pullrods). Most likely packaging.

Regards,

Kurt

[mep]

Not to forget that when you place suspension parts low you must replace components already occupying this space so in effect it is not sure a pullrod will lower your CoG.

[ringo]

It's interesting indeed.


compare:



handy piece of work

Continuity is one reason of not switching. The tyres are new, and on that basis you want to relate to past data maybe. They may have an idea, but not know exactly what's inside the RB6 bell housing either.

If this new way of doing push rod system achieves the same goals as pull rod, then no prob. Not every team will think of what ferrari did however, and it doesn't represent the aero outlook on conventional pushrod systems.

I too would like to hear the reasoning. Be it KERS batteries, or that they actually have suspension parts in the box as well. So the same goals are achieved.

[ringo]

Not to forget that when you place suspension parts low you must replace components already occupying this space so in effect it is not sure a pullrod will lower your CoG.

Assuming components are there. Any shots of the rb6 suspension?
This isn't it, but it's not much to fit in the bellhousing.

scarbs has a good drawing, but it's not from the side and doesn't have all the parts.
Maybe he can source some more images.

[mep]

Assuming components are there. Any shots of the rb6 suspension?
This isn't it, but it's not much to fit in the bellhousing.

What???
You dont think thats much?
Well I think thats alot of stuff which will take space from your gearbox parts.

[myurr]

NOBODY saw that Ferrari setup coming! I think it's dishonest for people to say they expected it.

It's dishonest to say that anybody said that they expected it. No one did. All the news reports, 'leaks', and 'insider' information pointed to a pull rod setup on the Ferrari and no one here questioned that.

The point that I, and many others, have been trying to make is that each system has it's strengths and weaknesses, that each team will choose whichever works best with their design rather than designing the car around a particular suspension layout, and that we wouldn't be worried if any top team went the push rod route. What we're now trying to point out is that Ferrari have vindicated those views.

What is dishonest is for people to now claim that Ferrari going with a push rod suspension is only because they've invented some magical suspension and that the pull rod is still the default no brainer answer. It's also dishonest to maintain that their earlier views that teams would be stupid to not go the pull rod route have somehow not been invalidated by Ferrari's launch.

[ringo]

The redbull did very well with space.

scarbs interpretation of the suspension:

I would imagine the torsion bars are housed in the casing walls.
The clutch and hydraulic unit are the only things in that area.
you got some space:

from f1 snake's thread.


It would be nice to hear ferrari's reasoning. But keep in mind, their system is different than the typical pushrod.
I doubt other pushrod users will think up the same thing; until it's time to blindly copy for 2012.

I have a feeling the KERS motor is cramping the pull rods style.
That hollowed out are is a nice place to but batteries as well.

[myurr]

Ferrari stated that their batteries are under the fuel tank. I believe the motor is also mounted to the front of the engine on the Ferrari but could be wrong on that one. Either way I doubt that KERS is getting the in the way.

If you look on scarbs picture what I think is going on is that the area to the sides of the gear box that is full of torsion bars and dampers etc. is required by Ferrari for aero reasons. This may be to house other components that would otherwise be displaced in the way of the aero, or to allow cooling air to route past that part of the gearbox to the inner of the two openings in the engine cover, thus keeping the rear as tight as possible width ways.

By using a push rod displaced forwards they've also been able to keep the rear of the car low, getting the best of both worlds aero wise.

[marcush.]

the pull rod angle is already very awkward when angling forward towards the clutch housing .I doubt that Newey has chosen a even more awkward angularity to the axis of rotation for the torsion beam .This looks completely wrong to me.The funny angle Newey has chosen for the pushrod leads to a loss of motion anyways so you cannot afford to loose more in the lever to the torsionbar.So I would expect to see the torsion bars mounted almost horizontally and arranged in a V- shape opening to the front of the car .The lever would catch the pullrod at a decent angle -with no sideloading.-the lever would even be a bit longer to double up as the fixing point for the damper to allow for some damper travel.
On second thoougts there might be a possibility to mount the torion bars on the sides but inclined forwards to the engine valve covers ,but I doubt this would be possible witout considerable sideloads...
I would love to see this arrangement.

[Giblet]

This whole thread is completely insane.

You guys might as well be arguing "hot vs cold".

They are just different, and only one is best for a given situation, and Ringo is right, the pull rod was put to great effect on the RB6, and if this Ferrari setup proves to be the best, it doesn't mean that simply copying it and slapping it on the RB7 would make it a world beater. They would have to package everything else like the F150 to make it a complete package where the gains of their particular system can be realized.

I would actually like to know what Ringo is arguing, and if he can't make his point in a couple of succinct sentences, then there is no point at all. He prefers pull rod and wants to see it on every car and that's the end of it.

[ringo]

This thread is to have as much considerations as possible for both iterations listed then contrasted for the 2011 regulations.

It spilled over into madness becuase i said i would hastily pick the pull rod as it is a proven foundation with some very obvious aero benefits.

[segedunum]

If a pull-rod suspension wasn't the way to be going then Ferrari wouldn't have come up with a push-rod configuration that tries to apparently mimic a pull-rod layout as much as possible to open up space in the channels leading to the diffuser. All they will end up with is a compromise.

The reason of course is that they probably didn't have time, so they hacked this on. A pull-rod layout requires the gearbox and every single component to be designed for the purpose. If anything is the wrong shape, angle or size back there it won't work. Mike Gasgoyne, clever man that he is, bought in a Red Bull gearbox so he could do exactly that. He's already got himself a leg-up there.

Given the fact that channeling air efficiently to the diffuser is going to be even more vital this year, owing to the downforce lost through a smaller diffuser, then you simply can't compromise.

In addition, there is the the lower centre of gravity advantages that might be very important when you take into account the whole car and the addition of KERS.

[PlatinumZealot]

It's dishonest to say that anybody said that they expected it. No one did. All the news reports, 'leaks', and 'insider' information pointed to a pull rod setup on the Ferrari and no one here questioned that.

I didn't say any one did!

The point that I, and many others, have been trying to make is that each system has it's strengths and weaknesses, that each team will choose whichever works best with their design rather than designing the car around a particular suspension layout, and that we wouldn't be worried if any top team went the push rod route. What we're now trying to point out is that Ferrari have vindicated those views.

No one disagrees with this. We do agree that pull rod has more strengths though right? lower COG and cleaner rear?

What is dishonest is for people to now claim that Ferrari going with a push rod suspension is only because they've invented some magical suspension and that the pull rod is still the default no brainer answer. It's also dishonest to maintain that their earlier views that teams would be stupid to not go the pull rod route have somehow not been invalidated by Ferrari's launch.

The races haven't begun yet!! Ferrari tested it so it may only appear that the "No Brainer" was invalidated.

If we want to break it down, making the rear cleaner was a no-brainer for 2011 and Ferrari have crossed that off the to do list. Up until now that was a major advantage of the pull rod suspension. Most of us did not expect Ferrari to pull it off so nicely with push rod (did you?). It is still not as clean as the RB5 but it's a very good improvement over what was there before. So, with reducing an inherent disadvantage they are one step closer. There are still other advantages to using the modern pull-rod.

I think this argument carries a lot of gut feelings... even if the Ferrari won every single race, we still don't know if it was down to the new suspension. Heck my belief that the push-rod is a no brainer is just a belief. Your belief that it is not, is just a belief. Ferrari too, believes that their solution can be just as good as pull-rod. They won't know if they are right until that special moment when you are off the pace by half a second in Turn 8.

[myurr]

To save us going round and round in circles, can we take a look at one new aspect that is suddenly appearing in this thread and others: that Ferrari went with a modified push rod suspension because they didn't have time and / or resources to develop a pull rod suspension. It's been said several times now as an excuse as to why Ferrari didn't just run with a pull rod setup.

So taking it as a given that Ferrari, one of the best resourced teams on the grid, did not have time / resources to be able to develop a pull rod suspension layout in the last year that they've been developing the F150 and the last two years that they've been looking at and evaluating the pull rod. Would it not follow that other teams up and down the grid that are not as well resourced, and that have not bought the solution from Red Bull, will also not have had the time or resources to develop a pull rod suspension system? So a prediction of yours would be that all the other teams, except Lotus, will also stick with the push rod?

After all if Ferrari don't have time to develop such a system and therefore have to resort to trying to make their push rod layout have some of the benefits of the pull rod, then other teams such as Mercedes, McLaren, Renault, Force India, Williams, etc. will have to resort to something similar or even just stick with a bog standard push rod layout.

My opinion, for what it's worth, and prediction is that Ferrari developed their push rod system as the pull rod held disadvantages for them with their car and overall philosophy making a developed push rod the better solution for them, and that at least one other team on the grid will have developed their own pull rod solution proving it can be done. I have no idea if all those teams will make the switch, but as I said waaay before the Ferrari launch I would not be surprised or alarmed if any of those teams stuck with the push rod system. I believe the difference between the two solutions is marginal, with both having their own sets of advantages and disadvantages, and with neither of them being an automatic or no brainer choice.

Lest we forget that Torro Rosso also ran a pull rod layout last year and the only teams they could beat were the three new ones that were new to F1 and had half the time to design and build their cars as the established teams. If it makes such a difference why did Torro Rosso suck so bad?