The relative benefits of a pull rod suspension

[ubrben]

Here's an example to demonstrate how relatively ordinary these cars are.

OK it's clear to me that you've never designed and built a racing car. Packaging all the subsystems together is massively underrated by anyone who's never done it before.

If the end result looks simple, it means some complex engineering has been done very well.

BTW I think you're completely wrong about gearbox packaging. The way the gearbox is laid out is fundamentally linked to the rear suspension layout - it's actually the main reason (IMHO) why pullrods aren't a no brainer.

But like I said - go away and try and design a racecar and show us your efforts. I severely doubt you'd still be trivialising the process...

Ben

[ringo]

A gear box intended to fit a 2011 ferrari engine will fit any 2011 ferrari engine, regardless of which team is using it. That is basic logic, if it didn't ferrari would be supplying a different engine to the teams.

Talking about packaging subsystems and whatever generalizations, is besides the point in this example becuase it has already been considered in Torro Rosso's gearbox. The thing will simply fit, you can't deny that.

Torro Rosso's chassis shares a common interface with the Ferrari F150. Think about that for a while. The Ferrari is not unique, a pull rod gearbox can fit their car at the engine interface as proven by Torro Rosso.

[RacingManiac]

http://www.amazon.com/Advance-Adapters- ... B000FQ07PM

Such thing exists in F1 too...just because the engine is the same doesn't the rest has to be. Unless you are Sauber or Lotus or someone who buy an entire rear end from another team, you will be making your own gearbox and all the auxiliaries to suit the engine to your car, not the other way around. The way STR packages their hydraulic, sump, and other hardware does not have to be the same as Ferrari even if they use the same engine. The gearbox internal layout doesn't have to be the same even if the input shaft came in the the same angle. Go to a Formula SAE event, look at how many teams runs the EXACT same engine, same differential and how all of the packages differently.

[ringo]

I am not discussing the gear box and it's packaging. I know that they are different; that's the point i'm putting across.
I am discussing whether a Torro Rosso gear box will fit the back of the Ferrari F150. The answer is yes it will fit.

And before I forget:
http://www.autosport.com/news/report.php/id/89239

Williams technical director Sam Michael has said that the team has pushed so hard in this area because of the ban on double diffusers this year, which has put an emphasis back on getting as much performance as possible from the rear wing.

"The main target was to clear all the area to the rear lower wing because it is a performance differentiator now," he said during Valencia testing.

"You've got to have the underside of the rear lower wing completely free, so we took the decision to lift the top wishbone and the track rod and go to a Z-bone layout – which was commonly used in the early 90's – to get that all above the underside.

"It means that all the weight is in line with the trailing edge of the legality box, so you are nowhere near the underside of the rear lower wing, and it's completely free airflow."

Michael also believes that the push to get the airflow tidied up at the rear of the car meant that a pull-rod suspension configuration was a must.

"The pull rod was a no-brainer," he said. "It doesn't matter what you do with a pushrod, even if it is swept forwards or backwards, you've got a load going into the rear lower wing, whereas a pull rod is completely out of the rear lower wing. That was an easy decision.

let's wait for the responses. "what i meant to say was..."
"Sam Micheal's no engineer, he never considered everything like Ferrari"
"It can't be a no brainer.. It can't!!!"

People just put this thing on a pedastal. Engineering is engineering, F1's not mount olympus. We can think and rationalize just the same.

Ferrari better go borrow a Torro Rosso gearbox.

[RacingManiac]

People just put this thing on a pedastal. Engineering is engineering, F1's not mount olympus. We can think and rationalize just the same.

Just like how pullrod is the one true solution to all of the team's design package right? Since everyone uses it, it must be right? Because engineering is all about copying the next guy's solution....

To Sam and what he was working with, be it as his engine, gearbox, rear wing, suspension system, and whatever, pullrod for him is a no brainer. And that might be true to MGP, RBR, Lotus or whoever. That still doesn't mean it has to be true for Ferrari. Sure like he said, the pushrod will put an input in the the rear wing flow regime. How does he know, if Ferrari or whoever decided that using pushrod is ok, that they didn't design that into it? How does he know that by keeping one type of packaging, if Ferrari did not gain in other area, maybe chassis stiffness, maybe suspension compliance, maybe polar moment of inertia.

If finding a no brainer, naturally optimum solution is so easy, everyone can design something and have it be perfect. Maybe then I don't have to spend hours trying to design a shock that has 350mm+ of stroke and I am still looking for dead length reduction of millimeters.....

[Mysticf1]

hahah yeh it was a no brainer 2years after Redbull implemented pull rod and the whole slim rear end to maximize rear wing efficiency.

[ringo]

Stop the hyperbole about packaging please, a pull rod fits in a void in the gearbox. It's not competing for space with anything.

Ferrari aren't trafficking refugees under the engine cover.

[Jersey Tom]

Stop the hyperbole about packaging please

As has been said... when you design a vehicle (or anything), you'll gain an appreciation for how challenging good packaging is. IMO, a lot of the vehicle dynamics work in picking kinematic rates, roll center heights, relative amounts of spring and bar, camber, alignment... is easy compared to the mechanical design of packaging it all.

Sam M can say what he wants... hasn't exactly had a great run in the past few years

[raymondu999]

Saw this from the F150 thread, imightbewrong posted this: http://i.imgur.com/6SIHi.png

It's an Animated PNG, which only certain browsers (such as Firefox) support. If not you'll just see a static image of an F150. You really see the difference in the tail end packaging

All credits go to imightbewrong. Maybe someone could do this for the Red Bull and the Williams? Those seem to have the packaging most extreme.

[PlatinumZealot]

Sam Michael my boy. =D> He must be reading this forum!

[RacingManiac]

Stop the hyperbole about packaging please.

I wish designing everything is just about ticking boxes in a form, since thats about the only way the packaging is only a hyperbole of designing anything...seems like you are a much better engineer and system integrator than me, so I am sure things comes much easier for you and never having to worry about such trivial matter...

[hankalis]

I am not discussing the gear box and it's packaging. I know that they are different; that's the point i'm putting across.
I am discussing whether a Torro Rosso gear box will fit the back of the Ferrari F150. The answer is yes it will fit.

let's wait for the responses. "what i meant to say was..."
"Sam Micheal's no engineer, he never considered everything like Ferrari"
"It can't be a no brainer.. It can't!!!"

People just put this thing on a pedastal. Engineering is engineering, F1's not mount olympus. We can think and rationalize just the same.

Ferrari better go borrow a Torro Rosso gearbox.

here is what that same Sam Micheal said today regarding the push vs pull

Q&A WITH SAM MICHAEL, TECHNICAL DIRECTOR
WEDNESDAY 02 FEBRUARY, 2011


Q: There has been a lot of interest in the rear end of the FW33, what is the philosophy behind the new design?
SM: The main changes revolve around the gearbox casing and location of the differential. Like most other teams, the target is to have as much clear flow to the rear wing assembly as possible. It is clear that we have lifted the top wishbone and track rod, and opted for a Z-bone layout, which was commonly used in the early 1990s. Using a pull-rod was an easy decision for our particular design, as it means there’s less blockage to the rear. This is the smallest and lowest gearbox we have ever made, with the most extreme driveshaft design. We made all these major decisions in March 2010 and have subsequently worked hard to ensure reliability through plenty of mileage on the dyno.


http://www.attwilliams.com/downloads/pd ... ichael.pdf

without rehashing one more time the arguments for pull-rod superiority, I've got simple question: all the arguments, you mentioned, in favor of pull-rod must have been true for the past 2, 3, 4, 5 years ago. the question is then how comes pull-rod was not a no brainer over all that period?

[myurr]

Saw this from the F150 thread, imightbewrong posted this: http://i.imgur.com/6SIHi.png

It's an Animated PNG, which only certain browsers (such as Firefox) support. If not you'll just see a static image of an F150. You really see the difference in the tail end packaging

All credits go to imightbewrong. Maybe someone could do this for the Red Bull and the Williams? Those seem to have the packaging most extreme.

Whilst the Red Bull certainly has better packaging than the Ferrari that image isn't 100% fair as it also shows that the Red Bull is the longer car by a few inches which makes it easier to produce that nice tight rear.

[ringo]

Keep in mind Ferrari is historically stubborn:

"the horses pull the car rather than push it".

"Aerodynamics are for people who can't build engines."

Don't be surprised if they come to their senses later. Though i must admit their new car is still very strong and it works well.

[ringo]

without rehashing one more time the arguments for pull-rod superiority, I've got simple question: all the arguments, you mentioned, in favor of pull-rod must have been true for the past 2, 3, 4, 5 years ago. the question is then how comes pull-rod was not a no brainer over all that period?

Why weren't exhaust blown diffusers used?
Complacency and underestimation i guess.