uniseriate

I was browsing through Google's new patent search engine and found patent #7328909 submitted by Honda Motor Co.

Regardless if you think that strut bars / tower bars make a measurable difference in handling or not, I thought that it was interesting that Honda was able to get a patent on something that has been around in one form or another since the 1960s.

For example, here is the engine bay of a 1967 Ford Mustang with a factory equipped strut bar:



Here's the link for all the patents submitted by Honda. It is interesting to comb through if you have some time to spend.

apekd

actually its a brace. Trust me on this, i get to work on your average pos ford each day. when you look up the parts for this "strut bar" you get nothing, when you look up strut BRACE you get it, they were used like a strut bar and in fact they are using the same principles, but missing the 3rd link in that triangle only makes the left to right roll more noticable.

johnlear

A strut is a brace is a strut is a brace...

Trust me..

That makes zero sense.

The Lobster

^ its not triangulated and he is saying that design is poor since it still lets the towers flex more then what a straight bar would.

mrdeadman

Does that ford brace even do anything?

Targa250R

I've read this post like 5 times and still can't figure out what you're talking about.

How? And it is triangulated when you look at the underlying structure of the car.

They couldn't have added an additional straight bar across the top even if they wanted to, because the carb and air filter are in the way and there isn't enough hood clearance.

Trust me, just about any sort of additional bracing is an improvement in a floppy 1st-gen Mustang chassis.

PatrickGSR94

iTrader: (1)

Did those 1st gen Mustangs actually have front struts? Most likely it's a shock tower brace, just like every one used on 80's and 90's Hondas.

uniseriate

Good call. I thought Mustangs always had Macpherson struts but turns out that they weren't introduced until the Fox body generation in 1979.

As an aside, shouldn't the forces on the front towers on a unibody car not differ significantly between a shock and strut based car, assuming all other things equal? I understand that a strut will introduce vertical forces that would otherwise be handled by an upper control arm, but isn't the end result still tension and compression on the tower just at different attachment points?

TunerN00b

I think something to keep in mind is not the structure of the suspension, but rather the structure of the unibody/frame.

It doesn't matter how much force is applied where, if the factory part is sufficiently stiff against bending in that direction. Reinforce where its weak. Reinforcing a strong section does nothing.

For example, what if the structure inside that shock tower on the Mustang is sufficiently reinforced to prevent bending inward, but is susceptible to bending aft (towards the cabin)? In such a case, that tie to the firewall might be significantly more beneficial than a straight bar across the engine bay.

johnlear

More or less, yes.

With a Honda (where the upper wishbone is located near the top of the tower), the spring / damper forces will be reacted into the tower in an identical manner as for a similar chassis fitted with Mac struts. With a high upper wishbone, the locative forces seen in the wishbone and at the wishbone chassis mounts will be relatively low.

With a Mac strut, the top of the strut rod will introduce locative loads into the towers in a manner that's somewhat similar (but not exactly the same) as a high mounted upper wishbone. The locative forces seen at the top of the Mac strut and tower will be of a similar order of strength to those seen in the upper wishbone (as above).

With a Mustang (I assume with a more or less generic older Ford front wishbone suspension as you might also find similar on an older Australian Falcon), where the upper wishbone isn't very high relative to the lower wishbone, then the forces in the upper wishbone and chassis mounts (upper wishbones attached to the same substantial crossmember to which the lower wishbones are attached?) will be similar but greater than seen in a high mounted wishbone. Spring and damper forces will be reacted into the chassis towers in more or less the same manner as for a Mac strut or high upper wishbone suspension.

The brace on that Mustang looks very flimsy being only pressed metal, where it should be at least significantly rigid tubing. Better than nothing, but if it were my car I'd be changing the filtration arrangements in order that I could fit a proper beam across the engine bay (yes I know, but then it wouldn't be original...).

Some older Volvos have a somewhat similar pair of tower braces.