How far back do I need to box the frame? I've done each side like this, is this far enough or should I do a little more?

 

I boxed back a little further, just past that big hole in the side of the frame rail. to where the chassis has widened out.

sam

 

OK Thanks. I guess I'll go back another 6" or so.

 

Don't forget to add the closer pieces at the Tower/Frame junction.

Volare's had problems with the K member tweaking at the towers and
causing alignment problems. If you search on my handle - I published an article I found on the subject.

I think my P.O. boxed back to the firewall.

There is an interesting video of the volare install - shot in the 80's so watch out for the hair -do's!!. If you are interested I will look it out for you.

One thing I did find out - but its too late for you - the time to replace all the bushings is while the clip is still in a heap on the floor and not installed, so you don't have to crawl around underneath.

Good luck

Chris

 

yes, some say all the way back to the firewall..

I did weld in a filler for the space between the A arm mount and the chassis.

I also got to crawl around to replace the bushings... where were you when I needed that info about 8yrs ago?!

sam

 

Mine is also boxed from the front member back to 4" in front of the cab mount. More stability is never a bad thing. And all my suspensions parts are in a pile on my garage floor waiting for new bushings to arrive. It's completely torn apart to bare frame right now. Now is the time.

 

well, if you are going to clean/powder coat the arms.. NOW is the time, before you put new bushings on.. you have to burn the tops ones out.. probably messes up the powder coat..

sam

 

Going to pick up a sand blasting cabinet in about 30 minutes actually. lol Everything is getting cleaned up, blasted, powder coated and then reassembled.

 

I was already planning to put the filler piece between the frame and towers. I completely rebuilt it before the install so that's not a problem. I appreciate everyones input.

 

I guess that after 30 years of engineering I look at these situations a little differently. The first question I ask is; where is the force being applied on any given point in this structure? I see a structural member (the Volare crossmember) that is made to be independent, that is, it requires no other support to function as a structural member that supports the complete front suspension and steering. That said, what are the forces on the frame? The frame sits on the Volare IFS and attaches at two "points" (actually the load is distributed across a distance on the frame rail), on one side on each frame rail. The weight of the frame exerts a downward force on the IFS crossmember. My last question is left for the reader, what function does a boxing plate perform in this system?

Chris has a valid point about the upper a-arm/shock tower but I am still not convinced that boxing plates add anything but weight.

 

True, the Volare clip is a "self-supporting" system. However, if you take into account that the original setup had a much wider load distribution due to the length of the leaf springs, you would be putting more force in one location on the frame vs. the distribution from the 3' leafs. Granted you have more contact with the Volare then with the two shackles. But then again, the rear shackle was located much further back on the frame then the Volare clip location. Meaning the Volare causes a longer span between loading points. Also, many of the trucks that have taken the time to install an IFS are going with much larger, higher output engines. The original frame was not designed to withstand 300+ horsepower. You could really argue it back and forth all day long. The additional material does create a more stable frame. Not just weight. Just my $0.02. Not trying to be a jerk. Just stating another view point.

 

Pictures always help...in Fig.1 I have depicted an F100 frame and a rough approximation of the loads applied to it and the locations. This is very rough but it does demonstrate how a truck frame remains rigid across a very wide span...110 inches. Fig. 2 shows a segment of Fig. 1 where the Volare IFS and the front spring shackle forces on the frame are depicted. If one were to make the assumption that the removal of the springs and the addition of the Volare IFS created the need for reinforcement of the frame then you would have to ask yourself, how does the frame support the span between the wheels if it can't support the span from the Volare IFS to the rear shackle? In reality, the addition of the Volare crossmember in and of itself adds considerable rigidity to the frame over the span in which it is welded.

To answer the original question regarding how long and where to box the frame, one must first answer the question of where is the frame so weak that it needs to be reinforced. This discussion has nothing to do with HP.

 

You are correct. Horse power (I meant to say torque) was not brought up in this discussion. However, as a general rule of thumb it is something that needs to be taken into account. And I think a good possibility why so many professional builders box the frame in the first place. Yes, you are correct that on a case by case basis it is probably more often unnecessary. However, as a general rule it is not going to cause any harm to add additional support to the frame. Maybe a slight weight gain. Which is of no concern to the vast majority. Those who are concerned about weight need to get more into the engineering and structural aspects. Then again, those are the people with high hp/torque engine setups. For this discussion, you are more then likely right. It is unlikely boxing is necessary. However, I'm only tearing into my frame once. And I may want a big block bruiser down the road. So, I over build now and don't sweat it later...

Edit: Let me put it this way... So many well respected builders have recommended this for so many years that I have come to believe it is due to experiencing failures of some kind at some point in time. Yes, one of my favorite sayings is "Just because you've been doing it for 20 years doesn't mean that you've been doing it RIGHT for 20 years." lol I however have heard it from so many people in the profession of building these vehicles that I would have to see proof otherwise before I would go the other direction. You very well could be 100% right, but I don't have the means or ability to prove otherwise. So... I go with what the majority has deemed the "correct" way. Hope that makes sense.

 

so, like me, you are a lemming!..

Sam