I think Im going with new shocks...the way I read on these sway bars is that it will increase my potential to "power slide" and lose the rear end.

Yes steering would be improved because you transfer the load from the rear inside tire to the front steering, but on a tight turn in the rain you may end up whipping that back end around.

Please dont take it the wrong way but I dont think they are a good idea now that Ive seen them explained on a race car site.

 

Hi guys,
Sorry I've been away from the board for so long, but I've had some issues that required my presence away from the factory.

As I promised earlier, we have been working on a "fix" to be compatable with the newer FX4s. Our 7621 kit is going to be revised by changing some bracketry and spacers, and updating the crummy instruction sheet.

The design part is done, as is some test fitting. I'm sending out a beta version to one of the board members here for some independent evaluation. Between that and completing our paperwork procedures, the new version should be available within two weeks.

It is important to note that although the 7621 kit is pretty universal for all post '97 F150s, the '02 and '03 FX4s are going to require a kit manufactured AFTER 09/15/03. During the transition period, I will be happy to assist you in getting the correct kit from your supplier, and should you end up with the older version we will be happy to ship you an upgrade kit at no charge.

Just as an update, we have done some initial work with the new 2004 F150, and sadly determined that it is going to require completely new anti-sway bar designs for the front and rear. (Nothing is ever easy...) Give us about 8 to 12 weeks. I like the new truck- I may need to upgrade...

Please feel free to contact me with any questions, either through this thread or by email.

Thanks,
Jim Mitchell
Vice President
Hellwig Products Company, Inc.
jmitchell@hellwigproducts.com

 

Welcome Jim.

If you have read above, I am afraid to install a sway bar on the rear to eliminate sway in my truck for the potential of sliding out the rear. Should I replace the stock front bar with a stiffer one, and a new one in the back (none there now) for improved highway driving and to keep the rear wheels with "stock" traction (but reduce roll)?

Thanks

 

Could you please provide me with the source of your information? I believe that perhaps something has been taken out of context. There is a kind of "benefit threshold" associated with the upgrading or addition of an anti-sway bar. There is a definite increase in control and stability unless you overdo it. (Too large a diameter for the bar, arms too short, etc.) Too my knowledge there is no reputable aftermarket anti-sway bar manufacturer out there that will proudce such a part. A lot of our research and development involves finding the right combination of factors to get to the "sweet-spot" between under-steer and over-steer.

Thanks,
jim

 

Looks like I'm getting a little out of sync with you on the posts.

If you want, I can put you in touch with our engineer for a bunch of theorys and formulas, but let's talk about the real world for a bit. I can assure you that if you put anybody's rear bar on your truck (ours is the best of course... ) you will notice a significant difference in handling without any negative factors. Upgrading the front will make a difference also, but it will not be as immediately apparent. I can back that up for you with numbers from my engineering department, but probably the best evidence of this is the opinion of the folks who have already done the upgrading. We have sold hundreds of thousands of anti-sway bars over the years, and we hardly ever get any feedback that complains about performance. (Of course, you can't please everybody, but we seem to come close.) I love these types of forums because you can get real feedback on stuff by the toughest critics. So anyways, remember that I'm biased, but I'll be happy to provide you with any information that I can.
-jim

 

Jim,

Thanks very much for the updated information on the 03 FX4 rear swaybar. I will definitely wait a bit to order one, but I will definitely be getting one!

I may need your assistance in sourcing and getting the correct kit for my truck. I also plan on upgrading my shocks and would like to do so before this winter.

Thanks again and your right, this forum is great!

Regards,

Jim

 

Instead of worrying about what MIGHT happen with a race car, why not listen to some of the experiences of the forum members here?

Do a search on "Sway" and read a little. Trucks handle way different than cars and comparing info on the two is slightly relevant at best.

If you take a look at how the shocks are configured (staggered) you could probably envision how they could not possibly reduce body roll anywhere nearly as effectively as a sway bar.

I've had mine for quite a while now, and spent some serious high speed time in the mountains over the summer and I can tell you that the shocks alone do not account for the cornering capability I have now.

A member here (Big Deal) is the reason I bought the sway bar for my truck. His straight-forward reporting of how much better his SuperCrew behaved while driving was a deciding factor in my purchase.

Anyway, good luck with your decision, whatever it may be...

 

I've got Bilstein shocks, a Hellwig rear bar and a Quickor front bar on a 4x4. The front bar made the biggest improvement, really tightened things up, flat cornering now. I had the infamous thump or pop on inclined right turns after the Hellwig bar went on. Robert from Hellwig worked with me changing bar mounting locations, end links, tightened bed and body mounts, removed skid plate, nothing improved. Also had to clearance the gas tank skid plate mount to eliminate interference with the left end link bracket. This was a couple of years ago and they denied knowledge of the problems with the skid plate when I reported it. The reason I bought the Hellwig rear bar was that they were to release a front bar for the 4x4 and I wanted a matched set. After waiting for months I was told the front bar would not be produced. The only front bar for 4x4 I have found is the Quickor, it is 1 3/8" diameter 4140 chromemoly. The Hellwig was a good value for the money, but I would have never bought it knowing a front bar was unavailable and the noise issue. BTW, after installing the Quickor front bar the pop from the rear bar disappeared! Most have tightened the chassis up to the point before where the flex was accruing. I am really happy with the total package now of shocks and front and rear bars. It rides a little rougher, but really corners flat and instills confidence.

 

How does shocks staggered vs. not staggered effect body roll?

I have no trouble envisioning how shocks with much greater slow speed damping will reduce body roll - could you please explain why am I wrong?

BTW, you put your rear anti-sway bar on first and noticed a big reduction in body roll. I put shocks on all 4 corners first and also noticed a big reduction in body roll. Maybe, just maybe, shocks and anti-sway bars can each be effective in reducing body roll.

Our stock shocks are a joke. Flatter cornering is just one of the benefits of throwing the stockers in the garbage.

Sean - IMO a rear bar is a nice addition to a street driven F150, but you will get more bang for your buck with 4 high quality shocks. And as Ghz indicated, a larger front bar should not be overlooked if flat cornering is the goal. Afterall, the vast majority of the weight is over the front wheels (and most of us only corner aggressively when there is nothing in the back).

 

DirtBikeDave -

If you read my post carefully, you will see that I simply stated that the shocks could not reduce body roll as effectively as a rear sway bar. I did not say they wouldn't help at all.

If you crawl under your truck and look at the angles the shocks are mounted at, you can see that, unless the axle is moving a significant distance (over a bump for instance), the shocks do not get compressed very much at all.

Have 2 or 3 of your friends get to one side of your truck and bounce together to compress one side of the rear. Watch how little the shocks are compressed while this is happening. (Note that this type of compression is greatly exaggerated when compared to the shock compression experienced while cornering)

Also, shocks do not prevent compression, they simply slow it. If you were to take a long, tight sweeping turn, the shock will eventually (within a second) compress and provide no body roll resistance at all.

Look again at the distance between the driver side shock body mount point and the passenger side shock body mount point for the shocks. Do you think the torsional stresses are the same, given the huge difference in distances involved ?

The stagger of the shocks is more to help control axle-wrap than anything else.

The primary purpose of a shock absorber is to dampen spring rebound and to help the tire stay in contact with the road, especially over rough or uneven pavement.

The primary purpose of a swaybar is to reduce body roll.

Go to a parking lot and take a few pics of your truck in slalom mode.

Install a rear sway bar and do it again.

I bet you will be surprised at the difference in body roll.

 

It is true the shocks have less vertical movement than the wheels. So what does that have to do with anything? Try having your friends jump up and down on the truck with good shocks (i.e lots of compression and rebound damping) versus weak shocks or no shocks. With the good shocks the suspension will compress and extend less each time they bounce. You seem to disagree. If the friends just stand still in the bed, I do agree that the weight is carried by the springs and the bed will eventually settle to the same point whether the truck has good or bad shocks.

Up until the shock is bottomed out, slowing compression is effecitvely the same thing as preventing some of it. Your statement proves that in any corner that the outside shock does not immediately bottom out, some body roll is prevented by shocks with more compression damping. BTW, it isn't just the outside shock that comes into play during a corner. The inside shock needs to extend for the body to roll. A superior shock with more rebound damping will also reduce body roll up to the point it is fully extended.



The shock is there to fight up and down movement. If by torsional stress you are referreing to the side to side movement and forces on the suspension and body, the shocks (wherever they are located) are an insignificant part of the equation. As long at the right and left shocks react the same to up and down motions, things should work fine.

Exactly. So why even bother to introduce it into this discussion like staggered shocks effect body roll?

Try the same experiment without shocks and I bet you will be even more surprised.

 

No, I don't seem to disagree. You are proving why shocks exist - to help with bumps, not cornering. When you corner, there is a constant pressure exerted on the springs and shocks. The shocks compress as far as the springs compress. They absolutely are not supposed to help support the weight of the vehicle. They are there to dampen spring / axle movement. When you hit a bump, there is a rapid up /down movement of the spring /axle assembly and the shock dampens the rebound effect of the spring.

Nope, what I said does not prove anything of the sort. A shock does not prevent body roll, it only may slow it somewhat. A swaybar PREVENTS body roll, of course up to a limit.

No, I was referring to the fact that the vehicle is not a static item, with a perfectly rigid structure. If it were, what you say would be more plausible. But, because the front wheels are compressing / extending at the same time the rear end is angling AND the frame itself is flexing / twisting, the torsional stresses on the chassis are a significant portion of the equation. Have you not ever looked closely at a car that is designed to corner? They rely heavily on:

1. Super stiff chassis and spaceframe

2. Properly designed sway bars

3. The lowest possible un-sprung weight

4. Quality shock absorbers

Notice that shocks are last on the list. That is because they are nowhere near as important as the other items in the list.

No, that would not be an accurate comparison. The springs and shocks were designed to work as a package. A realistic way to try and prove your point would be to do a test with factory shocks; then repeat the test with aftermarket shocks.

I'd bet you that the slalom sway difference between functional factory shocks and aftermarket shocks is less than the slalom sway difference between the truck with and without a rear sway bar.

 

Not sure why I am wasting my time on someone who thinks that shocks "help with bumps, not cornering".

The example of no shocks is to help illustrate a point - that shocks do effect body roll and cornering. The opposite extreme of no shocks would be to replace the shocks with rigid metal rods and go on the same slalom course. Even on a bump-free road, I think most people understand there will be a difference in body roll and cornering between these two situations.

If you can understand the above, it should not be so hard to understand that not all shocks are created equal in terms of cornering and reducing body roll. If you make a graph with a line connecting 'no shocks/lots of body roll' on one end, and 'rock hard shocks/virtually no body roll' on the other, you can understand that some shocks can be relatively closer to the 'no shock' point, and some are closer to rigid. (BTW. the above is a gross simplification re: soft vs. rigid, as a quality shock can differentiate between rapid, sharp movements like potholes and relatively gradual shock shaft movements like cornering. It can be soft on one and firm on the other).

Example 1
Let's say with good tires on a grippy road that is as smooth as a billiard table, Shock A can be compressed fully to 4" in 1 second under maximum cornering forces.

Shock B will fully compress 4" in 4 seconds under the same forces.

In a corner that lasts 1 second, Shock A compressed 4", while Shock B compressed 1". That's called less body roll for Shock B.

Example 2
Using the same shocks, lets say we stay in the corner for 4 seconds. Shock A compressed 4" in the first second, and it stayed compressed for 3 seconds. For the entire 4 seconds, Shock A had an average compression of 3.5".

Shock B also eventually compressed 4", but it was only fully compressed for an instant, and it had an average compression of 2" during the 4 second corner. Even though both shocks eventually compressed the same, the vehicle spent a whole lot less time at full sway with Shock B.

Both examples demonstrate how slowing body roll (which you admitted shocks can do) is the same thing as preventing some of it (which you say shocks cannot do).


BTW, I well understand that shocks do not support the weight of the vehicle.

Also, I have added rear anti-sway bars to other vehicles besides my truck, so I know a little about the topic. IMO, on a road going truck that has most of its weight on the front, quality shocks at all 4 corners will do more for handling than will adding a rear anti-sway bar. Better tires are probably more important still, but that's a different topic.

 

Jaguar, this is just my opinion, but then that's what you asked for right?

I say for the biggest anti-sway/anti-roll effect, get a rear bar. I would then later add a new front bar, followed by new shocks... maybe not in that order on the latter two, but I would start with the rear bar.

I recently added Addco front and rear anti-sway bars, but it's been to wet out, and I've been too busy to really take it out, and test it, but from what driving I have done with them I can tell you it's a big difference... and well worth it...

I plan on getting new shocks before too long, and so I will keep track of what people have to say here. I've been thinking Edelbrock, but don't really know... would like to hear what anyone hear has to say about the Edelbrocks... I'll have to search around later...

As far as recommending the sway bar. The Addco front bar was a breeze to install and seems worth it. However, certain models of trucks have a different shock mount, so the Addco rear bar mounting kit will not work. They are supposed to be working on a fix for this, but I went ahead, and made my own fix... You can see pix in my gallery of both bars. Although, due to the rain I don't think I have any real good pix of the rear...

good luck whatever you do...

 

I like the example of replacing the shocks with steel rods, that would be correct as you approach the limit of stiffeness in a good shock.

But I also agree that shocks are only meant to dampen the spring rate.

I present this...if good shocks do more than have a quick return, how do you install a good pair of shocks? Are they hard to compress by hand? Better, are they any harder to compress by hand then a cheap pair of shocks?