So I have been doing some research on sway bars for my tundra and have heard several people claim "sway bars are just a bandaid for poor spring rates". Wondering what truth (if any) there is to this statement.
I have added 2.5" fox shocks and springs that come with the TRD pro and plan to have some custom rear springs made by Alcan once I have all the weight I will carry in the back. So my spring rates should be "right". In the process of installing my suspension the front sway bar mount nuts welded to the inside of the frame snapped off, so this leaves me the immediate options of 1) Removing the front sway bar and 2) Tack welding the bolts to the frame and grinding them off later for a proper fix....either fix will involve a grinder. Any input would be appreciated.
dps214
HalfDork
4/8/21 7:33 p.m.
On a purpose built race car on a smooth race track...some truth. On a truck...absolutely none.
In reply to dps214 :
I'm assuming the difference being the wide range of conditions a truck would face versus the relatively controlled conditions of a track?
Spring rates set the ride and pitch frequency. Also, you want the rear ride frequency to be 10-20% higher than the front to avoid getting lots of pitch motion from every bump.
As a result of those springs, you now have a roll rate and a lateral load transfer distribution. These are then adjusted to desired values with anti roll bars, aka sway bars.
There is lots of more or less technical stuff to read. A sample:
http://downloads.optimumg.com/Technical_Papers/Springs%26Dampers_Tech_Tip_1.pdf
On a truck, if you off road at all, you would want fairly soft anti roll bars and springs to allow lots of twist between the front and rear axle - avoids lifting wheels, which is bad for traction. Used to be the open section frames did a lot of the twisting (international scout - holy crap to they twist!), but modern truck frames are fully boxed and thus stiff in torsion, forcing the suspension to do more work. Is the Tundra still an open section frame? It had an open section mid & rear 5 or 10 years ago still ...
In reply to burgermeister :
The frame is c or boxed in different sections....obviously were I need to get to the nuts the frame is boxed! I think I have a solid grasp of the cons of sway bars off-road and plan to take the end links off for longer off road trips.
The truck only has a front sway bar from the factory, but I was planning on adding the TRD units front and back until I ran into this problem. Not really sure how to go about welding the nuts back to the inside of my boxes frame.
Why care about a Tundra's handling? It's a frickin truck. They aren't supposed to handle good. It's a compromise here. Want a truck that can off-road? Leave it as is. Want a truck that handles *slightly better* than stock, but still handles worse than your grandma's Buick? Waste some money on roll bars, or springs.
AT least in suspension design for motorsport, there is a philosophy of being all spring and little or no bar, and a philosophy of soft spring and lots of bar.
Herb Adams in "Chassis Engineering" suggests that running all spring and no bar requires so much spring rate that the car will handle poorly, and -still- not be able to control roll effectively. He suggests running springs that are only stiff enough to keep it off the bumpstops, and controling chassis roll with all bar.
I believe in determining spring rate based on a suspension frequency target, and do the rest will lots of sway bar.
However, you have a truck. I don't do four-wheeling. I have zero experience, but I have 100% opinion.....
Based on what I know about suspension, for a four-wheeler, I would run pretty much as soft and as long a spring as I can get away with to gain the most articulation (wheel travel). I would run probably the fattest sway bars I can get - but I would connect them with quick-release spring clips or lynch pins or something that I can quickly disconnect for wheeling, and reconnect for street.
A big, tall, soft, four wheeler with zero sway bars would be a nauseous ride on the street. And a tight lots-of-sway-bar truck would be useless on the trail.
You can't really have both, unless you just keep it stock, which is usually the best compromise.
I've never actually owned "stock" anything.
But that's just my opinion. You have to form your own.
The way I see it, WRC have acres of suspension travel, bizarre suspension damping strategies, and stabilizer bars at both ends.
Formula 1 have millimeters of suspension travel, using mostly the tires' deflection for what road accomodation is necessary on ultragroomed tracks, heavy downforce, millions of dollars spent on suspension tuning... and they have stabilizer bars (or, rather, the pushrod suspension equivalent)
NASCAR seem to use stabilizer bars exclusively vs. springs.
I'm seeing a pattern.
So it seems my original plan of running TRD sways front and back and then removing the end links when needed is the way to go. The truck is my daily so having a truck that can tow and handle safely is important. I will go ahead and tack the stock front sway in place for now to eliminate the clunk until I upgrade to the TRD units.
Any advice on how to reattach the nuts to inside my frame rails?
In reply to 80sFast :
Some suspension articles from our archives might help, too.
80sFast said:
Any advice on how to reattach the nuts to inside my frame rails?
Make or buy something similar to these? Drill a couple holes with a step bit to enlarge the original anti-sway bar mount holes in the frame and weld in place. Another option is to pretend you're playing the old game of "Operation" and hold something inside the frame you can screw into. https://lab-14.myshopify.com/products/75-81-late-2nd-gen-f-body-front-sway-bar-mounts
