Inexpensive front sway bar upgrade

I'm interested in rears as well. I'm in So Cal so pick up is good

 

ElMore Toyota, Ryan Hone, Parts manager, (714) 894-3322. Hit him up for the parts hit me up for the install

 

Thanks for all the info in this thread...
I also upgraded the my 2012 Prius Plugin with the RAV4 front bar and bushings.
Last week I ordered by the bar and bushings by part numbers found in this thread: 48811-0R010, 48815-0R010 and 48815-0R020. Today, unbolted the driver's side control arm from the ball joint. Since I don't have access to a lift, I found it easier to unbolt the central bolt on the control arm to give additional play to get the sway bar out.

If you decide to take this on, make sure you have the appropriate tools. A floor jack, jack stands for the frame rails, wrenches, six point sockets, torque wrenches, ... For additional safety, I used the jack stands and floor jack to support the vehicle.

Here's the recommended torque specifications for the bolts on reassembly, added a few extra:
64 ft-lb - Front suspension brace right & left (4 bolts each) (aka sway bar bushings bracket)
66 ft-lb - Front lower ball joint(three: 1 bolt & 2 nuts
55 ft-lb - Front sway bar link assembly (1 nut each )(If the end joint turns use a 6mm allen wrench, I didn't need to)
172 ft-lb - Central control arm bolt (1 bolt)
158 ft-lb - Rear control arm bolt/nut (1 bolt/nut)
76 ft-lb - Front Wheels (5 bolts each)

Here's two pics of the sway bars; first my original(24.2mm) and the RAV4(25.5mm).





I also weighed the bars with the bushings and they were 6.94 lbs vs 9.04 lbs.
The RAV4 bar fits perfectly. Since I had the lower plastic panels removed, I changed my engine oil/filter, rotated the tires and adjusted the air pressure. I've only driven around the block so far; all is good and it feels firmer

 

This is extremely interesting. Does anybody have any experience with a setup that includes both the TRD/Plus RASB + this RAV4 Sport FASB?

 

I am wondering it the stock bars mentioned are hollow and if the aftermarket bars are solid? The answer to this question is what would determine which one I would "upgrade" to.

 

The bars are not hollow, the additional stiffness is from the larger diameter of the bar.

SCH-I535

 

Prius sway bar hollow?

I measured the linear length of the original bar approx. 135cm.
I also re-weighed the sway bar without the bushings: 6.46lb
The diameter of the bar, as mentioned earlier, 24.16mm = 2.416cm

If we calculate the volume of a cylinder = length x Pi x radius**2
which is 135cm x 3.1459 x (2.416/2)**2 = 619.7 cm3

The density of iron is 7.86g/cm3

mass = volume * density = 619.7 cm3 x 7.86 g/cm3 = 4871 grams = 10.7 lbs

Since the bar is only 6.46 lbs, it must be hollow.

Please note, my measurement could be off a bit, but not by much.
There can be a slight difference since the sway bar is most likely an alloy
not 100% iron(Fe), the bar was painted, so the diameter includes the paint...
But even so, I don't think it will be off by 4 lbs...so it must be hollow.

If I do a similar calculations with the RAV4 bar...using some values above, since the
bar is installed on my car...

linear length: 135cm
weight of bushings = 6.94 - 6.46 lbs = 0.48 lbs
weight of RAV4 bar = 9.04 - 0.48 = 8.56 lbs
diameter of bar = 25.53 mm = 2.553 cm

volume = 135cm x 3.1459 x (2.553/2)**2 = 692 cm3

mass = 692 cm3 x 7.86 g/cm3 = 5439 grams = 11.9 lbs

Since the bar is 8.56 lbs it's appears to be hollow...

At least the ratios of the weight from Hollow/Solid seems to be greater for the RAV4 bar...

6.46/10.7 vs 8.56/11.9 (RAV4)

0.60 vs 0.72 (RAV4)

I drove my first commute day with the RAV4 bar, it seems to corner flatter and feels sturdy.

Factory Mustang and Corvette front sway bars are hollow! Personally I don't mind.
With the factory Toyota quality it's fine for me. I'll see how the car handles; if I feel the
need for a rear bar... I'll check PriusChat first... Thanks All!

 

Just did this mod. This RAV4 FASB went into an otherwise-stock Model Two with an existing TRD/Plus RASB, as mentioned here:

Thoughts on TRD Rear Sway bar.... | PriusChat

Right now there is a bit of additional harshness relative to prior, but coming from a similar experience with the TRD/Plus RASB, it should go away with a bit of time, perhaps a week. As of right now the roll resistance between the two ends feels more balanced, whereas with just the TRD/Plus RASB the front outside corner seemed a tad too eager to drop when I trail-brake into an entry. I will feedback with more later.

It needs to be mentioned that the FASB swap is considerably more involved than the RASB installation. I used both the factory manual and consulted this thread by Dark_matter_doesn't:

Tanabe Front Sway Bar Install | PriusChat

To anybody thinking of doing this themselves, it is certainly doable without special tools. However, my experience is that in addition to a 1/2"-drive torque wrench that'll go up to 172ft lbs, you really want a 1/2"-drive breaker bar and a set (3", 6", 10") of 1/2"-drive extensions to go behind that 22mm socket. That low arm front bolt is hell-and-a-half even with the right tools.

Notable things:

1. The RAV4 FASB is a dead-ringer for the stock bar, except that it is slightly thicker.

2. The front suspension design of the MC platform is impressively compact... but this is also the reason why it's impossible to work on the FASB without having to remove a suspension arm.

3. So you will necessarily need to remove one front suspension arm. Resign yourself to that. But you also need to remove only one wheel.

4. Dark_matter_doesn't recommends merely loosening the low arm rear bolt (the one with the nut on the other side) without removing it, and then using it a pivot to swing the arm back. That is a good idea. I failed to follow it and it took a bit more effort to get the bolt back through the arm, not that it was a lot more work. But his method is the better, more efficient way to do it.

5. Unless you have a lift or can get the car up high, you will have much more leverage to undo/torque-down that 172 ft lbs required for the low arm bolts from the wheelwell side of the car, not so much under it.

6. Factory manual tells you "stabilize the suspension" before you torque down the low arm pivot bolts. What they mean is to not torque it down in the on-a-lift/jackstand, suspension-full-extension state, but in its "normal" settled, sitting-on-its-wheels state. Ramps might make this easier to do. I did not do this, but instead was able to achieve ~100 ft lbs of torque in its sitting-on-its-wheels state, jacked up the car again, took the wheel off again, and brought that pesky bolt to the final torque 172 ft lbs.

 

One-day update. Geez, that RAV4 FASB softened up fast... which suggests that the break-in period is a function of the bushings (not surprising), as these OEM injection-molded ones are considerably more complex (and assumed to be better-fitted out-of-the-box) than the machined-urethane ones of the TRD/Plus RASB.

The feeling of roll-resistance is now much more balanced between front and rear, perhaps a bit more front-dominant, like the stock setup (i.e. the body attitude tends to reflect what the front is doing). Overall roll resistance has not increased dramatically past what was achieved with the TRD/Plus RASB, probably more of a testament to the effectiveness of that first mod than any statement to this one. Somebody who has/will do the mod in the opposite sequence can probably chime in someday to confirm/refute this.

The current setup now feels very OEM (except without excessive roll), and I am pleased. I have not had a chance to form any opinions on understeer/neutral/oversteer, so that'll be for later.

One thing I have noticed is that the now-confidence-inspiring roll characteristics has revealed how soft the springing is. In the midst of a hard (i.e. weight-transferred) U-turn on a level street, I managed to scrape an outside front wheel air strake on the asphalt. Wow.

I guess this tune was necessary given Toyota's reputation for inoffensive cars, and the harshness that LRR tires inherently introduce, esp. to a lighter car. For me that just means that I should drive the Prius with less brake-aggression.

 

I'm thinking of doing this, fits into my suspension under $500 goal.
Front sway bar $135.00 (bar, bushings and shipping)
Springs $100.00 (buying from member)
Total so far $235.00

 

Sorry to drag an old thread back up, but for anyone needing the information...I can confirm the stock front sway bar is hollow. (I just cut one open to see).