Originally Posted by mustclime

Next topic.....swaybars suck.

Have you ever though about how a swaybar( anti-roll bar) works? What are they good for? Have you ever thought "since the factory put a 25mm hollow bar on the front of my car, wouldn't my car handle better with a 27mm solid bar"?

Well, for the longest time I thought of swaybars(SB) as spring helpers. I thought that when you went into a turn, the swaybar(SB) being attached to the lca and the body helped hold up the car through the turn....WRONG!!!!

Think about what happens when you go through a turn......
1) the driver turns the wheel, the tires turn and bite, the car starts tochange direction...
2) As the car starts to change direction, weight shifts to the outside tires, the outside springs are overloaded and start to compress.
3) as the springs compresm the lower control arm starts to angle up.....the (SB) being attached to both lca's and the body is forced up on the outside side......
this is the important part!!!!
what happens on the inside suspension of the car???
4) the (SB) being nothing more than a "U" shaped rod/tube pulls up the inside lca because it "wants" to be flat not twisted.
think about that for a second.
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.
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Now, if down force increases grip( like having huge wings on a F1 car), what does up force do to grip???? Well, It decreases grip.....:uhoh:
This is why some people think of (SB)'s as grip reducers. Why would car makers ever put such a stupid thing on a car, why not control body roll with spring rates......simple, who wants to dd a car that can run over an ant and have the driver feel every bone in its body crush.....OK, what should you do with this knowage? IMO, understand that big sways on the drive wheels are really dumb, Understand that you should use the non drive wheels to control body roll because they are doing the least work in a turn. These are the reasons you wait till you have your tires, springs and dampers before you mess with the sways. (SB)s are for fine tuning the suspension not setting it up.

Originally Posted by mustclime

The following is a look at how to "tune" the ep3/dc5 suspension from a design point of view. First I would like you to really look at the front suspnsion......




First, look at the top pic, that is looking at the stock suspension from the rear. You will notice the LCA is angled down from center of the car. The tie rod is angled up from the center of the car. The suspension design is greatly effected by ride hight . What does that mean? Well, look at the top pic again. As you lower the the suspension the LCA goes flat and then past one inch of drop it starts to angle up. This is very bad for the suspension when you look at side loads( cornering forces). If the LCA is angled up and the weight of the car pushing side ways while the tire is trying to stick to the road, this force will "tend" to push the LCA up more and cause the suspension to blow through its travel. If the LCA is flat or angled down, the cornering loads are directed down the LCA in to the sub frame.
Cliff notes: LCA angled up from the center of the car = you blow through your suspension travel and get lots of under steer. So do not lower the car more than one inch.

Next issue to look at with the top pic is camber......Camber is a term used to describe what angle the tire is set at with regard to the road. In stock form, camber is not adjustable and the stock suspension is set for about zero degrees camber. This is great for drag racing and making tires last for 60,000 miles but it sucks for generating grip in turns. Having a couple degrees of negative camber helps the outside tire to take a set and helps keep the tire tread on the road surface. There are 3 ways to get more camber in a ep3/dc5.
1) Camber plates, these angle in the top of the strut and as a result angle the tire.
2) Crash bolts, these mount where the strut and the bearing carrier connect. This allows you to angle in the bearing carrier and allows you to angle in the tire inward.
3) Type-r LCA, these are wider than stock and as a result angle the tire inward. WARNING! If you decide to use these, you should not use your stock axles and you will need type-r front sways because of the extra width of the LCA.
What is the best camber setting for the front suspension? It depends on what you are doing and what tires you are using. As a general rule I would say -1 to -1.5 degrees for dd and about -3 for the autoX guys.
Cliff notes: Negative camber good for cornering in the front suspension.

Now look at the lower pic, the first thing I want to to look at is the front bushing on the LCA. That bushing is there to change toe settings as the cornering loads increase. It adds toe in as the gee forces go up, this = increasing under steer! Anyone that is trying to get our cars to handle needs to replace this bushing asap. Both Mugen and Energy Suspension make kits for this.
Cliff notes: The front bushing in the LCA needs to be replaced to make our cars handle.

Now I want to address the Caster angle of our suspension in the front. If you look at bottom pic you will notice the strut is almost strait up and down. The stock caster angle is around 1.5 degrees.....this sucks for handling and strait line tracking. If Honda screwed up anything with our cars suspension, this is the biggest thing. It is also the hardest to fix but it can be fixed. K-Mac makes a Camber/Caster plate for this. The strut towner's can also be re-drilled to angle the strut back. For road racing there are bushings for the LCA that shift the LCA forward to angle the strut back.
Cliff notes Caster good but hard to get.

Now the rear suspension layout





OK, you should notice a couple of things with this layout.
1) It is a unequal length duel control arm design. This means that as the suspension goes through its travel the shorter UCA pulls the hub carrier inward and increases negative camber. Negative camber is good for cornering and tires stay in contact with the ground.
2) It has a big toe effecting bushing on the front of the LCA. This bushing will add toe out as the cornering forces increase aid in turn in but it changes as the cornering loads change so the car needs more correction as it goes through the turn. For a more stable car, these bushings should be replaced with stiffer ones from Energy Suspension or Mugen.
3) The damper/spring combo are really short and placed away from the wheel. This means the motion ration between wheel movement and the damper movement is a lot different than the front ( .588 vs .90). This means you need a lot stiffer spring and higher damped shock in the rear than the front even though the rear has less weight over it. Any time you are looking at spring rates on coil overs, these rates should show this.
4) This suspension design is also really effected by ride hight. Lower it to much and side loads from cornering will force the suspension through it travel. The trick is to keep the LCA flat or angled down a little for the suspension to work right.

Overall Summery
In stock form, the car is designed to have a lot of under steer. With these toe effecting bushings, you get more toe-in in the front and more toe out in the rear so the rear will grip better than the front under load. You also get more negative camber in the rear than the front as the suspension loads. This is all to protect the novice driver and Honda of America. There is a old rule....car goes off the road front first, its the drivers falt. Car goes off the road tail first, its the car makers falt.

Originally Posted by DS21

Been reading as much as I can about the EP3 suspension. Recently got a '05 Si, all stock.
I can tell it needs some improvement in handling. I intend this for DD, I ordered new tires
B-stone S-04's stock size 205/55/16 on stock rims. I'd prefer to leave it stock height too. Reading here, it sounds like some camber plates for the front and front bushings for the LCR in the rear would accomplish most of what could be gained ? Is the third item, castor improvement in front more or less important than the first two changes ?

Originally Posted by DS21

Thanks for the reply. I just had the Bridgestone S-04's installed (205/55/16) on my stock rims and aligned. Slightly better, but still handles poorly, bump steer, wandering, rides like a skateboard.

Originally Posted by LostHighway

I don't know whether or not mustclime and some of the other erudite posters on the thread are still active but I could use some advice. My car is a near stock '04 EP3 running 205/55/16 Conti DW on the factory 16x6.5 cast alloys. I'm about to order the ASpec kit. The car is my mid-April through late October/early November DD and I have zero intention of doing any racing with it or lowering it beyond the ASpec drop. What is/are the next logical step(s)? Beefier rear sway bar? Mugen LCA bushings (not interested in the ES bushings, too many negative comments)? Full Mugen LFCA ($!!). K-MAC caster kit? Lighter, wider 17" wheels to run 225/50/17?
For strictly road use I assume diminishing returns kick in fairly quickly after fitting the ASpec kit. What makes sense and what doesn't given a decidedly finite budget?

Originally Posted by Nate8o8_EP3

There's already so much to read on this post that makes me feel so inferior in knowledge. Lol. But from what I have read, it seems like I basically have to build the whole front end at least. I was thinking of getting the Truhart Street Plus Coilovers, and now I think I'm gonna look into Coilovers with Adjustable Dampers, Camber Kit, and Switching out my LCA's and Sway Bars. A friend of mine has a Type S RSX for parts and thinking about his LCA's and SB's. Looking to try find the right balance to be able to DD and Drag/Grip with it at the same time. If that doesn't work out, I'll just hold off on that until I maybe get Aftermarket Brands. For the rear, it has been pretty difficult for me to look into anything because of my location. I live in the middle of the Pacific so that's pretty difficult. If there was a way for me to get the things I need without paying the arm and leg price would be amazing. Also, I feel like it's a bit much but I was looking into getting some 16x8 with +25 offset on 195/45R16's or 205/45R16's. I have a set of wheels I got from another friend of mine that is 17x7 +45 on 215/50R17's but the set up alone is really tall and I had rolled my Fenders to fit. Still debating on pulling my OE Fenders for the Flare or of just getting a Flare Kit/Over Fenders when I get the new set. In my head though, I think I should look into this kind of things after I'm done with the Engine and Trans work and the Mods I'm putting in.

I apologize for carrying on but this is something I really need to learn. Lol.

Originally Posted by tommycrx

That's a bit low in front, imho. But if you get no rubbing and that's ok with you, that's the important thing.

Nate, my summer rims are 17 x 8 +38 front and rear - only needed a little roll on the rear fenders; your offsets on both of your sets of rims sound off.