RotorJoe

Can someone give me a quick run down on exactly what would adjust each of those on the front and rear wheels of a 2nd gen Rx. I am about to install coilovers and I found at racing beat the rear suspension camber adjuster links. Are these needed? It states that they do not affect toe of the rear tire. Would I be able to adjust toe in and out with other suspension up grades or can you adjust toe on the second gen. So here is where I would like your help. Could some please explain Caster and Camber to me along with Toe in and out. I think I have the basics but I am not sure. Caster camber is when the tire either rides on the inside vs the outside of the tire. From what I uderstand you what the tire to be flat in the corner but with too much you can wear the insides of the tire fast. Not sure which one is which. For toe in or out, that is when the car looks duck footed or pigion toed and I don't think I want the back wheels or ever the front to have very much or any toe. Please some one help me if they can. I am about to install GAB revo coilovers with mazda speed sway bars front and rear along with cusco strut tower bars. Oh ya my coilovers have the adjustable pillow mount ball on the top. I will auto cross when ever I can but mostly it is going to be a street set up. Comments and ideas and suggestions are needed along with an explaination of how those tree things interact with each other (Caster, camber and toe in and out).
Thanks

Jerk_Racer

Quick run down, huh? That's a tall order. I sugest you do some homework to find out what all the terminology means and how they affect each other. Many books have been written on this subject and there's not way that all that can be covered in a few posts on this forum. Head out to a Borders and/or B&N to find some books on suspension tuning. They'll let you read for free all night long anyway.

Well, with a coil-over kit that comes with camber plates for the front such as the JIC FLT-A2 (I'll use them for the example because I have them on my car) you will not be able to adjust caster any longer. From the factory the FC has slightly adjustable camber/caster. With aftermarket camber plates, unless they are made to do so, you will not be able to adjust caster. Mine is fixed at 5* and it's just fine by me. With the JIC plates, the most front camber I can get for both sides is 1.9*. Toe in/out is aways adjustable.

For the rear, forget about caster. Toe in/out is adjusted seperately so don't worry about it either. Negative camber is increased the lower the back goes. There are two ways to correct this and set it to what you want. One way is a single link that attaches to the chassis and the subframe. This changes camber equally for both sides of the car. That's fine if both sides are already equal to start with. Then there are the two camber correction links that attach to the trailing arms. These can adjust camber indedent of each other.

While you are doing all of this, I suggest that you replace all of the bushings with all the poly bushings you can find. If none are available, then get the MazdaSpeed hard rubber bushings. Don't forget the Delrin bushings to remove the rear steer junk and to replace the upper bushings in the rear hubs. It's best to just drop the whole rear end and move it to someplace that's easy to work. All the bushings can be removed with just a mallet, junk screwdriver, and blowtorch. A press isn't needed either. Just break out the mallet again and use a small vice. Use plenty of lube.

Once you've got everything back together, take it in for a cornerweight/alignment at a shop that does race cars. Spend some time with the tech and let him know what you are looking for in a ride. That's what I did and I couldn't be happier. Sounds expensive to do this? It's not like you haven't already spent a lot for the parts and doing this will allow you to make sure your suspension is set properly.

Have you already started to race? If so, where? I'm over in Redmond but I go to Bremerton and Everett very often for autoX. I'll be in Bremerton this Sunday morning for the race there and will just drop in on the Everett race in the afternoon to say hello to some friends. Several club4ag.com bubbas are going to the autoX at Everett. If you ever come out to an event and they allow passengers then hop in for a ride. My suspension has been completely done up. Which car is mine? You'll know when you see (or most likely hear) it.

Mld>7

Ok, well I guess I'll just give you a run down of it all..

Caster is actually the way your tire is pivoted forward or backwards, similar to camber but in a different direction. When you have positive castor your tire leans to the front and when you have negative castor it leans to the back. Most people would say "Yah so who give a ****, the tire is round it will roll no matter how far you lean it!". But a real easy way to picture it is, say the whole suspension assembly is hanging from the strut tower! If the whole assembly was straight up and down then you have zero castor. Swinging the wheels forward would give you negative castor. This makes the car much more stable at speeds and in corners but it also causes a bit of resistance because now the car is essentially pushing the tire forward. If you do the same with negative caster now your car has less rolling resistance but it causes more instability while turning. A shopping cart is a good example of positive caster, the wheels are set behind the bolt attaching them to the cart which makes it very easy to push but when you try and turn it all goes to ****. 99% of cars today all have a little bit of negative castor. A little is all you need. Keeping your stock values (or in the case of the JIC's there only setting) should be fine so like Jerk_Racer said dont worry about it. However if you can and do choose to play with it, know that it comes with a price. Castor affects camber. The more agressive negative castor you set, the more negative camber will increase as you turn your wheel right or left! a good extreme example would be to lay the struts vertical down on the ground with the wheel on and reattach it to the car like that. Now turning the wheel no longer turns the car it ONLY cambers the tire in and out. Now there is no way you could do that on your car but just for an example I hope it clears things up a bit. Toe should always be the last thing you adjust because both camber and castor affect toe. The more outward toe you have the quicker and dartier you car will be. Outward toe is exactly what you want for and auto-x. Not too much but just a few degrees to give you that quick turn in. Yes it does wear out your tires a little faster and so I'll just let you take all the adjusting into your own hands and stick to providing you the info. However I suggest you buy after market toe links if you plan to be adjusting frequently. Hope that helps.

I'll think I'll let the others take it from there!

RotorJoe

Thanks for the help, I will grab a good book and read up for the filler material. I am in the Sammamish area and I have not made it out to the auto crosses in Bremerton or Everett. I have a hard time waking up at 7 or earlier on sats, but I need to go. I all ready have done the RB Toes steer eliminator bushing and I am looking into Energy Suspension bushing all the way around. The main part about that is I need to make sure the kit has the bushings for the lower A arm in the front. Jerk Racer, I am suprised we have not heard each other mine is very loud too. What are all the components that you have in your 7 for suspension? I would like to see your ride. PS when and where are the next autoXs going on in Washington.

Jerk_Racer

Cool, I'm up on the Plateau quite often. That's where I go to work on my car (friend's garage).

Local autoX info:
Bremerton Sports Car Club
Western Washington Sports Car Council
SCCA - NorthWest Region

There are two events tomorrow. One in Everett and one in Bremerton.

DamonB

In summary:

Toe In/Out: When viewing the tires from above the car the front of the tires point in (toe in) or out (toe out).

Camber: When viewed from the front or rear of the car the tops of the tires lean in (negative camber) or out (positive camber).

Caster: This is what provides the "leaning" of the tire as the steering is turned and provides a self centering action along with feedback through the steering wheel. Not to be confused with kingpin inclination. Rear wheels never have castor because they are not steerable.

If you would really like to learn about suspension geometry and its effects try reading "Tune To Win" by Carroll Smith. Suspension tuning is founded on geometry and physics with a little bit of black art thrown in there too