Pre-project research - Stringing a Mazdaspeed 3

I'll keep the start of this pretty brief.

I have not been overly satisfied with the alignments I've gotten in recent years so I'm starting to read up on stringing my car and starting a list of tooling I'll need. There are a few decent videos on Youtube but I wanted to get some input from the smart suspension folks like @Nliiitend1, @phate, etc. (I'm sure I'm leaving other smart folks out). I'm not sure if Tomas made it over here but he had a small section of a post on the other forum showing parts of stringing his car.

The plan is once i have a camber gauge and string setup to do it on my car and a write up.

 

@OCD; did this before.

 

Any first hand guidance would be appreciated. I was hoping to get this done before ENM but life happens and it'll be a month or more before I have a free weekend.

 

@ConeKiller;

 

Is there anything in particular you are needing info for?

Once you have a totally flat/level surface, it's pretty easy. You can get camber/caster/toe gauges from SPC or other companies, or you can build your own stuff.

 

I was leaning more towards a any nuances that might be helpful to know before starting.

Initially I was planning on using jack stands to hold the string but I may cut up and burn some tubing together that will temporarily mount to the car to make the resetup after adjustments go quicker.

I'm leaning towards a couple of the more reasonably priced digital angle/camber gauges.

 

Toe is probably the toughest one to do right in a reasonable amount of time.

If you can do rigid tube on car for strings, do that. Take your time and get it right once and it'll save you a bunch of headache. Setting up strings on jackstands/whatever every time is a pain, because I've never really found a good reference point to easily get a side square with the longitudinal axis of the car. Track widths can't be trusted, so you can't use anything in the wheel/suspension/subframe assembly to reference from.

You can do single axle toe using the two-tape method, or just measuring track width at points on the leading and trailing edge of the tires, then taking the difference. The problem with only using this method is that it gets toe to 0 (or whatever), but it may not be 0 (or whatever) relative to the car axis. As an example, you could be at 0 toe, but overall toe left or toe right without realizing it.


Camber is fairly easy if you have an angle finder of some sort and a flat floor. I use a Craftsman 6 or 8" digital angle finder, but it only reads in tenths. Nicer ones would have readings to the hundredths.


Aside from stringing and doing the alignment from scratch every time, another method (which I most often employ) is to start from a known good reading from a good alignment rack. Then do everything relative to those numbers. After a few changes, your settings start to drift a touch and will need rechecked on the rack, but I hear some places do lifetime alignment deals for a good price. If you can get your subframe shifted to a point where you have 0 cross-camber at min or max camber, you can take it in at min/max and just have them set toe to 0.

Most recently, I've made adjustments from known readings at full droop with the car on stands (which is fucking awesome because it doesn't require a flat surface). Once on stands, loosen tie rod jam nut, loosen camber adjuster since you had it at max or min (plates for you, ball joint for me). I use a laser level to project onto a wall ~10' away to compensate for toe. Shoot the laser at some point you'll remember, add or subtract camber using a gauge, tighten camber adjuster, then adjust tie rod so the laser hits that point it was originally hitting. You can double check toe when you set it on the ground, but so far this method has gotten things SUPER close.

 

@phate

Thanks for the feedback, it's background like that which should help make it a little less painful the first time out and hopefully allow me to retain my sanity and document the process. If you have some time at ENM I may pick your brain a bit more.

After watching some of the videos of folks stringing race cars with the setup temporarily attached to the car that would make the most sense with as much jacking and fiddle fucking may be required to get it where I want. For the reasons you mention about setting toe using the tape measure method I'd prefer not to use that method. I may not monkey with the subframe just yet, I'd like to get to a good baseline before I jump on that.

Camber gauges abound that only read to the tenth of a degree including the spendy Intercomp stuff but I have been perusing Amazon for angle finding devices that read to the hundredth position. At the end of the day if I'm within 0.1* of camber between both sides I'm probably doing pretty well for a street car.

Although it's been ~10k miles since my last real alignment on a rack so I'm not working from 100% known numbers but I should still be in the neighborhood. Part of my frustration with the shop I have the lifetime alignment with is unless I get a guy who really cares most just get close to what I ask for and not spot on. I'd like to get it spot on myself and go back for verification as you mention.

If all goes well I may end up doing the wif's Merc as hers is off slightly and with the staggered setup has a tendency to eat tires.

 

Been busy with other things and traveling for work, such is life. However, after running in the local SCCA club monthly autocross event last weekend it has rekindled my desire to get after this sooner rather than later. Part of this weekend is to turn a pile of steel in a usable tool. Standby for more.

From this....


to a set of these, my knock-off of Smart Strings at a much lower cost.

 

Made a few minor changes to my original plans but was able to cut and burn together the bulk of the set. Ignore some of the welds, I rushed the last set but the angles are good. Later in the week I'll have some time to test fit on the car and verify it'll work. All that remains before paint or powder is making the rods with measured groves.