What have you done to your Miata today?

[JamesCH]

Bought a laser line do use with my FM alignment kit. I'm going to state the obvious: lasers are WAY better than strings. By all of it.

I measured and marked a centerpoint on each subframe to establish a center line. I used the laser aligned to these two marks to cast the center line down onto the tape measures attached to the alignment hubs. This let me easily set thrust angles on each wheel and made it really obvious when I accidentally shifted the car when tightening a bolt (which happened way more than I thought it would). Huge improvement in how easy it was to do an alignment.

Final alignment specs-

Front
4.8deg caster
-2.2 to -2.3deg camber
1/16in toe out each side

Rear
-1.55 to -1.6deg camber
1/16in toe in each side

Was raining last night so I didn't take it for a test drive, but I will update once I am able to do so.

View from under the car while aligning the rear axle.

The alignment hub, camber gauge, and tape measures all attached to the front passenger hub.

The laser cast across the tape measures on the front axle.

Question: I see some people suggesting more negative camber on the rear axle, and many others suggesting less negative camber on the rear than the front. My thoughts in using less negative camber on the rear is that I don't want to sacrifice too much linear traction for lateral traction given the extra power my turbocharged engine has. Does anyone have any guidance or wisdom as to rear camber settings?

 

[WillD]

Very awesome James. Doing my own alignments is on my short list of things to do/learn how to do.

 

[aMaff]

Question: I see some people suggesting more negative camber on the rear axle, and many others suggesting less negative camber on the rear than the front. My thoughts in using less negative camber on the rear is that I don't want to sacrifice too much linear traction for lateral traction given the extra power my turbocharged engine has. Does anyone have any guidance or wisdom as to rear camber settings?

When I was in STS, we made offset Delrin bushings for the rear uprights so that we could take enough camber OUT of the rear. Having a ton of camber in the rear means you're not able to get on the power fast enough and makes it harder to keep the rear behind you. Especially with as much camber as the NAs pick up in bump. So, if you want mad skids, then sure, max out your rear camber. If you want to go fast around corners? Keep those rears as flat as you can.

 

[JamesCH]

Very awesome James. Doing my own alignments is on my short list of things to do/learn how to do.

Thanks man! It has been interesting (and frustrating) learning how to do all of this.

When I was in STS, we made offset Delrin bushings for the rear uprights so that we could take enough camber OUT of the rear. Having a ton of camber in the rear means you're not able to get on the power fast enough and makes it harder to keep the rear behind you. Especially with as much camber as the NAs pick up in bump. So, if you want mad skids, then sure, max out your rear camber. If you want to go fast around corners? Keep those rears as flat as you can.

Hrm, interesting. I guess in autox you'd usually want to sacrifice some lateral grip for gains in transitions because in autox there are usually lots of transitions and not too many sweepers. Unlike a road course or track where you will definitely have sweeping turns. I will definitely have to futz around with rear camber and see what works best.

 

[WillD]

Check out the STS setup thread on Miata.net, most of the guys post their alignments. Many of them top STS drivers nationally.

 

[JamesCH]

Check out the STS setup thread on Miata.net, most of the guys post their alignments. Many of them top STS drivers nationally.

Good idea. Seems that my numbers land a little on the conservative side of the pack, with a bit less rear camber than most would run with 2.2-2.3deg negative front camber. With a turbo I think that I made the right call, but we'll see after some experimentation. I think I'll try stiffening my front sway bar and maybe disconnecting the rear one after reading up on most of those setups.

For the curious: http://forum.miata.net/vb/showthread.php?t=492286

 

[WillD]

Thanks for the link, I was too lazy to go and find it!

FWIW, if my Xidas ever show up I'm planning on going with something in the ballpark of what Craig Klippel runs and fine tuning from there:

Alignment:
-3.3 degree camber front
-1.9 degree camber rear
-5 degree caster
-3/16 total toe out in front
-1/8 total toe in on rear

 

[JamesCH]

Thanks for the link, I was too lazy to go and find it!

FWIW, if my Xidas ever show up I'm planning on going with something in the ballpark of what Craig Klippel runs and fine tuning from there:

Alignment:
-3.3 degree camber front
-1.9 degree camber rear
-5 degree caster
-3/16 total toe out in front
-1/8 total toe in on rear

Dang son, those are some aggressive numbers!

 

[WillD]

Dang son, those are some aggressive numbers!

All I care about is going fast around corners.

I just noticed 3/16 front toe on his numbers, I don't think I'd do that. Or maybe I'd dial that in only for national autocross events.

 

[Tungsten6]

Got to drive a friends in the rain recently. Forgot how much fun that was.
Then merging on the interstate I remembered how slow it was.... lol

 

[brandini]

Only slow merging if you didn't carry enough speed in the turns. (2thumbs)

 

[Tungsten6]

Pft, trust me. Beat the s*** out of one for 2 years.... Well aware how to drive one, yet you fail to realize one thing. This is FL, turns are limited (which aside from me being uncomfortable is why the car was sold. Not enjoyable here.

 

[brandini]

Pft, trust me. Beat the s*** out of one for 2 years.... Well aware how to drive one, yet you fail to realize one thing. This is FL, turns are limited (which aside from me being uncomfortable is why the car was sold. Not enjoyable here.

It makes me sad you don't have turns... or hills.

 

[JamesCH]

My alignment turned out pretty well, I think. Steering feels a bit lighter, and the car is very eager to turn with the little bit of toe-out it has. It makes driving with a de-powered rack easier. I haven't raced with it yet, obviously, but it did feel very stable and very well planted in the few turns I pushed it through, without any annoying understeer or oversteer. The only obnoxious bit is that the steering wheel is just every so slightly off-center. Not sure if it's from the car trying to track the road crown or what... but I suppose it's a very minor annoyance that can be adjusted out by fiddling with the tie rods a little more.

We'll see what happens when I stiffen up the front bar and soften, or disconnect, the rear bar. Or maybe just go back to a stock rear bar.

 

[aMaff]

Dropped it off at Ye Olde Metal Fabrication Shop to have the cage wrapped up. Dave does fantastic work (see also: the roll bar / rear cage on my car), so I look forward to seeing how it goes together.

 

[chiefmg]

The MSM front sway was waiting for me when I got home, as well as the Porter-Cable polisher. That is a very nice piece of equipment, I'm looking forward to using it. Just have to decide what sort of polish I want to use.

I ended up getting the stock rear sway (as well as the bulkhead sheet metal piece for the rear) from Midwest Miata. They are located just south of Columbus Ohio, I drove up and got what I needed. Bonus for the trip was finishing up my clutch break-in. Before I left home I loaded up the second save point I had for the MS to see if there was anything done after that which was causing the excess gas. Unfortunately that didn't change a thing. I pulled the plugs this morning and they all looked good, however I'm going to do some research and make sure I have the correct gap on them. Could be that the gap is off and the spark is getting interfered with under boost.

 

[WillD]

Anyone have any tips on how to get the long bolt out of the lower rear control arm? I've been heating the s*** out of it and hitting it with an impact and it won't budge.

 

[JamesCH]

I used a wire wheel the clean up as much of the exposed shoulder as I could, heated the crap out of it with a torch, hit it with copious amounts of homemade Kroil (basically ATF and acetone), and used a punch (both a punch/hammer and an air chisel) to hammer it out while it was being spun with an impact or breaker bar (had a friend helping).

Getting oil between the bolt and the upright was key.

And that was from a 200k+old New England Miata. Yay salt!

 

[WillD]

Hmm... sounds like I might have to get creative. My Miata has never seen salt and only has around 90k miles. I've never encountered a difficult bolt until this one.

 

[JamesCH]

Just don't hit the end of the threaded bolt directly with a hammer. You'll roll the threads over and have a sad time. I used a fairly small diameter punch and a brass drift.