Camber greater than -3

[RebekahsZ]

I'm using EMI camber plates which have bolt holes instead of slots. Any of you road racers or autocrossers running with -3.5 degrees front camber? I'm just mocking up, then taking car for final alignment next week. Wanted to see if anybody could help me chose between -2.5 and -3.5 as I can't seem to hit -3 on the nose. Car is seeing minimal street time. (Mostly jack stand time lately). First autocross in a couple years is next Saturday. Please share your thoughts.

[johnc]

Oval the two holes in the strut tower.

[R3VO 3VOM]

Can you use this in conjunction with your camber plates? Only for the front though.

http://www.zccjdm.com/catalog.php/azcarbum/dt93255/pd1789104/CAMBER__BUMP_STEER_SPACER_ZCAR_http://www.zccjdm.com/catalog.php/azcarbum/dt93255/pd1789104/CAMBER__BUMP_STEER_SPACER_ZCAR_

Edited March 28, 2013 by R3VO 3VOM

[RebekahsZ]

Sorry folks-I need to be more clear. I can think of several ways to reduce my camber from -3.5 to -3.0. (The easiest would be to reduce to the 2.5 hole and have the alignment guy widen my track to achieve -3.0) I phrased my question poorly. I may elect to run it at -3.5 since last time I ran at -3.0 I was still wearing lots more on the outer edge of the tires. But I'm sure that can just as easily be related to me being a novice driver. I was really just fishing for some driving experience/impressions/testimonials about excess camber. Hoping a few of the serious autocrossers will weigh in. Maybe a little friendly chit chat on the subject with me intently listening?

[JMortensen]

If you lengthen the control arms, you need to worry about the tie rods. You can't go very far at all before you start running out of threads. You can make your own new ones, bjhines and I both did that and documented it here.

 

Did I see that you're running 225s on a 7? If so, I'd suggest you get wider rims, especially if you're running autox tires (DOTs or Rs). They tend to run wide, and generally speaking you want the section width to be the same or a little smaller than the rim width. Lots of Miata guys run 225s on a 9" wide rim. I would run them on an 8 or 9.

 

Aside from that, the trick is to do what makes the tires happy. Start with shoe polish over the sides to see how far the tires are rolling. Inflate to get less roll. After that you'll have to start taking tire temps to really get it dialed in.

 

When I was autoxing my Z I had camber plates and adjustable arms, and maxed out I had a little over 2 degrees neg. I never got enough neg camber and after a season you could look at my wheels and see that the tires were worn on the outsides. They looked like used skateboard wheels. I wouldn't arbitrarily try to make the camber less than 3, see what it actually wants. The main question I would have about running that much is would it be hard to drive, following ruts and all that on the road due to camber thrust. There are enough idiots out there who do it because it looks cool that I guess we know it can be done, but it might also kill your race rubber pretty fast...

[h4nsm0l3m4n]

What is your suspension setup?  Do you have adjustable control arms?  If not I would run the -3.5 setting in the front and the -2.5 setting in the rear (if you have radial tires, bias-ply take a lot less).  Then use tire pressure to fine tune based on what the tires like and how the car's handling feels to you.

 

Even with the LS motor my car would have a bit of steady state understeer, I would previously run a bit more pressure in the rear to correct this.  This year I'm running 275 hoosier A6s I plan to start at -2.5 front, -2 rear camber and hope to correct this issue.  I hear Hoosiers like a lot of camber (3+ degrees) but I drive my car on the street so I dont want to get too crazy. 

[RebekahsZ]

Thanks! Can you give me a quick lesson on checking tire temps? I'm a 1-man show and I imagine the tires cool pretty quick after a run. Tell me the routine. I have one of those infrared pyrometers-is that the tool to use? I bet I will need to be systematic and get out of the belts quickly?

[RebekahsZ]

Oh, this morning is just like Christmas-I'm hearing from most of the guys I was hoping to hear from! I'm not worried about my street tires-they don't see much action anymore. 90% of my driving last year was in 7-second, full-throttle bursts. I'm listening to each bit of advice.

 

My TTT adjustable front LCAs are on the shortest adjustment. I posted my full setup on the FAQs page for a couple of days but just got responses when I moved it here.

[h4nsm0l3m4n]

If you have adjustable LCAs I'd do what you said - set the camber plate at -2.5 and adjust out the LCA to get to -3.0.  -3.0 front -2.5 rear is probably a pretty good place to start.  -3.5 front -2.5 rear may be too large of a difference.  Hopefully your tie rods do not end up too short...

 

Regarding tire temps, I've never used infrared pyrometers on tires.  The infared units only capture surface temps, which can change a lot as your car drives back to the pits and sits around.  Pyrometers with a probe are typically used because it gets underneath the surface of the tire where the temps are more accurate and stable. 

 

Regardless of which gauge you use it may be good practice to measure the tire that has experience the highest load first, then do the others.  After youre done measure the first tire again, this may give you a reading on how accurate your measurements really are based on how the tires are cooling.

Edited March 28, 2013 by h4nsm0l3m4n

[RebekahsZ]

Sources for tire pyrometer with probe? How deeply do you probe?

 

Just found longacre economy probe for $100 at racer parts wholesale thru amazon. I read accompanying artical that explained things pretty well. If nobody objects, I'm gonna get one of these in the mail. Stupid question: can I flat my tire with the probe? I usually run my race tires until they show cords.

Edited March 28, 2013 by RebekahsZ

[johnc]

How deeply do you probe?

 

As deep as I can.  I really try to bottom out, but that's just a dream I have.

[RebekahsZ]

You know they have pills for that now, johnc! The lunatics are running the asylum!

 

I guess I'll just figure this out when the probe arrives. I just heard from my header coaters and they are taking Good Friday off so I may get my headers in time to install them Wednesday night (in stead of monday) and be at alignment shop on Thursday.

Edited March 28, 2013 by RebekahsZ

[RebekahsZ]

Managed to get -3 on the passenger side and -2.7 on the driver side by raising the rideheight 3/8" and rotating the EMI camber plate so that the front hole is max-in and the rear hole is pushed in one less bolt hole, so it also rotates the top of the strut backward a little (increasing caster?).  Gonna have alignment shop make it -3.00 on both sides by playing with the length of the LCA.

[heavy85]

What tires?

 

Things to consider - tracks around here are all clockwise so the front left takes a beating. Lots of camber there. Right side doesnt need as much. Lots of camber hurts braking and with a big bar leads to flat spots IME - its a trade-off to play with. Rear gains camber in bump so you dont need as much static camber. Watch tire wear and adjust accordingly or until lap times go the wrong way. IMO start high in camber and work your way down as tire wear can go bad fast with too little (ask me how I know ...).

 

Cameron

Edited April 9, 2013 by heavy85

[RebekahsZ]

BFG R1-roadrace tires that I've had in the rack for, I think, 2 years just waiting to be used (and getting harder by the minute). Tire wear pattern was perfect with 30# in front and 26# in rear.  Never tried going lower, but might have been able to.  I chose tire compound poorly and never could get any heat into the tires with 20-40 second routes, so I was ice skating all weekend.  Did some ride-alongs and it was totally different riding in cars that could be driven rather than kind of tossed in a general direction.  I think the highest tire pressure I saw was about 117 after car had been hot-lapped thru the course for hours.  I concur with you about the "handedness" of a course-this course was mostly left-handed sweepers and slaloms-the right front was always significantly hotter than the others.  Second day was a little more ambidextrious.  Only thing that bothers me is the differencce between what the shop says they aligned to and the readings I'm getting on my new Longacre camber/caster gauge-I don't know which to trust.  I might try to find another shop to traiangulate and confirm everything.   I did get to play a lot with weight transfer and getting car to turn, then to steer with throttle-a good day.

Edited April 9, 2013 by RebekahsZ

[h4nsm0l3m4n]

I've been taking my car to a good local shop for alignments for several seasons now.  They have good reputation with local racers and are cheap.  I've always trusted their readings without much hesitation.  Maybe this isnt the thread to have this discussion but I've always wondered why people DONT trust the measurements they get out of an alignment shop?  I've seen the alignment machines and they dont look so complicated that it'd take a scientist to get good readings.  I'm sure, as with anything else, if its possible to get things wrong people WILL get it wrong. 

 

It seems like a reputable shop that knows how to work their equipment will be preferable to having to take measurements with bubble levels/strings/plumb-bobs/whatever else people use to get their alignment right.  Is this job that difficult to get right that we go through all this headache to ensure we get what we want?  Where does the error factor in?  I wouldnt much like to do my own alignments but will change my ways if shop computers/alignment machines are really that much prone to error.

Edited April 9, 2013 by h4nsm0l3m4n

[RebekahsZ]

I haven't been at this long enough to have good judgment or wisdom on the subject-that's why I started the discussion-to learn from others. You are right-hard to know whose floor is more level, etc. I think it would be nice if I knew how to do my own alignments so that I can make changes without having to take the car somewhere. Reliable shop?-haven't found any place so far that doesn't leave a couple tools under the hood, a new rattle under the dash, grease on the carpet or a jam nut totally loose. When I find two or three things wrong, it is hard for me to trust the whole job. This is the kind of thing I have dealt with at the last. 2 shops I have tried. Double checking behind the mechanic has been absolutely essential here lately.

[JMortensen]

You can level out your garage floor with some 1/8" floor tiles, they work great for slip plates too, just put grease in between. I used the bucket of water with clear tube method, which is discussed here IIRC:  http://www.quadesl.com/miata_alignment.html. If you're adjusting a Z with sliding type camber plates, it's pretty easy to do it all on the floor. I tried on my Miata which has eccentrics on the LCAs and couldn't get under the car. Put the wheels up on some stacked up 2x12s and it fell off... twice. Don't think I'll be climbing under the Miata.

[tube80z]

I haven't been at this long enough to have good judgment or wisdom on the subject-that's why I started the discussion-to learn from others. You are right-hard to know whose floor is more level, etc. I think it would be nice if I knew how to do my own alignments so that I can make changes without having to take the car somewhere. Reliable shop?-haven't found any place so far that doesn't leave a couple tools under the hood, a new rattle under the dash, grease on the carpet or a jam nut totally loose. When I find two or three things wrong, it is hard for me to trust the whole job. This is the kind of thing I have dealt with at the last. 2 shops I have tried. Double checking behind the mechanic has been absolutely essential here lately.

 

The one thing that's really important for our cars is to make sure you are either in the car or have driver weight in the car when getting an alignment done at a shop.  If this isn't done then you may not be getting the numbers you are asking for.  Our cars are very sensitive to roll angle and sitting in the car puts a slight angle on the car that needs to be compensated for.  Once you know that info then you could do the alignment without being in the car.  Corner weights, ride heights, camber/caster are all in this boat.

 

For camber I bought a fancy digital tool (smart camber) and it can also be used for caster too.  Or if I had thought about it I could have used some trig and a carpenters square to get the same info.  The latter is very useful at the track when you want to quickly check something.  For toe you can build a string system that aligns with the car centerline and it makes things pretty simple.  You can also setup a long piece of angle or square steel at hub height and do the same thing.  And as Jon mentioned you can use floor tiles, carpet squares and even magazine pages to help level the floor.

 

If you're at a shop or at home doing this it's good to also learn what a flat or a full turn does to the alignment.  If you keep good notes you can always make a change this way at the track and not worry so much about all the alignment equipment.  But I would recommend checking it later to make sure it was what you wanted.  For camber you can use a tape measure with your camber plates to get similar info.

 

For taking tire temps as a one man show there are a couple of options.  If you don't have  memory tire pyrometer I would recommend a handheld recorder.  I quickly get out of the car and start with left front (inside, middle, outer), then left rear (same order), right rear, right front, and then left front again.  Then drive the car back to the pits.  Once there you can play back the temps and right them down.  If you can get a buddy to help or offer to do this for someone else and they help you it works even better but you don't always have that luxury.  Why do I do the same tire again?  That's to see how they are cooling and figure that into my temps as I came off the track.  And from the temps you can get fancy with averages to determine what end is working harder, diagonal, etc.  And make adjustments and go faster.

 

Okay, that's a lot to think about.  Feel free to ask questions.  There's a lot of knowledge on this forum and there may be far better ways to do this than I just offered up.

 

Cary

[RebekahsZ]

I can't find a shop that will let a customer come into the shop, much less sit in the car when it is being aligned-they all want your butt in a chair in the waiting area reading an out-dated Cosmo magazine or a Lady's Home Journal.  I've tried tipping and being super nice and I get no where.  I'm gonna have to keep looking or a better/cooler shop with a more interested owner.

 

At an autocross, you get so little time to adjust your car-the one I just attended was very hectic and you really couldn't bring your tools into the paddock.  I need to find a safe place to play skidpad or something like that in order to try to sort some of this out before getting to the race, then maybe I can make little changes once I'm there, but there really isn't a place/time to do any developmental adjustments.  Any suggestions for that?  We did (3) 40 second runs in the morning and (3) 40 second runs in the afternoon, with cone duty in-between and no lunch break-how do you find time to do adjust and re-verify on a race day?

 

For my drag racing there is test and tune every week, but the only place I know of for test and tune sportscar is on the streets, and that is a no-no.  Any more suggestions?