Mayolives Posted December 8, 2009 Share Posted December 8, 2009 For those of you who do you own alignment and set up, what tools are you using? I have a Longacre caster camber tool that attaches to the front wheel or hub and then I use a plumb bob to find the center of the car. From that center line, I pull measurements to each side and then mark tape placed on my floor for reference. Mark posted that he used a laser pointer to help with his set up. What type of laser devices are being used? How are they being used? I would like for this post to evolve into a "how to better and easier do your own alignment and set up". I know there are some smart people at Hybrid Z who have been there and done that and I would like to hear from them. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted December 8, 2009 Share Posted December 8, 2009 If you have a level floor to start with you are in good shape. I actually check my camber with a level against the rim flanges. Then I calculate using trig. You can get a digital level that will give you measurements instantly. I use a tape measure to set front toe with the steering wheel at center lock. Then take a drive and observe the steering wheel angle on a straight level road. Come back and adjust both end links the same way the steering wheel pointed. It usually takes one or two trys. Once you establish a few lines around the car with string or laser you can measure points to the rims and use trig to get all of your angles. The reference lines must be parallel to the car centerline and vertical. That's the hard part. One crude way to check front toe, quick and dirty, is to press a broom handle to the front wheel and eyeball it to the rockers on each side. Believe it or not, it gets you pretty close. Make it even on both sides with the steering on center lock. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted December 8, 2009 Share Posted December 8, 2009 I'd look at strings. That seems to be what most racers do. It's on my list, but my list hasn't gotten any shorter in a while... Quote Link to comment Share on other sites More sharing options...
johnc Posted December 8, 2009 Share Posted December 8, 2009 Longacre tow plates, Smart camber gauge, homemade thrust angle bars, jack stands, fishing line, plumb bobs, laser level, and a couple tape measures. Quote Link to comment Share on other sites More sharing options...
mark Posted December 8, 2009 Share Posted December 8, 2009 Looks like John has it covered. Quote Link to comment Share on other sites More sharing options...
jt1 Posted December 8, 2009 Share Posted December 8, 2009 John, for the unwashed, could you elaborate on the homemade thrust angle bars? jt Quote Link to comment Share on other sites More sharing options...
johnc Posted December 8, 2009 Share Posted December 8, 2009 Two 1 1/4" square .125" wall five foot long steel tubes welded to a 3" round tube that's welded to a palte that bolts to the rear wheel hub. I don't have them here (someone borrowed them a couple months ago) to take a picture. I bolt them to the wheel hub with the long bars pointing forward, level them, and the measure to a vertical point under the sill pate to make sure the thrust angle is correct. It was a quick way to check at the track. In the shop I just string the car. Quote Link to comment Share on other sites More sharing options...
jt1 Posted December 8, 2009 Share Posted December 8, 2009 Thanks. That was sort of what I was imagining, but I thought it might be more involved that that. jt Quote Link to comment Share on other sites More sharing options...
Mayolives Posted December 8, 2009 Author Share Posted December 8, 2009 Two 1 1/4" square .125" wall five foot long steel tubes welded to a 3" round tube that's welded to a palte that bolts to the rear wheel hub. I don't have them here (someone borrowed them a couple months ago) to take a picture. I bolt them to the wheel hub with the long bars pointing forward, level them, and the measure to a vertical point under the sill pate to make sure the thrust angle is correct. It was a quick way to check at the track. In the shop I just string the car. John, (or others) Could you fill us in on thrust angle and the importance of it? How does thrust angle relate to toe? I realize that the floor surface being used needs to be level and the laser level could be used for that purpose. How else is the laser level being used? Do you use a laser that provides lines that would be used like the strings would be used to measure toe? Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted December 8, 2009 Administrators Share Posted December 8, 2009 John, (or others) Could you fill us in on thrust angle and the importance of it? How does thrust angle relate to toe? Thrust is toe. Toe expressed per side, instead of total. Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted December 8, 2009 Administrators Share Posted December 8, 2009 I've been using strings for years. Not glamorous, but it's as accurate as the effort spent. Take your time, and you'll get consistent numbers. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted December 8, 2009 Share Posted December 8, 2009 Thrust angle is the deviation from straight ahead on the rear tires. You could in theory have the wheels totally parallel, but facing to the right 5 degrees, and the car would crab down the road (see old Volvos). Thrust angle shows you that regardless of the toe, the tires are pointed straight. Strings negate the need for the bars he's talking about because you measure from the string to the tire and that string is straight, so by verifying that you have the same measurement on each side of the car, you know that the thrust angle is good. Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted December 8, 2009 Administrators Share Posted December 8, 2009 Possibly food for thought, a close friend fab'd a set of toe bars for his M... Quote Link to comment Share on other sites More sharing options...
johnc Posted December 9, 2009 Share Posted December 9, 2009 Thrust is toe. No, its more then that. Thrust angle is the direction the car travels in relation to the vehicle centerline. You can have perfect toe numbers front and rear and the car can still crab. Incorrect thrust angle increases rolling resistance, creates asymetric handling behavior, affects tire temps, creates bind in the struts, and increases tire and suspension wear. Setting the rear thrust angle is a pretty important thing to do on a S30. The first things is to make sure the rear LCAs are perpendicular to the vehicle centerline at ride height and a couple inches up and down from ride height. Once that's established you can set rear toe. For the front its important to make sure the front LCAs move through the same arc and remain perpendicular to the vehicle centerline at ride height and for a couple inches above and below. Its also important to center the steering rack within its range of travel and then lock it down while toe is set. Quote Link to comment Share on other sites More sharing options...
johnc Posted December 9, 2009 Share Posted December 9, 2009 (edited) FYI... in the Smart Strings example above your initial setup should be to the wheel hubs, not a wheel and tire assembly. Later you can check against the wheel and tire but only after centering the front steering and locking it down. For those that want to learn the basic concept of stringing your car, the Smart Strings owner's manual is great: http://www.smartracingproducts.com/pdfdocs/011410_smartstrings_manual.pdf Edited December 9, 2009 by johnc Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted December 9, 2009 Administrators Share Posted December 9, 2009 (edited) creates asymetric handling behavior Or 'corrects' it. Our C4 in SS wouldn't balance the same left to right. The key was running less toe on the driver side and more on the pass side. I concede it's apples & peaches to an S30. I would also say, depending on suspension design and use, it may be beneficial to run asymmetrical toe. That's what I mean by thrust. It's easier for simple minds to grasp FYI... in the Smart Strings example above your initial setup should be to the wheel hubs, not a wheel and tire assembly. Absolutely. Edited December 9, 2009 by RTz Quote Link to comment Share on other sites More sharing options...
johnc Posted December 9, 2009 Share Posted December 9, 2009 Our C4 in SS wouldn't balance the same left to right. Are you referring to corner balancing or front/rear handling balance? If the former, the car has problems if toe changes affect corner weights. if the latter - well... what I'm describing is how you set the car up initially so everything is square. What happens later depends on driver feel and lap times. Asymmetric setups are pretty common for specific tracks. Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted December 9, 2009 Administrators Share Posted December 9, 2009 (edited) if the latter - well... what I'm describing is how you set the car up initially so everything is square. What happens later depends on driver feel and lap times. Asymmetric setups are pretty common for specific tracks. Yes, the latter. Agreed, thrust is a principle factor in square. Our car started life square, but handling wasn't balanced. There's only so much that can be done in stock, so one of the compromises made was adding thrust (ie, asymmetric toe). Edited December 9, 2009 by RTz Quote Link to comment Share on other sites More sharing options...
rsicard Posted December 9, 2009 Share Posted December 9, 2009 Ron: I use the same process in that Jack Stands and string is positioned parallel with the rocker panels of my 240Z. Then set the steering wheel straight and set the front toe with a tape, measuring from the front of the tire to the rear of the tire to the string on both sides. Also set camber and caster with a Longacre tool. The car handles and tracks very well. Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted December 9, 2009 Administrators Share Posted December 9, 2009 If you measure 0 deg toe on the drivers side, and 2 degrees toe in on the pass. side, you end up with a 1 degree thrust line, right?. In my eye's, it's synonymous with saying... Thrust is toe. Toe expressed per side, instead of total. Quote Link to comment Share on other sites More sharing options...
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