Roughly how much and which direction rotation is needed on each side to tweak 1/16" total toe in on a car with 0 toe and thrust angle?

 

I would check with one of the Tech Contributors!

You are a brave soul doing it without a toe tool. I have this tool http://www.jegs.com/i/Allstar+Perfor...FQaCMgodHVoAZA

It is only $65.

 

Never mind, found what I was looking for.

One complete turn of both tie rods will toe in (or toe out) the tires one inch so 1/2 turn of both rods will equal 1/2" of toe in (or toe out) and likewise a 1/4 turn of both rods will give you 1/4" of toe in (or toe out).

 

I recommend you search further. Each tire rod has six flats. I have found that each flat is about 1/32nd of an inch. Turning both tire rods one flat will equal around 1/16th of an inch toe change.

--Dan

 

Based on the price of tires, why risk "that I got it right" when you can do it right for not much money.

 

One flat is 1/32. Problem is gauging with your eye how far you have turned the rod. Light is sometimes poor and you aren't always at the best angle to judge how far it turned. If you get it wrong you will not screw up thrust angle but the steering wheel couold be turned one way or the other. To increase toe in at the front you turn the shaft Clockwise to increase toe out you turn it Counterclockwise. On the right front you will put a 13mm wrench on the shaft with the handle pointing toward the front of the car and then push up on the end of the wrench. On the left front you put the wrench on the shaft with the handle pointing toward the front of the car and pull down on the end of the wrench.

One thing to note. The tie rod end has some play in it so when you loosen the nut that locks the tie rod adjustment you may see the shaft turn just a little bit. It is important to note how much it turns since if that turn creates some slack in your subsequent adjustment to the tie rod you need to take that into account when measuring your one flat turn. You could turn what looks like one flat and not turn anything since all you did was take up the slop at the tie rod end.

If you decide to adjust the rear that is when you take a chance of screwing up the thrust angle. Also all adjustments in the rear are the exact opposite of the front adjustments.

You can buy Longacre toe plates for $50 to $60 and a Sears 24 inch laser level and a tape measure held by a helper will allow you to check/adjust toe/thrust angle in the rear.

Bill

 

Thanks Bill for this and all your other always detailed and very helpful posts, I have learned a great deal from you.

Thanks to the others also, I ordered a set of toe plates., This will be my first alignment experiment and hopefully learn enough move next to camber plates to switch between street and track settings.

I just had the car aligned and will make sure I can correctly measure the base line before doing anything.

 

You will be glad you bought the tools to set the toe with. Cheap investment!

 

Sorry, but I am not following what you're saying here.

--Dan

 

Trying to set the toe by guessing on how many turns you make is not very accurate. The toe plates give you fixed pints to measure so that you know what you did is correct.

 

Sorry I wasn't clear, never done this before so I just want to make my first adjustment in the right direction and relatively right amount.

Just took my first measurement with my fancy red toe plates and confirmed I'm starting at 0 which is where I ask them to set when aligned. Angle gage is on the way also for camber.



Thanks again

 

You are now on a slippery slope. There are all sorts of slippery slopes with cars. There is the slippery slope of tracking the car and there are associated slopes with things that you do to maintain the car when taking it to the track. I just decided to move up from my toe plates and laser level that doubled for a camber/caster gauge and thrust angle tool to a Fastrax caster/camber gauge that fastens to the wheel and a set of Smart Strings that I have lusted after for the last 7 or 8 years. I watched Froggy's video of how to use the Smart Strings on a C5 and determined it was finally time to take the step. Hopefully, this will reduce the work involved in changing from street alignment to track alignment and back.

Bill

 

. Yea, I fell of that slope multiple times all ready. I look at it more like education, always fun to learn something new. It's nice people here will respond to stupid questions and help get it right first time.

Take care!

 

I was describing how you adjust toe and use an approximate measurement (in flats) to move a certain distance which contradicted the OP's post #3 information.

I want to point out that any measurement of toe expressed in inches or mm is dependent on where the measurement is taken on the diameter of the wheel/rim. The farther out from center the greater the distance of the measured toe. Toe measured in degrees is constant. One degree at the edge of the rim equals one degree at the surface of the tire. The problem with degrees is that they don't work easily at home without calculation.

Because of this, I do not believe in giving "accurate" toe settings in inches as they depend on where it is measured. Perhaps all toe plates are the same length (e.g., 24" between F&R tape) but I don't know that. I do know that the link to Jegs shows a measurement tool that will not necessarily match toe plates. I also use a bar with contact pads to measure outer edge of tires allowing it to be a one-person job.

But, more often, I have my wife hold the tape in a tire groove and quickly get a number from the opposite side that I then change, as needed. Same in the rear except that once a month or so I'll use a laser to check thrust angle with the laser held against the rear tire and shoot to a 6" rule held on the F center cap to tweak, as needed. Adjusting thrust angle is the same process as centering your steering wheel.

As Bill explained so well, there's a lot of slop in the system when making adjustments. Changes are all relative to previous settings on your car using your tools and methods. My numbers maybe different on your car. One thing I check when adjusting toe is that the tire-rod end remains level as when tight to eliminate the problem Bill described. It just requires a wrench to hold it in place when retightening the jab nut.

I'm very happy with "close enough" in that the car drives well for competition and straight down the highway at speed. With the savings from the many alignments I've made in the last 7 yrs I can buy 4-5 sets of new tires. Plus, any tire wear due to variation in alignment specs is insignificant compared to a single autox day.

--Dan