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12 Sep 2007, 23:06 (Ref:2010638) | #1 | ||
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Toe Alignment- DIY?
My first post, and I must say that I've spent countless hours reading through this forum and I'm loving every minute of it!
I spend quite a bit of time on the track in my Lotus Elise (S2 and supercharged). I'm pretty handy and do all my own work. I even have a fairly complete machine shop in my garage I've been playing with the ride height of the car recently. Consequently, my front toe alignment changes as I change ride height. I'd like to do the toe alignment myself and have read about several different procedures for this task. I'd like to get some feedback as to what toe alignment procedures work best with the least amount of effort. Any experiences to the positive or negative associated with a procedure etc??? Thanks! Best, Phil |
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13 Sep 2007, 09:40 (Ref:2010953) | #2 | ||
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I just use string.
Two lengths of string running each side of the car, a little longer than the car. Find an accurate centre-line of the car, and make sure the string is parallel to that, by measuring from the line to both strings at the front and rear. Then, save time by measuring from the centre of each wheel to the string at each corner, so you can set the string up in a hurry. Now you just measure at the front and rear of each wheel, and voila a mm toe reading. Lasers aren't really an advantage, or more accurate. You still need to to the centre line thing, you still need to do some measuring. And string is cheaper. I'd rather save my money for some corner weight scales. |
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13 Sep 2007, 10:51 (Ref:2011010) | #3 | ||
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If the toe is changing as you change ride height you will have situation called bump steer which is not paticularly good usually caused by the lower TCA or wisbone and steering link from the rack not striking the same arc, check it out you may need to move the rack up or down to compensate or use spacers and rose joints instead of rod ends at the steering arms or move them, bend em, what ever is easier.
Last edited by Al Weyman; 13 Sep 2007 at 10:53. |
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13 Sep 2007, 14:46 (Ref:2011231) | #4 | |||
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Thanks for th replies. I'm familiar with bump steer. I haven't measured to be sure that the car has zero bumpsteer, but I would think it has some... seams like even the better suspension setups have some... enough to throw the alignment off a few mm I would think. I don't know from experience though, although I hope to find out soon.
When measuring toe, and the suggested spec calls for "x" degrees or mm toe, I would presume that measurement is from furthest point forward and the furthest point back on the tire tread right (in relation to the car)? In otherwords, if the spec calls for "X" mm toe in/out, wouldn't that measurement be derived from a point of the tire tread rather than the rim? If one were to measure from the rim, should the measurement be modified by the ratio of rim diamter to tire diameter? Hope that question makes sense... Best, Phil Quote:
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13 Sep 2007, 16:00 (Ref:2011306) | #5 | |||
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Quote:
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13 Sep 2007, 22:32 (Ref:2012026) | #6 | ||
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TURBOPHIL All the tracking gauges that measure off the wheel rim or tyre have a way of compensating for the diameter. There are various ways of setting steering track, some of them are over complicated as no car ventures very far from parallel. The easiest way for you would get it checked by somebody who knows what they are doing for a start. Not by some knob-head in a "Mr Tyre" shop who probably wouldn't know how to use it , and certainly wouldn't know how to calibrate the gauge to see if it was itself correct. After that you can work out a way of measuring it for yourself as you then have a reference.
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Balls of steel (knob of butter) They're Asking For Larkins. ( Proper beer) not you're Eurofizz crap. Hace más calor en España. Me han conocido a hablar un montón cojones! Send any cheques and cash to PO box 1 Lagos Nigeria Africa ! |
13 Sep 2007, 22:47 (Ref:2012037) | #7 | |||
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Thanks, Not sure if you've been to the states, but we're full knob-heads over here (myself excluded of course)...
Ultimately, my situation should be pretty simple as I'm going for zero toe in the front. I'm looking for 1.5mm toe in on each in the rear, which maybe a bit tougher. Finding the true centerline so the car doesn't dog-leg down the track seems slightly ambiguous, albeit doable with strings... The part I'm having the hardest time getting my small brain around is where exactly to take the measurement... I would presume that if I have 24 inch diameter tires, then I want to take my fore and aft measurements 12 inches from center and perfectly parrellel to the ground for each tire. If I take the measurement at the rim, I should compensate for the smaller distance from center... Does that follow good logic or am I out in the sticks? Best, Phil Quote:
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13 Sep 2007, 23:31 (Ref:2012067) | #8 | ||
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I know exactly what you are saying, that's why I said tracking gauges (like the dunlop one that hasn't altered for 50 years) has a calibration for diameter. Put it this way if you knew what it was for a start , and tied two pieces of 4ft flat wood onto both front wheels pointing out the front of the car then measured between them, you could replicate it at another time.
To "accurately" measure the track without a gauge of some sort would be difficult as you are only looking at a small amount. |
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Balls of steel (knob of butter) They're Asking For Larkins. ( Proper beer) not you're Eurofizz crap. Hace más calor en España. Me han conocido a hablar un montón cojones! Send any cheques and cash to PO box 1 Lagos Nigeria Africa ! |
14 Sep 2007, 03:43 (Ref:2012201) | #9 | ||
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If you are using standard type suspension arms which are not adjustable you need not worry about finding the centreline one the car you can use another reference point such as the hub face in the centre of the wheel.
Using parallel string lines is the cheapest pieces of equipment that you can make. If you use aluminium tube and fishing line you will have a nice light parallelagram. Use chassis stands at each end of the car to hold them up so that the string is in line with the centre of the wheel. Set them so that you have the same distance from the string to the wheel hub (reference point) on each side of the car. Dont worry if thsi distance is different each end just make sure that left front is the same as right front, left rear is same as right rear. Now you can measure and adjust your toe. Measure at the rim, do not adjust (or compensate) the measurement. This is toe at the rim as used by professional race teams. The measurement is only for your records and information so that you can compare with the last setting on your car. Do not use anyone elses toe settings unless they are running the same car on the same track and the same size wheels. Make sure to recheck your reference distances when making adjustments, I have seen cars walk sideways while work is being carried out which messes your settings. Do not use a road car alignment machine!!! most are not correctly calibrated. |
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14 Sep 2007, 09:46 (Ref:2012434) | #10 | ||
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I have a simple little devise like a giant internal micrometer that you just offer up to the front of the wheel(s) between both then to the rear and measure the difference off a little sliding guage, bit crude but seems to work OK and I have tested against the string method.
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14 Sep 2007, 10:29 (Ref:2012483) | #11 | ||
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Some basic guides on setting up the Elise suspension;
http://wiki.seloc.org/a/Geo_Alignmen...28Home_Made%29 http://wiki.seloc.org/a/Geo_Setups |
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14 Sep 2007, 12:34 (Ref:2012659) | #12 | ||
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I have DUnlop optical gauges and a spirit level type camper gauge, both seem pretty good if simple my tyres wear out evenly and it starts and stops in a straight line if thats anything to go by, except when I spin |
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14 Sep 2007, 13:04 (Ref:2012684) | #13 | ||
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I have a Churchill tracking/ castor/ camber gauge that I have had for years, and often have to re-set "so called "tyre shop balls ups.
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Balls of steel (knob of butter) They're Asking For Larkins. ( Proper beer) not you're Eurofizz crap. Hace más calor en España. Me han conocido a hablar un montón cojones! Send any cheques and cash to PO box 1 Lagos Nigeria Africa ! |
14 Sep 2007, 15:55 (Ref:2012864) | #14 | ||
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"Churchill, have I got 2 degrees of toe-in on the left hand side only?"
"Ohhh yes!" Sorry |
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14 Sep 2007, 17:18 (Ref:2012961) | #15 | |||
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This make sense to me and clears things up... few people in the states seem to do much in the way of home remedy and DIY. Not sure why. Laziness or fear...possibly combination of the two??
The instructions on SELOC along with this entire thread have been very helpful. Thanks everyone! Best, Phil Quote:
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15 Sep 2007, 14:44 (Ref:2013685) | #16 | ||
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15 Sep 2007, 19:29 (Ref:2013909) | #17 | ||
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As a really simple way of measuring the toe in/out and checking it against the centre line of the car, I use a cheap laser level bought from the local diy shop. I centre the steering then clamp the level to each of the wheels and measure the offset in/out at the middle of the wheel at the other end of the car. A simple bit of trigonometry based on the amount of offset and the wheelbase of the car will give you the toe in degrees. This does assume that the front/rear track is the same. If not then a simple addition/subtraction of half the difference in the track is needed in the trig.
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16 Sep 2007, 00:21 (Ref:2014133) | #18 | |||
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It can cost a lot and lead you in many and varied directions! |
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16 Sep 2007, 21:42 (Ref:2015014) | #19 | |||
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Fantastic site, the methods and information are spot on. There are a lot of people that look at the different forums that should check these out. |
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17 Sep 2007, 08:43 (Ref:2015373) | #20 | |||
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I've been far too lazy/busy this year to implement this though! |
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17 Sep 2007, 21:43 (Ref:2016256) | #21 | ||
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I find the biggest advantage of this sort of method is that it gives the toe of each wheel individually. It avoids the situation that can happen using a toe gauge of having one wheel straight and one with the twice the desired toe angle.
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24 Sep 2007, 21:29 (Ref:2022122) | #22 | |
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and putting my 2cents worth in just to possibly confuse you. In Speedway (Circle Track) we measure off the tread centre blocks. Set the right side wheels straight ahead and put all the toe out (2-4mm) into the the left front. This helps get the car into the corner. Totally useless info for your Lotus though......trikes
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25 Sep 2007, 02:00 (Ref:2022234) | #23 | ||
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Thanks again guys. This thread has been very helpful filling in the blanks.
The results from my DIY alignment were great. I could tell from the driving experience at the track last week that the alignment made a great difference in the car's handling. I'm sure my ride height changes didn't help the OEM's alignment, as the Elise's toe changes with ride height changes. It's not huge, but it clearly does have some bump steer... I put some simple pics up on my webpage, which is primarily used for hobbies and friends' projects. (not a business plug, as the parts we make aren't sold to the public ) www.boefabrication.com Our next project is going to be an attempt to make a new rear diffuser panel that's more function than form. I beleive the marketing folks at Lotus got the better of them when designing the diffuser (under-tunnel, venturi, or whatever you want to call it) for the Elise/Exige. It needs strakes to block the incoming air off from the rear wheels, needs to have deeper and longer strakes down the center tunnel too... I'm sure there's more, I just need to put more thought into it and gather some more insight from those that have done it... Best, Phil |
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25 Sep 2007, 07:27 (Ref:2022323) | #24 | |
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Elise diffuser
There have been a couple of interesting articles in Racecar Engineering's last couple of issues on the Lotus diffuser aerodynamics, based on a test session in a full size wind tunnel. IIRC they showed that the wheels and exhaust exit were both rendering the diffuser useless. You need to extend the side strakes and shift the exhaust exit out of the diffuser.
I'm sure they have back issues if you get in contact with the publisher. G |
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25 Sep 2007, 21:42 (Ref:2022990) | #25 | |
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Just had a look at the Lotus site pics and one thing struck me. When I set the toe the driver (and or passenger) are in the car as the toe setting changes laden or unladen and with fuel usage. One of our cars changes / adds 2mm of toe out laden and then with roll it changes (lessons just a little). Perhaps with the Lotus being such a light car it may be worth your while going back and rechecking things laden. One of my Gravity Racers is a 4wheeler and it's toe settings are extremely detrimental to performance with the driver being weighed during the days racing and the Racer sitting on scales as the driver climbs aboard prior to a run to ascertain the the toe and weight are at the optmal position. Bit extreme I know but if thats what it takes to win and my daughter only ever lost one Title race in 5 years by 40mm. Caused by a cracked ball bearing. She now races a trike say's four wheelers are too slow........trikes
Last edited by trikesrule; 25 Sep 2007 at 21:44. |
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