Toe Settings: Inches to Degree Conversion?
02-10-2011, 02:29 PM
#31
Lifetime Rennlist Member
i.e. - Both are correct, unlike lbs as a pressure.
02-10-2011, 03:27 PM
#32
Rennlist Member
If you have different sized wheels, this value will change. I think with the advent of the calculator, folks can get the angle they want pretty easily. But yes, I never do angle when stringing mine, its always a releative value, based on daimeter. diameter or radius, it doesnt matter. once you get the toe difference, the diameter or radius will trig out the angle just the same.
I use 1/16th of an inch toe in, but that is based on diameter, so if it was based on radius for the same angle, it would be 1/32". (.033 INV TAN) =.05 degrees or so.
mk
I use 1/16th of an inch toe in, but that is based on diameter, so if it was based on radius for the same angle, it would be 1/32". (.033 INV TAN) =.05 degrees or so.
mk
I think if you go back far enough, you will find that toe was always expressed as inches/mm. It was only with modern alignment machines that toe was expressed as an angle. That and the fact that almost all race cars are setup with toe as inches/mms and it seems to make more sense to me to talk about toe that way.
i.e. - Both are correct, unlike lbs as a pressure.
i.e. - Both are correct, unlike lbs as a pressure.
02-11-2011, 04:45 AM
#33
Three Wheelin'
Mark, that was actually what I wanted to hear, that you had a good reason for sticking with the passive toe-in! It makes sense, if it works, it works!
I have watched Mark Anderson with my own eyes dominate the Red group race at the POC Laguna Seca weekends running 1:30-1:31s, pretty serious stuff!
Not to hijack the thread, but how much does your 928 weigh? 1:36 is a pretty serious time! I have yet to break 1:50 in my 951, though it is a near stock '86 w/ 220 hp, 3,000 lbs on street tires and stock springs, only sway bars and an aggressive alignment to its name!
As for toe settings, with a machine or comparing when apples to apples, it will be in degrees. If your are measuring with strings, it will be in inches (or MM) and to convert to the actual toe angle will be dependent on wheel diameter. Use the SmartRacing chart that was posted earlier (which is actually a reprint from the classic book "How To Make Your Car Handle" by Fred Puhn) to convert to toe angle.
I have watched Mark Anderson with my own eyes dominate the Red group race at the POC Laguna Seca weekends running 1:30-1:31s, pretty serious stuff!
Not to hijack the thread, but how much does your 928 weigh? 1:36 is a pretty serious time! I have yet to break 1:50 in my 951, though it is a near stock '86 w/ 220 hp, 3,000 lbs on street tires and stock springs, only sway bars and an aggressive alignment to its name!
As for toe settings, with a machine or comparing when apples to apples, it will be in degrees. If your are measuring with strings, it will be in inches (or MM) and to convert to the actual toe angle will be dependent on wheel diameter. Use the SmartRacing chart that was posted earlier (which is actually a reprint from the classic book "How To Make Your Car Handle" by Fred Puhn) to convert to toe angle.
The slower guys all have "pinned" the Weisach. Mark A, ended up going full race, and didnt notice much of a differnce when changing in that functional regard.
No, no pinning for me. actually, the 928 is dead nuts straight and stable under braking, and had a big push as well as a resistant to rotate the car under heavy trail braking. a little additional toe out vs my original toe in setting, seemed to fixe that issue. now, im quite pleased and probably wouldnt change anything It has a greater ability to rotate the car now, and the exit speeds are faster with the push gone as well. Also added were more splitter and more wing to help in the higher speed corners. 1:36.1 at laguna for a 25 year old street car with 50 extra HP bolted on, and 15 year old bolt on suspension with used tires. (all original everything, bushings, airbox, radiator, brakes, no coolers, vents, no ECU changes, all stock)
ask B. Sofranas how my car was handling when he was behind me in his 2006 GT3 race car.
I wondered what happened to the design with the 993s going to the 996-7s. I assumed they kept that design. why did they change? for the reasons you stated. too much flex and slop, especially with all the weight and movemet in the rear of the car. Hey, I do agree that a proper set up would be to put all racing joints in the car. But, just think how long it would take me to find the right settings! I think much of my suspension set up is damped by friction of the bushings and bumpstops (seriously) if I removed it all, I would be lost.
No, no pinning for me. actually, the 928 is dead nuts straight and stable under braking, and had a big push as well as a resistant to rotate the car under heavy trail braking. a little additional toe out vs my original toe in setting, seemed to fixe that issue. now, im quite pleased and probably wouldnt change anything It has a greater ability to rotate the car now, and the exit speeds are faster with the push gone as well. Also added were more splitter and more wing to help in the higher speed corners. 1:36.1 at laguna for a 25 year old street car with 50 extra HP bolted on, and 15 year old bolt on suspension with used tires. (all original everything, bushings, airbox, radiator, brakes, no coolers, vents, no ECU changes, all stock)
ask B. Sofranas how my car was handling when he was behind me in his 2006 GT3 race car. I wondered what happened to the design with the 993s going to the 996-7s. I assumed they kept that design. why did they change? for the reasons you stated. too much flex and slop, especially with all the weight and movemet in the rear of the car. Hey, I do agree that a proper set up would be to put all racing joints in the car. But, just think how long it would take me to find the right settings! I think much of my suspension set up is damped by friction of the bushings and bumpstops (seriously) if I removed it all, I would be lost.
02-11-2011, 09:28 AM
#34
Race Car
Perhaps I should just use angles, instead. Pretty simple math, and I can always put a conversion chart on the plates.
02-11-2011, 10:16 AM
#35
Lifetime Rennlist Member
Really? I have always used toe plates, and measured the difference between the front and the rear. Should I be halving that difference to get numbers that are most frequently referenced? It darn sure is hard to dial in 1/16th on a 944.
Perhaps I should just use angles, instead. Pretty simple math, and I can always put a conversion chart on the plates.
Perhaps I should just use angles, instead. Pretty simple math, and I can always put a conversion chart on the plates.
I always try to use fishing line - it is very thin and you can keep it on a reel. It stretches and makes a very good measurement base. Then a caliper in mm - I find that much easier to read since you are dealing with whole numbers, rather than decimals.
I have not done 944 so I have no experience as to how hard it is to get 1/16. I will say that most cars I have done are pretty happy with 1mm toe out (per side) F, and 1mm toe in (per side) at the Rear. Now these are all cars with solid bushing suspensions - no rubber. Set the toe, roll the car back and forth a few times (only needs to roll a few inches) and remeasure. I would think that if you are having trouble getting 1/16, you may well have some slop in the suspension.
02-11-2011, 11:17 AM
#36
Race Car
Every race car I have worked on specifies the toe-in or out measured at the front of the wheel relative to the string. So yes, you are running half the suggested amount, unless that is coming from someone who is using the same technique that you are.
I always try to use fishing line - it is very thin and you can keep it on a reel. It stretches and makes a very good measurement base. Then a caliper in mm - I find that much easier to read since you are dealing with whole numbers, rather than decimals.
I have not done 944 so I have no experience as to how hard it is to get 1/16. I will say that most cars I have done are pretty happy with 1mm toe out (per side) F, and 1mm toe in (per side) at the Rear. Now these are all cars with solid bushing suspensions - no rubber. Set the toe, roll the car back and forth a few times (only needs to roll a few inches) and remeasure. I would think that if you are having trouble getting 1/16, you may well have some slop in the suspension.
I always try to use fishing line - it is very thin and you can keep it on a reel. It stretches and makes a very good measurement base. Then a caliper in mm - I find that much easier to read since you are dealing with whole numbers, rather than decimals.
I have not done 944 so I have no experience as to how hard it is to get 1/16. I will say that most cars I have done are pretty happy with 1mm toe out (per side) F, and 1mm toe in (per side) at the Rear. Now these are all cars with solid bushing suspensions - no rubber. Set the toe, roll the car back and forth a few times (only needs to roll a few inches) and remeasure. I would think that if you are having trouble getting 1/16, you may well have some slop in the suspension.
As far as the "recommended amount" goes, it is just stuff I read and hear. I don't know of anyone running more than just a little toe, so that's all I'm really after. It is just nice to see that I'm not running way too much when I have 1/8th front to rear. Tire wear hasn't been a problem, though, so I haven't been alarmed (especially once I got the rear to stop slipping, giving me max toe out - sure helped rotate the car through 10A at Road Atlanta, but it was squirrelly even in a straight line at over 110!).
I like the idea of strings, and I know some guys who run a race shop who do exactly that. I'd actually like to set up something for camber, as well, as the digital gauges I've used haven't been that reliable. I'd need to fab up a mount to put the brace on my car, but I'm pretty new to all of this, and it just takes time to collect everything.
02-11-2011, 03:25 PM
#37
Rennlist Member
Really? I have always used toe plates, and measured the difference between the front and the rear. Should I be halving that difference to get numbers that are most frequently referenced? It darn sure is hard to dial in 1/16th on a 944.
Perhaps I should just use angles, instead. Pretty simple math, and I can always put a conversion chart on the plates.
Perhaps I should just use angles, instead. Pretty simple math, and I can always put a conversion chart on the plates.
Mark, that was actually what I wanted to hear, that you had a good reason for sticking with the passive toe-in! It makes sense, if it works, it works!
I have watched Mark Anderson with my own eyes dominate the Red group race at the POC Laguna Seca weekends running 1:30-1:31s, pretty serious stuff!
Not to hijack the thread, but how much does your 928 weigh? 1:36 is a pretty serious time! I have yet to break 1:50 in my 951, though it is a near stock '86 w/ 220 hp, 3,000 lbs on street tires and stock springs, only sway bars and an aggressive alignment to its name!
As for toe settings, with a machine or comparing when apples to apples, it will be in degrees. If your are measuring with strings, it will be in inches (or MM) and to convert to the actual toe angle will be dependent on wheel diameter. Use the SmartRacing chart that was posted earlier (which is actually a reprint from the classic book "How To Make Your Car Handle" by Fred Puhn) to convert to toe angle.
I have watched Mark Anderson with my own eyes dominate the Red group race at the POC Laguna Seca weekends running 1:30-1:31s, pretty serious stuff!
Not to hijack the thread, but how much does your 928 weigh? 1:36 is a pretty serious time! I have yet to break 1:50 in my 951, though it is a near stock '86 w/ 220 hp, 3,000 lbs on street tires and stock springs, only sway bars and an aggressive alignment to its name!
As for toe settings, with a machine or comparing when apples to apples, it will be in degrees. If your are measuring with strings, it will be in inches (or MM) and to convert to the actual toe angle will be dependent on wheel diameter. Use the SmartRacing chart that was posted earlier (which is actually a reprint from the classic book "How To Make Your Car Handle" by Fred Puhn) to convert to toe angle.
my car is about 3000lbs with me in it. I think when I was back in the 240rwhp days, the best i got down to was a 1:45 or 1:46 . it wasnt until i bolted on some 285rwhp, did i get down to the 142s and then with the holbert car ,the 1:39s with 320rwhp. Laguna is really well suited for the 928 though. add some sound restrictions and then Anderson just has his way. But then again, when we went out to the GTGP race , organized by GMG, he was just one of the pack, like me again. the top 2-3 cars were running in the 1:26s. (WCGT cars , but now on real slicks)
02-11-2011, 05:11 PM
#38
Race Car
I dont know how else to be accurate, unless a group of folks have the same tires an wheels and post a inch based distance which they know works. it all trigs out to an angle and the angle is the same whether you measure radius or diameter, as long as you know what is what.
05-21-2012, 09:24 AM
#40
Mr. Excitement
Rennlist Member
Rennlist Member
I think if you go back far enough, you will find that toe was always expressed as inches/mm. It was only with modern alignment machines that toe was expressed as an angle. That and the fact that almost all race cars are setup with toe as inches/mms and it seems to make more sense to me to talk about toe that way.
i.e. - Both are correct, unlike lbs as a pressure.
i.e. - Both are correct, unlike lbs as a pressure.
depends on the wheel size. The math has been well geeked and there are some good charts availble.
05-22-2012, 01:56 PM
#41
Rennlist Member
05-22-2012, 04:15 PM
#42
Mr. Excitement
Rennlist Member
Rennlist Member
05-22-2012, 06:26 PM
#43
Rennlist Member
distance off straight ahead, 2mm as you say, divided by the diameter of the tire. ( assuming you are using the width of the two fronts of the tires vs the two widths of the rear of the tires.) that number INV TAN = will give you your toe in degrees.
06-21-2013, 01:03 PM
#45
1st Gear
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carerracoupe997,
if you still have access to the alignment rack and aligner, the simplest way to sort out your toe adjustment is to go into the aligner set up screen and select measurement format, then change it to any form of measurement you want, degrees, degrees and minutes, fractions of an inch, it's all there,,, let the software do the work for you. make it easy.
if you still have access to the alignment rack and aligner, the simplest way to sort out your toe adjustment is to go into the aligner set up screen and select measurement format, then change it to any form of measurement you want, degrees, degrees and minutes, fractions of an inch, it's all there,,, let the software do the work for you. make it easy.
