Rear toe with non-compliance ?

[asylum]

Finally I will have the non-compliance toe links and rear beam bushings installed. What rear toe should I run now ? Currently I have +3 to +3.5 mm each side. Without compliance I can deduce it to +1 mm ? Less ?

 

[CL65 Captain]

I remember reading a thread where Shad at DA said that he recommends going to 0 in the rear with the non-comp stuff in the rear.

Someone correct me if I'm wrong.

 

[Track Addict]

+1 on the 0* of toe in the rear.

 

[nsxhk]

zero rear toe in? What's the advantage?

Henry.

 

[CL65 Captain]

zero rear toe in? What's the advantage?

Henry.

Honda used a lot of rear toe in to make the car more stable as well as help tame the snap oversteer. With the rigid toe links it prevents the dynamic toe change so you don't need as much toe in to start with.

From the Wiki:

"Rear toe should be about 3-4mm toe in. The more toe in you have on the rear the more stable the car will be down the straight and the more stable understeer you will have in the corner. Some factory settings on certain models had up to 8mm toe in. This was to keep the car more stable. The tire wear was very high and many owners complained about it, so the next year they went back to lower settings in the 4-6mm range. In an ideal world, as the suspension moves the toe would never change, but it does. This is why we make the low compliance rear beam and toe links. If you don't believe me, do this simple test. Look at the rear wheel out your door and roll you car backwards and hit the brakes, see the wheel move in and out? This is toe change! The less you have the better."


I have never run 0, but my settings are relaxed compared to spec. I run 2mm compared to OEM 91-92s 6mm or 93+ 4mm.

 

[joove]

I remember reading a thread where Shad at DA said that he recommends going to 0 in the rear with the non-comp stuff in the rear.

Someone correct me if I'm wrong.

I tried searching for this but after trying several keywords nothing useful came up. If you have a link to the original post by Shad, I would love to read it.

 

[DrivingAmbition]

I remember reading a thread where Shad at DA said that he recommends going to 0 in the rear with the non-comp stuff in the rear.

Someone correct me if I'm wrong.

I have never run 0 toe in the rear, even with our race cars that have steel mono-balls on all the rear suspension points. We usually run about 1/16" toe in on both rear wheels for a total toe in of 1/8". Hope this helps, Cheers, Shad.

 

[asylum]

That is 1 to 1.5 mm each side. Thanks.

 

[joove]

I have never run 0 toe in the rear, even with our race cars that have steel mono-balls on all the rear suspension points. We usually run about 1/16" toe in on both rear wheels for a total toe in of 1/8". Hope this helps, Cheers, Shad.

Thanks for chiming in Shad.

 

[SFNSXguy]

I run the 1991 specs (6mm toe in... a touch less than 1/4" total) with the non-compliance setup. Quite happy.

 

[stuntman]

I have never run 0 toe in the rear, even with our race cars that have steel mono-balls on all the rear suspension points. We usually run about 1/16" toe in on both rear wheels for a total toe in of 1/8". Hope this helps, Cheers, Shad.

Agreed. The ballpark I usually work in is 1/8" - 1/4" (2-4mm) total.

Billy

 

[asylum]

I got it aligned today. I corrected also the front because I had to much camber when looking at the tire wear (it went to -4° which is too much).

Front :
Camber : -3.4 ° / -3.4°
Toe: -0.8 mm / -0.7 mm

Rear :
Camber : -3.0 ° / -3.0 °
Toe : +1.6 mm / +1.3 mm

 

[Hagasan]

I have been watching the post on this topic and wonder if someone can answer a few questions at the end please.

I run OEM 02+ wheels with H&R spacers, front are 15mm & rear 25mm. Just fitted new Yokohama AD08's (in UK). Also fitted Titanium Daves non-compliance front brackets and rear bush & toe-link parts.....

Car is used on the street but may do some track days......

On reading the alignment figures a lot of you were using I tried to come up with something that will minimise tyre wear but still handle ok....

My choice of setting were.....

Front, Camber -1 degree each side, castor 8 degrees and toe out 2mm total.

Rear, Camber - 1 degree 40 mins each side, Toe in 3mm total.


Had the alignment done and was in a hurry so had to take as it was set but toe is in degrees/minutes....

Can someone confirm the following in mm please or inches if that's easier....


Front toe comes out at - 0 degrees 16 minute total

Rear toe comes in at + 0 degrees 24 mins total


What do you think of these settings in general, good, ok, bad??


Thanks,

Gary


EDIT...so I tried working this out, can someone with a little experience check please

With the front total toe of 0 degrees 16' it looks like the toe for a 17 inch wheel is ~4mm

For the rear total toe of 0 degress 24' it looks like I have a value of ~6mm, again for a 17 inch wheel

I'd be grateful is someone can confirm my figures as I don't like the rear 6mm toe in as I want to save the rear tyes a bit more

 

[asylum]

You can consider that your wheel has a 630 mm diameter.
24 minutes means 0.4°.

Toe = 630 x sin 0.4° = 4.4 mm

 

[Hagasan]

You can consider that your wheel has a 630 mm diameter.
24 minutes means 0.4°.

Toe = 630 x sin 0.4° = 4.4 mm

Thanks for your answer. It got me thinking and searching again.....

I maybe (?) should have mentioned that the alignment was done on a Hunter machine. A quick google on "hunter alignment degrees to mm" brought me back to Prime!!!

http://www.nsxprime.com/forums/showthread.php?t=31986

Post 18 in this thread mentions the constants or reference that Hunter use with their machine....

Going by the calculations my 2mm toe out on the front and 3mm toe in on the rear I requested does actually come out to the 0 degrees 16' and 0 degrees 24' I ended up with.

EDIT....

Confusion over unit used?? 1 degree= 60 mins so.....

I wonder if, say for the front, the result of 0.16 degrees actually means 0.16 of 60 mins which is 9.6' and it's therefore ~10' that should be on the read out?

Also the rear of 0.24 degrees then comes out as 0.24 of 60 minutes which might mean 14.4' so again about ~14-15' for the 3mm rear setting?

Or does the arcsine calculation mean the value calculated is the true minute value?





I tried all the other calculations with actual tire diameters etc and they give 2.73 & 4.32 mm

I guess I should accept the Hunter reference and final measurements as being correct since this was the machine used in my case........

 

[stuntman]

IMO, 1 degree isn't enough camber, especially in rear. 6mm of rear toe would probably result in more wear than 2.5 degrees with 2mm total toe.

I would go with -1.5* front with 0-2mm total toe and -2 but rather -2.5* rear with 2-4mm toe.


0.02

 

[MetalSpikeRacing]

Wow, I am so cumfused .
Some of you are talking toe on millimeters others on inches and the alignment racks here in Toronto read degrees.

What is the value need it on degrees for a non compliance rear ?
Is 1.9* = to 1.5mm on a 18" wheel?
I think I am looking for 1.5mm rear toe Per side with non compliance, right?

-MSR

 

[BATMANs]

I love this stuff for spirited street use. I can really tell a difference.

 

[MetalSpikeRacing]

Well just came back from the aligment shop and here are the specs:

Front

Camber R -2.9. L -3.0
Caster R 8.5 L 8.6
Toe. L .07* R .07*


Rear

Camber. L- 3.0 R. -3.1
Toe L -.09* R -.09*


This setting are with comptech's front camber bushings and SOS non compliance rear toe links and Rear bar.

At the front I could not got any less than -3.0 on the left side, and the back I could not get less than 3.0 on the right side!!!!

I was looking for -2 at the front and -2.5 at the back. My car is very low so that might be the reason, I will to compensate the too-much camber issue with tire pressure.

Thoughts?


-MSR

 

[asylum]

Same for me. I cannot get under -3.5 front with the Comptech bushings. Anyway it is ok as it is a track only car with full slick tires. Driving on the street (a lot of straight lines) with such agressive settings is not really usefull but if you have a mixed use (street/track) you will have to cope with these and the inside tire wear.

 

[Ponyboy]

Rear

Camber. L- 3.0 R. -3.1

I think that you'll find that you don't need as much rear camber. In addition to how rear grip feels and how stable the car feels, a tire pyrometer will be a good indicator of what camber and toe #s may be ideal.

 

[MetalSpikeRacing]

I think that you'll find that you don't need as much rear camber. In addition to how rear grip feels and how stable the car feels, a tire pyrometer will be a good indicator of what camber and toe #s may be ideal.

You're right on the pyrometer, but the thing is that I don't have anymore positive camber.
-3 is as high as it goes. Pretty much all around.

I think I'm more concern about having -3 all around, instead of having -2.5 at the front and -3 at the back.

-MSR

 

[Ponyboy]

You're right on the pyrometer, but the thing is that I don't have anymore positive camber.
-3 is as high as it goes. Pretty much all around.

I think I'm more concern about having -3 all around, instead of having -2.5 at the front and -3 at the back.

Hmm, so you can't get any less than -3 on the rear? I was thinking -1.5 to -2 would be your sweet spot.

 

[MetalSpikeRacing]

Nope no less than three, the only way to adjust my steering bias would tire pressure, but then again that will depend on their temperature.

Why you think -1.5 at the back would good with the -3 at the front?to Help the car rotate better? I think I already have too much camber at the front.



-MSR

 

[Ponyboy]

Actually, I probably shouldn't just throw out numbers w/o seeing exactly what your suspension and tire setup is. That said though, the reason I thought -1.5 to -2 would be your sweet spot is that that has been my experience with a tire pyrometer. But I'm sure you run a more narrow rear than I do (285). Less rear camber will give more straightline traction.

Of course, you want as much rear grip as possible, which you'll want to then focus on maximizing front grip to find the balance you want. Just take a look at the front and rear wear patterns to get you in the ballpark.