Since this went back and forth, let me try to summarize what's been posted by ezchief.

1. When in motion, the vehicle toes out.

2. Ezchief's original total toe was .07 inches. This was enough to cause the feathering on the inside edge.

3. Ezchief's new toe has been set to .14 inches. This is what was computed as optimal by Hunter with their computer modeling.


If I have this accurately, then .07 is not enough toe-in to handle the toe-out change when the suspension is loaded. The tires go out like this \ --- / which causes wear on the inside.

Some number greater then .14 inces toe-in is enough to be too much toe-in for the suspension when under load. The tires stay toed-in like this / ---- \ which causes feathering on the outside.

Now if we go back to the first page in this thread the Service Manual states total maximum toe-in is .08 inches. So we now have another problem... the Service Manual is incorrect.

Only other variable that we're missing is change in suspension due to the bounce.

Comments would be appreciated on this one.

 

Sorry to lose you, john. The S2000 is a great car, I'm sure you will enjoy it.

 

Good explanation, YM. I have to laugh, the Service Manual is incorrect, so we could inform all members to have their cars front tires aligned to .14 or we could wait on the results of ezchief's experiment to see if .14 works even with the bounce. What do you think?

You could post your findings on the experiment as a benchmark and let it stand as that and say nothing else. If owners want to change to the experimental setting, its their choice since you/we are not recommending anything, just providing information about the experiment. I think I will just watch my tires and wait, unless they start feathering fast, and when Nissan changes their setting recs, have my dealer change mine. I am not making any recommendation, I'm waiting for results from ezchief's trial.

I would like thoughts from you and others on the findings, thats all. Nissan's Engineers are involved and looking for a solution and thats all I wanted. I feel no need to continue pressuring Nissan any longer and I won't. Thanks YM. Keith

 

EZ, that is GREAT info, good job and keep us up to date!!

a few comments

1. Why the HELL does NISSAN NOT have access to a real car to test and experiment?? was that some type of joke?? Computers and models?? come on, they need to have 5 techs running 800 miles a day with lap tops in the passenger seat and recording and calculating data ALL the TIME!!!! Come on NISSAN get with it!

2. you mention .14", my new align says ......total toe= 0*09'
*=degrees

what does 0degrees09' mean compared to 0.14"????

 

Someone posted the conversion earlier in this thread, I believe. I'm not sure how to search for it, but you could give it a try.

 

From Deb's Other Half:

exchief - Interesting info. My wife's car has .05 on each side for a total of .10. Does your SM feel that this is still not enough or is there a range he has determined inside or outside of the specs? I am still monitoring tire wear but with only 2000 miles it may still be early. When wife's car was checked at dealer prep, total toe was about 0 - glad I had them align it. I plan on having everything relooked for her at 3000 miles and I would like to be able to tell my SM (who is very good, by the way) about your SM's suggestion of increasing the toe to what seems to be just outside of the spec's I was given (max was .06/side or .12 total).

Thanks for some great work!

DOH

 

From DOH - Sorry about that, EZ chief! x and z are close!

 

Okay...it sounds like Hunter may have a solution. Did they perform any tests on the back tires? The Nissan manual calls for .07 on the back which is exactly what Hunter said the front should be. Interesting!!

 

I found some referrences, but they are confusing, could someone who knows how to do it, compute this for me??

I would sure appreciate it, THANX!!!

again, what does total toe of 0*09' mean in inches?? (*=degrees)

THANX!!

 

I hope you guys are right about a greater toe in setting to fix the feathering,, but I am EXTREMELY skeptical for the following reasons:

By adding one or two passengers, the toe changes by up to 0.14'!!!

and lets say your toe setting is for a total of 0.07 (within spec) and you still get feathering (like some people I've read about),, is it reasonable to assume a toe difference of 0.07 is enough to cause such significant tire feathering?

Finally, it was noted that the suspension is pretty solid. If thats the case, then how can the toe changing so much when just 1 person gets in the car. By adding load,, it cant amount to THAT much since its only a 2 seater.

Just some concerns I think we all should be thinking about before we blindly go changing our front toe to 0.14

RaymanZ

 

hey all...

I'm taking the car in tomorrow for a first look -- I have distinctly uneven tire wear on the inside front tires at 1900 miles, and my car's VIN # 015615, manufactured 02/02.

I'm already prepared for them to give me trouble about my car not being in the range covered by the TSB, but if so they're in for a fight...

-- Mark

 

From DOH - Be sure that you really mean .14 INCHES. If you do conversions from degrees/minutes into decimals of degrees (this is what was printed on my wife's alignment spec's) you would get the following:

0 degrees 9 minutes = .15 degrees
0 degrees 4 minutes = .06 degrees

Just divide the minutes by 60 to get decimal degrees or multiply the decimal by 60 to get minutes.

I'm not sure if this is the discussion here - just an observation.

DOH

 

They did check the rears but there is no sign of a problem on my tires. Miked and were smooth across the tread patches.

Remember that load means a body and speed or motion forcing the toe out.

Regarding real world tests and not having a car to work on is bit of a surprise to me, also. You would think that they would have a car at the Arizona testing grounds rolling all day.

I will type in my specs since I can not scan them in. Also, I have new specs from Hunter for the car which I think are different from anything we have seen.

Aggie, I have to say the SM wanted to see my car for a few inspections so the data can be sent to NNA. This is a test as of right now. I will go by this weekend as I will have close to 500 miles on it.

 

Here are the specs I was given by my SM after Hunter tested and NNA reviewed:

Front Left and Front Right:

Camber: Spec -Tol. +Tol.
-.06 * .8* .8*

Caster: 8.2* .8* .8*

Toe: .07 in. .02 in .02 in.


Cross Camber 0* .8* .8*

Cross Caster 0* .8* .8*

Total toe: .14 in .04 in. .04 in.

REAR LEFT and RIGHT

Camber: -.16* .8* .8*

Toe: .02 in .02 in .02 in

Cross Camber 0.0* n/a n/a

Total Toe .04 in .04 .04

That is alot to digest so I will do this in two posts. Remeber that this is per tire so you would have two fronts and two rears on the spec sheet. Totals are combined as per the spec sheet given to me.

 

Before Measurement:

Left Front___________________________Right Front

-.9*----------------------Camber-------------------- -.8*
7.2*---------------------Caster---------------------- 7.6*
.06 in----------------------Toe----------------------- .01 in

--------------------- .07 in Total Toe

-------------------- .06 * Steer Ahead

Left Rear__________________________Right Rear

-2.1 *-------------------Camber---------------- -.9*
.04 in---------------------Toe--------------------.02 in

---------------------.06 in Total Toe
---------------------.02* Thrust Angle


Current Measurements:

Left Front__________________________Right Front

-.9*--------------------------Camber---------------- -.8*
7.2*-------------------------Caster------------------ 7.6*
.07 in------------------------Toe---------------------- .07 in

----------------------------- .14 in Total Toe
---------------------------- 0.00* Steer Ahead

Left Rear__________________________Right Rear

-2.2*--------------------Camber---------------- -.9*
.05 in-------------------Toe-----------------------.02 in

------------------------- .07 in Total Toe
------------------------ 0.03* Thrust Angle


I hope this comes out clear. Again, I will fax this to someone who can scan it in. PM me and I can get it off to you.

 

that is a lot of good info, only problem is it still doesn't convert my measurement to INCHES

anyone??

 

I agree totally that all people should not go out and change the toe. I have said that this is a test based on some good analysis from Hunter and NNA. I will be taking my car back in a week or sooner to have the tires miked.

Your question about the suspension being solid is a good one. One concern Hunter had was that the suspension was "floating" backwards toward the engine as can happen on Audi's. This would be a major problem for the geometry and specs. Again, it was tested and it is solid. I do not know why the toe moves so much under load and driving. A memeber here brought his concerns personally that the shorter wheel base on the Z compared to the G35 could be the culprit.

If he wants to, this could be a good time to elaborate.

 

I have driven the G, the suspension is SOFTER, the only difference is NOT just the wheelbase, although that could have somehting to do with a more bouncy ride.

btw, the Z has a loooooooong wheelbase compared to most cars, but the Gs are super long.

 

Too bad. They looked at the distinctly odd tire wear, totally consistent with feathering, and said it was "normal." Also told me orally that they'd checked the alignment and that it was within spec.

Soooo I noted it in my notes and when it gets really bad I'll have more ammo to go on the warpath for new tires...

-- Mark

 

okay, ive been foloowing this thread on and off for about a week or so. i noticed a couple of weeks ago this road noise around 40 to 50mph and when i come to a stop. didnt think much of it, then i fell upon these threads on this site and i started to freak! i have 5500 miles on mine and know i can actually feel the "TEETH" on the inside of my tires.

i set an appointment up with the dealer for this thursday. can somebody tell me how to go about telling the dealership. now that i have noticable teeth showing should i demand tires? what if they want to switch the tires and align it, should i let them? my car doesnt pull from one side to the other, i dont want them to do further damage by messing up my alignment in addition to my road noise.

my plan was to ask for new tires and hope NISSAN figures out a fix by the next 5000 miles. is that what i should? also once i have it serviced, i was told to file a claim with NNA, right?