Technical question on sport shims, toe settings, tie rods-

[Vic]

There is only sport shims on the front, right? When I take em out, I'll get more negative camber, which is good, but which way does the toe go, after shim removal? A search result came up with conflicting views. One guy said you end up with more toe out, the other guy thought it was more toe in. Which is it?

And to correct for a fast track like Willow Springs, would I want 1/8" toe out, or 1/4"? Probably 1/8", right? Which way to turn the tie rod? If you say CW, (or CCW), please indicate which end you are looking at to determine rotation direction. CW from one end looks like CCW from the other end! I could answer the tie rod direction question myself by looking at the threads, I guess. But I haven't yet visualized how changing the camber can affects the toe, so if anybody can clue me in...........?

Finally, What will happen to the feel and handling of the car, say, on a constant speed and radius high speed turn? Will the front bite better now, with the more negative camber? (Yes) And since it sticks better than the rear, would the back end tend to break loose first, making the car now tend to oversteer more than before?

Or maybe you just turn the wheel accordingly, to compensate? Any experiences with this set up?

 

[Vic]

bump

 

[GTS Dean]

Vic,

Only the front suspension has a pivot bar for the upper A-arm, so only the front can use sport shims. When you pull the shims, you gain approximately 1 degree of additional negative camber, but your caster angle stays constant. The toe setting will go OUT. You will end up with between 1/8" and 1/4" toe out, depending on where you started from. This helps turn-in a bunch, but will tend to make the car a little bit more nervous at high speeds - but nothing you can't handle with both hands on the wheel like they should be.

All the tie rods on the Viper are right hand thread. AT THE FRONT, SHORTENING THE LINKS (clockwise rotation) WILL INCREASE TOE-IN because the rods are ahead of the wheel centerline. AT THE REAR, SHORTENING THE LINKS WILL INCREASE TOE-OUT because the links are behind the axle centerline. From time to time, you need to lift the inner boot seal with a small screwdriver and squirt a shot of silicone lubricant in. Do the same at the outer rod end threads too. This makes it easier to adjust the links. The driver's side rear link is a sumbeech to adjust with the wheel on because of the battery box cover.

Once your car takes a set in the corner, the toe is irrelevant and Ackerman angle has a greater effect on handling. You aren't likely to change Ackerman - ever. Once the car is set in a constant-radius turn, you should control your line through gentle modulation of throttle pressure, not steering input. Throttle steer response is most easily influenced by minor (2psi or less) adjustments in tire inflation pressure.

 

[Joel]

I've never removed mine, but if I did its going to get into a toe out situation. Therefore you will need to wind the track rod ends onto the rack a little more to get back to correct toe setting. Not sure about setting toe different from standard, probably need to experiment a bit. Suspect the neg camber might make steering very darty at high speeds, might be more of a sub 100 mph thing to do. Think it will turn in better but the rear may need a bit of catching. In theory anyway.

 

[Vic]

Dean, Joel, Dan,

Thanks very much for your responses. That is what makes this board great. You can ask a real question and get solid answers.

The VCA is the "in" place!

Dean, it didn't occur to me that the tie rods were ahead of the wheel centers. Now I see how shortening the rods increases toe in. When you say clockwise, you must mean as viewed from looking into the rack.

Now that I understand a bit more, it sounds like a good idea to just take the shims out, and leave the tie rod ends alone. Since a little toe out will help the turn in, I'll give it a whirl like that.

We'll see how it feels going down the front straight at 125. Hope its not too nervous. (like me!)

After the track, I'll stick the shims back in.

Thanks again!

 

[GTS Dean]

Vic,

I'm almost always under the car looking up and outward at the steering knuckle. I say clockwise from that perspective. I use a small pair of those Sears auto-adjustable pliers for tie rod work.

 

[Vic]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by GTS Dean:
Vic,

I'm almost always under the car looking up and outward at the steering knuckle. I say clockwise from that perspective. I use a small pair of those Sears auto-adjustable pliers for tie rod work.

<HR></BLOCKQUOTE>


Right, ok....


Thanks.

 

[GTS Dean]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Vic:
Dean, Joel, Dan,

Thanks very much for your responses. That is what makes this board great. You can ask a real question and get solid answers.

The VCA is the "in" place!

<HR></BLOCKQUOTE>

Remember - you asked a good question in the correct forum. You probably wouldn't have been so lucky in Off Topic or the "Alley."

 

[Vic]

Hmmm, yeaah, without a doubt!

 

[Fast Viper Dan]

Vic,
I have removed the shims once. It was at willow springs and what a difference! It dose change the toe to a neutral or little bit of toe out but I think that was designed into the car to do just that. If you are going to drive the track on the weekend and on the street the rest of the time I would not make any other adjustments to the toe. Also by removing the shims you will see wear on the inside of your tires. For that reason as well as handling I would put the shims back in as soon as you finish your track driving.
Try it!
Dan

 

[GTS Dean]

Bump!

This subject needs to make the Monday morning edition for wider circulation.

 

[SoCal Rebell]

Vic, the best mod for you right now is SEAT TIME. leave the mechanics alone and learn to drive the car fast and then start the mods, it'll make you a better "driver". I look forward to spanking your butt at WSIR this weekend

 

[SoCal Craig]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by SoCal Rebell:
I look forward to spanking your butt at WSIR this weekend

<HR></BLOCKQUOTE>

Ron, are your camera guys gonna put in on film

Vic, so when you're done pulling your shims how about doing mine

. Seriously, is this a simple thing to do? Are you doing it at the track or at home?

 

[Vic]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by SoCal Rebell:
I look forward to spanking your butt at WSIR this weekend

<HR></BLOCKQUOTE>

Your a sick man, you know that?

 

[Vic]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by SoCal Craig:
Ron, are your camera guys gonna put in on film

Vic, so when you're done pulling your shims how about doing mine

. Seriously, is this a simple thing to do? Are you doing it at the track or at home?

<HR></BLOCKQUOTE>

I don't know. I'm still learning about it, but so far it looks like you loosen the bolts that hold the upper control arm to the frame, and just pop out the horseshoe shaped spacers, then tighten the bolts back up. It appears that there is no way to screw up any other adjustments, because the arm just bolts on one way, without any slots and such to allow the arm to move around. Unfortunately, I pulled a back muscle snorting a line on a low coffee table, so I haven't been able to investigate any further right now. Maybe I'll get healed by Friday night, and do it then.

If you find out any more, please let me know.

 

[Serious Eric]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by SoCal Craig:

Vic, so when you're done pulling your shims how about doing mine

. Seriously, is this a simple thing to do? Are you doing it at the track or at home?
<HR></BLOCKQUOTE>


Holy crap, no! They're only on there with about 400 ft.lb. of torque. Best done on a lift. I pulled mine at the track once, groveling around on the ground with a box wrench and the car up on a jack. Lost one of the nuts doing it too ... popped right outta the ******, rolled across the garage floor and the pit-dog snarfed it up.

Do it at home where you can get a big cheater bar on there. I don't think pulling the shims alone helped me much. The toe was too outta whack. Best to realign the thing and do it right.

 

[Bad_Byte]

Hey Vic, Craig just a little from my 94's service manual. It says: The upper control arm pivot bar to frame nuts are torqued to 155 ft. lbs. which is considerable but not impossible.

More importantly it says:

"When sport shims are removed, front wheel static toe must be reset to production specifications. This can be done using a trammel bar and does not require an alingment rack.

When sport shims are replaced, front wheel static toe must again be reset to production specifications. This can also be done using a trammel bar and does not require using an alingment rack. All other alingment settings will not be changed from production specifications."

Again, I'm sitting on the sidelines

for this event. I'm still preping my car. You know, an ounce of prevention.... etc. I'm sure getting antsy to get out there with you guys though.

 

[HP]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Bad_Byte:
Hey Vic, Craig just a little from my 94's service manual. It says: The upper control arm pivot bar to frame nuts are torqued to 155 ft. lbs. which is considerable but not impossible.

<HR></BLOCKQUOTE>

155ftlb might be correct to retorque it, but I've found that
for removal sometimes it takes up to twice that to break it loose.

 

[GTS Dean]

Once you get them busted loose, the best tool to have is a 13/16" ratcheting box wrench. Even better is one that also has a 3/4" on the opposite end for doing the lower wishbones.

 

[Vic]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Eric Schieve:

Holy crap, no! They're only on there with about 400 ft.lb. of torque. Best done on a lift. I pulled mine at the track once, groveling around on the ground with a box wrench and the car up on a jack. Lost one of the nuts doing it too ... popped right outta the ******, rolled across the garage floor and the pit-dog snarfed it up.

Do it at home where you can get a big cheater bar on there. I don't think pulling the shims alone helped me much. The toe was too outta whack. Best to realign the thing and do it right.

<HR></BLOCKQUOTE>

Eric, the man! And here I thought you mostly tended towards literary pursuits! You have once again surprised me with your modern renaissance man attributes.

From classics such as "contemplating the fung shui of the bougainvillea" to "one of the nuts rolled across the garage floor and the pit-dog snarfed it up."

Now let me guess, you also have a golden gloves in boxing, and before that you were a still life oil painter, and before that you were into skydiving, concurrently working on your PHD in astro-physics, right?!

 

[Serious Eric]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by HP:
155ftlb might be correct to retorque it, but I've found that
for removal sometimes it takes up to twice that to break it loose.

<HR></BLOCKQUOTE>


Amen, and I found no way to get a socket on it ... at least with the car jacked up and the suspension hanging down. Had to use a box wrench to break that ~300ft.lb. Hence my comment about losing a nut. I think you need the car on a rack and the wheel jacked up to get the control arm out of the way.

 

[kverges]

On top of the torque to bust the nuts loose, the nuts are "self-locking" so cannot be turned by hand at any point (at least they can't on my Gen I car). I recommend a stubby box wrench for this task as the confines are pretty tight.

Total waste of time until you have some decent seat time; in fact it will take away some of the safety understeer the car has stock. I still have not removed the sport shims on my GTS; not enought track miles on it to warrant the change.

Finally, when setting toe, jot down how many turns on the tie rod it took to ge the toe setting you wanted and then write it down. Then you can just go back & forth than many turns for track events without measuring toe every time.