Squirrely Viper-normal?

[PatentLaw]

Stupid question here...but nobody has asked it, so I will. Noticed you are in Penn. One of the other people that had a similar problem was in......(drumroll) Penn.

Yes, the car can be darty, but what type of roads are you driving on? Before you start making mods, lets look at the basics first. What part of the state are you in? Driving with groove lines in the roadway for snow removal? Heavily trafficed road? Take the car to a very smooth road, do you have the same problem? Play in the steering at all?

 

[Randy]

I have replaced my with new tires and its still darty, it's just something i got used to. I keep two hands on the wheel if its a bad road! I swear one day i'm going to get pulled over on a crappy road because the cop will think i'm drunk lol.

I assume you've had it aligned, by a reputable shop. Not just toe-in, but camber and caster settings will have a big affect on dartiness, especially camber.

 

[Vic]

Vic, we agree then. The vertical position of the tire can result in different toe, which is the definition of bump steer, I believe. It doesn't matter how the tire got there, whether via a bump or weight in the car. The rear toe-in is designed for stability. The unsprung weight and jounce happens over rougher roads, but other than losing contact with the pavement, doesn't automatically result in toe changes.

Well, Tom, I think I have been using the term improperly. (Thats easier to say than I was talking out of my ****)

Doesn't look like anyone uses the term bump steer when discussing unsprung weight. Or hard tires.

Ok, yeah, if you got hard tires, or heavy control arms, and you are going around a turn and over some bumps, and the car just sorta steers itself in a new direction, (But not due to the angle(s) of the tie rods) that can't be defined as bump steer. Thats just a car steering itself, after going over bumps!

Longacre's website has a real good article on true bump steer, if anyones interested.
http://www.longacreracing.com/articles/art.asp?ARTID=13

 

[JUCD VPR]

I have replaced my with new tires and its still darty, it's just something i got used to. I keep two hands on the wheel if its a bad road! I swear one day i'm going to get pulled over on a crappy road because the cop will think i'm drunk lol.

I assume you've had it aligned, by a reputable shop. Not just toe-in, but camber and caster settings will have a big affect on dartiness, especially camber.

YEs i have but i'm taking it in for another alingment when i get back home, PBJ is going to help me out.

 

[Gavin]

Check to see if the factory 'sport shims' (I'm not sure if they came on your model) have been removed.
If they did come on the Gen 1's and they are not present, you will have a squirrel on your hands.

On Gen 2 cars we take these out for track events as they are a quick way to put a lot of camber in the car - have to re-check the toe each time they are taken out and or re-installed.

If Gen 1 car does not come with these shims then I beleive your car is set up with too much camber and or you have a real [******] set of tires.

Remove a front wheel and look at the upper a-arm - the shims go between the a-arm and the chassis - the bolt that holds the a-arm holds the shim, one per bolt. I can email you a picture if that would help.

 

[Randy]

Check to see if the factory 'sport shims' (I'm not sure if they came on your model)

I believe the sport shims are on all Gen I (and Gen II) Vipers; I'm sure they were on later Gen I's, at least.

 

[Gavin]

Hey Randy - its been a while - When are we going to see you at a track event!!!

So if the sport shims are not there - there is the source of the problem- if they are there, borrow a good set of Michelin Pilot Sports from one of your Viper buddies and see if that make the thing drive right.
These are 'don't spend money' solutions.

 

[Randy]

Hey Randy - its been a while - When are we going to see you at a track event!!!

Likely when we go to the same track event. I've not done Laguna Seca across the street from you in a while - last time for me was Sears Point.

So if the sport shims are not there - there is the source of the problem- if they are there, borrow a good set of Michelin Pilot Sports from one of your Viper buddies and see if that make the thing drive right.
These are 'don't spend money' solutions.

However, note that an alignment will clearly show if the sport shims are missing, as you'll have about 2 degrees (the sport shims add a constant camber angle - I don't recall for sure if its 1 or 2 degrees) additional camber - I may be using the wrong positive/negative, so, to illustrate: if looking at the front or rear of the car, the top of the tire will be tilted in X degrees toward each other for camber. The removal of the sport shims (U-shaped washers with bent-in tabs on the upper A-arm to frame attachment point) will cause a 1 or 2 degree additional "inward tilt" (camber) on the wheels.

 

[Gavin]

I've seen 2.5 degrees on my 96 with the shims removed.
Also wore the hell out of the inside of the tire, 3,000 miles and a brand new set of Pilots were done - that included a number of track events. Those shims went back in darn quick.

On the race car we leave the shims in and adjust the camber the usual way - a sledgehammer - seriously, 2 degrees is enough or we just go thru a lot of race tires.
\
I really would like to know if he still has the shims on the car or not

 

[viper spray]

My 95 had a bad rear control arm and it torque steered and darted badly . I replaced it and had a good alignment done and put on new rubber , it was a different car after that. It made a HUGE difference.
spray...........

 

[venms96]

syldog,
Where'd ya go, lots of guys asking questions...
PatentLaw brings up something important...I know the PA. back roads, they are pretty consistent, no matter what part of the State you are in. Some are better than others, but if you are "jumping" around on bumpier back roads, that would be expected.
But the most important thing here is, are your tires original ?? If so...12 years of that same tire means you are asking for it. I can say this from experience. I just removed my original 96 tires, even tho they had extremely low mileage on them, and with the NEW Michelins on the car, it's been a world of difference just doing normal driving, highway, backroads, wherever. I can tell a big difference, and I'm just a hobbyist, not a racer, etc.
This has all been said many times. Get new tires IF you have the original ones still on the car. They are hardened, and moreover, UNSAFE. $1366.00 is a tough one to swallow for 4 tires, but not when your LIFE is riding on four pieces of rubber at whatever speeds you decide to travel.
JMHO of course.

venms96
1996 GTS
SDMF !

 

[Asp Man]

"I swear one day i'm going to get pulled over on a crappy road because the cop will think i'm drunk lol."

Yeah, I've been afraid of that myself.

 

[syldogRT/10]

Been away for a couple days guys, but I wanted to drop a note and give a big THANKS to all who chimed in! The tires are in fact the original OEM so I will get them replaced ASAP, along with a check of the whole front end and an alighnment to 95 specs. I'll let you know how it turns out! Thanks again guys, your help is always appreciated!

 

[Jack B]

It probably has all been said, but, not in one post. ALL the dart can be taken out. If the suspension components are in order, then, get an alignment. There are many ways to go, but, for the street, a bit more agressive camber and toe will stabilize the car. The alignment alone will change the car's personality.

Tires are next, the MXX3's and earlier tires seem to catch the creases in the road. The new PS2 tires are a dream and the traction is better.

 

[GTS Dean]

The early XGT had softer sidewalls than newer MXX3 and Pilots, so the transients feel different. It would be more compliant for road handling, and I believe the sidewall traction number was lower (stickier) at 140 front, 100 rear, than newer tires, but the more abrupt breakaway takes a little getting used to.

It was mentioned, but check the inner tie rods, under the rubber bellows boot. If the boot was torn or has a hole, the joint will wear quickly. You don't have to buy a complete rack, a Dakota inner tie rod can be modified and used. (I did.)

I'll take Vic on his offer to question authority - why would unsprung weight be correlated with bump steer? Bump steer is a steering rack position adjustment that causes toe-in or -out during droop and jounce. A Gen 2 can have bump steer.

Spot-on assessment.

 

[Tom F&L GoR]

I feel old spouting details of tires many have never driven with...

 

[PaViper]

But the most important thing here is, are your tires original ?? If so...12 years of that same tire means you are asking for it. I can say this from experience. I just removed my original 96 tires, even tho they had extremely low mileage on them, and with the NEW Michelins on the car, it's been a world of difference just doing normal driving, highway, backroads, wherever. I can tell a big difference, and I'm just a hobbyist, not a racer, etc.
This has all been said many times. Get new tires IF you have the original ones still on the car. They are hardened, and moreover, UNSAFE. $1366.00 is a tough one to swallow for 4 tires, but not when your LIFE is riding on four pieces of rubber at whatever speeds you decide to travel.
JMHO of course.

Let us know if handles better when you actually take it out of the driveway