92 MTX Oversteers

[ShelbyDoug]

In a recent rebuild of the suspension, the car got the brake upgrade, Tokico struts, Intrax springs, all new bushings, 225-55-16 tires and a 26mm rear bar.
The car oversteers pretty bad. It will change lanes on an entrance ramp to a highway without moving the steering wheel.
The rear is "pushing" signifiigantly.
This is not fun this way and quite frankly it is dangerous on the street.
I still have the stock rear bar that I took off. I don't remember if it is 22 or 23 mm. I tend to think it is 23mm.
Before I put it back in I was wondering if anyone else had this problem and what they have done to remedy the situation?
The front bar is stock 24mm.

 

[NotSoSlowSHO]

Are you SURE the front is a 24mm?

Also, has the car been aligned since the new suspension?
Subframe alignment and wheel alignment (front and rear) will play a large roll in steering response.

 

[ShelbyDoug]

Yes I'm sure it's 24 in the front. Yes it has been alighned as well. There is no question that the rear is pushing.

 

[NotSoSlowSHO]

The setup you are running is quite common, and Ive never heard of OVERsteer associated with it.

Im running a similar setup myself, and it UNDERsteers quite a bit.

Something else is up.

 

[ShelbyDoug]

Yes I know it is a popular set up. That is the reason I'm asking.
I would add that I do find it strange that when I jack the front tire off the ground that the corresponding rear tire raises as well.

 

[NotSoSlowSHO]

Is the suspension decompressing all the way?
If you push down on the rear bumper, does the suspension compress and rebound fine?


I can see how a car could drastically oversteer if the rear is somehow locked in a compressed state, but if it is indeed compressing and rebounding normal, it must be something else.

 

[ShelbyDoug]

I know that the 20/26 bars make snap oversteer and I would say that's what I have now. I'm original owner of this car and the front bar has never been changed. I put the 26 in at the recommendation of just about everyone here.
I'll check it tomorrow but I'm pretty sure that I measured it before at 24mm.

 

[ShelbyDoug]

It's normal for the Tokico/Intrax, firm, very firm

 

[jedhead]

Make sure that the rear toe is zero. If you have any toe out your rear end will be squirrely.

Bob

 

[CALL AAA]

You wouldn't happen tohave a front strut tower brace, would you?
I have Eibachs and a Tokico/Koni mix with a 26mm R/24mm F sawybars and some other stuff. It feels pretty good in a turn, until I add the front STB to the mix. The only time I ever spun the car was with the front STB.

 

[ShelbyDoug]

Just checked it this AM. Toe is good, camber good, suspension tight, 24 mm front bar, hooked up with new bushings, 22mm rear bar (stock) hanging in the garage. New Ford recall subframe kit tight and functional.
The only thing to do is change bars and see if it clears up.
It is having a problem on entrance ramps where the turn is to the left, inclined and the pavement slants away to the right. It wants to follow the pavement to the right. I think it is picking up a rear tire and pushes the wrong way. I have to treat this like rear end steer like on a Mustang. There is no other way to look at it.
What I was thinking is that maybe a 24mm rear bar would be right for me. I know there is a 22, I heard of a 23, is there a 24?

 

[zak]

There was a 25 mm rear bar used on Police Tauri, 92 to 93 IIRC. There should be a Ford part number over on SHOtimes. Uses the same bushings as a 26 mm. Cost was around $100 from a stealership.

Seriously, check the rear toe, it should be toed inward at least 1/16 total. Any toe out will make for a very loose rear suspension on these cars.

Are the rear tires much older than the fronts? Check the date codes on the sidewall (numbers punched in raised oval give month and year of manufacture). What rear tire pressures are you running? Not much weight in the rear of a SHO, 30 to 32 lbs max ... zak

 

[Minnesho]

There is no way the 24/26 combo should be causing that problem, Myself and many others are running even 22/26 combos with no problems. Even a 20.5/26 shouldnt make you feel out of control like that. Try adding a rear STB?

 

[Minnesho]

The only time I ever spun the car was with the front STB.

Thats odd because the front STB really dosent do much on our cars.

 

[CALL AAA]

It was a cheapo GM bar. When I put that thing on, the car turned into a wild animal. I don't use that bar anymore.

 

[TankII]

What are your rear bar end-link bushings?
I have a 91+, 22MM front, 26MM rear, STOCK front bar-to-body bushings, PST rear bar-to-body bushings with Hellwig endlinks in the rear. Slight oversteer now vs snap oversteer with the ADDCO kit. The Hellwig kit forces the bar to react at the slightest change in suspension position, not after partial suspension compression.

The Quaife made things wierder until I went slight toe-in in the front, near MAX rear toe-out. Then my torque steer went away as well as my tire squeeling in corners.

I run 4.1 front Camber as I recall.

The car understeered with the 24mm front bar.

TankII

 

[pjtoledo]

,,,,,,,,,
It is having a problem on entrance ramps where the turn is to the left, inclined and the pavement slants away to the right. It wants to follow the pavement to the right. I think it is picking up a rear tire and pushes the wrong way. I,,,,,,,,,,,,,,?

On that screwey of a curve, what did you expect? How does it handle on normal roads?

Perry

 

[ShelbyDoug]

I still can't find this.
I put new front wheel bearings in, alighned it front and back, equalized the tire pressure.
I did the subframe bushing service kit.
I'm wondering if what is happening is that I'm loading the suspension to such a degree that the subframe is moving on me?
Will solid subframe bushings tighten up the suspension?

 

[AREA 91]

Yop. Get some ALSFB's in there. You won't regret it.

 

[RJ-92]

Try ruinning 2-3 PSI more air in the rear tires and get some AL SFBs and put a reat STB in it. I couldn't believe the difference the rear bar made in my car. I am also running a 24 - 26 combo and my car is almost dead neutral. It will drift the tail a bit under lift throtle conditions through turns. Don't lift through turns, it will upset the balance and cause the rear to get light. Try to find a good speed and hold a steady throtle or even slightly power up through turns.