New to FC, have a 86 Base. It understeers, is that normal ?Been driving my 85 SE for 2 year now, they don't drive the same. I'm trying to find a LSD for it, will that help or make it worst?

 

So you are turning the steering wheel and it's still going straight'ish? Just only had a RWD car understeer when I had crap tires up front.

 

Yes, entering a sharp corner I turn hard and can feel the tires not gripping and front end pushing. Still going straight ish. Had the same tires on my FB and did not behave the same.

 

Because it's a different car.

There are numerous things that affect how your car will handle, what kind of setup are you running?

 

PO had installed no name aftermarket 1 inch lower springs and stockish struts. Every thing else is stock.

 

I want to get it to an alignment shop, are factory setting the best for stockish street car

 

Are your tires stretched onto the wheels? That will cause oversteer

Rotary > Pistons

 

There are 195/60-15 on 7 inch wheels. Hadn't thought of that possibilty

 

Lol, everyone is missing the bus.......
FB has a solid rear axle, FC has IRS.

Get wider wheels and 225/45/15 tires all the way around. You won't be under steering anymore.
A cheap quick fix is a used larger/thicker rear sway bar, or just disconnect the front sway bar.

 

I'll try sway bar disconnect tonight, quick and cheap. I was planning 225s for when the turbo upgrade was done. Thanks

 

Most auto makers setup their cars to understeer. Supposedly it is safer since most people hit the brake when they start to slide. You just have to load up the front tires more when cornering.

 

I'll try sway bar disconnect tonight, quick and cheap. I was planning 225s for when the turbo upgrade was done. Thanks.

 

I meant it will cause understeernot over steer.

Rotary > Pistons

 

wait...if your FC is understeering its absolutely normal from stock. I had the same problem and got RB springs and tokico blues with DTSS eliminators and Im getting over steer. Or maybe i learned how to drive the car and know how to make it over steer not sure. I also switch over to some 17s and got rid of the balloon tires.

 

WDYS82 "I meant it will cause understeernot over steer" I knew thats what you meant
2ND Pink, do you have an LSD?
I did not have time tonight to disconnect the sway bar. I did lower front tire pressure 2 psi (23 rear and 21 front), will see what that does. I also filled the gas tank (was time) that should balance the car as well. I'll through it around tomorrow on the way to work.

 

No lsd.

 

so on the way home this evening, with 3/4 tank and 50 pounds of sports equipment in the in the car and a driving approach adjustment did much better. at the apex the rear end seemed to grip than slip, grip, slip. kinda like wheel hope. could it be the tires, or 155K miles on the bushings in the rear end? would lowering rear tire pressure maybe help

 

If you want it to slide on tires with a huge sidewall like yours increase the rear tire pressure.
Cheap drifters that use balloon tires on the rear run like 55-65 PSI in the rear tires. I don't reccomend going that high on the street, you put yourself and others in danger.

 

I want the car to grip or very slight oversteer. not looking to drift.

 

Your suspension bushings are probably pretty worn. DTSS eliminators will help the rear grip more consistently. Also, like most production cars the FC is factory tuned for oversteer. Adding negative camber to the front really helps. I've also found that as you add more tire the car moves toward oversteer, especially under braking. My car runs -2.0* camber up front on 17" "street" tires and -3.0* on slicks, with a stock TII front sway bar and no rear bar.

 

Thanks for the help, I want to get this handling sorted before adding the turbo motor. Seems I have some suspension work to do

 

23/21 PSI in the tires?! I know each car will differ with the various suspension upgrades and what not, but stock is 32PSI! You are nearly 10PSI off, that cannot be good.

 

Yes you do and good luck figuring it out.

Chassis dynamics are fiendishly complex and you- like most of us- lack the adjustability and instrumentation needed to understand/address what's going on. You also probably lack the resources (basically, a track and crew) to test under repeatable conditions and verify outcomes.

The best thing I can recommend is to only change one thing at a time and keep good notes.
The second thing would be to apply severe skepticism to your initial response to a change. The butt dyno (chassis or engine) is notoriously inaccurate and the inherent desire for a change to be "better" can blind you to problems.

It's also useful to remember that YOU could be the problem, not the car.

 

Thanks, points well taken. Will proceed with caution and patients. (I'm 49, nothing moves too quickly)

 

+1 on the one thing at a time. however...

it IS nice to start with some known baseline. a known good alignment, a reasonable starting tire pressure, make sure all the bearings/bushings and tie rods are in good/excellent shape and things like that is a good place to start.

if this was a race car, we'd start with a more aggressive alignment than stock, ie, zero toe all the way around, as much negative camber in the front as you can get (with stock parts this is only like -.5, which is fine on the street).

in my experimentation, they front toe doesn't really do a ton for handling, but it does feel best @zero. however the rear toe has a huge impact. @zero rear toe, the car feels awesome when you can be on the throttle @turn in, however if you're not on the throttle it feels unstable. stock runs a lot of rear toe and feels planted all the time. so the rear toe had the biggest impact on how the car reacts. i was happy with one hash mark on the adjuster toed in from zero, but ymmv!

on a street car i set tire pressure cold, because its repeatable that way, on the race car, we set em hot, because its repeatable that way. in a street car i would probably start at the stock 32psi, and go up, but play around with it, the happy place is different for every tire, so far.

and please note all of this is subjective, its all how it feels, there is no lap time on the street.