Lowering question

[mmari270]

I'm lowering the front. Reading Porsche 101, it calls for a front end alignment after lowering. Is really an inch or two going to make that big a difference that I need an alignment? What's the down side? Just irregular tyre wear? Bump steering? Time frame of realignment? Input appreciated....

[James Brown]

most likely not, but to be sure, get it aligned, at least the front. 1or 2 inches is a lot don't know if there is enough adjustments without indexing the TB's. give it a shot and see what you think. Oh yeah i see the white targa, way too high

[DRACO A5OG]

For sure tire wear, but if not lowered evenly you will get more camber on one side and it may start drifting to the less cambered side.

1 inch, probably wont need a bump steer kit. past Euro height, it is recommended.

Jim

[Driven97]

If you lower a lot (2" is a lot,) you'll most likely change your toe and camber. Realistically, the camber is not a huge deal, as there isn't a lot of camber gain in a MacStrut curve, so you can't make it all that wacky with just lowering.

The toe, however, can be an issue. Out of whack toe goes through tires very quickly. Too much in will also make the car turn sluggishly, while too much out will make it sort of wander at freeway speeds.

Of course, a 4 wheel alignment is the best action. The rear is a bear to deal with, imho, I would have a specialty shop take care of it. If you do the front only though, it's like any other car and a mom and pop tire shop could do it if your were brave.

[T77911S]

you WILL change camber and toe.

i look at lowering as a domino effect, which usually hits the wallet too.
for a stock height, as you go around a right turn at a given speed and radius, lets just assume constant radious, the outside suspension compresses. now picture a circle with a line drawn from the center to about 8 oclock. that line represents the lower control arm. as that suspension compresses, that line moves in a CW direction to 9 oclcok. if you draw a verticle line intersecting the 8 oclock then one intersecting the 9 oclock, you will see that the 9 oclock is further to the left. this adds negative camber in an attempt to keep the wheel perpendicular to the road. anything past 9 oclock, the wheel starts to go in a postive direction.

as you lower the car, you get closer and even reach the point where NO negative camber is gained with suspension travel. you may even reach the point where the susension can not be aligned to get the proper camber adjustment. this can increase tire wear on the inside, which can be negated somewhat with a little more toe in, but then that effects handling. (part of the domino effect)

the same thing happens with the toe. as the wheel moves up and down, this changes the angle of the tie rod, thus making the wheel turn out or turn in. this is where bumpsteer comes from.

now to the really voodoo stuff.
as the car gets lower, the big advantage is a lower center of gravity(CG). as the CG gets lower, the car can now go faster through that same turn,

another change is roll center.(RC)
the RC and CG work together like a cheater bar. the longer the cheater bar, the more torque that can be applied to a bolt for the same amount of force at the end of the cheater bar.
as the car gets lower, the CG goes down, but so does the RC,and usually at a greater rate than CG. just to through some nubers, out there, lets say the CG is 8 inches higher than RC for stock. you drop the car 2 inches, the CG goes down 2 inches, but.....the RC could go down 3, 4 maybe 5 inches. now that breaker bar has gotten longer. so when you lowered the car, the force on CG increased due to CG going down AND the car being able to go faster thru the turn, but that force has been multiplied that is applied to the RC due to CG and RC being further apart.

due to this, now there are more forces trying to compress that outside wheel, which we dont want because now we have lost any gain in negative camber as the suspension moves so we have to make the suspension stiffer to reduce wheel travle. (the domino effect)

this is for track purposes, if you want to lower for looks, then your real concern is will you run out of adjustment to get the camber setting for low tire wear, and will bumpsteer be effected.
another concern is the suspension hitting bottom. if the suspensin cant move due it sitting on bump stops, the ride will be very harsh and you could damage suspension parts.

yea im bored.

[bkreigsr]

I say wait to have the alignment done.
If the car doesn't pull left or right after lowering the front - you should be okay in the short run.
Why wait ? It's only a matter of time before you lower the rear, so wait till that's done, and get a full alignment and corner balance all at once.
If the car is not your daily driver, tire wear isn't a concern. Most of us let the tires go way past their optimal time frame anyway, so tread depth and shoulder wear shouldn't' be a major concern.
Bill K

[mmari270]

The car is not a daily driver and no tracking in the foreseeable future

[T77911S]

i tend to agree with bill.

too much of a nose down thing will not look that good and you will likely want to lower the rear, so the best thing is to try to get the ride height where you want it, then get an alignment and a corner balance.

mine is not a DD eother. i cant seem to get rid of the inside wear on my rears. it kinda sucks to put expensive tires on there and not get much mileage out of them due to the insides wearing out long before the tire does. i keep cheap tires on there just beause of this.

[mmari270]

I'm not looking for the nose down. If you look at the pic of my 86 in my garage photo it almost has a nose up. I'm looking to just level it.

[Driven97]

Originally Posted by mmari270

I'm not looking for the nose down. If you look at the pic of my 86 in my garage photo it almost has a nose up. I'm looking to just level it.

Well, assuming there is enough room on your adjusters you can just go ahead and crank them down three turns each and see what the car drives like. If you count the adjustment, you can always undo it in 5 minutes. Just make sure you jack the car up (and support it with jack stands) so you unload the adjusters before you turn them.

[DRACO A5OG]

Measure the height of the rear fender lip to the ground at center of hub then lower the front 1/2" higher then the rear then you will obtain zero rake and she will have a proper stance.

Remember to bounce her to take the preload off so she will settle down after adjustment.

Watch the tires and deliverability due to toe affects.

Jim

[Chuck.H]

Whenever I change ride height, I see a huge swing in camber -just jack the car up and you will see the wheel go to severe positive (outward) camber. As it lowers, the top of the wheel tucks under the wheelwell quite a bit. And yes this will also affect the toe, but to a much lesser degree.

HTH,
Chuck.H
'89 TurboLookTarga, 343k miles