I recently dropped the Eibach Pro Kit in my PT Cruiser, along with replacing
the bushings with the Energy Suspensions Master Kit (LOTS of rubber in THAT
suspension, linkages galore in the rear...). At the same time, I put one set
of crash bolts in to gain some negative camber in the front. The relationship
of camber to toe in this car (Macphearson strut design) is such that you can
lower the car and the camber doesn't change, but if you adjust the camber
negative with crash bolts - the toe goes out accordingly.
Ok, that being said, here's what I have going on - hopefully some
suspension/chassis wizzes out there will have an idea of what I should
check.... When I accelerate, the car will pull to the left. When I lift off,
it pulls to the right. Under purposeful braking, it tracks pretty much
straight after adjusting for the right pull. I don't think it's torque-steer,
since this happens at very low throttle levels and under the slightest throttle
lift.
Alignment settings: -1 deg camber per side, some (unmeasured) toe out - maybe
as much as 1/16" - 1/8" per side.
I know that running toe-out will cause squirrelly handling, but I've already
experienced that in this car, and it's not really the same. It tracks okay
once you've dialed in the right amount of steering correction, whereas with the
rubber bushings in it - it really wanted to just wander all over the place if
it didn't have a little toe-in. The factory spec for the toe is zero.
My guess? The stiffer springs and (near) zero compliance urethane bushings
have revealed a more severe sensitivity to alignment. I had guessed that the
car was already very sensitive to the alignment settings after noticing some
accelerated wear on the tires and noting that the toe was out (after a mech
shop had replaced the bearings - they forgot to align it). After getting the
car on some balancing scales, I was shocked to find out that it's EXTREMELY
well corner balanced (still 60/40 F/R though), and the weight of the driver is
the main contributor to unequal corner weights. Could it be that with the toe
out condition, that my weight over the left side tires is causing that front
tire to drive along it's toed-out path and pull me to the left (until I
correct), and then when I lift off the weight transfer to the front of the car
is causing both tires to grip, but especially the right front now, which is
pointed to the right - and therefore pull me to the right?
I think this car does this naturally with any amount of toe-out in the front,
but the rubber bushings soaked it up.
My solution: adjust the toe to a 0-toe condition. If this fixes it, then
great, otherwise replace the crash-bolts with the factory clevis bolts to
eliminate camber as the culprit, and adjust the toe back to zero.
I know, I could just take it to my favorite alignment shop and they'll probably
fix it, but I'm an engineer at heart, and I'm trying to gain an understanding
of how all the zillion components in this suspension interact to make the car
go AND turn :)
Any takers?
Thanks,
Ken in OKC
#STS 101 - '01 PT Cruiser Limited
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