The hopping 951
03-19-2003, 08:23 PM
#1
Racer
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The hopping 951
I recently started driving my '86 951 again after reviving it from it's winter hibernation, and I am quite dissatisfied with the handling.
Last year I replaced the control arm ball joints and tie rod ends as part of a front-end rebuild. This significantly reduced the amount of steering wheel vibration at highway speeds (60-70 MPH). I also replaced the rear shocks with new Koni yellow sport shocks. The front struts are original Sachs style from another car with about 80k miles. The car has the stock springs in front and the stock torsion bars.
When I am in first gear and going slowly (e.g. through a parking lot), the car has a very strong tendency to "hop" as I apply the throttle. The whole car tends to tip front to back as the engine speeds up and slows down. Does this indicate that the front struts need to be replaced?
Also, last year I had the rear ride height lowered using the eccentric bolts to its lowest position. The car now sits virtually level. When driving at a moderate speed (40-60 MPH), I hear very loud thumping noises every time I go over even the smallest bump. Is it possible that the rear suspension is "bottoming out" due to the lowered ride height? Maybe I should have the rear ride height raised back up to provide more suspension travel with the relatively soft stock torsion bars.
Overall the car feels like it is very "unsettled" on any road except the smoothest surface. I am willing to spend the $$ and time to upgrade the front struts to Koni yellow sports, but I just want to make sure that this will solve the problem (they certainly couldn't hurt I'm sure).
Last year I replaced the control arm ball joints and tie rod ends as part of a front-end rebuild. This significantly reduced the amount of steering wheel vibration at highway speeds (60-70 MPH). I also replaced the rear shocks with new Koni yellow sport shocks. The front struts are original Sachs style from another car with about 80k miles. The car has the stock springs in front and the stock torsion bars.
When I am in first gear and going slowly (e.g. through a parking lot), the car has a very strong tendency to "hop" as I apply the throttle. The whole car tends to tip front to back as the engine speeds up and slows down. Does this indicate that the front struts need to be replaced?
Also, last year I had the rear ride height lowered using the eccentric bolts to its lowest position. The car now sits virtually level. When driving at a moderate speed (40-60 MPH), I hear very loud thumping noises every time I go over even the smallest bump. Is it possible that the rear suspension is "bottoming out" due to the lowered ride height? Maybe I should have the rear ride height raised back up to provide more suspension travel with the relatively soft stock torsion bars.
Overall the car feels like it is very "unsettled" on any road except the smoothest surface. I am willing to spend the $$ and time to upgrade the front struts to Koni yellow sports, but I just want to make sure that this will solve the problem (they certainly couldn't hurt I'm sure).
03-19-2003, 08:42 PM
#2
Nordschleife Master
Not sure what you mean by hopping. My car developed what seemed like a lot of slack in the drivetrain that resulted in jerky on/off gas transitions. Replacing some rubber pads in the rear suspension fixed that problem, the old ones were hard and flat.
03-19-2003, 09:00 PM
#3
Racer
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Sorry for the lack of a more descriptive term. When I say "hopping" I mean that when I apply the throttle then release quickly at low speeds <20 MPH, the car "hops" by raising the front end [gas on] then diving excessively [gas off].
Could you be more specific about the rubber pads you replaced in the rear suspension? Which parts are these?
Could you be more specific about the rubber pads you replaced in the rear suspension? Which parts are these?
03-19-2003, 09:06 PM
#4
Race Car
sounds like the front struts need to be replaced. in my 951, driving over the uneven highway expansion joints of OKC made the steering wheel shimmy badly and the noise was horrible. that was with about 100K on the car. i had all the struts and shocks replaced with new konis, installed the 200# front springs, and lowered the rear end to match. the car rode beautifully.
your rear end is not bottoming out. what it might be is either a binding sway bar bushing or bad ball joint (even though they have been replaced).
your rear end is not bottoming out. what it might be is either a binding sway bar bushing or bad ball joint (even though they have been replaced).
03-19-2003, 09:27 PM
#5
Nordschleife Master
Dude. There is nothing to fix this. The car has a wheel base of 94.5 its not made for short burt followed by engine drag (altho I think its fun) its always going to produce alot of (Squat) followed by diving of the front end. Change rear torsion bar's add in front 200# springs or better to reduce this. The thumping is torsion bar hitting (this bar has to be re indexed) or its just simply a horribly bad transmission mount. Sways are only going to help your side to side roll. Stiffen the suspention to help stop the front to back or back to front action.