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Bill Verburg Bill Verburg is online now
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Originally Posted by hoss4659 View Post
Setting up an '88 911 for comfortable touring and satisfying personal taste on appearance. Some conflicts here. I would like to minimize the gap between the edge of the fender and the tops of the tires. To my eye this gives the car an unwanted "up on tippy-toes" look and means some lowering. How far to go before ride quality is compromised?

Running 7 & 8 X 16 wheels with Continental Extreme Contact DWS 06 tires 205/55 and 225/50 (recommended by TireRack). In retrospect I should have gone for 15" wheels and 60 and 65 series tires for higher sidewalls.

Current work underway:
--Renew all rubber bushings front and rear
--Adjustable Koni Sport strut inserts and shocks. As a first try will set these up and one notch above full soft.
--Turbo tie rods
--Stock torsion bars front and rear
--Install Elephant Racing's adjustable spring plate kit.
--Probably some lowering. How much TBD
--Probably some sort of rack spacers to counter act bump steer.
--May have to trim the fender lip flanges, depends of the amount of lowering.
--Alignment (Raises the question of the utility of corner balancing for a touring car sometimes with and sometimes without a passenger.)

A note of thanks here to Bill Verberg for all his informative posts to various ride height threads. Useful stuff

Now the Key question: How far can the car be lowered before ride quality is adversely effected? How to measure? My preference is to use the wheel center to torsion bar center dimension usually shown as dimension C in various diagrams. Will start with stock, front 108mm +/- 5mm, rear 16mm +/- 5mm. Admittedly the fender lip to floor measurements are easier, but no one ever notes the rolling radius of the tire.

"Ride Quality" is a very subjective thing. I would appreciate hearing from people who have some experience or have some analysis on the effect of lowering on the ride quality. Thanks
Besides some of the stuff i've written before, i've been doing some further research playing w/ an articulated model of the 911 suspension.
some further comments
stock the Roll center is well above ground and jacking and packing forces are minimal(like bump steer these can't be eliminated but can be minimized). As the front is lowered the roll center drops and will eventually go beneath the ground at this point the handling gets really ugly regardless of bump. I'd caution to go no lower than having horizontal A-arms static, a slight droop is preferred,

It is very worthwhile lowering the cg limited by the above
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Bill Verburg
'76 Carrera 3.6RS(nee C3/hotrod), '95 993RS/CS(clone)
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Last edited by Bill Verburg; 10-26-2015 at 02:16 PM..
Old 10-26-2015, 02:12 PM
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