'93 C4 cornering improvement advice.
Thread Starter
Melting Slicks
Joined: Oct 2012
Posts: 2,156
Likes: 273
From: Dunedin NZ.
'93 C4 cornering improvement advice.
There is a corner in the road climbing the hill to where I live that is slightly off camber and also has some ripples in it. When I drive around this corner (its a 20 mph corner) the back wheels always step sideways, not using hardly any power when this happens, would the addition of a little negative camber help in this situation? When I round the same corner in my C3 at the same speed it doesn't do this, it used to judder (not step sideways) more like axle tramp a bit, but no longer since I fitted a monospring and Bilsteins to it. The C3 is running some negative camber but I can't recall how much. The C4 has 63k on the clock and as far as I'm aware std suspension all round, the sway bar link bushes in the rear have been recently replaced by the PO but thats it.
Melting Slicks
Joined: Sep 2008
Posts: 2,376
Likes: 111
From: Cherokee National Forest TN
C4 tire aspect ratio is less than that of a C3 tire = the C4 tire has less compliance on a washboard road.
For urban use my C4 gets 30 psi + the FX3 ride control stays on the softest setting suggest less air pressure.
Shocks control the wheel / spring it may be time for better shocks.
Good luck
For urban use my C4 gets 30 psi + the FX3 ride control stays on the softest setting suggest less air pressure.
Shocks control the wheel / spring it may be time for better shocks.
Good luck
Le Mans Master
Joined: Sep 2013
Posts: 6,192
Likes: 750
From: near the thumb in the mitten
How fast are you hitting 20 mph corner? Does it feel like rear is "rolling over" or sliding. Condition of rear shocks? Air pressure and adding negative camber are thrifty. You will need to reset toe in after adjusting camber if you DIY. YouTube is loaded with how to "string" alignment.
Last edited by Kevova; Dec 13, 2018 at 09:21 AM.
Le Mans Master
Joined: Aug 2015
Posts: 6,092
Likes: 1,972
From: St. Charles MO
Just changing swaybar bushings won't necessitate a new alignment, but if you haven't verified the alignment since you bought the car it would be worth at least checking it. Some negative camber always helps grip at either end, but the main thing to check is that you don't have toe out in the rear. But other than toe, I don't think alignment is like the issue. Make sure the D-bushings for the rear swaybar were the correct size (i.e., not smaller than the bar diameter and therefore causing it to bind). Also, make sure that the end links weren't tightened down while the car was still on the jack with suspension at full droop. Those should only be tightened after the car is at normal ride height.
Beyond the above, the biggest issue about maintaining traction over bumps is the dampers. Do you know what shocks are on the car now, and how old they are? It may be time for replacements. I have found my Koni Sports to be very compliant when not set near full stiff settings. I also believe the Ridetech HQ shocks are a killer value in a high-quality monotube (Fox internals) adjustable shock, and would be a great choice.
Beyond the above, the biggest issue about maintaining traction over bumps is the dampers. Do you know what shocks are on the car now, and how old they are? It may be time for replacements. I have found my Koni Sports to be very compliant when not set near full stiff settings. I also believe the Ridetech HQ shocks are a killer value in a high-quality monotube (Fox internals) adjustable shock, and would be a great choice.
Thread Starter
Melting Slicks
Joined: Oct 2012
Posts: 2,156
Likes: 273
From: Dunedin NZ.
I'm on;y doing 25mph around this corner, its the combination of corner camber, ripples in the surface and the car set up. I believe the shocks are original and I assume they are Bilsteins?? The car feels like it steps sideways, its definitely not rolling and I'm starting to think that the low profile tires don't conform to the road surface on the ripples like the 55 series 17" ones I use on the C3.
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Brett Foote
Team Owner
Joined: Aug 2004
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From: Park City Utah
^This, IMO.
^That is way too much pressure on a car the weight of a C4, with that wide a tire. I believe the car calls for 30 PSI. I actually fun mine at ~25 pounds on the street with a 265 and 295 tire.
^That is way too much pressure on a car the weight of a C4, with that wide a tire. I believe the car calls for 30 PSI. I actually fun mine at ~25 pounds on the street with a 265 and 295 tire.
Le Mans Master
Joined: Sep 2013
Posts: 6,192
Likes: 750
From: near the thumb in the mitten
25 mph in 20 mph corner I used to say that ...Nobody ever believed me. But none the less if it's kicking out something has to be worn, loose, or broken. Washboard or not with good tires that hold air and a dry surface it should not kick out 5 mph over.
Thread Starter
Melting Slicks
Joined: Oct 2012
Posts: 2,156
Likes: 273
From: Dunedin NZ.
Will be pulling the rear shocks to double check they're okay, all the bushings seem to be okay, rear wheel alinement still to be checked though. Tires renewed in Sept.