914-6 susp. upgrades

[911pcars]

I'm inquiring for a friend. He's currently running a 3.0l engine with a 15mm front sway bar and 6x16 Fuchs. He wants to cure an oversteer situation. Shocks unknown. I suggested trying shorter front sway bar arms and/or larger bar and more differential between front and rear tire pressures (he was 35/35). He just had it corner balanced.

If the above modifications aren't enough, what suggestions do you guys have in the sequence of susp. mods? He doesn't want to spend an arm and a leg, but you know how that story goes.

Thanks,
Sherwood Lee
http://members.rennlist.org/911pcars

[Early_S_Man]

Sherwood,

He can probably alleviate the oversteer to a great degree by switching to 29 psi front/35 psi rear tire pressures immediately!

A 19 mm adjustable front anti-roll bar wouldn't hurt, either!

------------------
Warren Hall
1973 911S Targa
1992 Dodge Dakota 5.2 4X4 parts hauler

[campbellcj]

If it sees track use, he might want to look at 22mm front t-bars, 22mm front swaybar and 180lb rear springs.

For a street car he could probably get away with stock (18.8mm) front t-bars, 19mm swaybar and 140lb or 165lb rears. But with the 3.0 I'm not sure - he may need 180's in back.

It could be that whomever did the 3.0/6 conversion put bigger springs in the back without making a compensatory change up front -- i.e. recipe for major oversteer. A larger, adjustable front swaybar by itself might do the trick in that case.

He may also want to try disconnecting the rear swaybar, if he's got one.

Those tire pressures sound high too. I've gathered that most 914 guys run between 27-32psi. The car could be pretty skittish at 35psi cold, which could hit 40-42psi hot. This is only a 2150lb car...possibly less if it's been stripped at all...

Cheers,
Chris C.



[This message has been edited by campbellcj (edited 08-25-2001).]

[J P Stein]

I had a similar problem with my 914 when I swapped out the 2.4L T motor and installed
a "hot rod" 2.7L.
The car went from a nicely ballanced handler to a power oversteering monster.

I have since upgraded the 205 X 50 Dunlops on sixes, all around, to 205/225 X 50 Kumho Vracers, on sevens. Throttle applications are still a bit dicey when the cams are on the boil (where the fun is), but now it is catchable.....mostly. Still tuning the engine, suspension....and driver( the largest part of the problem).

I would recommend an adjustable front anti-roll bar to ballance the car, but this is not the complete solution. More tire is desirable but it's tough the get much under the fenders at the rear. I had to flare mine which ruined a decent paint job.

There are some pics over at the 914 list under the thread "New Digital Camera"

JPIII

[Joe Bob]

Just remember that when you start beefing up one area, others get undue stress. I had a problem with my front strut mounts punching up thru the pan after adding heavier torsion and sway bars.

I also had problems with the suspension console under the battery tray. Remember you are putting new technology under a car that is 30+ years old.

In both cases I had to fabricate braces and plates to beef up the car's suspension. It is not the same with every car, this was a relatively rust free chassis with a 3.0 CIS powerplant.

Just my $.02.

[Early_S_Man]

Another thing ... 19 mm through-the-body anti-roll bars are stiffer than 22 mm anti-roll bars for post-73 911s! Because the lever-arms are shorter!!!

------------------
Warren Hall
1973 911S Targa
1992 Dodge Dakota 5.2 4X4 parts hauler