Side to side pulling at highway speeds

[peter canepa]

Front wheel drive torque steer has always been the norm with this car, at low speeds and hard acceleration.
Now though I put new tires on it (Continental Extra Sports) and it pulls to one side upon light throttle. First to the left, then I switched side to side, now to the right? This is a new problem I've never encountered. Any Ideas out there.
Peter Canepa in Calif.

[FunElan]

This is all assuming it's been to an alignment shop?

[Rambo]

When was the last time you checked your suspension Peter? ie bushings, CV joints etc... These can be contributory factors too. It's not necessarily all down to tyres.

[dapinky]

As well as the answers above, I'll throw in a cheap & simple thing to try.....

..... what pressure are you running your tyres at? The numbers in the handbook are a great guide, but were set for the OE tyres on the car - with modern technology, the materials behave differently now (flex vs rigidity etc). So I'd try letting a few psi out, than adding a few more and see if any of that helps.

[peter canepa]

Guys, Thanks, for the reply's.
The fact that I switched the new tires side to side and the pulling followed. The suggestion changing tire pressure, that's easy. Alignment, no not recently, usually alignment , the car veers, without acceleration. This only happens with acceleration. The driveshafts, we can inspect. The car is going to the shop those elastic bands need to be replaced.

[tigerdog]

Hey Pete, reactivating an old thread to see if this behavior was 100% attributable to the tire, or if you found other suspension issues.

[HJ2]

Surely must have been an alignment offset…

[peter canepa]

Side to Side pulling,
Tigerdog, I posted yesterday on another thread. I just saw your post. a month old.
Fixes were, Alignment,, wheel balance,It took 3 times, 2 different shops. Replace Front Sway bar bushes. Way better, but the car still does not feel planted, Tire pressure next, ordering more bushes from SJ. maybe even replace the Continentals.

[Giniw]

Have they aligned the rear wheels too? (especially toe angle and while they are at it, also the camber)
And have they aligned the wheels at the correct ride height?

[peter canepa]

Never have I heard of aligning the rear wheels. Camber & height. I do see the specs in the Service Notes Section DD. Thanks for the tip. I'll get back with results
Peter

[lotusflasherman]

Never have I heard of aligning the rear wheels. Camber & height. I do see the specs in the Service Notes Section DD. Thanks for the tip. I'll get back with results
Peter

If rear wheels aren't aligned you may suffer 'rear wheel steering'; also it was designed to provide a bit of 'rear wheel steering' when cornering hard, but not when driving straight! I do find it strange you can move your problem by swapping wheels...

Lotus also designed equal length driveshafts to eliminate the usual FWD torque steer but 25 years ago I test drove an Elan with a BBR Starchip and bigger turbo that had a 'dyno sheet' showing 235 bhp at the wheels, and I don't know if it was torque steer or CV joints locking up. but it was just plain "nasty", particularly through bends.
I run with an Everest Chip, approaching 200, and no significant torque steer is noticeable.

If the rear is significantly out of alignment it can cause "bump steer" from the rear. Measurements in Manual are for 15" wheels and Toe In is stated in mm.

I run 17" wheels to accommodate bigger discs and 4 pot calipers so ° is preferable measurement. Hanger 111 did my 'front check & adjust' and measured the rears at the same time. You may find this a useful reference as they sensibly use ° for target and tolerance, like the majority of checking equipment.

geo sm.jpg