Tramlining & Excessive Torque Steer.

[Bullet Fast]

Eddy did you ever make any bump steer geometry improvements?

[Eddy]

Eddy did you ever make any bump steer geometry improvements?

Hoyhoy.

No, all I done was lift the front up a bit.
I have bigger bump steer problems than any one else because the clutch diff shows it up more.
Last October when going down to Waky towing a trailer, I accelerated hard overtaking a truck on very uneven surface, the effect pissed me off.
Mind you that on the track & even rough surfaces it's great to drive.
Since then I done a series of GoPro vids underneath the Little Blue Girl, finding some interesting things going on.
The rear Seat bush even after years of use held up superbly.
Then the fronts surprised me, Fulcrum made me a special set in 95 duro which is the same material as Superpro but a bit harder, they came out looking brand new.



But the videos showed that they could flex too much for my liking.
After researching & talking around I got a set of bushes made with a product called Acetal.



Test run gave great improvement as to bump steer concerns.
Time will tell as to how they go.

[simon k]

I've made myself a set of these "Sub-frame hanger bolt cam sleeves" - I'm very happy with the change

I'm happy to make a set for anyone who wants them, no need for a group buy. Similar money to the bloke who made them for Eddy

[sambb]

Did yours require the subframe to be reamed for them to fit Simon or were they a snug direct fit?

[simon k]

Did yours require the subframe to be reamed for them to fit Simon or were they a snug direct fit?

direct fit Sam - I sized it to slot into the subframe

[Sydneykid]

More caster can help with minimising tamlining, plus FWD's are often very sensitive to toe settings. Different camber settings side to side can also contribute to torque steer. In order, maximise the caster, even up the camber and then I'd suggest trying a few different toe settings. Toe out will make it handle better but maybe accentuate the torque steer. So try some toe in, say 2 mm each side and see how it feels. If it mostly torque steers one way then I'd also check the wheelbase, side to side.

The most common cause of torque steer, once worn or out of alignment components is eliminated, is excessive scrub radius. With negative scrub radius the wheels tend to self align, that's why it's often found on some manufacturers FWD's. If you have changed the wheels and/or added spacers then I'd suggest checking the scrub radius. Zero or a small amount positive is OK, but too much, say 10 to 15 mm, will commonly cause torque steer.

Cheers
Gary

[sambb]

Yeah I must admit when I was running my ET43's with 20mm spacers it had more torque steer than my ET40s with 8mm spacers. Effective ET23 vs ET32. Even with effective ET32 wheel offset, the scrub radius position couldnt be too far off standard (standard wheels were ET43- ET3 , going from 3mm front toe out total to 1mm has a definite beneficial effect on torque steer all things being equal. Having said that I ran 3.5 ish mm total toe out at Wakefield and barely noticed it (smooth surface, flowing track) but then with even with more tyre on a bumpy public road hillclimb, 2mm felt like It was going to be spit me off into a tree - the amount of wheel fight was crazy. So for me, the way track surface can promote loss of adhesian (and kick off torque steer) is also a big determinate off how much front toe out I can feel comfortable pushing with. So like Gary said, starting with slight toe in and working your way out from there would be a good way to find the torque steer threshold you are comfortable with.