inverted tie rod end or Roll centre adjuster?

[chargeR]

This is an Internet forum, you're not going to get professional assistance.

The DC5/EP3 front suspension is unstable for a number of reasons, it has a lot of bump steer, high SAI, not a lot of caster and usually scrub radius issues with aftermarket wheels fitted. Your alignment sheet shows that your SAI is 1.6° different left to right which to me is enough to indicate there may be some damage to the suspension, and this difference in SAI will result in a difference in scrub radius from left to right and may be contributing to the pulling and steering kickback you're experiencing. I'd look carefully for any damage to the suspension.

What size and offset are your front wheels?

To improve the behaviour you're describing you have to increase the stability of the front steering system. There's a number of obvious ways to improve this:

- Add positive caster
- Less negative camber
- Reduced SAI
- Reduced scrub radius
- Improve the bump steer behaviour further. The J's RCA have probably improved this slightly, but measurement and then tie rod attachment point modifications are the only way to do it precisely. Due to the rack location the DC5/EP3 will always have bad bump steer behaviour over a large range of suspension movement.

[SHRUKA]

This is an Internet forum, you're not going to get professional assistance.

The DC5/EP3 front suspension is unstable for a number of reasons, it has a lot of bump steer, high SAI, not a lot of caster and usually scrub radius issues with aftermarket wheels fitted. Your alignment sheet shows that your SAI is 1.6° different left to right which to me is enough to indicate there may be some damage to the suspension, and this difference in SAI will result in a difference in scrub radius from left to right and may be contributing to the pulling and steering kickback you're experiencing. I'd look carefully for any damage to the suspension.

What size and offset are your front wheels?

To improve the behaviour you're describing you have to increase the stability of the front steering system. There's a number of obvious ways to improve this:

- Add positive caster
- Less negative camber
- Reduced SAI
- Reduced scrub radius
- Improve the bump steer behaviour further. The J's RCA have probably improved this slightly, but measurement and then tie rod attachment point modifications are the only way to do it precisely. Due to the rack location the DC5/EP3 will always have bad bump steer behaviour over a large range of suspension movement.

I appreciate your suggestions/feedbacks as I really want to get rid of this heavy pulling on the steering.

In saying that, I will do the followings you mentioned to improve it.
But in order to add more positive caster, reducing SAI/scrub radius, what would be the first step?

I can adjust the camber at the front as Im running BC BR coilovers but not the rears (no rear camber arms) meaning I would have to raise the car but I like how it is sitting at the moment.

At the front, Im running 17x9 +35 (225/45).


ALSO
I've read and got told, with Tegiwa Steering rack raisers, it will correct the angle of the tie rods bringing it back to OEM angle which is a reason to this steering pulling issue but I'm not 100%. Don't hear many EP3R use them.

[chargeR]

It's not fundamentally the angle of the tie rods that is the problem causing bump steer, it's the relationship of their angle to the lower control arm angle/position and the strut top location. It's the motion of the front knuckle/upright relative to the steering tie rod that produced bump steer. The only way to fix it for sure is to measure and then make a change. I doubt that the Tegiwa rack raisers will fix anything, and will likely make it worse.

Going to a wheel offset closer to stock will reduce your scrub radius and likely improve the steering behaviour, see if you can borrow a set of +45 offset wheels and see whether it makes much difference.

It is the front camber that is affecting this behaviour, but the amount you have is not excessive so I'd look for a solution elsewhere before reducing negative camber.

You could fit aftermarket strut tops at the front to increase the caster, like these: http://dvrace.com/caster/ I've used a set like these on my DC5R and noticed an increase in straight line stability under acceleration due to the added caster (with -5° camber and 17x10+18 wheels).

If I were in your position I'd start with the wheels, and then add some positive caster, and after doing those two things then get someone to fix the bumpsteer properly, not with garbage parts like those Tegiwa things.

[SHRUKA]

It's not fundamentally the angle of the tie rods that is the problem causing bump steer, it's the relationship of their angle to the lower control arm angle/position and the strut top location. It's the motion of the front knuckle/upright relative to the steering tie rod that produced bump steer. The only way to fix it for sure is to measure and then make a change. I doubt that the Tegiwa rack raisers will fix anything, and will likely make it worse.

Going to a wheel offset closer to stock will reduce your scrub radius and likely improve the steering behaviour, see if you can borrow a set of +45 offset wheels and see whether it makes much difference.

It is the front camber that is affecting this behaviour, but the amount you have is not excessive so I'd look for a solution elsewhere before reducing negative camber.

You could fit aftermarket strut tops at the front to increase the caster, like these: http://dvrace.com/caster/ I've used a set like these on my DC5R and noticed an increase in straight line stability under acceleration due to the added caster (with -5° camber and 17x10+18 wheels).

If I were in your position I'd start with the wheels, and then add some positive caster, and after doing those two things then get someone to fix the bumpsteer properly, not with garbage parts like those Tegiwa things.

Guess Ill start first by chucking back on my stockies and come back with an update.

OR what if I swap my wheels around?
At the moment Im running 17x8 +32 at the rears, 17x9 +35 at the fronts. Do a switch over and see how that works out.

Adding more positive caster will be good but caster plates are not so cheap so Im leaving this as a last solution.

[amant02]

You can buy bushings that increase the castor angle.

[SHRUKA]

You can buy bushings that increase the castor angle.

Is it the bushings for the front LCA?

I read a post saying Mugen / Energy Suspension provide good quality bushings for this kind of issue.

[amant02]

Hardrace and super pro makes em.

[SHRUKA]

*UPDATE*

Switching 17x9 +35 to the rears was a mistake as they were scrubbing the trailing arms.

Ive put my stockies back on (17x7+45) and its making quite a difference in holding straight but still slight pulls here and there and steers to the left when accelerating/VTEC.

Guess running 9's at the fronts are not so ideal but if you're in for the looks then why not?
But not sure if I want to run the 9's as much, as it gets quite annoying for daily driving.

Next upgrade would probably be the bushings as amant02 mentioned, maybe caster plates if I want to spend bigger.

Also to try to get my crappy wheel aligning mechanic to properly fix my bump steer. I don't know where to start...

[Super-DA9]

Dunno

[SHRUKA]

Okay so bump steer is out of the way now. On to torque steer.

My steering pulls to the left when I flat-foot the acceleration but when I let go of accelerate, it cruises fairly straight.

What is causing this?

[curtis265]

Okay so bump steer is out of the way now. On to torque steer.

My steering pulls to the left when I flat-foot the acceleration but when I let go of accelerate, it cruises fairly straight.

What is causing this?

your driveshafts are different lengths and therefore have different torsional resistance, i.e. one flexes more than the other cos it's longer

the fix for this is to buy a rear wheel drive car

[amant02]

Bump Steer + Torque Steer is just the fun part of owning a ep3/dc5.

I get hectic Torque Steer, specially with the new light flywheel.

Fix = Hold the steering tight and be prepped to counter if required.