Steering vibration on corner exit acceleration

[alpine2530]

Hi all,

Last week I took the car to the track for the first time and I’m struggling to put the power down on corner exits. I wasn’t pushing the car however I’m getting steering vibration when I apply the throttle at corner exits. I tried to be as gentle as I could with the throttle. The steering vibration goes away when I release the throttle.

Could this be a tire issue? I was running 40/41 hot on PSS. It was a hot a day. Came out, bled the tires but didn’t bother to go in for another session due to the vibration. Could it be a driveline issue? Ie. Guibo, CSB, U-Joint? Everything about the car is stock ie. control arms, dampers, bushings etc.

The steering vibration I experienced only happened while accelerating exiting a corner. I’ll be putting the car up on the lift to have it inspected but just wanted your opinion if anybody has encountered this issue. I’ll post a video up soon.

EDIT: Problem solved! Thanks all for your inputs.

[omgzirra_exe]

check your lug bolts / nuts if stud converted..

also if its shaking badly on acceleration... you might be having a miss fire issue.

[alpine2530]

Originally Posted by omgzirra_exe

check your lug bolts / nuts if stud converted..

also if its shaking badly on acceleration... you might be having a miss fire issue.

Thanks for replying. I don’t think it’s a misfire issue as it doesn’t shake when accelerating hard from a dead stop in a straight line. It does this accelerating out of a corner, the shaking stops when I let off the throttle. Never had any issue on the street exiting ramps however. Probably because I wasn’t driving it as hard. I’ll be checking the torques on my lug bolts before my next outing at the track.

[omgzirra_exe]

Originally Posted by alpine2530

Thanks for replying. I don’t think it’s a misfire issue as it doesn’t shake when accelerating hard from a dead stop in a straight line. It does this accelerating out of a corner, the shaking stops when I let off the throttle. Never had any issue on the street exiting ramps however. Probably because I wasn’t driving it as hard. I’ll be checking the torques on my lug bolts before my next outing at the track.

how was your fuel level? during lateral G turns fuel is sloshed left and right or just to one side and the engine is struggling to get fuel. which would cause a misfire

[alpine2530]

Originally Posted by omgzirra_exe

how was your fuel level? during lateral G turns fuel is sloshed left and right or just to one side and the engine is struggling to get fuel. which would cause a misfire

Never thought of that. Thanks for chiming in. Fuel was slight below half. Curious now what would be ideal then? To have a full tank at the start?

[omgzirra_exe]

Originally Posted by alpine2530

Never thought of that. Thanks for chiming in. Fuel was slight below half. Curious now what would be ideal then? To have a full tank at the start?

generally i haven't experience fuel starvation, but i tend to keep my fuel level above half just because..

even at 50% there shouldn't be issues.

[alpine2530]

Hoping it’s the lug nuts. Had new tires installed recently. I have a track day coming up. I’ll report back in a few days.

[rhyary]

Lug nuts are easy to check, but wheel bearing requires more testing.

Can you tell if it does it on both left and right exits?

Wheel bearing can be tested by removing the wheel and rocking the hub, or twisting back and forth to detect any grinding. It should be smooth as butter even when leaning on it or pulling on it while rocking back and forth.

A wheel bearing starting to go bad will be fine going straight, but under load (turning on throttle) may show this.

I would think any play in the joints will vibrate when straight and not under pressure.

Good luck and hoping for lug nuts

[alpine2530]

Originally Posted by rhyary

Lug nuts are easy to check, but wheel bearing requires more testing.

Can you tell if it does it on both left and right exits?

Wheel bearing can be tested by removing the wheel and rocking the hub, or twisting back and forth to detect any grinding. It should be smooth as butter even when leaning on it or pulling on it while rocking back and forth.

A wheel bearing starting to go bad will be fine going straight, but under load (turning on throttle) may show this.

I would think any play in the joints will vibrate when straight and not under pressure.

Good luck and hoping for lug nuts

Thanks for sharing rhyary. Yeah I’ll be checking the wheel bearings too. Funny that you mention that I’ve only noticed that it shook on right exits. You think this might be the left front / left rear bearings?

[rhyary]

Originally Posted by alpine2530

Thanks for sharing rhyary. Yeah I’ll be checking the wheel bearings too. Funny that you mention that I’ve only noticed that it shook on right exits. You think this might be the left front / left rear bearings?

Front if you can feel it in the steering wheel.

[tdott]

Traction on?

[alpine2530]

Originally Posted by tdott

Traction on?

Traction off.

[admranger]

I'd check all suspension nuts/bolts up front as well.

[Estoril Blue]

Based on the video and when it happens - I'll go with a suspension component or bolt.

If you find it was a bolt or stud/nut - then ALL bolts or studs and nuts on that wheel need to be replaced without delay.

[alpine2530]

Thanks all for the inputs. Turns out the lug nuts on both of the front wheels weren’t torqued to specs. I’ll be converting to studs and replacing all the control arms. I’ll be sure to include new bolts.

Thanks again all.

[omgzirra_exe]

Originally Posted by alpine2530

Thanks all for the inputs. Turns out the lug nuts on both of the front wheels weren’t torqued to specs. I’ll be converting to studs and replacing all the control arms. I’ll be sure to include new bolts.

Thanks again all.

yah you might want to take it easy for now then, the lug bolts are probably fatigued to heck now.

[tdott]

Originally Posted by alpine2530

Thanks all for the inputs. Turns out the lug nuts on both of the front wheels weren’t torqued to specs.[/url]

That is scary as hell.

As a habit I usually check them before the start of each track day.

[fsmtnbiker]

Check your motor mounts. You can see the shifter leaning back and forth in your video, and if the mounts are bad the motor can move enough to contact the steering shaft.

[dparm]

Originally Posted by alpine2530

Thanks all for the inputs. Turns out the lug nuts on both of the front wheels weren’t torqued to specs. I’ll be converting to studs and replacing all the control arms. I’ll be sure to include new bolts.

Thanks again all.

I would replace all of those bolts immediately. Have the hubs inspected well for visual damage like hairline cracks. Avoid driving the car until you can do this.

Is there any galling on the bolts and/or wheels? That's a sure sign they were fatigued.

[dogbone]

How far away from 88 ft/lbs were the bolts?

Friendly advice: No matter your experience level, EVERYONE should check their wheel bolts before the first track session of the day. In my opinion, there is NO legitimate excuse for not taking one minute to check torques. If you don’t have a torque wrench, then it should be your next purchase.

Going to a track puts unique stresses on a car. You want to minimize problems by making sure things like wheel torques are proper.

[alpine2530]

Hey all. To be honest it wasn’t a proper track day. It was a parade around the circuit to celebrate 50 years of M. The organisers gave us 20min to drive around the circuit at our own pace after. And because there were more than 60 cars, it was impossible to push on track. The video I posted was the only drive I drove ‘hard’ around the circuit. And because of the vibration experienced, never bothered to go back out. Hence the question that follows.

That being said, the wheel bearings are good and a set of stud kit is on their way over. Also what dogbone said. Double triple check everything before a track day.

[alpine2530]

Originally Posted by omgzirra_exe

yah you might want to take it easy for now then, the lug bolts are probably fatigued to heck now.

Definitely, it’s off season here now too hot for the track. The next time I’ll be bringing her on track will be in winter. In the meantime, a lot of parts to replace till then.