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I seem to be having issues putting power to the ground when turning left at the track. As in every time I'm no a left hand bend, be it sharp or sweeping the left rear wheel lights up.

It was obvious at Marulan last time, with the wife mentioning it as well.

Today at Ringwood Hillclimb it was the same thing, any left handers, the inside (left rear) would light up. Right handers, I could get on it early and the car would just power right through the corner as you would expect.

I was thinking maybe my torson diff has given up, but I thought it would be similar behaviour on both left and right handers if that was the case? (and make a hell of a racket if something was broken which it does not)
I did do some *ahem* "testing" and both wheels are spinning.

It's almost as if as soon as the weight (through body roll) is transferred to the right side, the left lights up almost instantly.

It's been suggested that maybe the rear swaybar bushes are binding, not allowing the left wheel to droop enough when the body rolls. So I will slide it along and grease the bushes.

Any suggestions?

Are you sure you have an LSD ?

It sounds like your suspension on one side is not allowing enough droop, or is damped harder than the other side or...?

I know that I don't attack left and right corners the same as eachother. I'm more likely to lift a wheel in the turn I feel most comfortable attacking. Unless this is a new development, this might be the result of some preference on your part, favouring one corner over the other?

I'm yet to become a successful 'ambi-turner'

Easy to check if the bushes are binding, jack up the left side of the car.
While she is up, check nothing is broken or bent, left and right sides.
Have you confirmed tyre pressures are equal?


cheers,
Stephen

It could also be the front rolling too much on the opposite corner. So without any real info provided. It is up to the OP to investigate themselves.

Code4 wrote:Are you sure you have an LSD ?

The SE comes factory with a Torsen diff

The American wrote:It sounds like your suspension on one side is not allowing enough droop, or is damped harder than the other side or...?

I know that I don't attack left and right corners the same as eachother. I'm more likely to lift a wheel in the turn I feel most comfortable attacking. Unless this is a new development, this might be the result of some preference on your part, favouring one corner over the other?

I'm yet to become a successful 'ambi-turner'

This is something that has just started happening over the last few track days, but your theory on side preference has merit. However I did get a ride in an MX-5 with a known working torsen and the driveout of corners was what I would expect. Ian then jumped in my car and was saying there's definitely something wrong there.

greenltd wrote:Easy to check if the bushes are binding, jack up the left side of the car.
While she is up, check nothing is broken or bent, left and right sides.
Have you confirmed tyre pressures are equal?


cheers,
Stephen

Tyre pressures are even. Nothing is broken as far as I can see. The cars been jacked up and down so much recently I should invest in a gas lift But I'll check the swaybar bushes this week. There isn't any creaking etc when it is being jacked up, but I'm going to grease the bushes anyway.

project.r.racing wrote:It could also be the front rolling too much on the opposite corner. So without any real info provided. It is up to the OP to investigate themselves.

This is happening all the way through the exit of the corner so the weight has already transferred to the back/right of the car. It's not until the car is dead straight that the left wheel stops spinning.
In the same situation but on a right hand bend, the car behaves as you would expect.
What 'real' info would you like?

What Spring rates/suspension setup do you have? Corner weights/ride heights/sway bar sizes etc? The American has already suggested droop as an issue this has merit. Further, a larger rear bar will also cause the inside rear wheel to lift.

If a torsen lifts a wheel it will act like an open. When I had a similar problem it was more about changing the line to avoid lifting the inside rear wheel going through the dipper at QR. have you changed the line through the corner? For what it is worth I fixed my issue with a clutch pack diff.

I'd check the diff bushings aswell. Just an idea.

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Lefts T2 & T4 at Ringwood seem to show up traction problems more so than other turns.
Don't know about Marulan though.

Roadrunner wrote:

project.r.racing wrote:It could also be the front rolling too much on the opposite corner. So without any real info provided. It is up to the OP to investigate themselves.

This is happening all the way through the exit of the corner so the weight has already transferred to the back/right of the car. It's not until the car is dead straight that the left wheel stops spinning.
In the same situation but on a right hand bend, the car behaves as you would expect.
What 'real' info would you like?

Any 'real' info more than just the current offered "I'm turning left and I'm getting wheel spin."

If that is all the info that you can give. Then that is fine. Investigate it yourself like I said.

Roadrunner wrote:However I did get a ride in an MX-5 with a known working torsen and the driveout of corners was what I would expect. Ian then jumped in my car and was saying there's definitely something wrong there.

The torsen relies on suspension compliance and 'The Tree" corner is hard AF in terms of this.

In order to get the LSD to work at all (ie drive the outside tyre) the inside needs to actually be on the tar with good contact.
This is the 1.5/2 way advantage, this is especially noticeable on ripple strips with high HP where the car with a torsen loses 100% of its drive as the tyre leaves the ground each bump on the ripple strip where the car with a 1.5 or 2 way keeps 80% of the drive to the tyre on the tar. Watch the fast well sorted EVOs struggle on Tree Corner and youll appreciate what I am saying.

Ians car gets traction because his suspension complies and keeps the tyres on the tar, not because his LSD is better.

Dann

Magpie wrote:What Spring rates/suspension setup do you have? Corner weights/ride heights/sway bar sizes etc? The American has already suggested droop as an issue this has merit. Further, a larger rear bar will also cause the inside rear wheel to lift.

If a torsen lifts a wheel it will act like an open. When I had a similar problem it was more about changing the line to avoid lifting the inside rear wheel going through the dipper at QR. have you changed the line through the corner? For what it is worth I fixed my issue with a clutch pack diff.

Thanks for the tips Magpie, springs are 8/6kg, height is 12cm to the pinch welds, 1/2cm higher in the rear, standard SE swaybars front and rear (SE has a bigger front than standard NB I think?)
I'm thinking The American is on the right path. Just not sure how to test/check that? And just so I understand properly, when you say 'droop' you mean when the car is leaning to the right the left rear suspension doesn't extend enough to allow the left wheel to have weighted contact with the road? This makes very good sense as the left handers are rather tight.

RS2000 wrote:Lefts T2 & T4 at Ringwood seem to show up traction problems more so than other turns.
Don't know about Marulan though.

Your right, T2 and T4 (and T5 if you do a second loop of the top) are quite tight left handers. I was thinking it was my driving style coming out of those corners, but just the slightest throttle spins up the left rear instantly.
At least I have a local hill climb to test this out on when I start poking around for issues!
Hopefully its just the rear swaybar binding (was the most common suggestion from other participants on the day)
Thanks everyone for all your suggestions of what to check.
I'll stick my head under there and see if I can spot anything.

Hi Dann, as always what you said makes complete sense .

I'll double check that the torsen is working first and then start checking over suspension components.
At the next hillclimb day if it is still happening I'll disconnect the rear sway all together and see if that makes a different as a test.

Droop - this can be tested by just jacking up the rear and see if the suspension 'droops' to the limit of the dampers (with the sway bars disconnected). Does the rear spring become uncaptive at full droop?

Do you have coilovers? If so then you may need to set them up correctly to use the full amount of travel.

Disconnecting the rear sway will make the car oversteer more, be aware of this!

This is a discussion on a similar issue (mine) http://mx5cartalk.com/forum/viewtopic.php?p=872568#p872568 There maybe some ideas in this thread, note it does get into helper/assist springs

Video of going through the dipper on the Sprint layout with various mods on the car:
Green - AD08's, 4.3 2 way diff, BC ER's, 1.9 ltrs, E85, 1027 kg, V4 splitter (05/2016)
Blue - FZ201's, 4.1 torsen, Pedders EXA's, 1.9 ltrs, E85, 1,027 kg, V4 splitter (02/2016)
Red - R888's, 4.1 torsen, BC ER's, 1.9ltrs, 1,080 kg, V1 splitter (28/11/2013). This was the first run of the new engine so not pushed too hard.


This is a view from the rear left whilst going around the National at QR (T4/T5 are lefts)


I'll get the camera on the RL again for the sprint layout one day.

I actually find disconnecting my rear swaybar for Ringwood improves my times, due to getting more grip out of corners like that.