Turbo tried to bite me

[thaelim]

Hi folks,

I'm not quite sure this is the right forum in which to post this question, so mods please move as required...

The other day I was having a bit of fun in my AH Turbo (within the law, naturally) and I entered a fairly tight corner at about 60km/h. This was on a smooth, dry road. As I turned the wheel into the corner I quickly noticed that the car started to understeer. No biggie, it's happened before so I thought the car would just run a bit wide and that's that. Suddenly about halfway through the bend, SOTP is telling me that the car is sliding, i.e. no longer traveling in the direction it's pointed. The ESP lights up and the steering wheel tries to wrench out of my hands.

The car did recover very quickly and kept going where I had the steering wheel pointed, however there was definitely a brown underwear moment there. I'd really like to know what happened so I can avoid it in future if possible. My only guess so far is that I may have lifted off the throttle when I felt the understeer begin, which caused snap oversteer. Not sure if the AH is prone to this however...

[Nurb608]

I think you've nailed it on the head, lift-off oversteer. Have had it once or twice in mine and was really surprised with how the car was able to gather it all back, but yep, shit myself aswell because I wasn't expecting it lol.

[Jerram]

happened to me once in the vectra of all things (how considering they're notorious for tyre chirping understeer I'll never know)

Of course i didn't have the luxury of ESP so I ended up pointing back where I'd come from.

I guess the Astra doesn't have the world's longest wheelbase either which would make it more prone to go round. - Maybe you dropped a rear onto a line/catseye or something?

[thaelim]

Hmmm... so is there a handling mod that might help alleviate this issue?

[Jerram]

Hmmm... so is there a handling mod that might help alleviate this issue?
whiteline rear sway bar perhaps?

[tomtom]

Tyre pressures will play a vital role in how the car handles as well.

Generally speaking on a FWD...

- Higher PSI at rear: More oversteer
- Lower PSI at rear: More understeer

Go to your servo and check out what pressures you're at. Not sure if you have a H or TS but I've found on mine that if the pressures are equal all round, the car is pretty non-event and safe. A lot of people tend to ignore their tyre pressures not realizing how vital it can be for performance. You could have all the best suspension gear but run weird pressures on your tyres and make it all for nothing.

I run F 35psi R 39psi on both my 17s and 18s.

[thaelim]

IIRC this was just a week or so after I got the car and I hadn't got round to checking the tyre pressures. When I did, they were down to about 32 PSI all round. I reinflated back to the placarded pressures but I haven't had the opportunity to check the handling after doing that.

People seem to say that the Astra is not the best-handling hatch out there... all I know is that coming from a VE Calais with its expensive multilink sports-luxury suspension, my Turbo would eat that car for breakfast around some fast corners.

[03srit]

I thought I read somewhere that that's a feature for the H to overcome understeer? I could be wrong but I thought it was designed to do that..

[kabel]

The Whiteline bar won't help with the lift-off oversteer.
I have seen an AH Turbo on a skidpad do a very nice imitation of a drift-car !
That car has my OEM VXR springs in it and an adjustable rear bar.

Tomtom advice seems good !

P.S
I have decided to upgrade the handling on mine just a bit further with a set of coilovers.
Will report on the improvements once they are installed.

[dizzydumb]

I posted a query thread 2 months ago regarding this. Is urs a H-VXR or H-SRiT ? It scared the shit out of me when it snapped into oversteer at 40km/h around a roundabout. VXR's pivot point is near the gear lever, while the SRiT's pivot is more towards the engine block. FYI I was running 38PSi tyres all round. I reckon I should reduce the rears to 36 now that the wet season is coming.

[thaelim]

Mine is an AH SRi-T

[dizzydumb]

Drove my mate's AH SRi-T hard (frequently) before I bought the vxr, and didn't have any problems. Just lots of understeer. I reckon it might be the tyre pressures, or maybe even the tyres themselves?

[dieselhead]

I People seem to say that the Astra is not the best-handling hatch out there...

I understand why they say that, especially when compared to my current daily drive :)
I have experienced over steer in a couple of instances in my CDTi. However, due to the heavy engine the under steer tended to be more of an issue. Found that running all corners at 38 psi was best on 18".

Just take it easy champs, not worth ruining your car (or worst!) just to find its limits on a public road.

[Bloodnok]

I understand why they say that, especially when compared to my current daily drive :)
I have experienced over steer in a couple of instances in my CDTi. However, due to the heavy engine the under steer tended to be more of an issue. Found that running all corners at 38 psi was best on 18".

Just take it easy champs, not worth ruining your car (or worse!) just to find its limits on a public road.

My worry is accidentally finding that limit when I wasn't trying, and having it bite me as a result. I know my Vectra degenerates into ever increasing understeer very rapidly if I even think about pointing it at a corner with any rapidity. It's done it several times - admittedly never seriously, but I've seen it, and I know what happens. I've never had any hint of losing the back end though.

I suppose understeer is at least predictable - sudden oversteer can snap around and require much more presence of mind to deal with effectively...