47 replies to this topic

[Nev]

Edit, what are peoples thoughts on the 1" ARB, can someone summarise what effects it's likely to have over the standard one? 

 

My overall impression was a perceived reduction in the "flapping about" of the front wheels. Remember that you can't just shove one in without affecting other dynamics of the car. For a start a far stronger roll bar will effectively mean your front spring rates will increase on sweeping corners, which in turn will affect turn in (in theory reducing your oversteer which is specifically what you sound like you want).  

Have you tried increasing rear damping yet, that might help.

[Andy_VX]

If your car is standard power or got a jerky remap?

 

No it's not standard, running around 250bhp with similar torque. It's quite jerky on the road but nice on track. It was a really early Courtenay tuned car with the original Pace charge cooler system. It's a lovely strong engine but the turbo is a bit worn and the map could do with tweaking. 

 

Yeah i've played around with the damping on the shocks, i always have the same front and back though so maybe it's worth going a couple of clicks harder on the rear? 

[Andy_VX]

 

Edit, what are peoples thoughts on the 1" ARB, can someone summarise what effects it's likely to have over the standard one? 

 

My overall impression was a perceived reduction in the "flapping about" of the front wheels. Remember that you can't just shove one in without affecting other dynamics of the car. For a start a far stronger roll bar will effectively mean your front spring rates will increase on sweeping corners, which in turn will affect turn in (in theory reducing your oversteer which is specifically what you sound like you want).  

Have you tried increasing rear damping yet, that might help.

 

 

That's kind of what I thought in my head but I read some conflicting views from an old thread. I guess the point is that a new ARB is always going to be better than one that's endured 70,000 miles of being banged around... you can adjust stiffness by moving the mounts so I guess i need to book a cheap track day and have a play around until i find a good balance. 

Edited by Andy_VX, 25 October 2016 - 11:29 AM.

[Aerodynamic]

I have 425 in the front t and 550 in the rear. And yours is even more agressiva with oversteer. I found better balance when but a MBR 1" in hardest settings and a small rear wing.

[Madmitch]

As said above, smoothness is next to Godliness.........but why the snap oversteer?  Is there something loose somewhere or is it a twitchy right foot?  We always used to say that the ideal balance was slow speed oversteer turning to minimal high speed understeer.  As has been said, stiffening the front ARB slightly will improve adhesion at the rear but go bit by bit as high speed understeer needs to be kept under control.  Play with the dampers front AND rear, they don't need to be the same at both ends and likewise tyre pressures.  If you do a track day take somebody with you who can note all your lap times and the changes you make to the car, what feels good may not be the quickest and vice versa!

[oakmere]

Some have front dampers harder than the rear and some the opposite have a play around. 1 click can make a noticeable difference.

[Aerodynamic]

Do you have any toe angles? Br, Per

[Jimmy-Boy]

Mine was doing this and the answer was snapped engine mounts so check these, previously i also had a cracked subframe which was welded, also a bent up right... if the car is mechanically sound threw out i would check your driving style. Federal Rsr's will get you confident and pedalling quick! Most people who slate have either done to many heat cycles or are clearly not exploiting. 

[DanGT]

The thing that springs to mind, which I have experienced on mine, is that the toe link is set wrong and you dont get enough toe in on bump at the rear. Its a strange feeling that could be described as snap oversteer. If you are comfortable playing with your own set up then you could chuck a few washers in between you hub and the rose joint to see if it changes things, assuming they are converted to bolts on your set up.

 

Even with a twitchy foot you wouldn't get what you would call snap oversteer. It would be pretty obvious what is driver provoked and what isn't. I would get another geo done and ask them to check for worn rose joints/links/anything fouling or the above. Everything else about your car is fine.

 

Oh and blue is the fastest so that might be why.

[Andy_VX]

I've been in contact with Bill at MBR and have bought one of their 1" ARB, lovely bit of kit so look forward to fitting that and seeing what effect it has. 

 

I did get a video emailed through from Silverstone but it wasn't very clear from the car behind as he backed off and let the track. I found an old video from Brands a while back, this instance wasn't as bad as Silverstone but it still "let go" quite easily. I know my line wasn't great and as a result I had to put more steering angle on than was necessary but I still think it should be more planted / stable. 

 

Skip to 3:40

 

 

Thoughts appreciated, crap driving, play in a toe link, too much roll? 

 

 

[Exmantaa]

Mine was doing this and the answer was snapped engine mounts so check these, previously i also had a cracked subframe which was welded, also a bent up right... if the car is mechanically sound threw out i would check your driving style. Federal Rsr's will get you confident and pedalling quick! Most people who slate have either done to many heat cycles or are clearly not exploiting. 

 

Never heard of that before, but does/can that happen to an upright?

 

I'm still searching while my track car behaves so much differently ('unstable") that another VX/Speedster that has a very similar set-up, tires & static geo...

(Replaced ball joints, all bushes and even the rear subframe. Next is measuring the bunpsteer behavior, despite running the exact same toe-link spacers as my mates car... )  

[2-20]

I've installed BOE toe links (11.3 mm dia in the subframe). For unknown reason(May be bad torque settings) I had a lot of play on RHS toe links inner joint due to an élongated hole in the subframe... This gave me à strange behavior (snap oversteer) on track that i could not reproduce on the road

[james_ly]

I've been in contact with Bill at MBR and have bought one of their 1" ARB, lovely bit of kit so look forward to fitting that and seeing what effect it has. 

 

I did get a video emailed through from Silverstone but it wasn't very clear from the car behind as he backed off and let the track. I found an old video from Brands a while back, this instance wasn't as bad as Silverstone but it still "let go" quite easily. I know my line wasn't great and as a result I had to put more steering angle on than was necessary but I still think it should be more planted / stable. 

 

Skip to 3:40

 

 

Thoughts appreciated, crap driving, play in a toe link, too much roll? 

 

 

 

Thanks for the video. It does look pretty oversteery! What's weird is that you don't get instability on any other corner so I doubt it's a mechanical problem (and in the Snetterton video it's a right hander so it's the same problem both sides of the car?) The video looks like turn in oversteer due to lifting off but can't hear the engine in the clips so can't be sure. My car is more twitchy on high speed corners than low speed, but as soon as I touch the gas it stablises (meaning you use the rotation to turn in, then kill the oversteer once pointing at the apex)

 

I still think the tyre pressures sound a bit high but then I haven't used the Federal tyres. And I would try turning the damping down and doing a few sessions to see if that makes a difference (I don't muck about with dampers I just set them for ride quality on the road and leave them be - tried going stiffer for track once and all it appeared to do was make me notice extra ripples in the track surface. But what do I know )

[Tonie Pettersson]

I had the same tendency last year on a track with a high speed corner. It was really hot that day so the tyre pressure on the rears was 0.3-0.4 bar to high. So by letting some air out and soften up the rear dampers 3-4 clicks the oversteer was gone.

[Ormes]

I am no expert but I don't think the car looked like it handled adversely.  You carried a lot of speed in, started to drift early into the squence and therefore you couldn't correct 100% accordingly or back out of it, so it carried on drifting until a fairly big correction was required.  Not being at all pedantic but I wouldn't call that snap oversteer, just pushing the limits a bit Maybe try softening the rear slightly.

[Nev]

I agree with Alex, if you go in too fast, something has to give. If you're oversteering then you more grip on the rear of the car will likely help (lower tyre pressure, softer coilvers etc).

Edited by Nev, 08 January 2017 - 03:00 PM.

[Andy_VX]

Thanks for all the feedback, sounds as if it's probably driver error and some setup changes rather than a mechanical issue. This video isn't the best example of the issue because I did carry too much speed into the corner, I find it a difficult section to get right because you have to lift which gives oversteer as James said. This was towards the end of a long stint so I expect tyre pressures were a little high by this point. Need to do some reading into heat cycles and plan stints accordingly. I'll try starting with a lower pressure and reduce the rear shocks a few clicks. I hope the bigger ARB will help with rear stability too. I'll let you know how I get on, can't wait to get back out there. Must get some more tuition too!

[siztenboots]

Arb will transform it

[Andy_VX]

Arb will transform it

  Hope so! 

[chris_uk]

Based on that brands video my immediate thoughts was that the front end looks very pointy, but also to the high rear spring rate, the car seems to slide round rather than grip and be overwhelmed. so that suggests to me that something is too stiff, i cant tell if the weather was perfect and the sun was just low of if the track looked a little greasy, either way first thing i would look at tyre pressures and dropping the rear spring rate a little. (pressures first obviously) 

 

You have spitfire toe links on there, do you know your toe settings?