GraemeI

My driving is pretty consistent so I am sure I will work it out eventually - plus I plan some seat time with a professional suspension tuner to make sure

Hi All, back again for some insights, wisdom and possible abusive commentary I had some challenges with a wayward rear end when I got the car back in August 2017, which didn't feel right, so ended up with adjustable LCA's new PS4's and a good alignment job, and whilst that improved it a lot, I always felt like it was still way to eager to step out unpredictably, or just very early - for what is essentially quite a low torque output. Much forum reading and talking to people suggested tail happy was a normal character trait, so I chose to live with it. Today, I went out to CAT Driver training and did half a day with Colin Hoad, and the short version is he didn't even want to do the handling circuit at high speed in my car after testing on the skid pad, as it is too flighty at the rear. You can push the back out on demand even when doing push on understeer with just 5% more throttle! In Colin's words, he said that isn't even possible in a 600bhp Ferrari 488 with all the traction turned off, so it shouldn't be happening in a GT86!! So, with that background out the way, I am looking to go get the car's geo set up again, but was wondering if it was worth doing something with the suspension at the same time (or just before), as it's going to get very expensive to keep re-doing these things Colin's comment was the car is pretty sorted apart from the rear end, so no (other) weird suspension or handling traits, but I am looking to get a slightly more compliant ride for road use and be able to stiffen it up for the occasional TSS or track day, which I can't do with the current setup. What I don't want to do is mess things up even more, so struggling with leaving as is or putting some Flex A's or similar in, then getting the geo dialled in? What do you vastly more experienced people think?

I didn't think it was the caster, just mentioned it as the other major change. I am doing about 6 of the Sprint Series rounds this year (if the plan works out ), and maybe a track day or two, so with that in mind, camber is up in the front to 2.5 and rear to 1.75, neutral toe front, 6' rear toe in. Not massively different to before, mostly the front up, but obviously with new springs and dampers. Still learning the EDFC adjustments and trying different settings to work out most effective for road and separately for track. Once I have that figured out, I will consider if need any ARB's or other changes to help.

Not exactly sure what fixed it tbh, but I replaced my suspension with some TEIN Flex A's (+EDFC) with a complete geo setup, including changing the caster at the front end by rotating the coilovers. This gave more front end and feel in the steering too which is a good thing Something in there fixed it, so all good. 100% agree on getting more front end rather than reducing rear grip!!. My intention is to spend some time tuning it to get max grip all round, probably with a slight understeer bias. This is only because on track I trail brake which loosens up the rear anyway, so will ideally make it neutral to slight oversteer, as I quite like steering with the brake and throttle. Will make road driving a bit more boring but tbh, I drive like a grandparent on the road anyway, so it will rarely affect me. All in theory mind you - still got to work out how

Yay, success! After the suspension mods, the issue has been resolved! Went to visit Colin Hoad at CAT again and he did a test drive of the car and it has been cleared of it's previous affliction! It seems to have been slightly 'over-cured' though and now resists oversteer at all costs which was not the intention! Now to tune some oversteer back into the car

I would definitely echo what Lauren is saying. The new one as stock makes cornering on corrugated roads a much better experience - the rear doesn't skip about like the early model. I test drove both models for over an hour each, back to back on the same day on the same roads, which is what I am basing this on The interior of the newer model is also nicer (imho), so worth considering. OR, you could do what I did, and buy an earlier model and use the saved money to change the bits you don't like - like suspension, exhaust, mapping etc Not the option to take if you're concerned about modifying the car, and it's a slippery slope In short, if it's a daily driver and you're likely to keep it stock, definitely try and get the newer model.

I know they are not forged, so It's nobody's fault but my own - when I initially saw Rays and the word Light in the same vicinity, I got over enthusiastic

The 17x9's are 20.2lbs or 9.16kg, so pretty much the same weight as the stock wheels. To be fair, you do get an extra 2" of width, so from that perspective it's better, but still not 'light' imho

Nice looking wheels, and a good price, but should not have the word 'light' anywhere in the name

Great question! It’s been like that since I got it - trip home after picking it up, it got sideway in 3rd gear on the straight going up the A41 I then got the alignment checked and camber was all over, so bought adjustable LCA’s and new PS4’s, followed by a full alignment, all within first 2 weeks. Car was much better than it was, but Cadwell was still interesting Most exciting was mass oversteer before turning into Gooseneck because I didn’t brake way early and the back just let go because it’s a slight turn coming in. I turned it down again after that, and got as fast as I could without coming off, which is why if you look at the times, my last two were within hundreths of each other, but a good 8.5s off yours! I put it down to a lack of talent at the time as I accepted the ‘fact’ (according to most people) that the 86’s have a flighty rear end. It still never felt right to me, which is why I booked thr 1/2 day with CAT Driver Training - either to learn how to drive the car properly, or confirm it wasn’t right before I spent money on coilovers etc. Sadly, the latter was confirmed - i.e. it just isn’t right.... Now I am kind of stuck with what to do next, but will test the new settings a bit more before thinking about that too much.

+1 good reason for owning the car from new I guess It is a small amount, but 4mm total difference in the wheelbase side to side, suggesting something happened at some point, but as you say, I will never know... I am definitely conscious of the fact that the weather, temperatures, road surface and road conditions all affect the handling so am not expecting dry summer handling I do allow for it, and have been for the last 6 months, but what is frustrating is when an expert tests it and doesn't want to run round the track at, or even near the limit - then you know the unpredictability is a problem, and it's not 'just a bit loose'. At least with yours, you know it's sideways for a good reason with the toe out , and is probably predictable and controllable. Mine, not so much - lol

Really appreciate the offer Kevin, thank you. I really need to drive it a bit more with the new settings to understand what it is (and isn't) doing, and can then take it from there. Tony suggested I try another car to see if it's me, which is 100% logical, but Colin eliminated that already I think - he has driven enough of them to know what's right and what's not

Well, it’s still a mystery.... Toe was slightly off at the rear, but not by miles (see the Before column in the first image). Tony said they often have way worse, particularly if people have been doing Time Attack or airfields, as it rips the toe out of alignment... He has now set it up with some toe out at the front, and toe in at the rear to see if that helps. Everything else checked out within reason assuming I don’t want to go full track attack and the car still needs some tyre and bearing life on the road He checked all the components and checked for anything being loose or broken and nothing there, so that’s something eliminated, if not closer to the answer.... I haven’t really tested it yet, but on the one roundabout I pushed it a bit, the back came round very easily again, so it’s still more lively than I would expect, so there is a mystery for sure. Front feels a bit more remote and has lost a little feel, but is definitely quick to turn in now, and is stable in a straight line, so will continue testing it to see what it feels like. Of more interest to me was the left/right misalignment, even if only very slight, plus the slightly different wheelbase side to side - suggests someone did something unnatural to the car at some point.... *scratches head* FWIW, this looks difficult to read, but is really simple First (Before) column is as it says. Middle (Target) is also what it says - before they start the work, they enter the target figure and range, so this is just a record of that - probably not totally necessary, but does give a reminder of what was being aimed at. Lastly, the Actual column is what it says too - the actual readings after the alignment. We had agreed not to touch the camber for now, but that is the next option. This next one shows contact patch n the road for the front wheels - too little comes as a result of high camber of course - great for track, not so much for road This one is simply track and wheelbase - concerning the left and right don't tally! Confirms the second image showing the left to right offsets.

Happens to all of us at some time or another, some more than others, so I just learnt to live with it

Sounds fair Lauren - I do the same thing myself, and tbh, if you're happy with how it's handling, then leave it like that I am going to get mine 'checked' tomorrow so will see what the outcome is.

Genius - love it

Thanks for sharing Lauren! Brain pain has increased however, as this is even more confusing if you don't have as much oversteer as you would like in the car, AND it's toe'd out! Your driving style and description of how it handles suggests your first view was correct, yet these things make it seem different again! Good grief, why can't these places standardise on output!? I will just make sure it's definitely toe'ing in for now (physically, forget the readings!) and see how that works out Thanks again everyone for your input - your time is appreciated!

Exactly this! The different rigs seem to show it differently, but what Lauren & Kevin both said earlier is all I have to focus on - i.e. make sure the front of the tyre points inwards, not outwards, and then get the two sides to be the same, regardless of whether the machine says + or -

My brain hurts more than I care to admit! Because this is multilink instead of a double wishbone setup, I am not even sure what I am looking at when you say 'aft of the wishbone' I got a pic from a different angle which may make it better or worse If I look aft (rear) of the drive shaft, there is the LCA, and anti-roll bar, and fore (in front?) of driveshaft is the tie/track rod? Or have I lost the plot again?

Yes, I am thinking similar or maybe even slightly more - will see what the start point is first, and I am hoping it has moved. It doesn't feel different to me, but I am no guru on these cars (yet!)

Spoke to Tony at Blackboots again, and he confirmed the positive readings are toe-in, so mine is just slightly toe'd in at the rear, which is what I remember him saying. He dis say it's confusing as it appears to be different to camber where positive is top out. Summary was camber positive is top out, toe positive is rear out, and caster positive is top further back than bottom. Taking it back just for him to do a check to see if anything has moved, which tbh, would be the best outcome - it's not like he doesn't know what he is doing . If that isn't the case and he can't spot anything obvious, I will take it elsewhere for full checkup.

100% agree with instability comment. You do have a way with words Lauren - the non edited version literally made me LOL and I have people looking at me funny

Now that’s what I always thought, but could not find anywhere on Google to back that up, which is odd. Every single site describes it the other way round for toe, but the same for camber.. - camber is described as top in more than bottom, and - toe is described as rear of tyre further apart than front.... From my car work of nearly 3 decades ago, I (vaguely) remember the same as you’re describing Lauren, so I also wondered if it may be because different machines show it differently, but then would expect to see evidence somewhere Hate being (even more) confused...

That was Colin’s (and my) first thought, but the skid pan we were on has bumps and undulations and it didn’t bottom out once. The reason is because they are progressive springs, so stiffen up with compression. I have only managed to bottom out twice ever and that was with unseen holes in the road. Besides - in an 86, comfy is a relative term

You're not kidding Kevin! Mind you, right now, I can't even get the road car to behave on the road!!! In it's current state, just the slightest provocation of lift, throttle or even gear change sets it off How much toe did you put in to stabilise things? More than happy to balance on the throttle