This could be long and rambling!, so I will apologise up front.
Basically looking for an answer from all you experienced track day super heroes.
I did a track day at Hethel end of October time. I had only bought the car on the Monday, the track day was on the following Sunday, so apart from a basic safety check I had no idea how the suspension was set up. Weather was dry and cold! So I did my usual from the last Exige of dropping the tyre pressures down once hot to something like 24 fronts 25 rear.
Straight from the off the car was balanced with no under steer at all. I was being a pussy as it was a new car and a new track ( to me ) Still though already faster than my 240pp.
I gradually built my speed up, until by lunch I was going as fast as I dared. The last session before lunch though I started to get low speed under steer in the two hairpins. This carried on getting worse as the day went on. I tried having a play with various tyre pressures again but it never changed or improved any, just got worse. Strangely though mid and high speed corners were giving more grip, I could actually feel the downforce pushing the car down into the curves giving more grip the more I pressed the gas. Felt a little bit like oversteer.
Now! i was getting faster as the day went on so was wondering weather the under steer was just me pushing more as the wall around the hairpin was getting less scary, I personally don’t think this was the sole cause. Logic tells me it was the tyres, ( though i am a bit thick :tired:) I was thinking the front tyres might have had a fair few heat cycles or had been to old to keep performing, though they looked in great nick and had plenty of tread. I Noticed the ARB was on its softest setting, so previous owner had obviously had some issues with under steer. I am of course going to get a good Geo done and find out how the Ohlins are set up but was just wondering if anyone else had experienced these symptoms and could explain.
Well get the geo done, find a good setting or two (no more imo) and keep an eye on the tyre temps.
I can email you some recommended settings which are easy enough to fiddle with regards your Ohlins. What spring rates, are they just Lotus spec 36mm 2 way? I think I may have used two maybe three settings with my 36mm including wet, although with wet I adjusted tyres to suit the conditions.
Also what tyres, maybe get some idea on what most on here set to?
[quote=jonnyfox]Well get the geo done, find a good setting or two (no more imo) and keep an eye on the tyre temps.
I can email you some recommended settings which are easy enough to fiddle with regards your Ohlins. What spring rates, are they just Lotus spec 36mm 2 way? I think I may have used two maybe three settings with my 36mm including wet, although with wet I adjusted tyres to suit the conditions.
Also what tyres, maybe get some idea on what most on here set to? [/quote]
The tyres are A048 LTS, standard fair. I am pretty sure they are just the standard Ohlin springs. I would appreciate some settings advice as a starting point, cheers.
[quote=MarkyB]Would appear to me to be a combination of you getting faster, and maybe too high an entry speed eventually, which conveys itself as understeer…
Also as you push harder, your tyre temps and pressures will go up. Too high and you lose grip.
On the hairpins, try some trail braking or a slower entry. [/quote]
I think you could be right about the entry speeds, it did feel faster overall throughout the hairpin when I went slower, it just felt to slow for what I perceive it should be capable of getting round. My entry speed was probably a lot slower to begin with. Probably get a pat on the back from Pesky but I think this year I really need to invest in some proper lessons.
Could be a combination of things, and I’m going to throw lines in to the mix. You say low speed, but would you say that that low speed was the same as it was earlier in the day? It seems and I’d expect not, in which case did you make any adjustment to the line you were taking in entering the hairpin? A wider line in, using your new (faster) entry speed could cancel out that understeer.
does your car have an LSD? Was it pushing on when you got on the gas? My car suffers from this, I have found to be a little more gentle on the throttle sorts it out.
I’m going to sound like a sales rep for Racelogic here but I would recommend you beg, borrow steal, a Racelogic VBox.
It collects all the timings and data from your day, so you can look through later and get a feel for how fast you really were and what impact the changes you made actually had.
The fun bit is, once you’re home you can re-live the day all over again in second by second detail, watch side by side video footage to see what difference alternative lines make, and what speed you’re carrying at any point, etc, etc.
Mmm…? I have been in a few Mk 5 Golfs with diffs and I could hear and feel them working. I havnt experienced this with my Exige, also I have researched the extra spec of the Cup and there was no mention of a LSD.?
What Exige model (S2) get them.
[quote=Top cat]Mmm…? I have been in a few Mk 5 Golfs with diffs and I could hear and feel them working. I havnt experienced this with my Exige, also I have researched the extra spec of the Cup and there was no mention of a LSD.?
What Exige model (S2) get them.[/quote]
Ah! I don’t know my diffs, but I thought you meant the open type ( I think that’s what they are called ) don’t all Exige S have these torque-sensing diffs. ?
No…all Exige S most definitely do not have an lsd as standard.
I think Lotus offered a different type of lsd on the earlier cars (plated) iirc.
As an optional extra…
John is quite correct here, there was an option for an LSD on all models but the type varied a little over time. My belief is the Cup 260 had a torsen type as standard (happy to be corrected). If you imagine the diff trying to drive both wheels at the same speed when you apply the power all the rear of the car wants to do is go straight, this has the tendency to make the car push wide on exit which induces understeer on exit
[quote=jfk]No…all Exige S most definitely do not have an lsd as standard.
I think Lotus offered a different type of lsd on the earlier cars (plated) iirc.
As an optional extra… [/quote]
I’ve got conflicting information regarding which type my car has! Then again the document Lotus gave me also suggests I have a 5th injector! This is what happens when you cut and paste tech data from the 240R spec!
I’m sure I’ve seen something mentioned on here about the ao48 LTS compound fronts being pretty hard which won’t help with understeer. I may be totally wrong though. i have noticed similar understeer issues with my s2 but that’s probably a bit of bad driving on my behalf possibly too high an entry speed as has been mentioned.
Felt a little bit like oversteer.
