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Thread: 2013 FSAE-A Drive Swap

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    2013 FSAE-A Drive Swap

    2013 FSAE-A Drive Swap

    While it’s about a month late I thought it might be a good idea to finally get this thread going.
    Hopefully some of the drivers still have vague recollection of the events? It would be great to hear for guy’s like Pete, Malcom, Travis and Andrew Gun, who had a chance to drive multiple cars, on the differences between them.

    We (Curtin) though the drive swap day was an incredibly beneficial experience, and were lucky to have 20 8-lap stints between 16 drivers.(Tim, malcom, trav, drew, pete, scott, mat, christo, Toko denki guy#1, paul, nick, andrew, shay, tom, mitsutakau &chris) A huge thanks to all the drivers for their great feedback, and apologies to Chris, andrew and any other drivers who lost laps due to our lack of fuel/electrons late in the day.

    For reference our vehicle was in it’s endurance config- Tyres were our comp set, used from Friday onwards for all comp events a few bonus laps. Aero was set to a medium DF/drag setting, due to the high speed straight on track.
    Tyres -- 13x7 R25B : Aero -- Est ClA 4.0, CdA 2.0 :Weight -- 270kg (no driver)

    Best times achieved by drivers (hand timed) were:
    Pete Marsh (UWAM) 39.8
    Tim S (CMT) 39.9 (multiple stints..)
    Andrew Gun (MUR) 40.15 (4 laps only)
    Travis (MMS) 40.19
    Malcom Finch (UoA) 40.26
    Chris (MMS) 42.5 (2 laps only)
    Shay (CMT) 42.6

    I had the opportunity to drive Monash’s car (thanks guys!), and have some comments below.
    I should probably preface this by noting that I do not have a particularly strong motorsport background, with all driving experience to date in the CMT vehicle. Most comments are based on performance differences between CMT and MMS only.

    Monash:

    Ergonomics
    I got the impression that the ergonomics are very well suited to perhaps a somewhat differently shaped person to me. Seating position and belts provided a lot of support and excellent rigidity though I felt that the seat shoulders were too narrow and position a bit more upright ; though not enough to notice it much when driving.I found the headrest somewhat uncomfortable and would probably want the headrest moved slightly rearwards as well --it felt like my head was pushed forward too far relative to the seat-back.

    The adjustable pedalbox was perfect as usual, can't really comment on pedal weights as I was never braking on the limit; but I assume they had to be good as I didn't really notice them. Shifter (manual) required a lot of weight; but certainly worked. The paddle shift option was awesome too; it allowed easy shifting even on the high speed “twitches” during the straight, compared to ours where it was best to shift and stay in 4th prior to this section. The paddles required very low force to actuate-- not a problem after a few laps, but interesting to get used to straight away.

    Driver aids/ displays I think could be improved on this car. While the green lights for “shift now” were effective I definitely missed the CMT dash as it provides a much clearer indication of engine RPM. While I don't imagine the MMS drivers need it, less familiar drivers might benefit from a larger and more obvious tacho so they can get the downshift points etc right.
    I also think that the control/ buttons could do with being labeled; it takes 5 minutes if you have a $20 label maker and you’ll get that time back at a single sponsor drive day IMO. From memory there is something in the design event about controls being clearly understood/marked, so some nice labels/decals could even be worth points?

    In terms of vehicle dynamics I felt the car performed amazingly in all corners and transients. The vehicle felt much more “crisp” and stiffer than ours, and seemed to handle the bumps around the hairpin quite well. There didn’t appear to be noticeable understeer or oversteer at any point; probably because I was driving way off the limit
    Steering weight was moderate to low and the lock-lock required was far lower than CMT. While personally I would have liked a slower rate for the comp track we saw this year, I imagine that for the usual hairpin etc the current MMS steering would be ideal.

    Aero was excellent. Available grip in the fast sections was definitely higher in our car (guessing 15-20%?) and I don't think I was getting near the limit at any point there. Can't comment much on DRS as I was putting too much focus into shifting and avoiding cones to really pay attention. It was notable that the vehicle balance was not substantially affected with DRS open as handling still seemed OK on the twitches at the end of the straight with the wing open.

    Power-wise it felt OK; though definitely less power than our RR. While the paddle shift certainly helped keep the power on, I wasn't a fan of the short gearing and need for so many shifts.

    So, what to change to make it better? Some minor changes to the dash and ergo could make the car nicer for less experienced drivers, and more power output over a broader range could make it faster on such an open track. I’d probably try a thinner headrest and see if the drivers find it more comfortable too. I’m very interested to hear what Pete has to say about VD; unfortunately I don't have enough experience to know what could improve there. Overall a bloody awesome car- it seems to do everything that is important very well.


    Short video with best laps from a few drivers: http://www.youtube.com/watch?v=H_bb9GFhIiU

    Tim
    Curtin Motorsport 2009-2013

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    Woo hoo! Its on. Thanks Tim for initiating this, I look forward to this thread. Hopefully we'll get some good input here.

    Unfortunately the only driving I did at comp was driving you all to distraction with bad karaoke over the commentary. And I don't think anyone wants to re-live that...
    Geoff Pearson

    RMIT FSAE 02-04
    Monash FSAE 05
    RMIT FSAE 06-07

    Design it. Build it. Break it.

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    More please!

    Z

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    Karaoke, Z??
    Geoff Pearson

    RMIT FSAE 02-04
    Monash FSAE 05
    RMIT FSAE 06-07

    Design it. Build it. Break it.

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    Cheers to Tim and Curtin for starting this up and the feedback on M13. The videos are great to watch.

    Driver swap is an amazing event and we take our feedback straight to design. It is also a great event to spend time with the other teams and to drive their cars.

    Travis and Chris are both waiting for new accounts but have given their feedback.

    *****************
    Chris

    ---Curtin Motorsport Team---

    "Curtin's car was amazing! I only did 2 and a half laps, but already got down to a 42sec lap before it ran out of fuel half way through my third.

    Ergo: Overall it was good, the seat held me in tight giving good feedback though was not moulded quite right to my ribs, there were other seat inserts I noticed so maybe another one would have fit me better. the pedal box felt good though could have been about an inch further away, this is a very minor issue though. The steering wheel needed to be about 50mm further away to give better elbow room for a tall driver like me. The manual shifter located behind the wheel was the best one I have ever used, it had a really positive feel to the upshifts with low weight and the downshifts were a simple tap. It could do with some sort of ignition cut system to allow flat upshifts. My ability to settle into the car so quickly had a lot to do with the good ergonomics.

    Setup: good in general. It could do with a little more pitch stiffness when diving under brakes and the brake bias leaved a bit to be desired as it ad a tendency to pinch the fronts pretty easy. Last year I drove ECU's car and I have to say that I think Curtin's car was better overall though ECU's car was sharper, this could be down to weight (50kg or so extra) or maybe the fact that ECU was on goodyears. I think Curtin could use wider rims to up the responsiveness of the hoosiers.

    That engine If you keep it in the powerband there is no way our new car could keep up though I shudder to think how much fuel it would use doing a full pace endurance. The engine didn't seem to run out of puff like our 2010 car did, it just screamed all the way to 13000. This may have something to do with plenum volume or maybe our injectors/ pumps were not sufficient.

    Aero: significantly less downforce than our car, I would say it has just a little more than our 2010 car if I had to guess though it greatly improved the car's stability and gave me a lot more confidence than I have with the non aero cars.

    *****************
    Travis

    ---Warwick Racing---

    The Warwick car was quite interesting, as I was expecting it to be very difficult to drive being so wide and with 3 pedals and old tyres and quite a significant lack of power. However it wasn't too bad, as the general ergonomics were pretty good (apart from having 3 pedals and having to use the clutch to change gears, this significantly reduced the potential to get the most out of this car - you should never continuously have to use 3 pedals in an FSAE car, a hand clutch would have been a much better option).

    The steering was relatively easy to use and not too heavy, the steering wheel was a good distance from the driver and there was enough elbow room to play with for someone my size. The pedals were a little far away for me to be fully comfortable, but not too far that I couldn't use them properly (I'm not sure if they were adjustable but it would be a handy feature). The seat left a little bit to be desired, as I was sliding around a bit (not as bad as some other cars though) which caused a delay in the car giving feedback to the driver after initial turn in. This would be fixed by having some simple moulds for each driver or a more secure one size fits most seat like our car. The manual shifter was pretty good, but the main thing holding it back was just having to use the foot clutch for every shift, which obviously slowed it down a bit.

    Dynamically the car had a bit of understeer everywhere, but the initial turn in wasn't too bad. The problem was you needed to do a lot of turning with such a wide car (not great for FSAE-A tracks). You couldn't really fight the understeer with generous applications of power, as there wasn't enough power to do much. Once the car got near the top of the rev range it moved ok down the straights, but it is significantly slower than most other FSAE cars. The brakes were terrible. The pedal was quite solid but didn't slow the car down much at all even with quite a hard press on them (it must have been quite an effort to pass brake test). If the car was quicker down the straights this could be a big problem, but the car was never going fast enough to need significant amounts of braking so I did most of the slowing down by the using the gears and just scrubbing off speed by turning. I wasn't expecting much grip from those old narrow Avons but they actually weren't too bad at all, and I had forgotten how forgiving and easy to use compared to some of the other FSAE tyres, just keep adding more steering for more grip. I never really got to the full potential of this car as I was never comfortable with the understeer in the high speed sections - the good initial turn in could be quite misleading in the grip potential (it was also a bit hard to judge due to the lack of secure seat). In its current state there was probably another 1-2 seconds to gain in lap time with more confidence/experience but if the understeer was dialed out and a better seat was there and much better brakes, it would greatly improve the confidence of the driver and maybe increase the gain to about 3.5 seconds.


    ---MUR Motorsport---

    Not a bad car, there is a good reason why this car finished 3rd overall. It had a fantastic powertrain, very nice linear engine with plenty of power and great response. The car was quite well balanced with a decent turn in response and predictable results so in that sense it was easy to drive. You could make the car understeer or oversteer at different times and neither felt like it was holding back the potential of the car However the main thing holding this car back was the steering effort and ergonomics. I feel sorry for the guys who had to drive a whole endurance in this car, as it would have been a painful experience. The very heavy steering effort was made worse by the fact that there was no elbow room for the driver, so the effort was all focused on the same arm muscles for the whole time. It is much easier to have unlimited elbow room so that you can use your arms and shoulders more and if you get tired you have the ability to change the way you steer a bit to try and use different muscles. I also felt that the driving position was too high and upright (not helping their CG either) and it just generally didn't feel too comfortable compared to our car. The shifter was pretty good and easy to use, and the pedals were also fine for me.

    I also found like the car was lacking a little bit of overall grip. It wasn't the lack of aero, as I have driven quite a few other non winged cars. It wasn't much but I think it just didn't have as much overall grip as what it should have had. This was not from a balance issue as that was fine but I'm not sure what was causing it (could be non optimum tyre pressures, camber, geometry or the tyres themselves).

    Overall generally a pretty good car. Just fix the steering weight and ergonomics and maybe try to squeeze a bit more grip from the tyres and it will be a very good car. I don't think the lack of aero is holding this car back much at all and it will not give the gains that many would expect.

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    ---Curtin Motorsport Team---

    I drove their car last year as well so I have a good idea of what has been achieved this year. Firstly I would like to congratulate them on the reliability of this car. It was incredible how well this car worked all weekend and they were happy to put as many drivers as they could in their car and never had any issues other than running out of fuel. Nice work, this goes a long way to performing well at competition and it showed.

    I will start by saying that I was unaware that they still had the adjustable steering column so I am not sure what position it was in while I was in the car, but the steering wheel was far too close to me (and I'm not a very tall driver so it shouldn't have been). I wasn't able to use my shoulders and my arms felt very constricted, so I wasn't getting the optimum feedback from the steering wheel. The seat was pretty decent, not as good as ours but it held me in well enough and I wasn't sliding around while driving. I'm sure it would be better if the insert was moulded off me rather than using someone else's insert. The shifter was very good last year, and it was even better this year reaching up behind the steering wheel to be able to make upshifts without taking your hands off the wheel. It had so much feeling and worked so easily that it would be very difficult to miss a shift. The only things I would change about the shifter would be to move it slightly closer to the steering wheel so you didn't have to reach so far from the steering wheel to upshift, and I also found the clutch handle was a little to high up the shifter and close to the steering so it interrupted my movements a couple of times. The pedals were just a little bit far away for me to be completely comfortable but I didn't really have much trouble fully utilising them (I'm not sure how much/ if any adjustability is built into them). The steering weight was not bad, though there could be more elbow room for the driver to reduce fatigue (I also had a fair bit of trouble due to the steering wheel being too close to me, which increased the fatigue greatly).

    Dynamically the car had improved a fair bit from last year, however I found they had only improved the biggest problems, not eliminated them (except they seem to have reduced the scrub radius to a good amount). The car had a little bit of understeer everywhere. The understeer seemed most obvious to me in high speed large sweeping corners. The understeer wasn't so bad at low speed if you used the power to drive around it, but it was still there slightly. I never once felt like the car was going to step out and oversteer on me unless I encouraged it with lots of power, so the understeer was always the limiting factor at the grip limit. The car still pitched too much under power and brakes like last years car. I found it to be more of a problem under power as the front wheels would lose too much traction when trying to steer while using a fair bit of power (and increasing the understeer), which was especially noticeable in tight sections of the track on corner exits. However it didn't really feel too soft in roll (it could probably do with being a bit stiffer, but it was easy to drive and wasn't too slow to react). The brake bias was still off, and the fronts would lock well before the rears, reducing driver confidence and braking performance but it was nowhere near as bad as last years car. Pedal feel was pretty good though. The initial turn in of the car was ok but not great. I think there are gains in using wider wheels for those fat Hoosiers, and its a pretty heavy car so this also would have influenced the transient response quite a lot.

    The powertrain was very similar to last years car, with not much at all down low before just taking off around 8000rpm or so. There is a lot of power up there and much quicker than our car. It is great when you keep it the rpm in this zone (it never seems to run out of power until you hit the limiter which is great) and this can be done well in combination with the great shifter on this car, however if you made a small mistake and dropped out of the powerband, it would really hurt your lap time as you would lose so much speed on the following section. After driving Melbourne's car I think this torque hole below 8000 should be fixed as they had a similar amount of power but it was linear the whole way and never punished you so hard for small mistakes. Swinburne's 2010 car had a powertrain package that delivered similar results to Melbourne's but had another level of power again (definitely the most powerful FSAE car I've driven, what an engine! but the suspension was woeful). If the low down torque was improved, it would also allow more economical driving without having to keep it screaming the whole time while being easier to drive.

    The aero has helped this car feel more stable and improve the grip levels, but there is still plenty of development left in this car without the wings. Overall a great car and quite easy to drive dynamically, though to get the most out of it you had to drive it well and use the power whenever possible which would take a lot of driver training. Great improvements and I hope they keep going in the right direction because it is already a great car.

    *******************
    Travis

    "In general there seems to be many cars that don't place ergonomics as highly as they should. The best thing you can do is make your car easy to drive so the driver can actually get the most out of what you have before trying to make it faster. There is no point in having the fastest car if you can't drive it properly."

    *******************

    We look forward to hearing from other teams on their experience at driver swap.
    Good luck to everyone in 2014!

    Kind regards,
    Ryan Ockerby
    Monash Motorsport 2012-2015

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    Unfortunately we weren't able to get the UWA car out for drives again this year. We managed to snap a Bunnings cheese bolt off in a tapped hole in a difficult to access spot, and so that was that. Next year... I promise.

    Thanks to Monash and Curtin for a drive in their cars, and to some others that offered, but it didn't quite happen.

    I drove Monash's car first, and have the benefit of having driven most of their cars in recent years. I also recorded my feedback this year for the first time, as a memory aid for this write up. This is not a transcript however, more of a considered summery. I'll follow Tim's format.

    Ergo - Really good! BIG lesson for any (every) other team who got to drive it just how important this is to get right. I commented more about this during Curtin's feedback than Monash's but it really is just so comfortable to drive at speed, and totally lets you focus on the job at hand (driving). Seat support and belt placement are very good, as is the steering wheel, possibly the FSAE car in history with a wheel higher than needed. Good adjustable pedals that your feet stay on and nice weighting and travel everywhere. My comment to Curtin - "you could do 100 laps in theirs". The only things I can think of as a negative is the shifter paddle effort is too low, and you can easy shift inadvertently.
    VD - Steering! This team has (must have) worked hard on getting the front end geometry "just right", a big deal with ludicrous down force and lat loads involved. I never remember to get any good spy pics of what they have got, but it sure is nice to drive. Very fast rate, with great feel, but not heavy at all. This makes a HUGE difference if you look at the actual work required from the driver over the enduro event. As with the good ergo, it just lets you get on with the job.
    Now the bad bit... My initial feedback went from 'nervous' to 'unstable' in the rear end. A total contrast to 'planted' car Monash usually produce, and a destroyer of confidence, speed and 'fun'. This tendency was eliminated when on the power. After spending some time with the guys and the car I was shown some 'suspect' rod ends giving some (actually a lot) of play in the rear toe. Playing back the recording, I'm now pretty convinced it has toe out in the back except under power, and this fits well with some of the shenanigans that were going on out there.
    AERO - Yeah OK, so they do work then. Clearly has lots of downforce, but also lots of drag. The outright lat grip was lower than I expected, maybe tyres, although I didn't go to the limit in the faster sections. The DRS is VERY effective and you can see lots of potential to run most of the track open and only close in a couple of spots, which I didn't try at all. (holding the button down would be a PITA). A big selling point for the wings has been the ease it brings to driving and letting anyone (novice/amateur) have a red hot go, but not this car as it is quite 'edgy' and just doesn't give you that "your wish is my command" confidence.
    Engine - Sufficient I said on the recording. And that is about all. It is technically very good, no lag, (enough) torque everywhere, excellent shifter. But I still don't like it. There is no excitement from it, and for some reason it feels like your hurting it quite often. Just a bit harsh up top maybe. BUT, it is small and light and gets the job done, this car no longer slows down in the fast corners at full throttle like the previous one did, and it feels MUCH faster overall because of it, and I'm led to believe there is more to come.

    OVERALL - Great car..again! BUT something is just not quite right this time. After this I drove Curtin's car, and it has what this is missing, fun, excitement, and reward for effort, all making you feel like the best driver in world. I'm sure the Monash crew will sort the rear rod ends, and find the hidden personality of this car, and when they do, look out Germany!


    Curtin -

    Ergo - Pretty good really, but a hard act to follow Monash. The steering wheel position is not quite right, too low, too close and too much 'bus' angle. Not by a lot, but a little of each and I had wrist and forearm cramps after a short drive. This is not helped by both a slower rate and considerably heavier effort requiring a lot more steering. Also the pedals and leg bay didn't capture your feet and I managed to get behind the pedals on some bumps. Seat and leg position is comfortable enough, and although it's not in the recording my memory was the shoulder belts were a little high and you moved under them a some.(might not be your car though).
    Neither the steering or anything else was bad enough to distract/detract from the experience on a short run however, so you could still get into it. The gear shift was spectacular for a mechanical shift, even if it does operate in the wrong direction. That said, clutch lever position and weight was spot on to give perfect down shifts just by giving it a thump, so my usual complaints with these pull up/push down shifters would be unfounded in this case.
    VD- The car had plenty of turn and a great 'hook' or 'set'. There is a sizable time delay in the front end thanks to the tyres, but once you adjust for that it is great. It really rewards aggression and gives the confidence that Monash's just didn't. You can tell it's heavy, but it is not immediately obvious it is on min wheelbase, and it can be made to dance around no problem at all, so you quickly forget all about the weight and just get into it, and the more you push, the more it gives. I would have said the difference in outright grip was not that much (in Monash's favour), but I also think I carried more speed and used more road in this car, so maybe the wings confuse the issue some. I don't know my time in Monash's car(no DRS), but my understanding is I was quicker in this one.
    The bad bit, it has a nasty side hop/bounce at high lats that gets close to two wheeling and can/could be unnerving. I would have blamed the tyres had I not known they were at high pressures, so I suspect something more compliance related, and/or roll centres too high. It didn't bother me enough to ruin the experience, or fun, but it was getting there, and without the fantastic 'hook' from the rear axle would be really scary.
    Aero - Strong, works, looks OK. The car could be controlled any way you wanted at any speed, so the balance must be OK.
    Engine - PLENTY of power, but all up the top where it is hard to use. I found the throttle control lacking when in the meat of the power, with car pitching in the corners and impossible to blend a smooth corner sequence and exit. Out of the power control was fine, good even, but then you got the floor just when you wanted to explode down the next bit of road and had to wait for it to arrive. On occasion it would come into the power at the right time, and then it was fantastic! Still, it was angry and FAST and just wanted to thrashed some more. FUN! A power band just 1500rpm lower would make a big improvement, as well as some work on the mapping at part throttle to get some control of it.

    OVERALL - Another big step forward from Curtin Uni. A REALLY fun and exciting car to drive that rewards your effort and bravery with speed, and super solid and reliable to boot. Crazy heavy, but who cares, it's awesome!

    Out of these two, despite there being no doubt in my mind Monash's car will be faster, and has much higher scoring potential at FSG, I would still choose Curtin's car to buy for my own. Much in the same way a Porsche GT2 owner might grumble about being beaten by a Nissan GTR, there is no way he is going to go out and buy one!

    PS - this new system that logs you off while your typing so you loose the post is a PITA!!!!!!
    Last edited by Pete Marsh; 01-19-2014 at 05:48 AM.

  8. #8
    Thanks Guys,
    You are sure making our concept design a lot easier for this year :D

    I'd agree with some of Pete's comments on MMS. "edgy" would be exactly how I'd describe it feeling.
    If toe compliance exists on MMS I can certainly imagine a large effect of stability. We have had approx 1mm of slop in our toe link mounting at a past track day due to an incorrectly (i.e not) torqued bolt. As a result the entire car felt completely different to usual; unpredictable with substantial over-steer in steady-state corners, which was eliminated once the bolt was tightened. I think Pete actually happened to drive our car in this condition ( a few years ago).

    Would excessive shock travel and reaching bump stops explain the side hop/bounce you refer to Pete?
    I believe we were getting close to, if not hitting these frequently on the rear axle.

    Glad our successfully-achieved design target of "crazy heavy" was enjoyed :P
    I know I've put a lot of work into achieving this in recent years :)

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    Many thanks to the above reviewers so far (hope there are still more to come...).

    For those of you, in and out of Oz, who are starting your big-picture analysis of what to concentrate on with your next car, two of the standout points so far are (IMO):
    ~o0o~

    1. ERGONOMICS!
    ================
    From Travis (in Ryan/ausracing's) post above:
    "In general there seems to be many cars that don't place ergonomics as highly as they should...
    There is no point in having the fastest car if you can't drive it properly."
    From what I heard after the Driver Swap day, many of the other cars also had terrible ergo. This includes a team that claimed that in 2013 ergo was "a big focus", and their car was the "most comfortable and driver friendly" that they had ever built. Tsk, tsk, tsk... Perhaps this also explains why so many modern passenger cars are so uncomfortable.

    Anyway, this is an easy problem to solve. At worst, just find another FSAE car that is considered to have good ergo, take all its vital dimensions, and COPY IT. "Feel" of the controls is a bit harder to measure, but the goals are again quite simple. Steering and throttle should be light and precise, which means NO stiction or slop! Brakes should be rock hard, and again with no initial free play.
    ~o0o~

    2. COMPLIANCE and SLOP!
    ====================
    Originally posted by TimS:
    We have had approx 1mm of slop in our [rear] toe link mounting at a past track day due to an incorrectly (i.e not) torqued bolt. As a result the entire car felt completely different to usual; unpredictable with substantial over-steer in steady-state corners, which was eliminated once the bolt was tightened.
    See also Pete Marsh's post.

    Like ergo, this should be from the Department of the Bleeding Obvious. It must have been mentioned thousands of times on this Forum. Yet it seems that even the top teams are not immune to this sort of problem.

    Again, like ergo, the solution is quite easy. Stop wasting your time "optimising" the mass of uprights, and suspension links, and rod-ends+++, by shaving off a few grams here and there... and ultimately ending up with an undriveable car. If you must "optimise", then do it for genuine (!) simplicity and robustness, which then takes you a long way to good stiffness and driveability.

    Z

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    Quote Originally Posted by TimS View Post

    Would excessive shock travel and reaching bump stops explain the side hop/bounce you refer to Pete?
    I believe we were getting close to, if not hitting these frequently on the rear axle.
    Insufficient shock/suspension travel I guess you mean? Only if it has very long and progressive bump rubbers, in which case insufficient rebound damping to suit the extra rate of the rubbers might cause something like that, but, my guess is no, it didn't feel like the stops causing it, but it may well be getting onto them during it.

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