Neil Haughey
New member
Chris Dyer's in car footage up on Youtube http://www.youtube.com/watch?v=jnlOt52K0Rw Brilliant listening to it, that is one guy who sure enjoys his racing, almost like that clip of Senna winning in Brazil.
The 2012 PCGB Club Championship
- Thread starter paulf968
- Start date
Bit dissapointed but as expected no significant improvement on the dyno (certainly not enough to make any difference or outgun some other cars) so I am now glad we concentraed on the handling etc. All we mnanaged was to get a bit closer to the allowable limits (better than nothing I suppose). Added some brake cooling ducts this week (that should help they got so hot some balance weights fell off the wheels) and are trying different spring rates and trying to find a better balance to avoid rear end break away - but the weather forecasts don't provide a dry test anywhere yet before Donington - very tough weather to try and sort out a new car! I think the next race is going to be a bit of a lottery and down to luck in the settings again - when will we get a dry run? Baz
Neil Haughey
New member
I am sure you will get there Baz, its really early days with those cars. Something odd about the spring rates is that the stock and factory enhanced sets have much stiffer rear than front, however for the spec series the merkins went for 450 front 500 rear. On one level its understandable as on the 944/968 race spring rates are more biassed to higher front to rear ratio than stock but when I looked around some other cars it seemed to me that a lot of race spring rates were really more like stock springs just stiffer front and rear by the same amount. Something else I have noted, not an anomaly but a model many may have overlooked. The post 05 boxster S 987 variant. As a stock road car it had almost identical track test lap times to the 996.2, several seconds faster per lap than the earlier 986S for example. 1.5" wider front track, 1" wider rear track. An interesting oddity is that all boxster S models can use the 18" tyres but the big size on the 987 was those sizes on 19" rims. To put it another way using the 18" wheels and tyres from the regs gears the car down by about 4%.
Maybe that's why its not been included in the Championship regs yet?! We have 3.2-engined 987s in our series but to date you couldn't draw any conclusions as to whether they are any better/faster than a 3.2 986. At Snetterton in the wet, a 987 won all three races; at Cadwell Park in the dry a 986 won both races; at Brands it was mixed. #88 Chris.
Neil Haughey
New member
It is in the PCGB regs, Boxster S 2005-2007 280 Bhp. Its in the two Appendix lists just ahead of the 993. Its weighted up pretty heavy though, only a bit lighter than the 996 but of course in many ways this makes the prep vastly more straightforward. I think maybe everyone just overlooked that model, its an oddity in that its such a new car relative to the majority of those included. Its almost impossible IMHO to draw conclusions from the relative performance of the different models based on their relative performance in a race series/championship where the cars have different preparers and drivers. I have said it before but its worth highlighting again, back 10 to 12 years ago the S2 was nothing like the class killer it later became. When I asked a guy back then how to mod an S2 for track work his advice was go and buy a 911! (This was Steve McHale btw for those who have long memories of club racing). The SC was a very popular race car back then but fastforward a decade and there are none in the club championship. Nothing really has changed other than that the outfits that got into racing the 944 and 968 developed them to the point they overtook the performance level of the other cars. Really IMHO the only valid comparisons that can be made are based around the stock performance which shows the inherent basic capabilities of the car. Then one can make educated guesses or simulate/calculate likely performance level with moderate mass changes and grippier tyres etc. One thing is for sure though Chris with the boxster in stock configuration, the 3.2 987S is massively quicker than the early 986S in pretty much every magazine track test I could find. It will do 1:10 flat round Silverstone Nat on road tyres for example which is pretty amazing stock performance level. How good it ends up as a race car is anyones guess but my gut would always go with taking a vehicle that was already good as a road car. The 944 turbo as an example was quicker round the track than the 911 turbo despite having 50 Bhp less, this showed the inherent capability of the car which many seemed to overlook for a long time when considering the 944 S2 as a race car.
berty987
New member
The 987 has a power advantage over the 986 as well as different gear ratios , even comparing similar M96 engine (3.2) variants. The addition of the secondary intake plenum resonance flap and split intake (post throttle body) on the 987 , coupled to a larger airbox and filter capacity also allows the 987 more low end torque whilst improving top end power. The cylinder heads , cams and bottom ends are identical between 987 and 986 S models , the different power curves are achieved through the ECU tune and these two modifications to the intake, along with a revised exhaust manifold and silencer arrangement. The 986 550 anniversary was the first car to experiment with a larger filter element and airbox and achieved a power gain over the standard 986 S of the same year as a result. The 987 has a wider track which improves stability but reduces the turn in , as a result the 987 isn't as "agile" as the 986 IMHO. The 987 also feels a little more "Tail Happy" than a 986 , perhaps due to the wider rear track. Porsche experimented with a softer rear ARB to reduce this effect, but it never made it to the road cars, this may also explain why PSM became standard in the 987.
I must agree that the 987 looks the car to build - for although it is heavier - it falls the right side of my graph showing equality of performance data - but has much less of an advantage as the 996 (just look at the figures or draw a graph from the figures with power on one axis and weight allowed on the other and you can see how they interact and vary). Although I kicked up a bit of a fuss over the relative light weight of the 996 - I am beginning to realise that a new car built for the Championship is at quite a disadvantage compared to those who have had years to benefit from the combined experiences of drivers of older models Worldwide - what worked and what didn't - the components made over the years for them and most important of all the records of how they were set up and performed in previous seasons. Not only is this a disadvantage for newer cars but also we (and the others with Boxsters and 996's) new this season are finding all sorts of small issues that handicap reliability or cut down on testing time. The drivers are also more likely to get caught out as they push the cars to compete with others sorted out years ago and start to find the areas we need to improve and change. If this is why they have a beneficial weighting - I could perhaps understand it better but then the Boxster didn't have it the previous year and the figures for 2013 do not seem to reflect any corrections (as they probably should). Working out what to do about the suspension is proving a massive headache. There are just too many things you can change that then require you to adjust lots of other things to optimise - and with rain nearly every test session - we are no where near a good dry set up yet and probably it is more the skill of the drivers that is making us look better than we expected on wet or damp tracks. The drivers have been brilliant and we have struggled a bit to keep up - and having had 2 podiums in the first 2 events - we have probably over-achieved and are presently trying hard to lift the set up to meet the expectations now upon us (not easy). Our dyno man (as brilliant as Wayne is) already warned us there was little he could do with these engines and that proved to be the case - but then we expected that and that is why we left trying to improve them until now and concentrated on braking and handling instead. I do think the new cars have made the series much more interesting and relevant to the majority of Porsche owners - especially when they are seen to be very equall in performance to their older stablemates. There are very few competitive events that try and fairly mix it between lots of different models and succeed but if you look at the models in the results lists you can see that there is a lot of good fair competition amongst the teams and drivers and something for everyone to follow and get excited about. Whatever anyone says though - it is brilliant fun and very good indeed for the interest and experience of the guys here and we all cannot wait to get out again next time and see what we can do. Baz
Steve Brookes
Moderator
From a spectators point of view I completely agree with this. The club champs has never been so much fun to watch as it is now. [
]Neil Haughey
New member
I will have a dig around but this was on US sites such as rennlist or planet9. I imagine they read them out of the workshop manuals and converted from N/mm to lb/inch so yes as the springs are conical very hard to get comparable figures from. A few places have spring testers though, I can recall many years back seeing one at AVO in Wellingborough. Its a side point as I don't know if anyone does it in the club championship but I have read and heard on ten tenths about testing all spring sets used on a race car if for nothing else but to verify that the stated rate is reasonably close to spec and not have one spring at the top of the variability and the other side at the bottom.
Neil Haughey
New member
Assuming the wheelbase wasn't made longer wider track should in theory always make a car more nimble all other things being equal as the ratio of wheelbase to track width has been made smaller. I suspect something else is going on perhaps negative impact of bigger wheels etc. etc. Certainly the tail happy aspect sounds like a possible symptom of a wider track, we space out the track on the S2's 40mm wider than stock and it makes a massive difference to how the car drives, far sharper on turn in but perhaps a little more edgy, difficult to say as so many other changes. Paul F once said on this forum about spacers on the 968 that without them the car just wouldn't be competitive.
berty987
New member
From what I've read , increasing the track width at the front and rear by equal amounts , without changing the front camber can lead to a reduction in jacking effect on the front axle. My understanding is this reduces the effect of turn in whilst the track width reduces understeer by softening the suspension response. This seemed to be the effect I experienced when fitting modest 5mm spacers all round on my own car , the turn in reduced as did understeer. Changing rear anti roll bar rates to a stiffer value increased power oversteer in corner. There is obviously quite a science around the dynamics of vehicles suspension where changes in track width to improve scrub radius and levels of grip need to be countered with geometry changes and roll bar settings to maintain the balance of the driving dynamics . I guess this is why actual geo settings are such closely guarded secrets between teams.
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