I have now loaded a graph showing speed and lateral G for my best lap at Donington HERE
It was compiled from a DL90 datalogger including GPS mouse. This was, I think, my best lap…
The black graph shows speed and the red graph shows lateral G…
Read the lateral G by looking sideways along the trace from the start, and the left (up) peaks show right hand bends (when you are thrown to the left), and the right (down) peaks the left hand bends (when you are thrown to the right.
Notice the peak G pulled through the Craner Curves, aided by the downforce of the Exige - just over 1.1G !!
This was the largest size jpg I could get on the site, but if anyone wants the full screen file, please email me or ask in this thread.
Hey Mike, I am curious about the specifications of the DL90, coz I decided instead to go PSYCHO with the Stack system.
Your G’s are a little low, and let’s be clear I am not dissing you…I am a YAHOO driver. With A048’s I am getting 1.3G ALOT, and 1.5G’s are not uncommon.
I have an Exige 190 with a standard gear box, no mods except custom made Dynamics 3-way dampers by an engineer who helped make Christian DaMatta’s CART championship happen in 2002.
Midwestern American tracks are not twisty compared to Indy Brands Hatch, Oulton P, or Donnington, particularly its turn that precedes the chicane or the chicane itself (I assume you didn’t have the full track).
Now everyone, and I mean EVERYONE on this website discounts the value of a Dynamics damper, so given our damper comparison is EVEN with your suspension and tire setup, I’d have to say that there’s a G-sensor discrepancy, no?
Please go through your DL90 specs and lookup the sensitivity of your G sensor and we’ll whether you are driving a lot better than you perceive.
N.B. I have made a HUGE assumption that given that’s STACK’s G-sensor is used on scores of races teams every season, it must be more accurate than the GL90. If any of you readers dispute this assumption, please dispute.
Impromtu-after-thought-survey: did any readers upgrade their STACK in any way?
Just going on the figures provided in magazines for supercars (which I know ours is ) anything over 1.2g is seriously impressive.
I have Race Technogy’s ( http://www.race-technology.com/ ) AP22 Performance Meter, which is basically a non-GPS version of the DL90 with less memory. They claim to use the highest quality components, the same accelerometers as used in missles! I’ve never had a reason to doubt it and it gives pretty accurate 0-60 times. The highest I’ve ever seen (with std suspension on a 190) is 1.24g, throwing it (literally, it wasn’t the best line! ) into the tight right at the end of the top straight at Anglesey.
I’ll compare mine with Mike’s on 12th Dec at Oulton (and see if it’s just him being lilly livered ) but I pretty sure they’ll be similar.
I would love to know a G reading from the first bend after the start/finish at Cadwell. It’s a quite tight, cambered, up-hill left-hander that you can take pretty much flat out, knocks the wind out of you.
I’m just thinking about changing to a full stack system, how simple was the loom interface - I mean can the Stack ST system just accept the sensors from the standard loom for water temp, fuel level, speed etc ??
Any information you have on that would be great ! - Thanks
‘Semiconductor dual axis accelerometer with a maximum range of +/-2g and a resolution of 1/256th of a g. Output transferred to processor in digital format guaranteeing exceptionally accurate noise free measurements. Software correction for vehicle roll and pitch.’
I think perhaps the differences might come down to the installation of the hardware - I have the DL90 fixed directly to the chassis cross member, tight up to the gear lever surround - this is, as far as I can tell, the lowest and most central point possible - Race-Technology explain that if you mount the unit anywhere else, e.g. on the dashboard, or in the boot, the sensors will read higher, suffering from the effects of roll if higher, such as on the dashboard, and from the effects of sudden tail out moments, if in the boot… This is considered so important that the software is set up to detect and compensate for such effects…
Could it be that your accelerometers are mounted further from the centre, and perhaps the dynamics allow more roll ??
Does your software compensate for roll etc ?
I have tried to get higher G readings by playing ‘silly bggrs’ in a car park, and could not get more than 1.2 no matter what I did.
That car is the 88 Nissan which has was origionally based on a Lola chassis. Mine is the 90 car which has a whole new chassis/body and a four valve head and twin turbo’s as opposed to the single one used on the earlier cars.
These traces are from the first test with the car and the handling was way off. I expect to see some big improvements next time we are at Donington. I hope to be able to do the Craners flat as I have done in the past with other Group-C cars.
I would happily bring it along to a track day although I would have to get some seat belts in it. Not sure how the organisers would feel about letting it out on track with a load of road cars but would be worth a try.
It would be absolutely fantastic to see your car at a track.
A few of us were at Donington last Sunday, & had the great pleasure of seeing & hearing Paul Whight’s Aston Martin Le Mans car - totally awesome
I’ve also done a couple of trackdays at Donington (I think they were Bookatrack days), when a Nissan SR2 (Mallock prepared) was blasting round the circuit too.
I think the data refers to the point on the track map marked with an X, i.e. in the middle of the craner curves…
Hence the speed and G readout I quoted - so I imagine that the 17.34 seconds was how long it took from the start line to that point - still pretty awesome !!!
I know Paul quite well as we have both been doing the Group-C series for a number of years now. It certainly made me chuckle when he told me he was planning to strap lights to the top of the Aston and use it as a pace car. The fastest pace car in the world I believe! FYI Paul�s Aston had it�s first ever international race victory in the last race at Monza in the hands of David Leslie, something it never quite managed to do in period so a really big occasion for their team.
A lap of Donington in 17.34 seconds would certainly be impressive, I imagine the only things to get from one side of the track to the other that quick are the jet planes flying over head! My fastest lap that day was a 1:07.5, although the trace I posted up would have led to a quicker one though was curtailed by a misfire. That is a couple of seconds off the pace for a top Group-C (lap record is a 1:05.3) but I am sure I can close that gap before the next time I�m there as the car has had many handling improvements since.