Acceleration Times, who's up for it?

[ainarssems]

So did a couple of runs this morning, 1997 S8, about 40% of fuel , myself about 70kg and full size spare. Couple of things before I post times, first the car being older and without CAN sampling rates are a lot slower over KKL so accuracy is +/- 0.5s instead of +/-0.1s for Delboy. Secondly I have bigger tyres 255/45R19 instead of 245/45R18 so ECU see less speed than actual.

First order of business was to determine difference between actual speed and what ECU see. So I set GPS to km/h as the VCDS show speed in km/h in measuring blocks. Travelling at steady speed of 100km/h VCDS reading was jumping between 92.2 and 93.4km/h. So I took 100/93=1.075269 to find a mutiplier, which means that with actual speed of 60mph ECU only see 60/1.075269=55.8mph

I set the acceleration time to be measured 0-56mph, highlighted in bold below, this will be actual speed of 60mph. Here are the 2 results from 2 runs on the same piece of tarmac in opposite directions, not bad for 18 year old car with a book time of 6.8s

Sunday,21,June,2015,06:55:23:53046
Control Module Part Number: 4D0 907 557 N Component and/or Version: 4.2L V8/4V MOTR AT D01

Metric units
0 to 100 km/h: 7.4 +- 0.52s
400m: 15.1 +- 0.51s, @150 km/h
0-93 km/h: 6.6 +- 0.50s
200 meters: 9.8 +- 0.52s, @117 km/h

US Units
0 to 60 mph: 6.8 +- 0.50s
1/4 mile: 15.2 +- 0.51s, @93 mph
0-56 mph: 6.3 +- 0.50s
660 feet: 9.9 +- 0.52s, @73 mph

Sunday,21,June,2015,07:01:34:53046
Control Module Part Number: 4D0 907 557 N Component and/or Version: 4.2L V8/4V MOTR AT D01

Metric units
0 to 100 km/h: 7.0 +- 0.50s
400m: 14.9 +- 0.51s, @150 km/h
0-92 km/h: 6.1 +- 0.50s
200 meters: 9.6 +- 0.50s, @116 km/h

US Units
0 to 60 mph: 6.5 +- 0.50s
1/4 mile: 14.9 +- 0.51s, @93 mph
0-56 mph: 5.9 +- 0.50s
660 feet: 9.6 +- 0.50s, @73 mph


And here is graph of the first run with speed converted to mph and multiplied by 1.075269 to show real speed

[Delboy]

Great results Ainars, when we were all at the meet I noticed that there wasn't much between the D2 and d3 s8's.

Just goes to show how much good value a d2 is

[ainarssems]

I was in front of you on the run to Portmeirion, had to ease off throttle couple of times to let you catch up as you were disappearing from my rear view mirror.

[mattylondon]

Good results there Ainars

[Delboy]

The graph starting to get interesting, with cars edging past each other at different points of the run

[Delboy]

Originally Posted by ainarssems

I was in front of you on the run to Portmeirion, had to ease off throttle couple of times to let you catch up as you were disappearing from my rear view mirror.

Yeah yeah, in my defence I had to behave as the missus was feeling ill

[ainarssems]

Finally worked out how to get more than 1 run in the graph in Excel, so here are both of my runs to compare with Del's 1st run. The difference between the 2 of my runs is that on the first one not much is happening in first 0.25s, after that it is similar.

[M-A8]

Great graph Matty

The 3.7 with 150k on the clock is so close to the S8s that you will never be able to lose me and if my skills are better than yours then who know, you may be even inhaling my exhaust fumes coming out of them big 3" quads


The ones with sense of humor will get it

[ainarssems]

So did a couple more runs today with 90% full tank, this does not seem to have much effect. Did 5.9-6.0s to 60mph all the time. Also did a log with rpm so I can see gear shift points. Graph below with speed and rpm

[ainarssems]

Went to Santa Pod today, did 2 runs first 15.4343s and 92.54mph terminal speed , second 15.5027s and 92.54mph. Unfortunately they do not show 0-60 times. I was expecting around 15.0s and about 95-96 mph terminal speed judging by the VCDS logs. I blame it to the heat, first run car was showing 28.5C, second 31.5C, in reality it was probably 23C and 26C. It does get very hot and soak up a lot of heat while sitting half hour in the queue with engine running, I could feel straight away that car was not performing to it's best and felt that second run was slower than first. 6.0s 0-60 times I did testing with VCDS was in early mornings about 12C. I estimate I was doing about 6.5-6.6s to 60 today.

Wife should have some embarrassing videos on the phone with Civic beating me, will see if I can upload them later, now to some well deserved cool refreshments after baking in the heat.