eclou

that is smokingly fast Jean, especially for such low boost

TB993tt

Jean
Your 100-240kph time at 9.4s eclipses Jussi's 10.05....

Can this be correct at less than 1 bar of boost ?

Jussi

Yes, Jean's car is Fast now!
Did you swap turbos for modern and bigger like GT3071Rs?

My best 100-250 is "only" 10.9
Jean = 100-250kph: 10.6s (RUF RT12: 12.0s. Woodster: 13.5s.)

Jean has 2WD and I have 4WD but Jean's car has much worse Cd. If he tries without that GT2 spoiler.. that would be maybe under 10 seconds from 100 to 250.. Jean, could you test that?

LAT

Jean; what kind of HP numbers do you extrapolate from your own data?

Jean

I am surprised myself at the results. I know 100% that the datalogs are good, I have checked every single thing possible for the last 2 days, and this was the same day and run I was doing my coast down testing.

I will need to extrapolate the torque and HP curves to understand better what is going on. What will tell me the story is the peak torque, and the extrapolation of boost level from it, maybe the boost gauge got stuck or sth (very unlikely though as the boost controller also gave me the same readings).

Jussi nothing has changed vs. my previous setup, I could not have since I would need a remap (I am on pressure sensing) and for that I need to ship the engine to the US to put it on Todd's engine dyno or otherwise compromise an optimized tune. I might be sending my engine to Todd for a change in turbosystem and ignition to something more modern, I am still on archaic T04s and stock ignition, however I will be downsizing most likely in preparation to racing series in October.

Possible causes are:
- Taller tires, one shift less to 130mph , this one is obvious
- Grip. I still have wobbling lateral Gs when compared to others here, but much less than my previous run where I had to slightly lift and lost quite a bit of traction
- Cooler temperatures. Previous run was made at 38C if I recall correctly (it should be on the thread somewhere)
-Slope: Previous run had a slight upward slope
- Start of the run: my previous run had a very slow start, judging by the long Gs at 60mph that are much lower than anyone else, reason being that I accelerated right at the 60mph mark previously.
-Gearing: My previous and only serious run was made with the sequential gearbox, which I always knew had some unfavourable shorter gears
-Broken cam chain tensioner. It might have been there from the beginning, maybe as a result of flat shifting with the sequential gearbox and no ignition cutoff, I had been warned.
- I played with some settings on the boost controller that impact boost onset, initially it was set at zero as it came when new.

OTOH, I had slightly more weight now and less boost.

I will be looking at this closely to understand the differences in torque and HP. Maybe putting a few of our runs on one same chart will also help seeing the difference where they are coming from. Shifting timing might be the reason.

If I am home this week end I will also do a videotaped run, only problem is that I have to do them at night due to the heat and safety. Jussi, TB you are welcome to check the datalogs if you want to.

Jean

Here is the data table.



And in KPH.

M-Phibian

I ran 5.73 with 2-shifts at 0.98 BAR yesterday on 93 octane fuel. Overall, the run was slightly uphill, with a .37% incline. Weather was good (65 degrees, 45% humidity, 30.1 inches pressure). Car is RWD running GT35Rs, had 3/4 tank of fuel and weighs around 3,475-3,500 lbs with me in it.

Other than using different fuel, the only difference from this run to my best high-boost run (4.74 with 2-shifts @ 1.6 BAR on a slight incline) is the addition of slightly larger rear tires (went from 295/35/18 drag radials to 305/35/18 drag radials).

http://www.6speedonline.com/forums/a...8&d=1209583436

TB993tt

Two points:
Is this run under water
WTF is going on with the long G readings ? presumer this is a tip since there are no gearchanges apparent ?

M-Phibian

I live in Virginia. It's location (like much of the East Coast of the USA) is below sea level. But having to go uphill and shift twice makes up for that advantage.

My car is a 6-speed, not a tip. The shifts are there, but not as easy to identify as they are on my 4.74 run below:

Jussi

Your car is too fast already
I have GT28Rs and they are good for 700hp. How much those GT35Rs produce power, 900hp/900Nm?
What are your other times, like 0-100, 0-200 or 0-300 km/h?

TB993tt

Are you certain of that

The lowest point in Virginia is sea level where Virginia meets the Atlantic Ocean in the east.
http://www.netstate.com/states/geogr..._geography.htm

M-Phibian

Okay, if you don't want to take my word for it, that means my runs are never below sea level...which makes my car even faster than I thought. Thanks.

M-Phibian

My car makes 890 hp to the rear wheels at 1.6 BAR. My 100-200 kph time is 4.12 or thereabouts (I don't have that graph in front of me so I don't remember exactly).

M-Phibian

In all seriousness, that link you gave me is very interesting. We have all (those in my area with VBOXs) assumed that we were below sea level on some of our roads.

That said; I just spoke with Jim Lau at V-Box USA about this (248-953-3251). He told me that the GPS Datum (WGS-84) in the box resolves it's position in my area (Maryland and VA) incorrectly. So even though it reads below sea level, I'm actually at or above sea level. The variences in height are accurate, just not the actual elevation.

He also told me that the recorded acceleration times are not in any way affected by the elevation readings. They are two completely seperate things.

Okay, now I'd like to see your slope and elevation angles on your runs, TB. So I can verify that you weren't going downhill.

TB993tt

That is interesting - we have found before that the height readings are not at all accurate, giving varying readings for exactly the same place.
It is difficult to accept this is it not since isn't all the data extrapolated from the GPS readings - I have found the acceleration readings of the DB/PB to be very reliable - is there a possibility that you are doing your runs in a "bermuda triangle" type area which gives silly data ? Do you have any in a different location just to verify ?
Mine are all downhill apart from the 300kph ones which are uphill - will be sharing some more at the weekend