Camaro XV

[Stielow]

Originally Posted by dontlifttoshift

That's 0-60 in 3.2 if you could do .85 from a standing start. I'm guessing that sample was from the road course.

Realistically you shook the car down twice(?) before sending it to vegas. I would really like to see you dial the car in, if you can keep it long enough. What can you do about forward acceleration? Spring change, shock tuning, wider wheels, perhaps a taller tire if it doesn't mess with the ABS......they're never finished.

It is geeky engineer Friday. The graph below is the tractive effort curve from LVMS. Longitudinal acceleration vs vehicle speed.



The data shows I'm accelerating at about 0.85 G at 60 MPH and still pulling 0.6 G at 100 MPH. On the flip side I can generate 1.3 G decel at 120 MPH.

Just fun to look at the data.

On the temperature side this is the data from my last run the air temp was 85 degrees F.



After 15 minutes the water was at around 220 F and the oil was around 270 F. To road race a 900 ish car and to keep it cool is tough. I'm very happy with the data.

Looking at the data the temps are becoming steady state and they will stabilize below peak excursion limits.

Once I get out of the throttle look how fast it cools!

Mark

[wiedemab]

Originally Posted by Stielow

[IMG]



On the flip side I can generate 1.3 G decel at 120 MPH.


Mark

After hitting the brakes at 120mph.

[MSTSFabbed]

Such cool data!!
I had a prof that would always tell us, "If you can't express it with a number, you don't know anything!"

What are you using to record all this?

[Sieg]

Originally Posted by Stielow

Looking the data Hellfire lacks forward bite.

Looking at the data AWD would fix forward bite.

Need to add another dial on the dash........for traction management.

[Stielow]

Originally Posted by MSTSFabbed

Such cool data!!
I had a prof that would always tell us, "If you can't express it with a number, you don't know anything!"

What are you using to record all this?

http://www.race-technology.com/dash2_pro_2_31358.html

It will pull in the GM CAN data (All the information from the ECM). It has built in accelerometers, GPS and open channels for analog inputs. You can also link a GoPro to it to sync video and data.

The other thing I really like is you can program it for all the warnings you want and add math to the warning channels. For example if oil pressure is below 20 psi and RPM is above 2000 set warning lights.

Once you get used to using data it is hard to go back.

Mark

[sik68]

I've always wondered about onboard accelerometers for measuring lateral-g's. It seems to me that the roll angle of a car will amplify the measurement. If the sensor rolls by even just 3deg, that is still +0.05 apparent accel.

Is this an issue in data collection? Thanks!

[wiedemab]

I've been thinking about this dash for my car. I'm assuming the hookup is pretty simple given that it plugs into the OBDII port - right?

[Stielow]

Originally Posted by sik68

I've always wondered about onboard accelerometers for measuring lateral-g's. It seems to me that the roll angle of a car will amplify the measurement. If the sensor rolls by even just 3deg, that is still +0.05 apparent accel.

Is this an issue in data collection? Thanks!

It uses the internal Accels and GPS to give data. Not sure of the full logic but I do know the GPS is also used to help cancel roll effects.

Mark

[64G-lark]

Hi Mark
I love your builds and wondered if would mind sharing some part numbers or information (year and model)on the source of your radiator mounts, brake booster and master cylinder.

Thanks Mark

[MAP]

Hi Mark,

I came across this thread yesterday and haven't had the time to digest it all just yet (!) but some simple math tells me that a rear-engine design with something like a 40/60% F/R weight distribution might do wonders for forward acceleration. I know this is a huge transformation, but at the rate you're going, I might imagine you're not many iterations away from something even this bold. Assuming mu(s) is 1.4 from the braking data, then your attainment of 0.85(ish) g's long. accel. is right at the theoretical limit given your weight distribution and ignoring transient effects from anti-squat (I'm assuming WB is 108" and the COM height is 21".) Go 40/60%, and you could attain 1.15g's.

Best,
MAP