Hi all,

I thought I'd post this for those that are curious how repeatable the G-Tech can be. These are some runs I did for IC testing....



Also, these were power runs, so I shift early, and the 0-60 times suck. But they overlap nicely.

Matt

 

Matt,

Any suggestions for calibrating the GTech for the MCS other than what the manual says? I've got a JCW MCS with stock suspension except for the rear bar.

I bought Garretwp's (Competition model) and would be interested in any additional info you have found to increase repeatability.

Thanks,

Theo

 

I thought mine would come in at 2800 lbs, and I'm about 230 plus a bit.... But when I got my car corner balanced, it's closer to 2600. I've kept the heavy weight in the G-Tech because I'm in the middle of a series of tests.....

For good repeatability, testing procedure has more to do with it than anything else. I run on a freeway onramp. After I do a run, I circle around using the cruise control to keep speeds constant. After I stage again, I try to launch quickly, so heat soak doens't effect the reading. With the stock IC, I can have post IC temps down around 20 C (on a 16 C day) when I stage, and I try to launch before they get much over 25. If I sit and screw with all the data collection stuff for too long, or there's a bunch of traffic, the temps rise rapidly, and it will show in slightly reduced power numbers. So repeatable testing proceedures will get you repeatable numbers...

Matt

 

Time to go to the recycling center and borrow their weighting platform!

BTW - do you use the standard 2.0 pitch setting or have you taken that down a bit due the the MCS's stiff suspension?

Theo

 

Never changed it. I don't know if you need to, unless you're trying to get the numbers to match a drag strip. Also, while the car is stiffer, it sure is shorter as well! Who knows what should go here.

I've been crunching some numbers....

6 HP runs have a standard deviation of 2.4 HP
6 Torque runs (same ones) have a StDev of 2.7 ft-lbs
Same 6 runs have a st dev on 40-60 times of 0.05 seconds....

all are 1%-2% of average value. Works pretty well!

Matt

 

Thanks, Matt!

Theo

 

Dr. Obnxs - where is this on ramp? I have an older G-Tech but I never have a chance to use it because it's difficult to find a good testing area: one that is free from traffic and police.

 

South bay, peninsula, right near stanford university.

Matt

 

very cool.

I've had some pretty big swings - I need to go back and control my testing enviroment more!

 

Create a routine to condition the car. I use about a 6-7 mile loop to the next exit, set the cruise control at the same speed, and try to sit in staging for a short as possible a time before launching.
If the IATs are within about 5 C, you get the best repeatability...

Matt