good enough to read. obviously #4 is the problem child killing bringing up the averages. i am not sure when an imbalance in temps across the cylinders starts to become an issue. with the limited driving i have done, i usually don't see swings more than 25 degrees left to right. that is even pretty rare, but will see that occasionally. probably a major factor there though is a new engine vs. used as much as anything.

The best way to show all the data is to update the link for run 2. I will add more columns and one more chart to show what we have been talking about.

On the new vs used engine ... not sure, but I'm thinking used would have more tolerance (sloppyness) so perhaps it would run cooler ? :shrug: Can't offer any insite into this one ...

Sandeep

I'd agree but on no other basis than what you stated.

Thats about the same types of differences I saw on the dyno..

#4 is ALWAYS worse with ALL 911 set ups!

Told ya so.... LOL

Try changing drive ratios- THATS WHEN IT GETS VERY INTERESTING!

Yes, but that is in the 'warm-up' stage as it is the first recorded time (t=692 which is after about 11,5 minutes ?).
After a while, when t=929-930 secs, so at the hottest recorded temps, the temp differences are actually remarkeble small!! Only 7 degrees F, thats about 4 degrees Celcius :eek:
The absolute highest temps (324F) seem still very moderate as well.
Myth busted! ;)

What sort of header do you use? What sort of under cylinder tin do you use?

Thanks,
Walter

New columns added for run 2, check it out here. Its true that during the warm up stage the temps are uneven .. but later in the run they seem to stabilize. I'm using stock T4 under cylinder tins and a BAS 21152 header with dynomax super turbo 2 1/4" muffler.

I've got the rpm and rws sensors hooked up and hope to do some hard runs this weekend. There is some snow on the ground now but it is supposed to be gone for the weekend.

Sandeep

and that may even be an engine/tuning issue...who knows?

Thanks for the update and good luck on the run. Keep the car (and youself) in one piece!

Walter

Very interesting Sandeep....

But its not exactly what I have seen in my testing at all especially with that shroud...

I have never used an engine that small for the testing though, the smallest was 140 BHP.

Looks good. You may want to plot the running average of 5 seconds or so to smooth the data. Your resolution of 3.45F is making the data look more noisey than it probably is. I suggest you back off your full scale to 400F to get more res (2.1F, assuming 0-500F full scale). Taking the average of 1000 samples per second is great for reducing noise, but better resolution would help smooth the data. Either way, it's very useful information :agree:

Where do you have the AAT probe mounted? Seems to be picking up some engine heat when you backed off the throttle (t=1700s). Also, looks like there may be some ignition interferance at high revs. Did you route your TC's away from primary wiring? Do you have similar noise with the engine off?

I look forward to seeing more of your progress.

Great suggestions folks. I may have to do some minor reprogramming but not a big deal.

Run #2 at t=1471s is when I actually pulled into the drive way and shut the engine off. The FIT increased because the heat from the engine actually finds its way out past the fan :laugh: It decreases again because I started up the engine to adjust the idle and then shut it off again ... cool to see that in the graph though :)

The AAT probe is mounted so it just pokes out past the intake grill on the decklid. I've got lots of wire so I can reposition it but want to keep the wire length short as to not introduce additional noise.

I'll try to get a full run in this afternoon with RPM data :eek:

Sandeep