data logging questions

[Beanboy]

Posted yesterday in the sticky, have an additional questions since then, and figured some exposure would be good. :D

2nd gear pull with car fully loaded...good enough for useful numbers? Little concerned about running up to 90+ in 55 zone.

Other than not reaching boost target, is there a way to tell if you have a small leak somewhere? AF a little richer than it should be? EGTs a little lower? MAF g/s not matching boost for given RPM? MAF g/s not matching waste gate duty cycle for given RPM and boost level? Ugh, my brain is starting to hurt, hehe...

Curious what a cold start looks like, so I'll do that...
5th gear run from low RPM a good stress test with useful numbers?
Any other scenarios that I could get useful numbers from without braking the speed limit too much?

Thanks!

-B

[edmundu]

Do your pulls uphill. This will sufficiently load even 2nd gear, to get max load on the turbo/engine, similar to a 3rd gear pull.

Small leak as in exhaust or intake? An exhaust would/ should be very audible, unless it's after the turbo, in which case it really doesn't affect power. If you are referring to intake leaks, well, if you have experience in logging your car, you would see your Maf (v) and Grams/sec increase. Signifiying increased airflow, but without some expected change(intake), it should not change much, other than weather. This is where knowing your own car helps alot.

Also, if you were to have a pre turbo/post Maf leak, you would likely see timing being pulled and -KC values. If it were post turbo, then you would likely see increased wg duty cycles to attempt to compensate.

[ilh]

In the Boston area, the Rt. 2 west hill going past Arlington would likely be a good location for such uphill logs. You can even start from a stop at the Lake St. onramp.

--Lee

[rallispec]

have you swapped pipes lately that would lead you thinking you have a leak?

[Beanboy]

As far as leaks go, looking for more of a "what to look for" than particular problem with the car. Had non-noisy leaks before getting UP/DP bolts retorqued. Thought I had noticed a wiff again yesterday. Was just curious what to look for as I check out the logs.

edmundu, you provided the information I was looking for thanks! I'll make sure to post-up my logs this evening. Route 2 hill is a great idea; that's a beast of a hill and not too far away from me. Thanks ilh!

-B

[Beanboy]

Woohoo!

http://legacygt.com/forums/showthread.php?p=521900#post521900