Below is my Perrin FMIC data. Ambient temp was in the low 70's this day. I believe this was a 4th gear pull but it might have been 3rd. Stock turbo, pump gas, 26psi peak. Blue = MAF temp reading, purple = intake manifold temp reading (GM AIT sensor).

 

yep FMIC is in perfect condition, never ran in snow. so im preety sure of theres no corrosion....and im sure of theres is no oil in the cooler, cause i have never hooked the vent hooked up.

 

Kracka, next time you do a run like that get the AIT's stable before doing a log. On the dyno I always drop the AIT's back to where they are stable and then start the run. Starting at 100 degrees, cruising/boosting and getting airflow to drop the temps and then watch them rise again just isn't a great way to log. Just saying....

 

Unfortunately I've since sold my IX so I can't perform the test again. This was a log from the street though, not a dyno session, it was logged doing a pull up a long freeway entrance ramp. I feel it shows the Perrin's cooling ability pretty effectively though since MAT's only varied by about 7 degrees F throughout the entire pull and were almost always cooler than the intake air. The MAF and MAT always read dead-on to the degree with the engine off and cool so I feel they're an accurate comparison.

 

i only gained 3 degrees on my ETC 3.5 IC on a full pass at the track, and from what i can see the design on those is very very similar to the BR IC... maybe the perrin unit is just not that efficent and they should look at the design. Marco did the same with his intake manifold and the new one is even better then ever.

 

So the owner well be returing and purchasing a buschur race fmic? Did I read that right?

 

Yep. Post #4 on the 1st page of the thread.

 

I wasn't saying anything bad at all so there isn't much need to defend anything.

I was just saying the results that David usually sees is amazing to me since numerous others see very different results from my area using the same core. I think it shows that results can vary greatly depending on setup and ambient conditions.

That Garrett core still kicks the crap out of everything else up here, it just won't do what David has seen on the same core in his testing.

 

For sure the sample rate of the sensor is fast, but is the AEM setup to read it fast. I can see by your logs that its really slow acting and really choppy. Maybe you can adjust the sample rate? It looks be like 4hz. Try making that at least 10, but 50 would give you a better picture. Either way you and Dave are using the same sensors.

Also those are super fast 2 second runs. On the Dyno, it could be 12 seconds and for 100% you should see the temp raise higher.

Ok, great that does eliminate other weird things going on.
I am sure you are using the exposed element version, but is the thermosistor coated in or bare? I have see the proper temp sensor where the thermosistor is bare, and some where its coated in epoxy. The Expoy coated ones are slow acting compared to these. Or is it possible this is the first time you have use this new Air temp sensor?

Nope not at all, Engine RPM is exactly what i meant.

[QUOTE=davidbuschur;8466685]
Breaking down the compressor chart like you did with RPM written on it is, at best, a guess where the car is running in the map. VE of the engine, boost pressure etc. will change where it actually is. [QUOTE=davidbuschur;8466685]
Its not a best guess at all. I can recalculate a different VE if you like? What VE do you want me to use? I actually errored on low, but now i am thinking higher since it has head and Cams you installed.

Well with the data being provided, i am not saying its acceptable but trying to explain why its possible the numbers you are seeing.

The key factor to all of this is you only saw 122F at redline on that car. That is perfectly with-in the normal temps i would see. I Think its something else, like you are collecting data differently, or different air temp sensor, or something else. This would explain why your hp numbers are fine.

We talked to the customer today and we are getting the FMIC back so we can eliminate any potential issues with it!

(And thanks to Slorice for the Air Flow Calc from years back), been modding it and using it ever since!

 

It doesn't matter how modern something is, if it has a mass, it has a thermal time constant. The larger the mass, the longer the time constant and the slower it reacts. The sampling rate isn't really the issue.

The GM IAT IS NOT a fast sensor by any means and without a doubt, it's missing some of the change in temperature.

Also, you won't see the temperature continue to rise after letting off on a slow sensor. You have stopped putting heat into the sensor and there is no longer enrgy there to cause the temperature to increase. Thermal conductivity is a first order system, it doesn't really have "thermal inertia" that keeps temps climbing once the energy source is removed and you'll never get thermal overshooting like has been suggested.

But as Jeff said, if you use the same sensor, the results will be repeatable and meaningful, just not accurate. If you don’t believe me, hit up Scott or Robert at FP, they have some pretty tiny sensors they use for testing to insure the sensor reacts fast enough.

 

Any updates from this car, David? Did the BR Race FMIC make a difference compared to the Perrin?