Request: air intake temp AIT data
#22
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pretty sure that was the formula out of corky's book.
if you think about it, I have twice the amount of runners with a 12" tall core than a 6" tall core, so even if it's not as long, I have more internal flow, just because there's so many runners to go through.
but yeah, guess you're right, maybe I copied it down wrong. I'll take another look at it when I get home.
if you think about it, I have twice the amount of runners with a 12" tall core than a 6" tall core, so even if it's not as long, I have more internal flow, just because there's so many runners to go through.
but yeah, guess you're right, maybe I copied it down wrong. I'll take another look at it when I get home.
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yeah it looks like i kinda combined two formulas somehow...i always read that damn thing too late at night.
the correct formula is: Internal flow area = channel length x channel width x number of channels
then you divide that number by .45, as 45% is the average of the face area.
THEN divide it by your width....only to determine how wide of a core you need.
the problem with this formula is that it's setup for vertical runners like the old BEGi kits....let me see if I can't move some numbers around and come up with something for horizontal runners.
the correct formula is: Internal flow area = channel length x channel width x number of channels
then you divide that number by .45, as 45% is the average of the face area.
THEN divide it by your width....only to determine how wide of a core you need.
the problem with this formula is that it's setup for vertical runners like the old BEGi kits....let me see if I can't move some numbers around and come up with something for horizontal runners.
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ok, had a chance to skim back through corky's book.
first off, bar & plates are .125" wide, not 1/4"
So Rob, your intercooler would be 17 in² of flow area.
If 6 in² is good for every 100BHP then yours would be good for around 17/.06 = 283BHP
Mine, 22 in², 366BHP.
I was dividing by the depth of the core, which I shouldn't have done and screwed the pooch.
first off, bar & plates are .125" wide, not 1/4"
So Rob, your intercooler would be 17 in² of flow area.
If 6 in² is good for every 100BHP then yours would be good for around 17/.06 = 283BHP
Mine, 22 in², 366BHP.
I was dividing by the depth of the core, which I shouldn't have done and screwed the pooch.
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283hp looks about right given my 250whp. I might have/had another 5-10hp if AIT compensation were less aggressive.
Looks like your IC is safe.
Just checked my dyno sheet datalog- IGN retard from compensation starts at 6k rpm (40c). By 7k rpm AIT is 50c and advance is 7*.
so big it has it's own area code :gay: That's gotta help
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Looks like your IC is safe.
Just checked my dyno sheet datalog- IGN retard from compensation starts at 6k rpm (40c). By 7k rpm AIT is 50c and advance is 7*.
so big it has it's own area code :gay: That's gotta help
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#30
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ok, had a chance to skim back through corky's book.
first off, bar & plates are .125" wide, not 1/4"
So Rob, your intercooler would be 17 in² of flow area.
If 6 in² is good for every 100BHP then yours would be good for around 17/.06 = 283BHP
Mine, 22 in², 366BHP.
I was dividing by the depth of the core, which I shouldn't have done and screwed the pooch.
first off, bar & plates are .125" wide, not 1/4"
So Rob, your intercooler would be 17 in² of flow area.
If 6 in² is good for every 100BHP then yours would be good for around 17/.06 = 283BHP
Mine, 22 in², 366BHP.
I was dividing by the depth of the core, which I shouldn't have done and screwed the pooch.
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#32
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Got data.
![](https://www.miataturbo.net/forums/attachment.php?attachmentid=4610&d=1182264977)
I'm beginning to wonder if my sensor is just heatsoaking from the radiator. It's just plain silly. Note complete lack of change from boost. Note my coolant temp drops 6 or 7 degrees.
I'm beginning to wonder if my sensor is just heatsoaking from the radiator. It's just plain silly. Note complete lack of change from boost. Note my coolant temp drops 6 or 7 degrees.
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Last edited by y8s; 01-12-2009 at 12:37 PM.
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I agree- something is up with AIT starting at 50c (and at only 9psi) and not moving...hardly. I wonder if the peak at the end is an actually rise, or a rise in the heat that might be causing the soak.
That puts you in fuel and ign compensatons too.
My sensor is inside a pipe that comes off the coldside IC pipe, right near the tb. So it well shielded- and opposite the rad. Where is your sensor? The back side of that fat cold side IC pipe would be a good spot- sheild from the rad.
Is the drop in the AFR curve at the beginning of each gear intentional (for peak torque)?
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My sensor is inside a pipe that comes off the coldside IC pipe, right near the tb. So it well shielded- and opposite the rad. Where is your sensor? The back side of that fat cold side IC pipe would be a good spot- sheild from the rad.
Is the drop in the AFR curve at the beginning of each gear intentional (for peak torque)?
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the sensor is directly under the throttle body. you can see it here, in the inside of the throttle body inlet pipe's curve:
http://gallery.y8s.com/miata/turbo/D...geViewsIndex=1
it's wrapped in some foil backed fiberglass tape and that's what the datalogs are based on.
Sadly I didn't get to datalog the car before starting because my gf was in the passenger seat and already had tons of my crap on her lap.![](https://www.miataturbo.net/images/smilies/smile.gif)
I'd like to keep the sensor in the section of pipe before the TB but if this is the result of sensor heatsoak, well... I wont keep it where it is.
the drop in AFR is... I need tuning time and a perfect map by which to set my enrichments.
I can do TPSdot and MAPdot based throttle pump enrichment as well as "dynamic enrichment" based on how fast RPM rises. it also has a dynamic enleanment for rpm decreases. you can see that's too high too.
http://gallery.y8s.com/miata/turbo/D...geViewsIndex=1
it's wrapped in some foil backed fiberglass tape and that's what the datalogs are based on.
Sadly I didn't get to datalog the car before starting because my gf was in the passenger seat and already had tons of my crap on her lap.
![](https://www.miataturbo.net/images/smilies/smile.gif)
I'd like to keep the sensor in the section of pipe before the TB but if this is the result of sensor heatsoak, well... I wont keep it where it is.
the drop in AFR is... I need tuning time and a perfect map by which to set my enrichments.
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#38
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still trying to erase that image from my mind :gay:
My sensor is about opposite of that, but I still can't see yours getting "that" heat soaked. I wonder if your wrap is acting more like an insulator?
I just can't believe your air temps are that high with that IC.
My sensor is about opposite of that, but I still can't see yours getting "that" heat soaked. I wonder if your wrap is acting more like an insulator?
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