Hentai's 1992 Mazda Miata (15th)

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Fred
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Re: Hentai's 1992 Mazda Miata (15th)

Post by Fred »

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Re: Hentai's 1992 Mazda Miata (15th)

Post by Hentai »

update
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Re: Hentai's 1992 Mazda Miata (15th)

Post by Hentai »

VE tracing nicely with output, though pretty sure I have an issue with the fuel pump dropping pressure, you can see at the end what looks like the ve correction pushing it further up than really it should be at.

CDT 209~f
AMBT 98f~
IDT 104f~
180kpa MAP
314kpa TIP

CDT starts at 136f at start, ends at 206f at the end of the pull, 3rd gear
5th gear had CDT at 222f~

More temp data to come

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Re: Hentai's 1992 Mazda Miata (15th)

Post by Fred »

I was going to comment here on the steps visible in the trace and their lack of correlation to any other figure, but Hentai gave us an update on IRC that it was his wideband on a slow output setting causing the steps.
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Re: Hentai's 1992 Mazda Miata (15th)

Post by Hentai »

wideband was on default output of mid range, low is worse and high is a lot better.
It sorta sucks that it changes the output as well as the display but eh its not too bad.
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Re: Hentai's 1992 Mazda Miata (15th)

Post by Hentai »

Probably buy a open element for the ambt sensor soon.

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Re: Hentai's 1992 Mazda Miata (15th)

Post by ivan141 »

That ducting solution for your air intake will probably lower your cooling efficiency. It relieves the pressure differential across your radiator somewhat, which in turn lowers the airflow through it.
One duct wont make a drastic difference, but I've seen friends who put a hole in the panel next to the radiator loose precious seat time at track days due to overheating problems they didnt have before the mod.
An airbox would be the best solution for a good supply of cold air.
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Re: Hentai's 1992 Mazda Miata (15th)

Post by Fred »

Looking forward to seeing this data once we get you all setup with calibration and logging for it! :-)
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Re: Hentai's 1992 Mazda Miata (15th)

Post by Hentai »

I'm not sure whats going on with the MAT sensor, when the throttle shuts you can see the temp immedaitly spike up, its probably more drastic than what it shows. i wonder if this is from the compressed air getting trapped in there with no movement for a couple cycles or some other reason. Once the throttle opens the MAT sensor value goes buy CDT is going up, IAT is slowly going down, perhaps the ducting? while the pre throttle post ic sensor stays pretty steady

around 91-92f for pre throttle, post ic sensor pretty much the whole way though those pulls.
CDT = Compressor Discharge Temp
IAT = Inlet, compressor Air Temp
MAT = Manifold Air Temp
AMBT = Ambient temp
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Re: Hentai's 1992 Mazda Miata (15th)

Post by Hentai »

Baldur brings up a good point
"<TekniQue> There's another possibility
<TekniQue> this could just be reversion air
<TekniQue> when you have the throttle shut there's going to be a lower pressure in the manifold than there is in the cylinders at intake valve opening
<TekniQue> so some amount of reversion is going to happen
<TekniQue> sucking hot air from the cylinders into the inlet manifold
<techsalvager> I thought about that
<techsalvager> air is escaping from the cylinders back into the manifold
<TekniQue> the fact that it's a transient change supports that theory
<techsalvager> because of pressure difference
<TekniQue> when you lift off and coast, the air momentarily gets hotter and then it cools again
<techsalvager> I know why I didn't suggest it, thought I was gonna sound like ass
<techsalvager> yheah you can see it on any trasients like this a spike in mat temp
<techsalvager> I think boosting makes it more know, you can see it easier
<TekniQue> yeah probably"
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