Intake Air Temperature affect on Ignition Timing
 

At what temperature does the ECU start backing off on timing advance? I saw a temp/timing map somewhere (I'd swear it was on this site) but can't find it again. Searching the site and using Google wasn't much help, but maybe I'm just using the wrong search strings - "intake air temp timing", Nissan 370Z timing", &c. Any help with locating the map and/or suitable search string will be appreciated.

that would be a good question for Uprev

I called UpRev and Omar was very helpful (especially considering I wasn't buying anything). He didn't answer my question about IAT/timing, but said that oil temp and coolant temp are bigger factors. According to Omar, the ECU starts backing off on timing when oil temp is above 230 and/or coolant temp is above 190. Thanks Omar/UpRev and cdoxp800. :tup:

I'm still wondering where IAT comes in. If anyone can point me in the right direction, I'll be beholding.

this definitely explains alot !

That sounds about right.

I plan on monitoring my intake and coolant temps on a regular basis now that I got a Bluetooth OBDII dongle and the iPhone app Dash Command!!

http://www.the370z.com/attachments/i...ience-odb2.jpg

Ooooh, Daddy like. How much was the Dongle?

SouthArk370z good search , but allow me to ask why would you need to know this? do you have an issue with ignition timing after using some aftermarket intake ?

Mainly just curiosity. I like to keep everything within spec if I can. My bone-stock (only things I've added are a passenger-side seat cover and a ScanGaugeII) '09 Touring seems to run on the hot side in stop-and-go traffic when S AR temps go up in the Summer. Not a big problem as I try to keep my toenails out of the radiator when it gets that hot.

Whilst out driving a few minutes ago - 101F, 44% humidity, stop-and-go traffic plus a few miles of highway - I saw engine coolant temps in the 201-208 range, oil temp pretty steady at 220, and intake air temps as high as 134 when stopped. Coolant temp would drop to ~198 and IAT down to 118 or so at 25-40mph. At 65mph, coolant went to 190-195 range and IAT would drop to 113-114 (didn't drive far enough to see if oil temp would go down.) I'm guessing coolant temp would have dropped some more with a bit more highway driving. Edit: All that with the A/C off.
All that tells me that I could use a little extra cooling, especially engine coolant, on very hot days. I may look into high-flow radiator fan(s).

If you get uprev cable and software for tuning, you can also control fan duty cycle.

Excellent suggestion.
I already have a ScanGaugeII, a CAN-to-USB interface, and PC software. If I were starting anew (or the temps were high at 80F ambient), I'd give the UpRev stuff serious consideration, but just can't justify the cost at this point.

A Q&D search of the Intertubes shows I can get high-flow replacement fans for $40-80. Just have to figure out which ones will fit.

PS: I don't like the factory coolant temp gauge - never got above the LED two LEDs down from the top of the thermometer symbol, even when ScanGauge showed 208-209F.

Was a hot day 88 degrees! This is 5 minutes of heatsoak in my driveway after my commute home with my Typhoon HAI's ;)

http://www.the370z.com/attachments/i...e-obd2-hot.jpg

i dont have the uprev fan control yet but with my toggle switch.i turn the fans on at all red lights or slow moving traffic.works wonders on my 09

Sounds like a great idea! I have a spot available for a switch between the seat heater switches and it should be a lot easier than changing the fans. Now to find an illuminated rocker momentary switch that will fit the hole and match the interior (basic black shouldn't be too hard to find heehee). Schematics should be in the FSMs available on this site. Will search later for any DIY instructions.
Thanks for the tip.

I received this e-mail from Jared at UpRev. Posted here with Jared's permission: