ECU pulls timing at high oil temps?

[brillo]

Perrin and others have hinted at the fact the the stock ECU pulls timing and reduces power if the oil temps exceed around 225f. I don't think I've seen this issue discussed in detail. While I know a stock syntethic oil can handle temps greater than 225f (Amsoil said they weren't concerned about temps of 260-280f), it appears the engine considers this unsafe for a reason other than lubrication.

Is this a function of the high compression and DI? Is the oil used to cool the pistons? I don't believe that the ECUtek can tune this out (not sure I would want it to either), but I'd be curious to see what the reasons could be.

I know the 370z has similar issues as well.

[so26]

I don't recall them saying that it was actually pulling timing.

[brillo]

Perhaps I heard that from someone else, ill have to go back and re read their thread

[cf6mech]

I'm of the belief if your plans are to really run this car hard in all conditions with a lot of bolt ons for power , that we will see that it needs a stand alone ECU.

[Black Tire]

Perhaps Subaru/Toyota was concerned about thermal runaway, where the heat completely overwhelms the cooling system without a chance for recovery. If so, then perhaps they programmed the ECS to avoid any possibility of encountering this situation. HKS found a problem with the oil temps as well. See the writeup on this link:

http://ft86speedfactory.com/hks-s-ty...42a0a5aeecb8b9

[Calum]

Originally Posted by brillo

Perrin and others have hinted at the fact the the stock ECU pulls timing and reduces power if the oil temps exceed around 225f. I don't think I've seen this issue discussed in detail. While I know a stock syntethic oil can handle temps greater than 225f (Amsoil said they weren't concerned about temps of 260-280f), it appears the engine considers this unsafe for a reason other than lubrication.

Is this a function of the high compression and DI? Is the oil used to cool the pistons? I don't believe that the ECUtek can tune this out (not sure I would want it to either), but I'd be curious to see what the reasons could be.

I know the 370z has similar issues as well.

Which viscosity was Amsoil referring to? 0W20 is pretty thin as temperatures increase. I could see a xW40 working well at those temperatures but amsoil's 0w20 may have a better VI then I'm expecting.

Everyone seems to want to add an oil cooler, has anyone investigated adding a larger oil pan? The increased dwell time may be enough for most applications.

[brillo]

I specifically asked about the 0w-20 as that is our stock spec.

[markitect]

All I've seen is speculation. Has anyone actually checked. Torque can show both oil temp and timing advance. Can someone going to a track investigate this further?

[Huehuecoyotl]

Originally Posted by Calum

Which viscosity was Amsoil referring to? 0W20 is pretty thin as temperatures increase. I could see a xW40 working well at those temperatures but amsoil's 0w20 may have a better VI then I'm expecting.

Everyone seems to want to add an oil cooler, has anyone investigated adding a larger oil pan? The increased dwell time may be enough for most applications.

Before I say this, its fine to run whatever oil you like, and what I am about to say is ONLY my opinion, so dont get offended:

Not to bust open the oil can, but you do know that 0w20 usually has a better additive pack than most Xw40s, right?

I track mine heartily on 0w20 in AZ heat, I just use the top notch stuff. I'm actually scared to increase the pressures on valve gear at redline using a thicker oil. Ester based vs non ester based matters more to me than the SAE rating. Same with Moly and zinc content- ol skool flat tappet upbringing.

I've considered both 0w30 and 0w40 and couldnt find a rational reason to use or recommend a thicker oil for the FA20's internal clearances.

idemitsu, eneos, motul and subaru or toyota factory all have great fortifiers and are spec'd right for our engine. Keeping the oil cool is key, so a cooler helps more than a bigger sump. Starvation doesnt seem to be an issue like with my m3. When using a oil cooler, a 0w20 will take advantage of the cooler better as it can transfer heat faster than a Xw40, so $50 says if I run both oils same car same track, my car will run hotter with the heavier weight oil, just sayin.


(grease proof flame suit on!)

[brillo]

would love to see a data log if someone has one on a dyno or the street/track showing oil temps and ignition timing after the car has heat soaked properly.

[Calum]

Originally Posted by Huehuecoyotl

Before I say this, its fine to run whatever oil you like, and what I am about to say is ONLY my opinion, so dont get offended:

Not to bust open the oil can, but you do know that 0w20 usually has a better additive pack than most Xw40s, right?

I track mine heartily on 0w20 in AZ heat, I just use the top notch stuff. I'm actually scared to increase the pressures on valve gear at redline using a thicker oil. Ester based vs non ester based matters more to me than the SAE rating. Same with Moly and zinc content- ol skool flat tappet upbringing.

I've considered both 0w30 and 0w40 and couldnt find a rational reason to use or recommend a thicker oil for the FA20's internal clearances.

idemitsu, eneos, motul and subaru or toyota factory all have great fortifiers and are spec'd right for our engine. Keeping the oil cool is key, so a cooler helps more than a bigger sump. Starvation doesnt seem to be an issue like with my m3. When using a oil cooler, a 0w20 will take advantage of the cooler better as it can transfer heat faster than a Xw40, so $50 says if I run both oils same car same track, my car will run hotter with the heavier weight oil, just sayin.


(grease proof flame suit on!)

No, I hadn't looked at the additive packages, thanks for the heads up. I just went with Amsoil's Signature Series 0W20 as I don't plan to track my car, and the ambient temp here doesn't get very high.

You're tracking with an oil cooler which is regulating the temperature to, or close to, ideal. Have you tracked without the oil cooler? If so, did the oil pressure drop off as the temperature climbed?

With the larger pan I was thinking the oil's longer dwell time would allow it to cool more before it was reintroduced into the oil circuit. For applications like mine that might be enough, even for the occasional track day.

The last car I modded was actually pretty infamous for having oil that never got hot enough if you ran an aftermarket oil sump. One after a few hard laps would the oil finally get fully up to temperature.

[Calum]

Originally Posted by brillo

I specifically asked about the 0w-20 as that is our stock spec.

Good to know, especially considering I'm running their oil.

[jr429]

Originally Posted by Black Tire

Perhaps Subaru/Toyota was concerned about thermal runaway, where the heat completely overwhelms the cooling system without a chance for recovery. If so, then perhaps they programmed the ECS to avoid any possibility of encountering this situation. HKS found a problem with the oil temps as well. See the writeup on this link:

http://ft86speedfactory.com/hks-s-ty...42a0a5aeecb8b9

Why would this happen? The motor is not a lithium ion battery...

[AVOturboworld]

The ECU pulls the IAM back at high loads, we noticed this during the marathon road test/tune for the turbo kit. It puts timing back in once loads decrease. Now, high engine load would have the oil temperatures/coolant temperature increasing as well due to the situations you'd see that high engine load figures, so attributing the timing being pulled to oil temps would be bad science.

Given that one of the situations where we saw the timing being pulled (temporarily) was in the mountains at near freezing temps, and that at that particular time the oil/coolant temps were not going up much (in contrast to the desert testing), we'd not point our fingers at the oil temps being the cause at this time.