2010 Prius Grill Blocking strategy

I'm guessing it's daytime high ambient temp.

Obviously Ken is very informed on the topic, but it appears that other people are running more blocking at higher temps while monitoring ICE coolant temperatures with a SG. Ken stated earlier in the thread that the radiator fan kicks on between 203F and 212F and anything over 212F is engine overheat. Theoretically it doesn't matter what the ambient temps are as long as you carefully monitor the coolant temp and make sure you don't push over 212F. Running hotter than 203F is going to draw excessive kw to run the radiator fan, so this should be avoided as well. And to take things to the next level, the ICE runs most efficiently at some temp (don't remember what) below 203, so that could also be target to monitor against.


ICEInverter by bendertj, on Flickr

The above graph shows a month of driving without blocking. I figure that gives me a decent "safe" temp range to shoot for - well below the overheat temps Ken provided.

Earlier this week I 100% blocked lower / 0% blocked upper. This afternoon the ambient temp was around 75F. Despite my best efforts to make the engine hot enough to run the radiator fan, the temp never exceeded 199F. A/C on max, hills (highway and city both), high-speed and stop&go. We're taking a longer trip this weekend so it will give me a chance to log some data on extended highway trips & ice coolant temps.

 

Folks die in water of average 2' depth. Which is to say, averages don't apply here. Similarly, highs are not relevant unless you are driving at that time. So to me, it is current temp, meaning you will not be perfectly in line with any guideline all the time.

I've not thought of these as city or highway, but for either. That said, if going out for a 500 mile freeway segment, one could reduce blockage percent for sure.

If only doing short segments, one can block more than stated, but remember to remove before prolonged drive and watch temp.

 

^^^ Thanks for the good feedback!

I have 50% of bottom blocked right now but I am taking a trip to Texas here before long and am wondering if I need to remove it. I suppose I can just watch Torque and judge for myself.

 

Just curious when you you say 1/2" foam, do you mean insulation FOR 1/2" pipes or the actual measurement is 1/2"? (ex. I saw 3/8" foam for 1/2" piping) I went to home depot and didn't know which to get for grille blocking.

 

See post #289 and 290 from earlier:
2010 Prius Grill Blocking strategy

 

Has the proper grill blocking location for the GenIII been confirmed?
I would like to give it a try, in stages, starting with 1 insullating tube.

Thanks,

 

Yes, its all in this thread. Just start reading backwards from this page, we had a pretty detailed conversation within the last month.

Lower grill is ice/ac heat exchange. Upper grill is inverter heat exchange. Ken@Japan listed acceptable blockage percentages for each based on ambient temps earlier in the thread. Follow those

hope this helps

ThunderBolt ? 2

 

Just got back from a road trip and learned a few different things.

First I learned that grill blocking and interstate driving don't really mix. Second I learned that even at around 65 mph with temps in the 60's and no grill blocking that the engine can still easily get to 200 degrees.

 

Down at true winter temps, some blocking on the freeway seems fine on my car. I've never seen more than 195F, though I do not always watch it. Maybe the '12 uses different paramaters than the '10?

 

I should have mentioned in my previous post that it was on the hills when the temp spiked.

 

I've found, with previous cars at least, freeway driving is where a car is most likely to run cold. Relatively low cruising rpm, and very good air flow. On level ground of course. This was where I discovered a failing thermostat, actually. Would pull off the freeway and see the coolant temp gauge was down at the bottom: thermostat was stuck open, over-cooling.

Of course with the Prius, unless you get yourself a ScanGage: no coolant temp gauge for you.

 

Whats the point of blocking the grill? Does it give better MPG?

 

Please actually read the thread you just posted in.

 

Do you have any data/observations to support your first statement?

 

I was watching the coolant temp the whole time and had no problem staying at ideal temp and it even got a little hot a few times. Obviously if the temp was a lot colder this wouldn't be the case.

 

Anyway:

1. Warms the car up faster.

2. Get's the car to operating temp (190 def F~) in winter when it's so cold it otherwise wouldn't get there.

3. Might improve aerodynamics a little.

 

Ohh, thanks for replying, I don't work with cars that much so I wasn't sure what was the reason people using Styrofoam to block their grill. Do you guys block them during summer time? Or does overheating creates problems as well?

 

If you block in summer, you should definitely be watching temps with a scangauge II or similar. The car can likely handle the temp in Hagerstown summers, but there is no point in making it pump that water and spin that fan when the car is already warm.

 

That's my thought with using grill blocking for long interstate road trips. No point having it on there when interstate speeds can easily hold it in optimal range.

 

What really needs to happen is Toyota adding a shuttering system like Ford did. Then the computers could operate it as needed. Aftermarket kit would be fine too.