Just finished installing my AEM water injection system. (thread here: https://www.rx7club.com/auxiliary-in...stall-1012665/ )

I was out doing some test runs today.

Check out how much air intake temps are lowered when using water.

The first pic is air and water temp after easy warmup.
(39c air intake temp, 73c water temp -- that's 102.2 F / 163.4F)




This pic is 5 minutes AFTER charging up aggressively through gears at full boost.
(18c air intake temp, 77c water temp -- that's 64.4 F / 170.6F)



As expected water temp went up slightly, but air intake temp went down by 38F! woot.

 

sweet, look forward to installing my Coolingmist.

 

Didn't notice the numbers.....to distracted by the odometer....29,820 miles. Wow. That was a long time ago for me. Now back to the thread.....

 

Yea man. AI is great. I forget what the lowest I have seen was close to winter. It was in the single digits. I could have sworn I saw it hit -1. This was with wiper fluid as well. During the summer, I get low teens after boosting. One of the best mods ever!

 

with meth injection, i guess going VMOUNT is redundant?

 

Those water temps are too cold.

 

^^^^ that's right!! Too cold. I think the thermostat opens at 180F.
I run a mustang 160F thermostat and still see 190F-210F...

 

^A little cool, but this time of year I can cruise the interstate for 30 minutes and not get hotter than ~ 80 C. (taken from T-body coolant line).

I have my nozzle after the IAT so I don't see changes there. But like you, I did notice the lack of coolant temp spiking from hard boost. Maybe one or two degrees C. is all even in hot weather. Nothing like what I used to see after even a brief hard boost period.

 

it was a foggy day on the SF coast. The knightsports v-mount working too well . Normally my running temps hover in the 80-85c zone. Ill take too coold over too hot any day.

 

Absolutely not. If I got stuck in traffic, my intake temps would rise and get exremely high. I had to play with the throttle to trigger my AI without boosting to get them down to reasonable levels and start be able to boost hard again but AI at least provided an active countermeasure to high intake temps.

 

exactly waht I was thinking , need to adjust the fans I think

 

OP is in San Fransico.... Temps there are always cool....

 

What kind of intake senor are you using? In the stock location? How long was the AI spraying before you noticed the temp drop? I also just added the AEM kit to my car during an engine rebuild I havent boosted yet to see if the AI is working right and I just want to know how the system should be reacting. Just wanna know how long it takes for the pfc to read lower IAT.

 

I've been running the same kit for years now and I had the same low intake temp readings as far as the WI cooling potential but when i got my car tuned, Chris at Rotary Performance said I was loosing 7whp because my system was set (by me) to inject too much water. I was only using the middle sized nozzle at the time. After his tune my temps were never dramatically that low again. But I will say that it is awesome to see the intake temps drop under boost rather than spike. Enjoy the kit as its a bad *** buy for our cars!

 

I'm using the fast acting IAT. My temps drop QUICK after about the second update to my PFC commander. After it sprays the temps keep dropping and then climb up slowly.

 

exactly what i was thinking, kinda unnatural to be running that cool. car has to at least get up to operating temperature.

 

stock sensor. I see the temps start to drop within a few seconds of running in boost. It's not instant but close (which could just be sensor delay)

 

how close is the temp sensor to the water injector?

 

Realistically, this is why methanol is awesome. The water suppresses knock, while reducing combustion temps. However, the methanol is what is sucking the heat from your intake charge.

I run a pre-turbo setup with 50/50. Intake temps are always in the low 30's. As the ambient temps have been cooling with fall coming, I have been seeing 20's more and more. Pre-turbo tends to cool the temps a little less, as much of the heat absorption is at the compressor. I'm not surprised to see your post-turbo IAT's radically lower than mine.

I feel that every turbo rotary should be running water or 50/50. With the degradation of gasoline quality, carbon buildup, and heat soaking, it is a a nice cold glass of water to a dehydrated man.

 

defnintely need one of these in cali!

 

I don't know why some people consider 70°C as too cold coolant temperature for rotary engine. MFR competition manual consider engine as warmed-up when oil temp reaches 70°C and normal operating temperature is between 70-90°C for coolant and 90-110°C for oil.

Higher temperatures are only good for slightly lower hydrocarbon emissions, otherwise all running parameters are worse and detrimental to engine life and power.

To the OP, I wouldn't jump on conclusion that actual charge entering the engine has 18°C, its probably effect of water sucking heat from sensor itself when it evaporates. Or does the engine feels noticably more powerful?

Otherwise I'm glad that people doesn't consider WI as some band-aid, but also realizing its benefits as total loss cooling system. In other worlds, who has powerful turbo rotary which can be used under full power for more than few moments?

 

I am looking into staggered water injection looks like the best option out there, I can then safely know the only thing getting hot is me in the 40 degree heat and not my car... why did i remove the AC LOL

 

+1

said it before and i will say it again. the sensor reading is skewed when it is soaked with AI coolant. it will eventually normalize once the sensor has dried.

this is also why you see pre turbo cars not notice such a huge dip in IATs, because they are more accurately reading the temps versus pre-throttle body injection. both methods work about the same but pre turbo probably gives slightly better IAT reduction where pre-TB injection gives better internal knock suppression from the water versus lower IATs. pre turbo more or less adds efficiency to the intercooler and on a slightly lesser scale knock suppression from the inert gas.

pre-TB injection gives a bit more of an impression of drastic IAT drops, which my assumption is just what i said above, it's just holding the minimum IAT for an extended period of time.

 

Agree....since water needs more time (compared to meth) to absorb heat from the intake charge. Water @ pre-throttle body location is simple and great at cooling the combustion chamber but not so much the IAT. Not enough time and it doesn't undergo that phase change. I relocated my IAT sensor up-stream from the nozzle. I believe that's what HC recommends as well.

 

Water injection are sweet