3rd Generation Specific (1993-2002) 1993-2002 Discussion including performance modifications and Technical Support Sections.
Sponsored by:

This is why water injection is awesome.

Thread Tools
 
Search this Thread
 
Old 09-23-12, 08:39 PM
  #1  
Full Member

Thread Starter
iTrader: (6)
 
killjoy7's Avatar
 
Join Date: Mar 2001
Location: SF
Posts: 164
Received 1 Like on 1 Post
This is why water injection is awesome.

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)

Name:  IMAG0377_zpse26cb9ca.jpg
Views: 3671
Size:  106.6 KB


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)

Name:  IMAG0379_zps52680ef2.jpg
Views: 3533
Size:  64.2 KB

As expected water temp went up slightly, but air intake temp went down by 38F! woot.
Old 09-23-12, 08:54 PM
  #2  
GT3574R equipped

iTrader: (18)
 
HalifaxFD's Avatar
 
Join Date: Mar 2007
Location: Bedford, Nova Scotia
Posts: 1,174
Likes: 0
Received 1 Like on 1 Post
sweet, look forward to installing my Coolingmist.
Old 09-23-12, 08:59 PM
  #3  
Senior Member

iTrader: (4)
 
sbnrx7's Avatar
 
Join Date: Feb 2007
Location: Tallahassee, FL
Posts: 442
Likes: 0
Received 6 Likes on 5 Posts
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.....
Old 09-23-12, 09:25 PM
  #4  
Lives on the Forum

iTrader: (83)
 
Supernaut's Avatar
 
Join Date: Jun 2008
Location: Los Angeles CA
Posts: 5,859
Likes: 0
Received 8 Likes on 7 Posts
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!
Old 09-24-12, 02:04 AM
  #5  
Full Member

 
Airwolf RX7's Avatar
 
Join Date: May 2012
Location: Orange County
Posts: 74
Likes: 0
Received 1 Like on 1 Post
with meth injection, i guess going VMOUNT is redundant?
Old 09-24-12, 06:22 AM
  #6  
Wastegate John

iTrader: (13)
 
RENESISFD's Avatar
 
Join Date: Feb 2008
Location: Long Island NY 11746
Posts: 2,979
Likes: 0
Received 9 Likes on 9 Posts
Those water temps are too cold.
Old 09-24-12, 07:57 AM
  #7  
It's finally reliable

iTrader: (18)
 
MOBEONER's Avatar
 
Join Date: May 2004
Location: NEW YORK CITY
Posts: 3,511
Received 9 Likes on 7 Posts
^^^^ that's right!! Too cold. I think the thermostat opens at 180F.
I run a mustang 160F thermostat and still see 190F-210F...
Old 09-24-12, 08:03 AM
  #8  
Urban Combat Vet

iTrader: (16)
 
Sgtblue's Avatar
 
Join Date: Oct 2003
Location: Mid-west
Posts: 12,011
Received 862 Likes on 611 Posts
^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.
Old 09-24-12, 08:41 AM
  #9  
Full Member

Thread Starter
iTrader: (6)
 
killjoy7's Avatar
 
Join Date: Mar 2001
Location: SF
Posts: 164
Received 1 Like on 1 Post
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.
Old 09-24-12, 09:34 AM
  #10  
Lives on the Forum

iTrader: (83)
 
Supernaut's Avatar
 
Join Date: Jun 2008
Location: Los Angeles CA
Posts: 5,859
Likes: 0
Received 8 Likes on 7 Posts
Originally Posted by Airwolf RX7
with meth injection, i guess going VMOUNT is redundant?
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.
Old 09-24-12, 09:41 AM
  #11  
Rotary Freak

iTrader: (5)
 
Tem120's Avatar
 
Join Date: Sep 2011
Location: Miami
Posts: 2,824
Likes: 0
Received 5 Likes on 5 Posts
Originally Posted by RENESISFD
Those water temps are too cold.
exactly waht I was thinking , need to adjust the fans I think
Old 09-24-12, 10:25 AM
  #12  
Committee Member #2

iTrader: (29)
 
NoPis10's Avatar
 
Join Date: Jan 2005
Location: Committe Chambers
Posts: 4,280
Likes: 0
Received 5 Likes on 3 Posts
OP is in San Fransico.... Temps there are always cool....
Old 09-24-12, 02:17 PM
  #13  
Senior Member

iTrader: (2)
 
Reno_NVFD's Avatar
 
Join Date: Mar 2011
Location: Reno, NV
Posts: 364
Likes: 0
Received 0 Likes on 0 Posts
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.
Old 09-24-12, 05:54 PM
  #14  
Who say's i need a Van

iTrader: (18)
 
Hotwheelz's Avatar
 
Join Date: Feb 2009
Location: Whatsittoya
Posts: 609
Likes: 0
Received 0 Likes on 0 Posts
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!
Old 09-24-12, 06:12 PM
  #15  
Lives on the Forum

iTrader: (83)
 
Supernaut's Avatar
 
Join Date: Jun 2008
Location: Los Angeles CA
Posts: 5,859
Likes: 0
Received 8 Likes on 7 Posts
Originally Posted by Reno_NVFD
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'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.
Old 09-24-12, 07:53 PM
  #16  
Toretto
iTrader: (2)
 
WesC2's Avatar
 
Join Date: Sep 2012
Location: S Florida
Posts: 51
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by RENESISFD
Those water temps are too cold.
exactly what i was thinking, kinda unnatural to be running that cool. car has to at least get up to operating temperature.
Old 09-25-12, 10:14 AM
  #17  
Full Member

Thread Starter
iTrader: (6)
 
killjoy7's Avatar
 
Join Date: Mar 2001
Location: SF
Posts: 164
Received 1 Like on 1 Post
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)

Originally Posted by Reno_NVFD
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.
Old 09-25-12, 10:18 AM
  #18  
Rotor or no motor

iTrader: (24)
 
R-R-Rx7's Avatar
 
Join Date: Oct 2006
Location: Limassol, CYPRUS
Posts: 3,337
Received 366 Likes on 222 Posts
how close is the temp sensor to the water injector?
Old 09-25-12, 10:42 AM
  #19  
Eats, Sleeps, Dreams Rotary

iTrader: (52)
 
XLR8's Avatar
 
Join Date: Oct 2001
Location: NJ
Posts: 3,902
Likes: 0
Received 10 Likes on 6 Posts
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.
Old 09-25-12, 11:35 AM
  #20  
Junior Member
 
fredricktsang's Avatar
 
Join Date: Apr 2010
Location: Los Angeles
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
defnintely need one of these in cali!
Old 09-25-12, 02:05 PM
  #21  
Senior Member

 
Liborek's Avatar
 
Join Date: Nov 2008
Location: Czech republic
Posts: 357
Likes: 0
Received 0 Likes on 0 Posts
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?
Old 02-21-13, 07:42 AM
  #22  
Work in Progress
 
AUS-FD3S's Avatar
 
Join Date: Feb 2013
Location: Australia
Posts: 129
Received 0 Likes on 0 Posts
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
Old 02-21-13, 12:47 PM
  #23  
Sharp Claws

iTrader: (30)
 
RotaryEvolution's Avatar
 
Join Date: Oct 2003
Location: Central Florida
Posts: 5,107
Likes: 0
Received 41 Likes on 40 Posts
Originally Posted by Liborek
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?
+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.

Last edited by RotaryEvolution; 02-21-13 at 12:54 PM.
Old 02-22-13, 05:24 AM
  #24  
Urban Combat Vet

iTrader: (16)
 
Sgtblue's Avatar
 
Join Date: Oct 2003
Location: Mid-west
Posts: 12,011
Received 862 Likes on 611 Posts
Originally Posted by RotaryEvolution
+1

....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....
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.
Old 02-22-13, 05:33 AM
  #25  
S366 is my Haven

 
TainoCo's Avatar
 
Join Date: Aug 2008
Location: Little Rock, AR
Posts: 149
Likes: 0
Received 0 Likes on 0 Posts
Water injection are sweet


Quick Reply: This is why water injection is awesome.



All times are GMT -5. The time now is 06:37 AM.