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RX-7 2nd Gen Specific (1986-92) RX-7 1986-92 Discussion including performance modifications and technical support sections. |
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02-17-2010, 03:43 PM | #16 | |
Don Mega
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I have a very old article from 1997 which I should scan and put up that shows a very similar system to mine that proves this with some official vehicle tests 3rd gear speed pulls. The clincher is when the other type of system was trialed (post turbo injection with boat bilge pump) with various switch on points and injection volumes and mixes of fluid, NO PERFORMANCE GAINS WERE ACHIEVED. In summary you can have your car fully tuned as is, then ad the right WI system and adjust it and you will get a safety increase and durability increase and to finish it off you will also get a measure performance gain
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www.riceracing.com.au Worlds best Apex Seals Coil on Plug Water Injection ECU Calibration |
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02-17-2010, 07:30 PM | #17 | |
Rotary Fan in Training
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How are you doing brother? So you are now using a 50/50 mix with your pre-turbo setup? |
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02-17-2010, 07:48 PM | #18 |
Test Whore - Admin
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So you're saying that right now, with my setup and current map, & I'm making 405rwhp on stock twins, that if I added WI I would GAIN power? Exactely how does injecting water, which is know to put out flames, gain power? Is it just through a cooler charge? If that is the case, than I doubt myself, or anyone with a very effiecent intercooler would see any real performance gains as my AIT's are near ambient anyway.
Correct me if I'm wrong but is the performance gain only though cooler AIT's? I can see strait meth and bumping the timing gaining a ton of power, but the way you're touting water injection, doesn't seem logical.
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-The Angry Stig- DGRR 2009, 2011, 2012 & 2013 - Best FC DEALS GAP!! WOOHOOOO!!!!! 2015 Audi S4 - Samantha - Zero Brap S4 2004 RX8 - Jocelyn - 196rwhp, 19mpg fuel to noise converter 2000 Jeep Cherokee Sport - Wifey mobile - Now with 2.5" OME lift and 30" BFG AT KO's! So it begins 1998 Jeep Cherokee - 5 spd, 4" lift, 33" BFG's - Rotary Tow Vehicle 1988 'Vert - In progress 1988 FC Coupe - Gretchen -The attention whore BEAST! I'm a sick individual, what's wrong with you? I'm pure Evil I'm still insane, in the best possible way. I think Brian's idea of romance is using lube. Your rage caused the meteor strike in Russia. The Antichrist would be proud of his minion. You win with your thread. Most everything It's a truck with a steel gate on the back. Just a statement of fact Motec M820, AIM dash, ported 13B-RE Cosmo, 6-spd trans, 4.3 Torsen, custom twin wg fully divided mani, Custom 4" split into 2x 3" exhaust, Custom HMIC, Custom custom custom custom I like to welder stuff.... No Bolt-ons allowed. Dyno'ed @ Speed1 Tuned by me - 405rwhp on WG.... WM50 cuming soon. -Angry Motherf*cker Mode ENGAGED- |
02-17-2010, 09:36 PM | #19 | |
frustrated!
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I do think that if the owner is running an efficient IC and has very well routed heat scavanging system/under hood temp control, then WI might not seem like a very big factor in gaining HP. I do think however if the owner was to road race /circuit, that the WI with water only would just be a smart choice because you know that your AIT's are gonna rise..maybe not to extreme temps if your ducting is functional but those AIT's will be hotter then a motor with WI would record.
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Same pig, new soul |
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02-17-2010, 09:58 PM | #20 |
Don Mega
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I don't want to come across the wrong way with this so I will try to explain as neutrally as I can.
If you run a blend of meth to water at 50/50 on top of your normal tune given the right ratio (all cars have a sweet spot) for turn on point and amount to inject. When you inject pre turbo you will realize a net performance gain, This is brought about by a charge increase into the engine (more air and more fuel over and above anything that the water may displace). People not associated with me in any way have tested this and listed very significant acceleration gains in real world tests. A rough rule of thumb is you want around 100cc per 150bhp from my experience (though note each car set up is different in what it will respond too for best power, but rest assured it will increase the power and not decrease it if you follow the above recommendations) The same qty and trigger points after the turbo yield no gains at all, but detonation is eliminated with either system. Injection of a 100% water mixture on top of your existing safe tune up will cost you power but increase reliability and durability just to be clear.
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www.riceracing.com.au Worlds best Apex Seals Coil on Plug Water Injection ECU Calibration Last edited by RICE RACING; 02-17-2010 at 10:04 PM.. Reason: extra detail |
02-17-2010, 10:51 PM | #22 | |
Rotary Fan in Training
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02-18-2010, 12:07 AM | #23 | |
Don Mega
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I have components in bottles of various solutions sitting for months/years at a time, I only started this one a month back... so far I can tell no ill effect on the above mixture.
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www.riceracing.com.au Worlds best Apex Seals Coil on Plug Water Injection ECU Calibration |
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02-18-2010, 12:33 AM | #24 | |
Rotary Fan in Training
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02-18-2010, 12:47 AM | #25 |
Test Whore - Admin
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This is just my OCD acting up, but something about the way you're stating it isn't sitting right with me. If you tune your car and then lower the AIT's, you're now in sections of the map/comp tables that you've never been before, so you can't really say it's 100% safe unless you test and tune for it.
The reason that the pre-turbo is better for performance is becuase the charge air temp isn't climbing nearly as high with the introduction of water. I would like to see a test done on the dyno where you make a few pulls with no AI at all and monitor L, EGT's AIT's and PRE-intercooler charge temps. I have a bunch of logs that show my AIT's rise 10*F after 10-20 dyno runs over the course of 5 hours and they are within 10-15* of ambient unless some sort of heat soak issue has occured. This log in particular is close to a 400rwhp on stock twins run, look at the AIT's pre and post intercooler. As soon as the pedal is matted in 4th, the charge temps go from ~100* to 250* and follow the boost as it rises. This is pysics, there is no way around it, compressing a gas makes it hotter. Adding water pre-turbo will take some of this heat out. Cooler air (relatively) into an intercooler will give you cooler temps out. Now I'm not knocking the knock resistance charateristics of it but to say that the addition of water without a retune is a little far fetched becuase you'll be in area's of the map that you haven't explored. Aside from the knock resistance charaterics of it, for me, it just seems like a band-aid, sorry. BUT, and this is a big but, if you're talking about big amounts of boost, then the benefits start to shine becuase lets face it, you can't escape pysics, more boost more heat, but for street cars and 250* charge temps, and near ambient intake temps..... I don't think it's really worth it. A properly ducted and sealed intercooler with good effeicency is more reliable than a WI system. Now if we want to talk about chemical intercooling, that's something totally different and something that I would like to explore on my FD becuase I have 500rwhp plans for that car and more experimenting..... plus it's time to finish the FC.... relatively speaking anyway.
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-The Angry Stig- DGRR 2009, 2011, 2012 & 2013 - Best FC DEALS GAP!! WOOHOOOO!!!!! 2015 Audi S4 - Samantha - Zero Brap S4 2004 RX8 - Jocelyn - 196rwhp, 19mpg fuel to noise converter 2000 Jeep Cherokee Sport - Wifey mobile - Now with 2.5" OME lift and 30" BFG AT KO's! So it begins 1998 Jeep Cherokee - 5 spd, 4" lift, 33" BFG's - Rotary Tow Vehicle 1988 'Vert - In progress 1988 FC Coupe - Gretchen -The attention whore BEAST! I'm a sick individual, what's wrong with you? I'm pure Evil I'm still insane, in the best possible way. I think Brian's idea of romance is using lube. Your rage caused the meteor strike in Russia. The Antichrist would be proud of his minion. You win with your thread. Most everything It's a truck with a steel gate on the back. Just a statement of fact Motec M820, AIM dash, ported 13B-RE Cosmo, 6-spd trans, 4.3 Torsen, custom twin wg fully divided mani, Custom 4" split into 2x 3" exhaust, Custom HMIC, Custom custom custom custom I like to welder stuff.... No Bolt-ons allowed. Dyno'ed @ Speed1 Tuned by me - 405rwhp on WG.... WM50 cuming soon. -Angry Motherf*cker Mode ENGAGED- |
02-18-2010, 12:49 AM | #26 |
Test Whore - Admin
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Might help if I post up the datalog......
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-The Angry Stig- DGRR 2009, 2011, 2012 & 2013 - Best FC DEALS GAP!! WOOHOOOO!!!!! 2015 Audi S4 - Samantha - Zero Brap S4 2004 RX8 - Jocelyn - 196rwhp, 19mpg fuel to noise converter 2000 Jeep Cherokee Sport - Wifey mobile - Now with 2.5" OME lift and 30" BFG AT KO's! So it begins 1998 Jeep Cherokee - 5 spd, 4" lift, 33" BFG's - Rotary Tow Vehicle 1988 'Vert - In progress 1988 FC Coupe - Gretchen -The attention whore BEAST! I'm a sick individual, what's wrong with you? I'm pure Evil I'm still insane, in the best possible way. I think Brian's idea of romance is using lube. Your rage caused the meteor strike in Russia. The Antichrist would be proud of his minion. You win with your thread. Most everything It's a truck with a steel gate on the back. Just a statement of fact Motec M820, AIM dash, ported 13B-RE Cosmo, 6-spd trans, 4.3 Torsen, custom twin wg fully divided mani, Custom 4" split into 2x 3" exhaust, Custom HMIC, Custom custom custom custom I like to welder stuff.... No Bolt-ons allowed. Dyno'ed @ Speed1 Tuned by me - 405rwhp on WG.... WM50 cuming soon. -Angry Motherf*cker Mode ENGAGED- |
02-18-2010, 08:49 AM | #28 |
Test Whore - Admin
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Well, this is the whole problem with MAP based systems. If you increase the mass of air moving into the engine without retuning for it, engine go boom. The extreme example is the stock twins @ 15psi vs a GT60 @ 15psi. 15psi is not 15psi and you need to be careful especially with a MAP based system. It the WI pre-turbo is really changing the mass of air entering the engine by way of cooler charge temps, then as you state here,
than I wouldn't think that slapping a WI system on is going to be safe. However, if boost levels are kept constant, the mass isn't going to change dramatically, the water is displacing some of the mass, and the cooler charge temps are being properly compensated, the difference is minimal. I just feel that to say zero re-tune is needed is a little sketchy is all.
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-The Angry Stig- DGRR 2009, 2011, 2012 & 2013 - Best FC DEALS GAP!! WOOHOOOO!!!!! 2015 Audi S4 - Samantha - Zero Brap S4 2004 RX8 - Jocelyn - 196rwhp, 19mpg fuel to noise converter 2000 Jeep Cherokee Sport - Wifey mobile - Now with 2.5" OME lift and 30" BFG AT KO's! So it begins 1998 Jeep Cherokee - 5 spd, 4" lift, 33" BFG's - Rotary Tow Vehicle 1988 'Vert - In progress 1988 FC Coupe - Gretchen -The attention whore BEAST! I'm a sick individual, what's wrong with you? I'm pure Evil I'm still insane, in the best possible way. I think Brian's idea of romance is using lube. Your rage caused the meteor strike in Russia. The Antichrist would be proud of his minion. You win with your thread. Most everything It's a truck with a steel gate on the back. Just a statement of fact Motec M820, AIM dash, ported 13B-RE Cosmo, 6-spd trans, 4.3 Torsen, custom twin wg fully divided mani, Custom 4" split into 2x 3" exhaust, Custom HMIC, Custom custom custom custom I like to welder stuff.... No Bolt-ons allowed. Dyno'ed @ Speed1 Tuned by me - 405rwhp on WG.... WM50 cuming soon. -Angry Motherf*cker Mode ENGAGED- |
02-18-2010, 12:43 PM | #29 |
Rotary Fanatic
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In my experience the tune doesn't change or need any changes when adding water (mine is preturbo). My AFR's didn't change at all when adding the water, my air temps didn't really change much either. They did seem to stay more constant on long pulls, and even when I increased the boost an extra 8 psi the air temps stayed the same. I never dynoed before and after the water or anything, but to me it felt a little stronger. I don't think it's a large increase in power if you keep the same boost levels, but when you safely add another 8-10 or more psi you definitely feel the power increase.
If IAT's were to drop then the ecu will compensate for the extra air by using the air corrections table. Another thing to consider is the knock killing effects of water would allow you to run the car leaner and still be safe. So even if the tune changed by adding water the water would protect it. (although.. again, in my experience the tune doesn't change) Peter (rice) how much boost are you running on the 50/50 mix with what turbo?
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500+ HP thanks to: Fast reacting IAT sensor thread! Mechanical Pre-turbo Water Injection Thread Dual Stock fuel pumps Thread T2 differential swap! |
02-18-2010, 04:59 PM | #30 |
Don Mega
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I have run up to 21psi, all tested with the best performance analysis gear on earth (Race Logic VBOX3i) and (no retune), but hey I am "sketchy"
I have customer in NZ with 8 sec drag car who runs 36psi same system set up and water meth (no retune) Numerous cars in Australia, running straight methanol with water/meth in front of the turbo (no retune) all make more power, run faster, and last much much longer When I get a chance I will try to scan this article that ran this exact same system (following all parameters I stated) that showed "massive gains" in on road performance V's no performance gain for post turbo. This has not changed since the last 100 years, everyone who has tried it who is qualified in mechanical engineering all agree and come to the same conclusions all others (not so smart or dare I say qualified to comment) call it a band aid
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www.riceracing.com.au Worlds best Apex Seals Coil on Plug Water Injection ECU Calibration Last edited by RICE RACING; 02-18-2010 at 05:36 PM.. |