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Meth / water injection - revisited
Quoting MM from another thread . This is worthy of more discussion as many people here are taking it for granted that it is 'the answer' to our FI engine blowing blues .
Originally Posted by MazdaManiac
(Post 3764030)
Not really a bombshell. At least not from this perspective.
Having tuned/accessed/dynoed/datalogged/etc close to two dozen FI Renesis applications with W/M, I have found that in every single case, the power loss that comes as the price tag for the "insurance" that W/M allegedly provides is greater than just tuning the motor to a margin that would preclude its necessity. W/M in concentrations where it does not cause excessive EGT increases (near 50%), adds so much fuel value that it completely negates up to .06 lambda in the fueling calculations. This is not acceptable to me. If you adjust the tune (timing and fuel) to accommodate the W/M, you completely negate its value as "insurance".
Originally Posted by MazdaManiac
(Post 3764055)
With the Snow, AEM, CoolingMist and Devil's Own kits, I could never get the doses small enough.
Even with the finest jets and latest turn-on times, power always dropped and EGT climbed. Because of the way air moves through the Renesis, even the smallest amounts of water quench combustion almost completely. Once I got concentrations up to the point that combustion would continue, the fueling values would shift. At those concentration, the damage to the metal bits becomes a serious concern as methanol dissolves aluminum. |
I'll go ahead and quote RP here for posterity:
Originally Posted by Richard Paul
(Post 877493)
[Dave] Zeuschel used water/meth on the Merlin race engines at Reno. This was 50/50 mix. BUT these were very highly supercharged race engines and also had 120+ fuel. I can't recall exactly how much boost they ran and if I did I'd have to kill you if I told. 40-50 psi might be in the ballpark.
The tune on these engines was so far beyond what Rolls Royce designed that they sent a telex saying GOOD LUCK. According to Rolls calculations Dave was running 3500 + HP. The H2O/Meth injection was used to control detonation and a complex anolog system of metering it was built custom. Realize that we are talking a lot of liquid to carry around on a plane for the entire race. Therefore it was regulated to use during critical times. as pointed out by the turbo user above it was only effective when used in a system that would otherwise not be viable. Ricardo has a section on water injection and I havn't read it in 20 years I think he basicly calls out that it makes more power then if it were detonating but iif you could not detonate you'd make more power without it. Don't forget while methonol has a much higher resistance to detonation it has half the BTU's. When in the presence of water it will obsorb same and really being used as a coolant. Put the fire out and it is cooler. But why did you start the fire in the first place? To get the heat and thus expansion to move the rotor. Ha, you thought I was about to say piston. It is not an explosion it is a controlled burn you want. So not to ramble on here the answer to your question is no it is not going to help the NA engine except in some odd cases. I don't see those cases being with the rotary. Don't put out the fire, use it. |
Here is the rest of the qoute from MM:
Originally Posted by MazdaManiac
At this point, I am recommending that people NOT use water/meth on the Renesis.
You gain far more power/reliability/safety from just getting the tune right. W/M generally causes an FI Renesis to lose power and increase EGT. With the Snow, AEM, CoolingMist and Devil's Own kits, I could never get the doses small enough. Even with the finest jets and latest turn-on times, power always dropped and EGT climbed. Because of the way air moves through the Renesis, even the smallest amounts of water quench combustion almost completely. Once I got concentrations up to the point that combustion would continue, the fueling values would shift. At those concentration, the damage to the metal bits becomes a serious concern as methanol dissolves aluminum. Very interesting stuff. So how much power loss on average do you see with using a 50/50 mix (on the same tune as running without)? In your opinion are there any situations where the charge cooling and octane boost would outweigh the potential damage to the engine from high EGTs and power loss like tracking or sustained high load driving in high temperatures? |
Originally Posted by IronTanuki
(Post 3764164)
So how much power loss on average do you see with using a 50/50 mix (on the same tune as running without)?
IIRC, on one of the ~280 HP cali cars, the power only dropped about 7 to 10 with a 7 PSI turn-on and small jet. My own car wont stop misfiring until the meth is essentially turned off. I removed it from the car today.
Originally Posted by IronTanuki
(Post 3764164)
In your opinion are there any situations where the charge cooling and octane boost would outweigh the potential damage to the engine from high EGTs and power loss like tracking or sustained high load driving in high temperatures?
BTW - meth is NOT an "octane boost" in the strictest sense. Though it has a higher octane, it has a significantly lower fuel value and higher mix ratio. |
Very interesting.....
Good information, thanks everyone |
This kinda leads on to another debate ...
MM - I have noticed your recent remarks about what AFRs you are running and tuning for . These targets seem to have gotten lower than what we used to regard as "safe" . If one were to streach the envelope with a small turbo (cough) producing very hot air - would going to say 11.0 AFRs be a better bet than using water meth ? |
Originally Posted by Brettus
(Post 3764199)
This kinda leads on to another debate ...
MM - I have noticed your recent remarks about what AFRs you are running and tuning for . These targets seem to have gotten lower than what we used to regard as "safe" . If one were to streach the envelope with a small turbo (cough) producing very hot air - would going to say 11.0 AFRs be a better bet than using water meth ? |
Originally Posted by MazdaManiac
(Post 3764177)
meth is NOT an "octane boost" in the strictest sense. Though it has a higher octane, it has a significantly lower fuel value and higher mix ratio.
Have you tried straight water? Or higher ratios of water vs. methanol? |
I believe Juan did some dyno runs with a variaty of jet sizes?
If I remember correctly he did have some demonstated power loss with the bigger sized jets. But with a total of 150cc ( 2 jets, one pre blower and one post) he did not? I do know if you spray during closed loop (boost or not) it mess's with your ltft's! I am curious as to to why some are seeing increased egt's with w/m use? I have not used an egt sensor, but when I track I do notice that the exhaust system seems to be not as hot. I relaize that is subjective only. People will try to selectively edit their way to get you to use water injection by stating "One can basically double the power output of an engine using water/methanol" and "It was used effectively in Formula 1 before being banned for adding too much power". This is pure bunk. Water or water/alcohol/methanol does not make power...superchargers and turbochargers make power. The cooling effect of the water injection only allows you to run higher boost pressures and leaner mixtures without engine damage. The increased density or higher pressure ratio is what makes the power, not the water. The last time we checked water wasn't a very good fuel. Aren't EGT's supposed to peak at around 13.2 afr? Besides to the best of my knowledge water injection is not for reducing EGT's, it is not about increasing octane, it is primarily used for reducing the chances of detonation from engine hot spots. All the other "side affects" are just observations used for marketing? Following with interest. OD |
Originally Posted by 999miki
(Post 3764388)
Have you tried straight water? Or higher ratios of water vs. methanol?
Originally Posted by olddragger
(Post 3764430)
I am curious as to to why some are seeing increased egt's with w/m use?
I have not used an egt sensor, but when I track I do notice that the exhaust system seems to be not as hot. I relaize that is subjective only.
Originally Posted by olddragger
(Post 3764430)
Aren't EGT's supposed to peak at around 13.2 afr?
However, they will go up and down depending on ignition timing and can spike significantly if the AFR is very rich. |
What i am getting from this is that on the same car at the same PSI more power can be had by tuning to a safer AFR rather then by running a leaner AFR with meth.
However turning up the boost on the same car and running more boost with the meth injection will produce more power. (Untill the meth injection fails and the motor detonates and destructs itself.) So using meth ONLY as a security measure, is not worth it. You would get more power and have a "safer" tune by jsut lowering the AFR's. Using meth as a tool to run more boost is effective but one still runs the risk of the meth failing and the motor detonating. Am i understanding this correct? |
1 Attachment(s)
Wait wait wait
..so um...what kind of charge cooling did MM use to push his turbo beyond its effeciency range and make uba powa? Attachment 251800 |
Originally Posted by Mawnee
(Post 3764637)
Wait wait wait
..so um...what kind of charge cooling did MM use to push his turbo beyond its effeciency range and make uba powa? |
Big power was through the use of fuel.
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nitrous?
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Originally Posted by Mawnee
(Post 3764677)
nitrous?
116 octane, 12.2:1 AFR, 14° of timing, 17 PSI on the GT3082r. |
Originally Posted by MazdaManiac
(Post 3764753)
No.
116 octane, 12.2:1 AFR, 14° of timing, 17 PSI on the GT3082r. btw..that seemed way too easy. I expected an epic game of mouse and cat. :lol: So was water/meth the only means of charge cooling you've used? I always had this suspicion you used something more exotic. |
Whp = ?
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Originally Posted by Phish806
(Post 3764779)
Whp = ?
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Not at all... Must not have been as big as Mawnee is makin it out to be
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Originally Posted by Phish806
(Post 3764779)
Whp = ?
Originally Posted by Mawnee
(Post 3764778)
So was water/meth the only means of charge cooling you've used? I always had this suspicion you used something more exotic.
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Originally Posted by Phish806
(Post 3764779)
Whp = ?
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Originally Posted by MazdaManiac
(Post 3764829)
For those pulls, it was straight methanol in a very small quantity. Phish its an old subject, but I never really got the answer I was after in 'that' thread. It was semi on topic here so I thought I might have more success :) MM is your assesment of water/meth renesis-centric or do you feel it applies to piston engines as well. What I mean is, is it a result of the renesis spark delivery inadequacies or the rotory compression method? |
Originally Posted by Mawnee
(Post 3764968)
MM is your assesment of water/meth renesis-centric or do you feel it applies to piston engines as well. What I mean is, is it a result of the renesis spark delivery inadequacies or the rotory compression method?
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I will give up my w/m when you pry its button out of my cold dead fingers.
Juan, per dyno did not lose power with the total of 160 cc/hr nozzles? Wouldnt adding more fuel also mean that carbon build up would be more likely? Good discussion--- but i have always thought that w/m was to help insure my octane level was ok? When you are pumping your gas (lol) you really dont know what octane you are getting. Then you add ethenol..... now if you just run straight ethernol:) How do the egt's rise, but the power goes down? That seems contradictory? OD |
More fire, less boom?
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EGT'S rise if the unused fuel is burning in the exhaust manifold......
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Originally Posted by dannobre
(Post 3766445)
EGT'S rise if the unused fuel is burning in the exhaust manifold......
W/M has been used for over 70 yrs to my miniscule knowledge for fuel conservation and a power boost, this all before SUPER boosting, draw your own conclusions. Yes I know MM, be professional and tell me to stfu. Case in point |
Originally Posted by dannobre
(Post 3766445)
EGT'S rise if the unused fuel is burning in the exhaust manifold......
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The exhaust won't last long with huge heat cycles like that...
We had an exhaust fail in an endurance race a few weeks ago on an NA car.....it had shrunk an inch from the heat....it broke at the collector and we had to weld it back together there...and then section the pipe to add back the shrinkage :) SS is a strange metal.......... It was ceramic coated as well...that made the welding a huge PIA.... |
If fuel is still burning out the pipe "piston or rotary" when the next fuel comes in, things start to melt. There is a place between all boost and tune and lo boost and w/m. Unless ye own Mr Fusion and a Flux Capacitor, which I'm sure some here do. loloo
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ahhhhh. Should make for nice track flame pics.
I am having difficulty (nothing new) understanding how this happened when he used the smallest jets (60 ml) and 150psi pressure system? No doubt w/m is not just a bolt it up and go mod. You even have to start thinking of lamba instead of the good ole a/f. For me that is a big deal:) I hit about 78-80 lambda with my set up. My end of the straight speeds are the same with it or without it. ??? OD |
I remember the post on the w/m forum about how the 8 compensates the lamda or was that wrong?
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Two points.
For those who don't realize, MM Posted those stats because hes obviously moved on to something better. What exactly... the world may never know. Secondly, wasn't there some cleansing benefit to W\M Injection? Carbon cleansing. |
Originally Posted by Symbioticgenius
(Post 3766687)
Two points.
For those who don't realize, MM Posted those stats because hes obviously moved on to something better. What exactly... the world may never know. . |
Interesting finds Jeff. I guess we will play around with that 08' we are finishing. If you have the coin no doubt race gas is better. However I have run as high as 29psi on pump with water/alcohol injection. Car lasted for 3 years like that...
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Originally Posted by olddragger
(Post 3766365)
I will give up my w/m when you pry its button out of my cold dead fingers.
Juan, per dyno did not lose power with the total of 160 cc/hr nozzles? Wouldnt adding more fuel also mean that carbon build up would be more likely? Good discussion--- but i have always thought that w/m was to help insure my octane level was ok? When you are pumping your gas (lol) you really dont know what octane you are getting. Then you add ethenol..... now if you just run straight ethernol:) How do the egt's rise, but the power goes down? That seems contradictory? OD Just run 75 methanol / 25 nitromethane in the spray tank :) Keep spare spark plugs.... The more nitro you add to the methanol, the leaner the A/F "acts" due to the Lambda of gas,methanol and CH3NO2 combining. It's also nice to see ice forming on the intake... :ylsuper: |
ha! I am not ready for that:)
116 octane is about $10 a gal? When you can find a fresh supply---or you can keep 50 gallon drums in your garage? No doubt more fuel going boom= more power--ethanol cars can do this. Trick is keeping the explosion/burn in the right place? T ruefully after my last track session in which i used a little over a gallon in a 20 min run--i got to thinking about doing this a different way. That run used about 5 gallons of gas which means my w/m was injecting at at 20% of my total fuel supply by weight? To much? Hmmmmm--more work to do. OD |
LMAO
It's all about where ye going with your car. I will go lo boost and a W/M addition. It will be for me. Ye gonna push the edge? All fuel and tune fer sure, MM is da man in here in this case. But to say I'm removing all W/M from builds is a misnomer. Apologies MM,, be more direct. |
Originally Posted by olddragger
(Post 3767378)
ha! I am not ready for that:)
~ That run used about 5 gallons of gas which means my w/m was injecting at at 20% of my total fuel supply by weight? To much? Hmmmmm--more work to do. OD If you use 50/50 water/methanol than the total added fuel was 10%, any water injected is not fuel, but coolant. |
Great thread, so much to learn....
For all you guys who are pouring out knowledge and experiences with this stuff, realize that for every person who posts in a thread like this, 10 more of us are just reading and learning on the sidelines about tuning and our engines. So thanks.... |
np dude we all started somewhere.
Rote dont you get your percentage by weight? You cannot discount the space that water is taking up---right. I hear you about the amount of fuel I added, but I am thinking about only injecting half as much per weight. As long as my track charge temps stay under control. And that is another question---What range of charge temps are the best? Where does charge temps become too high? I am speaking of the temps after the maf and after boost (for us sc guys). Since my charge temps are post maf and s.c. the iat really is not coming into play. OD |
Originally Posted by MazdaManiac
(Post 3764177)
On the last turbo car that I did a before/after comparison, the car went from 320 HP to 290 or so when the smallest jet was used with a turn-on point of 10 PSI or so.
IIRC, on one of the ~280 HP cali cars, the power only dropped about 7 to 10 with a 7 PSI turn-on and small jet. My own car wont stop misfiring until the meth is essentially turned off. I removed it from the car today. Sustained load is exactly where the meth is at its worst. I think its only useful application would be to have it turn on when you are exceeding your tune in some way. Maybe over-boost or something. BTW - meth is NOT an "octane boost" in the strictest sense. Though it has a higher octane, it has a significantly lower fuel value and higher mix ratio. ok, I think is crystal clear the case of water injection and loss of power. However I have two questions The car is the following Renesis Turbo @ 12 psi making 320bhp (at the crank). The questions are the following: 1- Running Water Injection (no ECU tunning ) on a very high ambient temps. I am talking about 104 F ambient temps on hot countries on summer etc. What do you think? Lose or gain power using water injection on 104 F ambient temp? 2- What about Fuel Consumption? Is there any negative or positive effect on fuel consumption using water injections The questions concern only turbo renesis at 12psi making 320bhp |
Originally Posted by 1Revvin7
(Post 3766837)
Interesting finds Jeff. I guess we will play around with that 08' we are finishing. If you have the coin no doubt race gas is better. However I have run as high as 29psi on pump with water/alcohol injection. Car lasted for 3 years like that...
wait...guys? ....guys? dammit...everybody left already you say...a year late eh?... lol Im def gonna run water meth in the summer for a greater factor ofsafety ...i wonder if my engine would have gone boom if the w/m had been operational at the time... :sad: |
So a few years go by and I start running more and more boost .... up to 17 psi now. After getting a few pings with a slight leanout (mid to high 11s) and chatting with 'the Wird' I decided to hook up my W/M system .
Now running around 270ccs switching on at around 12psi . Have kept AFRs around 11 and noticed no drop in power or increase in EGTs after several months of operation with numerous tests . I'm just now wondering about what efffect W/M might have on the lubrication/cooling of the apex and side seals . Does it wash away the lubricant or does the charge cooling effect have a positive benefit ? Anyone got any thoughts/experience to share on this ? |
I was planning to use W/M for my build regardless of the effects of power loss, coz let's face it, engine alive is way better than go boom. Still I've seen 8s run on W/M without power loss. I just want to know if this is an effect of not using modified uncapped stock injectors.
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Brettus I suggest sending a sample of of oil for testing, see how it is doing.
Posted From RX8Club.com Android App |
I don't see the point of uncapped injectors.
Posted From RX8Club.com Android App |
Originally Posted by Brettus
(Post 4567704)
So a few years go by and I start running more and more boost .... up to 17 psi now. After getting a few pings with a slight leanout (mid to high 11s) and chatting with 'the Wird' I decided to hook up my W/M system .
Now running around 270ccs switching on at around 12psi . Have kept AFRs around 11 and noticed no drop in power or increase in EGTs after several months of operation with numerous tests . I'm just now wondering about what efffect W/M might have on the lubrication/cooling of the apex and side seals . Does it wash away the lubricant or does the charge cooling effect have a positive benefit ? Anyone got any thoughts/experience to share on this ? When you say you didn't notice a difference in power was this the butt dyno? You probably won't be able to notice a difference of 10rwhp. |
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