(First off, ZOMG, N00B, et cetera...)

Has anyone looked into methanol/water injection for the s2 RX8? Snow Engineering has a "universal" kit for MAF controlled engines; do we know any reasons this would be necessarily bad for rotary engines? It seems "safer" to me than forced induction, not to mention NOX.

 

search no0b.

What are you trying to accomplish with meth inj, anyways?

 

The existing threads are pretty inconclusive and most applications seem to have been on turboed cars. Seems like a pretty big "meh" on using methanol/water on the Renesis. It'd have been for the purported performance increases rather than some kind of strange engine-cleaning device.

Thanks for the warm welcome, by the way

 

It won't help performance, especially on a NA car.

 

here is an article that might interest you

The Best Water injection system and water methanol injection systems at AlcoholInjectionSystems.com - Alcohol Injection Systems.com

and a thread on LS1/LSXtech forum

Is anybody spraying meth along with their nitrous? - LS1TECH

more info

Can I run 50/50 water/meth injection w NOS - Corvette Forum

Some is good some is bad I would like to know myself sure wish that there was a way to get a solid power increase on the 8 for a $1000.00 or less. -_-

 

I suspect the overwhelming majority of AI systems are on forced induction cars. It's particularly good at contolling knock, which a rotary is particularly sensitive to. Control knock and you can tune for more boost which = more power, which is where the performance gains are made. You won't see increased performance on a NA car JUST by adding AI.
It also can be used to cool the charge air and carries alot of heat away with the exhaust, reducing the load put on the cooling system.
I don't see anything "strange" about the cleaning effects. Rotaries tend to develope carbon build-up in the combustion chamber..both as a result of the OMP/pre-mix and due to the shape and relatively large surface area. AI controls it too.

 

LOL
They didn't make sense to you because you clearly have no idea what meth/alcohol is used for

 

Recovering_LS_addict..... Don't worry about not really knowing what methanol/water injection is for and how it works. I'm sure your not the only one. It's been around for a long time, but not widely used by the DIY'ers. Only relatively recently have 'kits' become available and it's use and knowledge base has become a little broader. I've done alot of study, bought and installed my own system and still far from being an authority.
It holds alot of promise in rotary application for the reasons stated above. I'm running it mostly for safety...to suppress knock (but don't tune with it) and for cooling. It's really reduced/removed the temp spikes after periods of hard boost. IMO anyone that's added FI to a Renesis should consider it....soon.

 

^There has been quite a bit of debate if a FI Renesis 8 should or should not use it. A former vender/tuner here believed it was not necessary and proper tuning was the better approach.

 

^What reason did the "former vendor/tuner" give? Or would you have a link to a thread where he gives his reasoning?

Not intimate with the Renesis. And while not absolutely "necessary" I'm not aware of significant differences between it and the 13bREW that would explain why AI wouldn't be really helpful. Both blocks are dis-similar metals, both have stock OMPs, AFAIK both have seal rise issues at the leading plug, and both have long narrow combustion chambers. In fact IIRC the Renesis is higher compression to begin with, increasing chances of pre-ignition with forced induction.
Tuning is always important but not the only solution for pre-ignition...and it's no solution to carbon, and heat-stressed coolant seals and other components from the FI.

 

Dude how much boost are you running?
Ummmm do you have an EGT? If yes what kind of effect do you see on that?

Ahhhh ummm lemme think,
You say it helps remove/reduce the temp spike after periods of hard boost does this mean you are using it when you are not WOT?
Or you're still under hard boost when you activate it and you can see the temps drop?

How much meth are you running?

Sadly it's illegal to use in Ontario, which is the primary reason why I went from Nitrous to T/C
(I need to find the law online again)
Basically it's illegal to introduce anything in to the air stream other than Gasoline.

 

Yeah me ... +1 post ... multi quote this bitches lol
right right ok I'm hung over and lazy sue me.

Signal, I do believe it was MM that did quite a bit of dyno testing with Meth.
I'm sure there is a thread around here with some info.
I know he spoke about it in his webinars.

Basically he felt: (I'll try and get this right and I can't remember the mixture he was using) ok ...

He felt that by the time you had introduced enough Meth/Water in to the Air/Fuel mixture to control knock you had effectively reduced the horsepower so significantly that running at a low boost level with a good tune served better.

I'm not doing it justice but what most people tend to forget is there is only so much room in the chamber for fuel, Air, and Water/Meth. If you add more on one element there is less room for the others. Case in point with the Water/Meth. You are displacing a significant amount of volume of air that could be used to burn fuel.

edit ---
Oh and you should tune with it, the myth that you shouldn't IMO only arose from those worried that they would be in a super lean condition and **** to knock if the Meth system failed or ran out of fluid.
If this is the case you're better to not use it in the first place.
Using meth with no tune will put you in a rich condition, it has too and the more meth introduced the richer the condition which in turn also has a cooling effect and so on and so on and so
If you're not going in to a rich condition using meth and you've not tuned for meth then you're not using enough meth to prevent knock.

disclosure: I've never used water/meth just pulling all this from my *** or what I think I remembered from Jeff's course.

 

Actually 'Dude' I'm running just a little over stock boost...aboiut 11 psi. Simple boost activated (@ 2 psi) system, post-IC, pre-throttle-body on an M3 nozzle (see below). Stock ignition and stock fuel. Makes about 300 whp. Nothing fancy, but reliable.
And yes, I don't see temps spike after hard WOT periods of boost. I don't see them drop, they just don't go up as they used to on both my PFC commander and analogue gauge.
I don't tune with it because it's for safety. If I tuned with it and the system failed I could toast a engine. My boost levels are still well within range of my fuel and ignition w/o AI.
And I WANT to cool with it. Yes, AI displaces some volumn in the combustion chamber, but what air goes in is much denser due to cooling from AI...especially if your system is pre-turbo and/or pre-IC. But again, mine isn't that sophisticated by choice.



If he's a tuner I won't argue. He has his reasons, I have mine. I was just browsing, spotted the thread and figured I'd chime in. You Renesis folks do what feels right, but these systems are really popular with the FD crowd.

 

Dude (lol)

Nice clean setup, looks good.

I'm running about 11psi on the Renny (haven't been to a dyno yet)

The current belief around the forum right now is the heat generated from boost is killing our corner seals.
As I'm sure you are aware the Renny's exhaust ports are completely different than the ones on your FC.

What I'm curious in trying is strictly using Water/Meth not to control knock but to reduce EGT and hopefully in turn help save our fragile corner seals (it's actually the springs that are failing)

 

Cool, that's what I figured from my own research, that it's pretty much useless on its own, but can be a beneficial adjunct to forced-induction. But since I'm not as familiar with rotaries as I am with reciprocating pistons, I (foolishly) thought I'd ask the forum.

Incidentally, the Corvette forum has some HORRIBLE spelling and grammar...

And hey, just be glad I didn't ask about which CAI is best

 

I'm just a small brain, but understand that methanol, and especially water's phase change from atomized liquid to vapor absorbs much of the heat from the combustion event and carries it out with the exhaust. It also effectively slows the burn rate, effectively raising octane level and thereby reducing knock. Absorbing the heat reduces the conductive heat to the housings and irons...and intuitively, corner seals. Since the heat is going out with the exhaust, it also reduces load on the cooling system but will actually cause EGTs to rise.

 

Must have missed this discussion - can you point me in the right direction ?

 

Did some research over in the 7 forum a while back with injecting water pre turbo then experimented on my own renesis setup .

Came to the conclusion that at lower boost levels (around the 10psi level) WI did nothing to help with power and was more of a nuisance than anything else. As far a knock protection - useful as a safety backup .

 

There is extensive information on RX7Cub, which will indicate that EGT readings decrease rather substantially

 

Well then I stand corrected. But I did qualify it. And if you've ever done water ingestion to decarbon a rotary you'll know the exhaust will glow after a very short while.
And almost 14,000 posts in 7 yrs? For the love of God...are you a mod or just don't have any friends?


Of course WI isn't a power adder. It's not a fuel or oxidizer. It's safety for reduced knock and carbon control. Water's 'specific heat' is really good cooling in the combustion chamber. Methanol is more effective at cooling the charge air (reducing IATs). It is a fuel. I think most street cars, especially those running higher boost run a mix and pre-turbo, pre-IC or both....depending on how sophisticated the system is.

Feel like I'm trying to sell ice cubes to Eskimos....and never really intended to sell anything anyway. Just thought a re-examination of the collective wisdom on things might help you FI Renesis guys.

 

Hey man it's all good, I don't wanna speak for Brettus or Team but its just the way things roll around here.
This is a great conversation.

Team has a large post count because he likes to contribute to the community. We all have our (sometime difficult) ways of posting/communicating you just learn what the poster is trying to convey.

@Brettus, dude yeah that comment might be a bit of fail on my part. However I'm sure that I have seen discussions on it here @ the rx8club but I don't believe they were dedicated Threads ... more like hijacked conversations.

Tell you what, for my own sanity I'll do some digging around and see what I can find and PM you the links or post here.

@Signal, can you run WI pre-IC? Isn't there a chance of the water/meth collecting in the IC?

edit -----
Signal (Deeewwd ) do you own an RX8 as well as a RX7?

 

Actually, there should be a slight power gain from water injection, because water expands a LOT more than air does when it absorbs combustion heat, resulting in higher post-combustion pressure. Also, since water's conversion to steam involves a state-change, it also results in a lower post-combustion temperature. That means more force exerted on the rotor and less energy lost as waste heat.

I don't know what the real-world improvement is, but it should exist nonetheless.

 

Real-world performance/power increase on my car isn't noticible.
What is noticed is lack of temp spiking in the cooling system and intuitively less stress on surrounding components...especially coolant seals. All on the stock ignition system, stock plug heat ranges. AND I now augment the OMP with pre-mix for additional lubrication and (hopefully) less housing and hard-seal wear without worrying about shortened plug life, hard starting and carbon build-up. Cost was < $350

As mentioned previously I'm not familiar with the Renesis, but can't think of any reason it wouldn't work just as well on a forced-inducation version.

 

I used water injection on my impreza when i drag raced it. It helped considerably to control det. It was only preasure controlled and i never got around to trying to use the stand alone controller to map it in with the engine or play with jet sizes. There was a company called aquamist who sold me my kit, but this was over 6 years ago.

I have not seen it used on a N/A car but if you are introducing a deatomised liquid into the intake would this not make the air denser giving a little more power?

 

Do you mean "atomized"? If so, yes...if that liquid has time to absorb the heat and cool that air it will make the charge denser. So it depends somewhat on where you position the nozzle for injection...pre-turbo, pre-IC or pre-throttle-body.
From my small-brain reading it seems like there are benefits and trade-offs for all those choices. It depends on the engine set-up, goals, injectant (water or water-methanol) and how sophisticated the system is.