Gabbiani

iTrader: (20)

I've tuned plenty on pure meth. It acts like a fuel and you see the changes as you add it in.

My vette is the first car I've tried to run 50/50 in. I know the arguments for/against, I'm just doing some experimenting.

So far I have seen very little change. I had two 8 gallon nozzles on the car. With gas air/fuel around 11.3 I could turn my controller up until the car lost serious power on the dyno but never really see more than a few tenths change on the wideband. But throw in pure meth and it will peg the wideband rich.

Kind of curious how all that water affects O2 sensors. Thoughts?

For now I've just settled for two 5 gallon nozzles, a couple extra degrees timing, and final a/f around 10.9-11.0. (MAF calibrated without meth)

stevieturbo

Water will have no real impact on AFR readings.

Once you start injecting water, you need proper control over flow. Simply dumping loads in as you do with methanol can easily cost you power.

But the fact you have 50% methanol in there, you should still be seeing a noticeable richening of AFR's on a wideband the more you inject.

turbotbirds

On my race car last year (Gen 1 SBC, blowthru), 100% methanol would drop my a/f a little over a point and a 50/50 mix would drop it about 1/2 a point. Water doesn't burn, so my car would slow down on the 50/50 but I was nervous about trying to lean it out or get real aggressive with the timing!

stevieturbo

No water doesn't burn. So don't try and inject as much of it is you did methanol. And once past peak torque, start reducing the volume of water injected too

35thsscamaro02

I always ran 75/25 meth/water. That was with stock bottom end. Thinking with my built motor I may just run pure meth.

turbotbirds

I think people get hung up on IAT's and that is what gets us in trouble with water injection.

stevieturbo

very much so.

But the common use of methanol, and the fact it is almost idiot proof, means when they try water without understanding how to make it work...they come off with it hurting power when they added water etc etc

It's largely because they just inject far too much. With methanol you can dump as much as you want in and it will pretty much always work.

With water you need to have better control over flow, and only use as much as is needed. It will get the job done, it will be far more efficient in terms of fluid use, but yes there may be a small trade off in overall power compared to loads of methanol.

But for some dumping loads of meth...almost seems like they run a methanol fueled engine with some pump fuel on top lol

Heavy H.P.

Are there any negatives in running pure meth?

stevieturbo

Other than high usage, it being very flammable, poisonous, hard on some components within the system like pump and lines, and it costs more than water etc..

Not really

Plus if you're only injecting via one or two nozzles into an intake that was never designed for wet flow, you could easily run into fuel distribution problems with different cylinders getting unequal amounts. The more "fuel" you add in this way, the more potential for issues depending on intake used.

Gabbiani

iTrader: (20)

Thanks guys. Pretty much spot on what I've been reading from the Buick guys too.

Of course water doesn't burn - but it does displace air and fuel so I expected a more dramatic effect. For the same volume 100% vs 50% I see right around half the a/f change with 50%. Makes sense.

Since I went with the windshield washer tank the only thing with 100% that hangs me up is the flammability. For daily driven entirely street car I got hung up on something that was safe and cheap.

I will probably keep this setup for now. (Only 600hp) But try to find a way to reduce flow up top. My controller is progressive and has a low/high boost setting. Guess I could set the high side to peak tq and step the nozzles down more. You can see my curve fall off up top a little vs just gas but if it is safer I don't mind a little power.

Really just need to cough up for a good kit with a dedicated tank I suppose.

Gabbiani

iTrader: (20)

Exactly what my experience has been, but at least with my setup you reach the limit very quickly. Much over the equivalent of 10gph and it falls on its face.

Heavy H.P.

So I take that going 50/50 or so, reduces some of the risk with all the things you named?

stevieturbo

yes Henry.

The problem with these "progressive" controllers, is that almost none are actually progressive in terms of injecting liquid based on need.

using boost....well there isnt really much progressive about it. Initial hit of boost you may have too much water, mid range a decent amount and top end far too much..

Boost doesnt actually equal demand, because on most turbocharged cars boost pressure will remain static once full boost is achieved.

Water flow often needs to almost mirror fuel demand.

Aquamists is about the only standalone kit that reflects this, where you can use injector duty cycle to control flow of the water injected.

Even using MAF is better than MAP...if of course you still retain the MAF.

So on that basis, I'd stick somewhere between 50/50 to 100% methanol unless you can control and map flow properly

Gabbiani

iTrader: (20)

For a centrifugal kit boost is a bit more predictable. The progressive controllers based on boost still don't really give control tied directly to fuel demand. Up to peak torque it does but then you have too much past that. Or you run to little down low.

stevieturbo

Yea, for a centri they are more effective, but for anything that runs a fairly level boost pressure, boost is not a good reference to use for injecting water or methanol

But from a controller point of view it is one of the easiest.