meth/water injection

[vmss10]

Does anyone run water or meth injection? If so, what kind of top end ignition timing are you running? I've got ported and polished heads with 2.02/1.60 valve, modified marine intake, 268AHR magnum cam, powerdyne running about 8psi tops. Have a water injection kit. When turned on at about 5 psi with ignition timing set at 19* it seems like the water is putting out the spark. Just wondering how high I should raise the timing. I know of a couple of guys with Grand Nationals that are running like 29* with 20 psi and up.

This Friday going to try some staight meth in it and see what happens.

Any input would be apprecated. Thanks

[rentedmule]

I'm running a progressive snow kit. Are you tuning for A/F? Mine went way rich when I started spraying it (50/50 water/meth) and my tuner had to take out a bunch of fuel. I'm not sure what my timing is at but I know he had to add a bunch back in when I put the meth on. What size nozzle are you running and is it a progressive kit? My guess is that straight meth will be useless at 8 psi.

[vmss10]

There are a couple here who run water/meth systems. Have you tried a 50/50 combination?

Have you done any data logging? Any knock?
I threw an MSD box on mine, but it's overkill. The stock ignition system is usually pretty stout.
Crane has a pretty decent box as well.

What do you tune with?

Yes, I have done data logging with Auto-Tap. And have taken out a lot of timing through out the tune with Jet DST. Have stock ignition other than a MSD blaster coil.
Just trying to get faster, into the 13's. Runs a 14.2- 14.5 right now.

[vmss10]

I'm running a progressive snow kit. Are you tuning for A/F? Mine went way rich when I started spraying it (50/50 water/meth) and my tuner had to take out a bunch of fuel. I'm not sure what my timing is at but I know he had to add a bunch back in when I put the meth on. What size nozzle are you running and is it a progressive kit? My guess is that straight meth will be useless at 8 psi.

No, it's not a progressive kit. Gathered the parts and made my own. Using a small nozzle, 1gph at 100 psi. Have the pressure switch that Snow Performance sells. I was going to try a 50/50 mix to start with. I normally do use a A/F meter, but a friend is using it right now.

[vmss10]

Hows your plugs look? You run coppers right?

I run A/C resister plugs. Think they are R43TS. Just replaced them last night, gapped at .035. Didn't look to bad. Light brown/tan coating on the inner porcalin and electrode. Think that might have been from spraying with staight water a couple of times.

[rentedmule]

I definately wouldn't run straight water - you'd be losing the octane benefit from the meth. You didn't say whether you checked your A/F ratio? If you're injecting 50/50 meth/water your A/F ratio can increase a full point or more and make it run very rich.

I can't remember the exact before/after dyno #'s but I know I gained significant power when we actually increased the timing and leaned it out for the meth vs. just spraying it untuned. I think it was a 15-20 HP difference and the truck felt much more responsive. I drove it for a month with the meth injection before I got it tuned and it was a whole different animal afterwards.

All of the benefits of meth come from the tune - the cooling effect from the water/meth vaporization is almost entirely offset by the reduction in oxygen content associated with replacing some of the intake charge with a fluid. The power comes from the knock suppression and from the increase in octane level in the cylinders.

[vmss10]

Just got home. Wanted to clarify on the plugs. R42LTS gapped at .035.

[vmss10]

Went to the track last night. Unable to get any runs in with the 50/50 in it. Started raining as I was tuning it with more timing. Took it out today. Felt a little better. Really need to get my a/f meter back to do this right. Just impatient. Will be back with more when I get the timing straight. Then I'll work on the fuel.

[Bone Crusher]

Not to kill your thread but did you ever run the truck without the boost and just the head work and cam....I currently have a project going to get my 268 in with P and P work and was wondering what to expect

[vmss10]

Not to kill your thread but did you ever run the truck without the boost and just the head work and cam....I currently have a project going to get my 268 in with P and P work and was wondering what to expect

Not really. I put the P/P heads and the modded marine intake on over the winter. Still working on the tune.

Last year with stock heads, intake, 260AHR magnum cam had 245 hp and 273 torque at the wheels. And it ran a 14.4-14.5 in the quarter. Had the water injection but never really used it.

These heads have the 2.02/1.60 valves and the 26-915 beehive springs. It only made 14.2. But the tune isn't right. Figured I would try to tune it for the 50/59 water/methynol injection at the same time rather than doing it twice.

[94s10]

i wouldnt run a 50/50 mix. you want as much meth in there as possible. water only cools, meth cools and adds octane. both decrease the likely hood of knock, allowing you to run more timing and leaner fuel mixtures, witch is where the true power comes from

i ran 25 psi through a turbo with 20+ degrees of timing on a bone stock 4.3 short block for a long time with a meth kit running nearly straight meth with a very small jet. needless to say i'm a believer in meth lol

now if only e85 where available in my area i would ditch the meth setup all together

[vmss10]

i wouldnt run a 50/50 mix. you want as much meth in there as possible. water only cools, meth cools and adds octane. both decrease the likely hood of knock, allowing you to run more timing and leaner fuel mixtures, witch is where the true power comes from

i ran 25 psi through a turbo with 20+ degrees of timing on a bone stock 4.3 short block for a long time with a meth kit running nearly straight meth with a very small jet. needless to say i'm a believer in meth lol

now if only e85 where available in my area i would ditch the meth setup all together


I was able to get it out with an old snap on scanner. Detination at about 4800 with about 18* and about 7psi boost. Scanner shows it was pulling anywhere from 2-6 degrees out. Wish iIhad my lap top back. Wouldn't have to try to look at so many things while driving. Pulled out 2+ degrees progressivelly from 4800 up.