Meth injection after throttle body
Thread Starter
Joined: Jun 2005
Posts: 2,265
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From: Oskaloosa, Iowa
Meth injection after throttle body Recently I broke my ls6 intake and needed to buy a new intake. I decided to go with the old Weiand ls1 intake. It also got me thinking about other things. I've been interested in water/meth injection for a while. I've always had e85 readily available so I just never needed it and kept putting it off. Well now that my car is down waiting for an intake I'm thinking now is the time to experiment with meth a bit. Then I decided why not try using the npt port on the side of the intake where my old ls6 intake had a vacuum port. I can use a small nozzle right there behind the throttle body.
My thoughts are... use small reservoir, pump, relay, pressure switch, back check valve, nozzle, and nozzle holder plus the necessary line. Simple on/off system with a very small nozzle like a 3 gph to start with on at 4 psi. Primary fuel will remain 50% ethanol. This is on a 377 with 10.6 to 1 compression with cathedral port top end and about 20 psi via over spun D1x procharger with large procharger air to air.
Thoughts are start super small and early injection then maybe add another small nozzle pre-iat sensor later. This lets me get some benefit of the water/meth without relying heavily upon it since I'm running 50% ethanol as a primary fuel.
I know there are some serious meth users here that can give me some solid input on this...
My thoughts are... use small reservoir, pump, relay, pressure switch, back check valve, nozzle, and nozzle holder plus the necessary line. Simple on/off system with a very small nozzle like a 3 gph to start with on at 4 psi. Primary fuel will remain 50% ethanol. This is on a 377 with 10.6 to 1 compression with cathedral port top end and about 20 psi via over spun D1x procharger with large procharger air to air.
Thoughts are start super small and early injection then maybe add another small nozzle pre-iat sensor later. This lets me get some benefit of the water/meth without relying heavily upon it since I'm running 50% ethanol as a primary fuel.
I know there are some serious meth users here that can give me some solid input on this...
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It's super simple stuff to mess with, you seem to already have the basics of it down. As for injection location, as long as it's before IAT sensor, anywhere is fine.
I think you'll have to use way more than a 3gph nozzle to start seeing it give you anymore tune to play with though, if that's what you're ultimately going after. I think at 20psi I would just go straight to a duel nozzle setup with at least 15gph of nozzle.
There are a couple calculators you can use and some charts to gauge the nozzle size you need but I made a guess at at 800hp at 20psi for your setup and that would use 15gph worth of nozzle...so two nozzles. I run a 10gph+5gph on a 5.3 with 9.3:1 at 22psi and its not enough, I need to make the 5gph another 10gph because I can't get past 6* of timing. But I'm on pure petroleum 90octane because we grow frost and snow here instead of corn.
Start with more nozzle, a lot more. If you go to the track, the reservoir has to be <1gal, but with that in mind, get the most reservoir you can fit because it sucks it down with high HP spray amounts.
I think you'll have to use way more than a 3gph nozzle to start seeing it give you anymore tune to play with though, if that's what you're ultimately going after. I think at 20psi I would just go straight to a duel nozzle setup with at least 15gph of nozzle.
There are a couple calculators you can use and some charts to gauge the nozzle size you need but I made a guess at at 800hp at 20psi for your setup and that would use 15gph worth of nozzle...so two nozzles. I run a 10gph+5gph on a 5.3 with 9.3:1 at 22psi and its not enough, I need to make the 5gph another 10gph because I can't get past 6* of timing. But I'm on pure petroleum 90octane because we grow frost and snow here instead of corn.
Start with more nozzle, a lot more. If you go to the track, the reservoir has to be <1gal, but with that in mind, get the most reservoir you can fit because it sucks it down with high HP spray amounts.
Thread Starter
Joined: Jun 2005
Posts: 2,265
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From: Oskaloosa, Iowa
What I'm actually considering is a small nozzle with an early start point of 4 psi behind the throttle body at the front of the manifold. So it will be after the IAT sensor. I want to see what this actually does for AFR with 50/50 then go from there. In other words baby steps since the tune is real good now with 50% ethanol. I'm at 17.5 peak timing now so not really needing the meth/water. It's something I want to learn with while not relying upon it and then see how I feel about using it more going forward. I just want to make sure what I'm thinking about starting with and the location of the nozzle I'm considering isn't completely retarded...LOL.
The next step if I like that would be a bigger nozzle, then possibly adding a second nozzle before the IAT as well. Just want to see how it goes first with the single small nozzle.
The next step if I like that would be a bigger nozzle, then possibly adding a second nozzle before the IAT as well. Just want to see how it goes first with the single small nozzle.
I'm thinking no problem at all considering Prometh actually makes a direct-port kit (probably cannot include a link). Not sure an IAT would be involved there and as said monitor AFR when activated.
You could drill and tap that new Weiand intake I bet
You could drill and tap that new Weiand intake I bet
Thread Starter
Joined: Jun 2005
Posts: 2,265
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From: Oskaloosa, Iowa
I wouldn’t be against drilling and tapping the intake down the road. For now I just want a single nozzle. The intake has an npt fitting on each side right behind the throttle body for hose barbs. I was thinking I could use an npt fitting reducing down to a 1/8 npt for a nozzle right there.
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I wouldn’t be against drilling and tapping the intake down the road. For now I just want a single nozzle. The intake has an npt fitting on each side right behind the throttle body for hose barbs. I was thinking I could use an npt fitting reducing down to a 1/8 npt for a nozzle right there.
With a catch can you control vacuum and boost from the intake ports behind the TB with a one way check valve. But those valves control air pressure, not liquid.
Thread Starter
Joined: Jun 2005
Posts: 2,265
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From: Oskaloosa, Iowa
IMO you will need to consider what occurs at the port when under boost or vacuum. The boost pressure (1 to twenty PSI) in the intake will be pushing against the the tip of the nozzle same as how pressure or vacuum reacts against the intake side of the tips of your injectors. The FPR increases fuel pressure and volume to account for the opposing pressure in the intake when in boost and reduces pressure and volume as well as when not in boost and there is vacuum. You will have suction (vacuum) at the methanol port from idle to WOT, but opposite when under boost.
With a catch can you control vacuum and boost from the intake ports behind the TB with a one way check valve. But those valves control air pressure, not liquid.
With a catch can you control vacuum and boost from the intake ports behind the TB with a one way check valve. But those valves control air pressure, not liquid.
How big of a nozzle could someone possibly run with a 4 psi turn on point with a simple off on pressure switch/relay setup without having issues? Also how much needs to be sprayed with a 50/50 mix to even be worth my time? Not so much using it for max effect, but to even be enough to be worth doing?
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I can answer part of that , I'm running the basic snow kit with the largest nozzle - 625ml/min 50/50 WM on at 4-5 lbs no issues at all . Pretty sure it sprays more volume than rated judging roughly by how much dissappears per pass
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Check valve and a solenoid would guarantee no leakage during vacuum with the nozzle post TB. I spray a single M10 post IAT/post MAF/pre TB set on an adjustable boost switch. Works great.
Thread Starter
Joined: Jun 2005
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From: Oskaloosa, Iowa
TECH Fanatic
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I personally wouldn't spray any after the throttle body unless its a direct port kit. You could end up with some strange distribution issues.
Also, why not just run more ethanol as your primary fuel and not worry about the meth at all? I've ran IATs at 300 degrees before on E85 with a fair bit of boost and never experienced any issues with detonation.
Also, why not just run more ethanol as your primary fuel and not worry about the meth at all? I've ran IATs at 300 degrees before on E85 with a fair bit of boost and never experienced any issues with detonation.
Didn't they used to make a nitrous plate that went behind the throttle body? I don't know how that worked out, distribution wise, when I ran a blowthru setup, I had a plate under the carb, used a 50 HP shot for cooling.
Yes, that was a pretty common way to spray a wet kit.
Thread Starter
Joined: Jun 2005
Posts: 2,265
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From: Oskaloosa, Iowa
Good input guys thank you.
Im currently running 1200 cc/min injectors and a 4303 pump with 58 psi base pressure. Hitting 90 percent duty cycle at 7200 rpm at 20 psi with 50 percent ethanol.
My blower is already over spun and no planning to add more power at this time. I have no issues with IAT and have ran as high as 18 degrees peak timing with plugs showing I could probably add another degree safely.
Long term I do want more power. My thoughts are to learn a little about meth injection while I don’t actually need it and see how much I like it. I’d like to be in the 1200 plus club someday still with a Procharger and the fuel delivery gets pretty crazy with ethanol in a street car at those levels. Ive considered a second 4303 or a brushless aeromotive with speed control aa well.
Just trying to learn as I do all my own work and tuning, but this car is making more power than I’ve ever personally owned so 1200 rwhp will definitely be uncharted territory for me.
I did run a nitrous plate spraying 150 shot on a 408 way back in 2006-2008. It worked well and I liked nitrous, but will never go back to it.
Im currently running 1200 cc/min injectors and a 4303 pump with 58 psi base pressure. Hitting 90 percent duty cycle at 7200 rpm at 20 psi with 50 percent ethanol.
My blower is already over spun and no planning to add more power at this time. I have no issues with IAT and have ran as high as 18 degrees peak timing with plugs showing I could probably add another degree safely.
Long term I do want more power. My thoughts are to learn a little about meth injection while I don’t actually need it and see how much I like it. I’d like to be in the 1200 plus club someday still with a Procharger and the fuel delivery gets pretty crazy with ethanol in a street car at those levels. Ive considered a second 4303 or a brushless aeromotive with speed control aa well.
Just trying to learn as I do all my own work and tuning, but this car is making more power than I’ve ever personally owned so 1200 rwhp will definitely be uncharted territory for me.
I did run a nitrous plate spraying 150 shot on a 408 way back in 2006-2008. It worked well and I liked nitrous, but will never go back to it.
WMI is good stuff. It's cheap, lasts a relatively long time, and is very effective at cooling/limiting knock. I couldn't really get above 10 psi before picking up knock at reasonable timing on 93. Added a single M10 nozzle with $3/gal WWF and can hit 15 psi with no hints of knock and planning on turning it up.
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Nitrous gets sprayed in at 900 PSI and turns to gas at -127*F. It evaporates and disperses almost instantly coming out of the nozzle.
Methanol typically gets injected at ~60-100 PSI (Pump ratings do NOT equal nozzle pressure) and turns to gas at 148.5*F, a 275.5*F difference from Nitrous. This is worse when mixed with heavier, harder to boil water.
Atomization and distribution between the two are like comparing apples to tractors.
Spraying meth 12-18" before the throttle body helps make sure that the distribution is roughly the same as the air distribution for each cylinder, so cylinders that get less air also get less meth, and the ones that get more air get more meth, helping with overall uniformity.
Thread Starter
Joined: Jun 2005
Posts: 2,265
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From: Oskaloosa, Iowa
I also found this interesting video about pre mixed water/meth. The -20 windshield fluid with a few bottles of heet is a solid way to make sure you are near 50/50.