Meth injection on the 4.6
 

Who here has put Meth injection on their 2005-2010 GT?

And if so, with an appropriate tune to go along with it, what kind of power gains did you get?
50/50 Meth to water mix or 75/25 Meth to water mix?

Thanks

not too popular on this site, but over on AllFordmustangs.com forum, alot of vortech non-intercooled users swear by them. Making a great amount of power as well.

:D

Yeah, I can imagine if you have a non intercooled supercharger on you'd want Meth to keep octane up and temps down and allow more boost which allows more power.

But I'm curious as to what, if any, Meth does for a non FI 4.6 V8 with just a tune for the "higher octane" properties.

Helps keep the engine clean.

Unless you're running an after-market computer setup that can dynamically change the timing/mapping based on when the Meth kicks in or fades out, it isn't going to be of any great benefit.

I think it'll be overkill with anything less than a built motor or FI...

I had it when I didn't have an intercooler. Dyno proven to reduce power output. Adding more timing or boost will bring the power back + some but then you are relying on meth to keep the motor alive.

Just a guess but I'd imagine your gains would be equal to a car tuned for and running e85 (105 octane). There are e85 sections of other forums that detail gains, maybe a google search would help you find the answers you seek.

Used meth on my car. Intake air charge temps were well over 200 degrees, pulling timing. The meth (1 jet pre turbo, 3 jets pre throttle body) greatly reduced temps. Car dropped 1/2 second ET immediately. Were running 100% on last build. Did have some issues with it. May use it again (at least new build includes its use) at much lower concentration, unless IATs behave and don't need it.

I'm going to get a kit and just run water only at first to help with the intake temps under boost. water absorbs heat something like 30 times faster than fuel, that's why it can dramatically drop intake temps where running rich will not drop intake temps. if you're running water with any amount of meth then you can effect the AF ratio. meth is combustible just like gasoline so you're basically adding more fuel that needs to be accounted for. that being said unless you're running a huge amount of meth it would only effect the AF ratio .25-.5 of a point.

on my friend's S2000 he's running a 50/50 mix to lower intake temps and be consistent from run to run more than anything. when he floors it now his temps actually drop in boost, pretty funny. he also has his ECU set up to take out a couple % of fuel (too compensate for the added meth) and add a little timing. he gains 15whp with the extra timing of the meth. meth lowers your tendency for knock, like running race gas, so you can get away with more timing if you want.

basically if all you want to do is lower your intake temps then you don't have to run meth, just run water. then you're not changing anything with the tune, you're just lowering the intake temps.

if you want to run more boost and/or more timing without having to run race gas then start out with 50/50 water/meth and go from there. the meth will act like the race gas and lower your knock threshold. the nice thing is that since it's only on during boost it's cheaper than running straight race gas for a street driven car. a gallon of meth sprayed only in boost will last way longer than a gallon of race gas being consumed the whole time the engine is running.

like I said I'm going to just run water to keep the temps from going up while in boost. down the road I may add 1 or 2 psi of boost and then run 50/50 water meth to help avoid knock. there's another guy on here with my setup running almost 550whp on a stock block with the water/meth injection. he's been running that for around 2 years he said.

Can a meth system running 50/50 mix be used on a non boosted engine with a custom tune to take advantage of the additional octane and the benefits of cooler IAT's?

Can the meth/water injection be set up to be used only at higher rpms, not boost calibrated? This way on a non boosted engine, it will inject when you get say, above 4000 rpms but not be used below that.

Most can be set to start spraying at a specified maf voltage and hit full spray at a higher voltage.