Meth Kills...

[gmtech16450yz]

...people mostly, but sometimes it kills motors.

I've seen some stuff lately about adding a meth setup to the LNF's, and figured I'd throw my 2 cents worth in. I don't like it. I put up with it on my car for quite awhile, mostly because I was using a very small nozzle and it wasn't working that bad. But once anyone starts trying to use meth for added fuel, I'm gonna say don't do it. It just doesn't work. Meth is ok for slight charge cooling, a smidge of added fuel and it does also help with keeping the valves clean. But it can be really bad if you go too far. I just saw another example of this, here are a couple screenshots of the logs...







The first log is from an LNF running a big meth nozzle. The second is from the same LNF with the meth completely shut off. Look at the desired vs. actual lambda, the first log looks scary! What you're seeing there is the meth taking way too long to come in, sometimes half way through the gear or not at all. The worst part is after the throttle is shut off, look at how rich it goes! The second part of the primitive delivery systems meth uses is that it doesn't shut off quick enough. What that log is showing is the HUGE amount of meth and water that's flooding the intake after the throttle is closed. That's how you blow a motor. You get enough raw liquid flooding the engine after chopping the throttle and you're gonna have a see-through block real quick. The other bad part is, even with that much meth, it still doesn't help the fuel starvation, as you can clearly see by the pressures and injector numbers. Perfect example of more boost without enough fuel = less power.

My advice... Be VERY careful with the big meth nozzles, and don't try to use meth as a fuel source. BTW, I've logged plenty with and without meth, it really doesn't do much for charge cooling on the LNF's. The other thing you have to remember, it's also water you're injecting. Start injecting a bunch of meth, and you're also filling the cylinders with water. Water doesn't burn. It just takes up space that could be used for fuel or air. It also doesn't compress very well, which is why that log looks so scary. If the meth is doing that to the wideband readings, how much water do you think is also going into the manifold when the throttle is shut off? Yikes!

[cobaltssoverbooster]

meth needs to be modified into a single injector kit. like litteraly a fuel injector so it can be suddenly turned on and suddenly turned off

[gmtech16450yz]

meth needs to be modified into a single injector kit. like litteraly a fuel injector so it can be suddenly turned on and suddenly turned off

Exactly. Kind of like this...





That's a 3.44 second 60-100, running E47 with no meth and stock cams. It put down 460/460 on a somewhat conservative street tune.

[stromboli86]

i always wondered about meth on the LNF, one thing that always concerned me was that the injectors are spraying over 2000psi and then you spray meth at a much lower pressure! Dont know if that would actually affect much but it catches my attention.

Guess its a good thing my buick is primitive tho. With meth injection went from 16psi and 15 degrees timing in third gear to 23psi and 19 degrees timing And the pump is designed to run 100% meth/denatured alky, no water in my bottle!

[cobaltssoverbooster]

the high pressure is to compensate for cylinder pressure since the injectors are directly in the cylinders. the pressure in the intake is much lower so to get the same flow the pressure can be lower.

[roadconetuning]

i've been considering running a meth kit with a small nozzle just for intake valve cleaning and some added knock resistance... i think its insane to use your avg cheap meth kit as an added fuel source on any motor... but thats just me...

[5_Liter_Eater]

What meth kit is this? I don't have an LNF but my Alky Control kit is progressive and works on MAP. I can't say I've seen a problem with it not coming in fast enough or continuing to dump meth when I've gotten out of it. I will say I get a neat fireball if I smack the rev limiter though.



I run it as "fuel" since I lean the tune out to ~11.5:1 on the meth. I take tons of timing out if the IAT's indicate a meth problem.

[cobaltssoverbooster]

ahh i remember my 94 2jz 8''( i miss her

[5_Liter_Eater]

ahh i remember my 94 2jz 8''( i miss her

[gmtech16450yz]

What meth kit is this? I don't have an LNF but my Alky Control kit is progressive and works on MAP. I can't say I've seen a problem with it not coming in fast enough or continuing to dump meth when I've gotten out of it. I will say I get a neat fireball if I smack the rev limiter though.



I run it as "fuel" since I lean the tune out to ~11.5:1 on the meth. I take tons of timing out if the IAT's indicate a meth problem.

Hi Bill, I remember you from the LS side. Did anyone ever figure out how to get the A/C clutch control settings to work properly in the E38's?

So every meth system I've seen is pretty much the same, except for the controllers. It really doesn't matter what the controller is or how it works, you're still basically controlling the meth by turning on and off a pump that's pretty much designed to pump water to the sink and toilets in a motor home. Some meth kits have a solenoid that opens and closes when the controller turns on the pump, but it still doesn't work that good. No matter how you turn on the meth, there's still gonna be a delay before it actually starts spraying in the manifold, or where ever you have it mounted. And no matter how you shut it (the pump) off, you're still gonna have an amount of liquid that's going to keep injecting until the pressure drops enough. Worst is the trunk mount systems without a solenoid.

So like I said, unless you just need a little extra fuel or you want the cooling effect or valve cleaning (LNF's have DI), I would stay away from using a meth setup for additional fuel.

And btw stromboli86, there is NO WAY I would have pure meth in a tank anywhere in my car. I was on pit row close to Rick Mears when he was burned badly at Indy, you could NOT see the flames but he was freaking out so you knew something was really wrong. Scary.

[stromboli86]

And btw stromboli86, there is NO WAY I would have pure meth in a tank anywhere in my car. I was on pit row close to Rick Mears when he was burned badly at Indy, you could NOT see the flames but he was freaking out so you knew something was really wrong. Scary.

Everyone takes risks, haha... i personally use denatured alky but it doesnt make much of a difference in that respect. But i usually only have just over half a gallon in the tank and dont plan on being covered in any type of fuel my car has in it.

[Iam Broke]

All it takes is a backfire and your intake is on fire dude. 49% meth/water is the non flammable limit. The water aids in cooling & cleaning anyway.

[stromboli86]

On a buick gn spraying 50/50 does not make/can not make as much power as 100 meth... it has been tested and debated to death. There seem to be a lot of factors affecting it but one of the biggest ones is where the meth nozzle gets placed. Water needs a smaller nozzle and higher air temps to work its magic... i.e pre-turbo injection. On most buicks the nozzle gets placed within a foot of the throttle blade, after the intercooler.

If a backfire manages to make its way all the way back through my t. body, intercooler, turbo, intake and filter, then igniting my engine bay then so be it... im not worried about that at my age

The facts are that guys running 50/50 in buicks see low 12's, high 11's at best. Guys running 100% have cracked the 9's... all on 93 octane!

Hopefully i dont seem standoffish, im just using what works... heck, it might only be a Buick thing!

[silverbullet08]

My findings with my AEM kit on my LNF are that meth should be used as a saftey device only. 98% of the time it works perfect and comes in at the predicted delayed time a lot like GMtech stated. The only issue I had with tuning it was say you made a third gear pull starting at 3000rpms. You will see meth come in about 500rpms later "some times longer" if you use the wide band or stfts to refrence. Then you make another pull in third from a higher speed at say 4000 rpms. When you initially floor it you have that 500rpms that your motor is revving and not seeing any meth. Occasionally I would catch a few degrees of Kr in those areas. I too would see fat rich spikes in my afr during a quick 3-4 gear shift. My end result was adding about a degree or two at 4500rpms then progressing up the rpm range keeping in mind the meth delay when out romping on the car. After a while I moved my regular gas tune back to 93octane limits and tuned the maf for the meth. If I am going to run the car hard I just fill up with a 50/50E mix and switch to my e47 tune to run the higher timing. I like the idea of having the meth and e85 in there when its run hard. Think about all the cooling and cleaning going on while im abusing the car lol.

[stromboli86]

Yea, im thinking its a vehicle by vehicle basis. The LNF is a completely different animal than a LC2 buick grand national! as much as id love to say it was advaced for its time, after getting hp tuners and playing with my cobalt everything buick looks like it belongs in the stone age lol

Buicks love meth and lots of it, LNF guys would cringe at the AFR numbers we get the most power/performance at!

[cobaltssoverbooster]

[QUOTE=5_Liter_Eater;287025]

hahah omg i cried from laughing......

[oldskool]

GMtech, can you quantify what you mean by "big" meth nozzle? I find this very interesting since I was planning on upping the water/meth flow when I go EFR turbo. Right now, I'm on 3 gallons per hour of 75/25 water meth, and made 307whp on that at 20-21 psi. It's a blast to drive and tuning wise, it seems as though it's very conservative. It's nice to get out of the car after a pull, pop the hood and feel an ice cold IC pipe

Maybe it's because it's such a small nozzle, but I barely had to adjust the LTFT, all but 3% in high load (meth turns on at ~13psi). Do you think you may have the meth turning on too early? That disparity in actual vs commanded lambda is scary! I haven't seen that yet and I don't want to.

I was hoping to double the nozzle size (or go with a second 3 gph nozzle) with the EFR install, but this has me thinking twice...


EDIT:: Looking more closely at the screenshot - it looks like a mad rich spike after shifting. Definitely too big of a nozzle, and also, where is it located? Correct me if i'm wrong, but i think the nozzle needs to be located as close to the intake ports as possible to avoid this phenomenon.

[Iam Broke]

Rat - I ran 5 gpm nozzle 50/50 meth injected in the elbow below the TB in the IC pipe. (stock turbo, metal CP) I never logged a rich spike that I recall. I had a simple pressure sw set at 10 psi. Didn't change the trims much at all when on E60.

[gmtech16450yz]

GMtech, can you quantify what you mean by "big" meth nozzle? I find this very interesting since I was planning on upping the water/meth flow when I go EFR turbo. Right now, I'm on 3 gallons per hour of 75/25 water meth, and made 307whp on that at 20-21 psi. It's a blast to drive and tuning wise, it seems as though it's very conservative. It's nice to get out of the car after a pull, pop the hood and feel an ice cold IC pipe

Maybe it's because it's such a small nozzle, but I barely had to adjust the LTFT, all but 3% in high load (meth turns on at ~13psi). Do you think you may have the meth turning on too early? That disparity in actual vs commanded lambda is scary! I haven't seen that yet and I don't want to.

I was hoping to double the nozzle size (or go with a second 3 gph nozzle) with the EFR install, but this has me thinking twice...


EDIT:: Looking more closely at the screenshot - it looks like a mad rich spike after shifting. Definitely too big of a nozzle, and also, where is it located? Correct me if i'm wrong, but i think the nozzle needs to be located as close to the intake ports as possible to avoid this phenomenon.

Hey Oldskool, nice to hear from you!

Those logs aren't from my car, so I don't know the exact size of the nozzles. It's an AEM kit, that log was with the "large" nozzle, whatever size that is? When that car had the "medium" nozzle it still screwed up the mixtures, but not as bad.

On my car I was using a Devils Own kit with one 3gph nozzle for quite awhile. Once I got the EFR and started going up in power, I tried a 5gph nozzle. Still not enough. I then tried almost 100% meth ONCE, since there was no way I was going to run it that way, I just wanted to see how it effected fueling. It helped but didn't fix the problem. I then plumbed a second nozzle, first with two 3gph nozzles, then with a 3 and a 5. During a long pull the fueling was somewhat ok, but before and after that pull fueling was a mess.

When I was hooking up the two nozzle setup, I had the intake tube off the car and I energized the meth pump to make sure the nozzles were both spraying. Holy cr#p! I could have emptied my entire washer bottle in a minute or so! That amount of liquid scared the cr#p out of me. I ran the two nozzles for a week before pulling the whole meth setup out of the car. Never again am I going to dump water and meth into my motor through an RV water pump and an irrigation system nozzle. Not only is it primitive and dangerous, you lose power. Like I've said before, that amount of liquid is taking up space in the cylinders. Water doesn't burn. You don't want or need any extra in the combustion process. While the two meth nozzles made the DI fueling ok, it actually made less power that way. The worst my car has ever run was with enough meth and water going into the motor to try to make the fuel rail pressure hold and the injection times within reason. The best it's ever ran was with NO meth and a 5th injector. With the same engine bolt-on's I've had now for awhile, my 60-100mph times have dropped from 3.45/3.6 seconds to a consistent 3.40 seconds by dumping the meth setup and going to a 5th injector. (At those speeds, a ten of a second is hard to gain. I'm still shooting for a 3.3X though!) I've never had this motor running this good. Make a pull in third gear from 30mph to 109mph @7500rpm and the thing pulls perfectly clean and strong at every spot in the rpm range. No injection window misfires, no ignition misfires, no fueling issues, injector timing perfect and fuel pressure holds perfectly flat at 2600psi.

Meth=

Additional fuel from a 5th injector=

[oldskool]

Ah yes, the AEM "large" nozzle with the newer 200+psi AEM pumps is a stupid high flow rate. It's fully understandable that it would have ill effects on fueling, especially with the airflow out of the stock turbo.

You have way more experience tuning the LNF than I, but I know my 3gph, on at 13 psi with 200 psi pump is fantastic. Like I said I run 75% methanol typically, and the fueling is not really adversely affected. However, I used to think that any previous LNF fueling cap could easily be made up for with large quanitities of methanol with nothing but benefits. Yea..I'm off that kick now We now have 5th injector systems, and HPFP lobe upgrades, along with all the beta goodies that will take care of any level I would ever take mine to.

Any forced induction car I own and tune will have meth injection, but all things in moderation. I'm more about the chemcical intercooling than anything.