Hulk

Yes because they increased boost and or timing, read the whole thread carefully and you will see that, Julio actually says they increased boost and or timing.

ajm55

I'm running the Weistec blower and have the nozzle installed in the elbow (pre-supercharger). I previously had a bigger nozzle installed and although I saw small (relatively insignificant) improvements in IAT readings, my AFR would drop from mid to low 11s without meth to high 9s/low 10s with meth. I did back to back runs on the dyno for comparative purposes - the first was a meth run and the second was a run sans meth. The no-meth run yielded about 7whp more than the meth run. I've since reduced the nozzle size and retarded the meth settings. This translates to a drop in AFRs from mid to low 11s without meth to high 10s with meth. My IATs are unaffected by the meth. I use the meth to improve octane (marginal as it may be) to compensate for our crappy fuel

Denroll

How do you have your meth pump activated? I noticed my engine would start chugging around if it sprayed at lower RPM. I have it activated via my Zeitronix ZT-2 and the alarm panel which triggers a relay. It's a really nice setup because you can program complex alarm parameters. For example, mine will trigger when [TPS >= 70% & Boost >= 11 PSI & RPM >= 3000] (the ">=" is equal to or greater than). I had the RPM threshold set lower, but I was going through my mixture much faster that way as it was triggering a lot more.

I've dreamed about installing an 8-port manifold block and putting a nozzle in the intake of each cylinder, but that would be:

a. Way too difficult
b. Expensive
c. Not really necessary
d. All of the above

jmb614

I was wondering if you were going to chime in here I have the aquamist HFS-3, it injects based on IDC, by default it is set to inject at 42% IDC and ramps up flow thereafter based on IDC %; I've noticed I really have to be heavy into boost before it starts injecting. This parameter is adjustable from 12-72% IDC, there is also a gain setting that can be adjusted for larger than factory injectors. Mine is set to the defaults 42% IDC with no gain. I could probably stand to lower the injection point a bit, but it is very conservative on fluid consumption. I checked the tank Saturday and I can't tell if it's really consumed any or not, of course it has but I can't tell.

ajm55

My set up is rather primitive. The pump is activated on boost via a Devils Own controller. The controller has only 2 variables. One dictates the boost at which meth injection will initiate. The other dictates the boost at which maximum injection will be realized. I assume that the rate of injection between the start point and the high point is progressive. I've set the controller to initiate injection at 8psi and to max out at 22psi. As I'll never see more than 17.5 psi, the rate of injection never reaches maximum. I've done it this way because any more aggressive a set up simply causes AFRs to plummet.

The end result is that meth offers me some octane and a little extra boost without rendering AFRs unpalatably rich. There is, however, no IAT benefit at all on my set up. If I could control the injection via the DashDAQ in a way which would help with IATs without killing AFR, I'd do it. I suspect, though, that this may not be possible on my set up - perhaps because I'm using only 1 nozzle pre-blower

uraberg

What sort of mixture are you using? It sounds like you could stand to increase the water fraction, so you can inject more without your afr going too rich

ajm55

I'm using a 50/50 mix. I did at one stage try a 70/30 water dominant mix but the car didn't like it. Seemed to retard performance and occasionally cause the motor to bog down

jmb614

Perhaps because the percentage of water to base fuel was too high, i.e., too big of a nozzle?

BC928

Technically, it seems (not you) people sometimes confuse what the Meth/water is there for, or what it can do from different input positions.

If you inject it at the back of the valve, you are staving off detonation - which is a great thing. Lowering EGTs, piston crown tempts, and cleaning the ports. All good.

But you are not specifically affecting IAT numbers that the computer can see. If you want to do that, you need to to change the air tempature before the sensor sees it (but also make sure this detonation reducing process actually helps in the chamber too!)

I don't see specific reason to shot the water meth at the supercharger screws. I have seen data that is inconclusive in that actually helping.

The best of both worlds would be e85 in the port, and meth/water in the intake stream so the computer sees it. Thereby increasing timing (not retarding really) and also reducing knock to near zero.

jmb614

Looks like the meth is doing its job here. I'm seeing nearly the same results every pass with the meth, at the top of third its holding IAT's about 10-15F over ambient.

Also attached is a log on the same day, about an hour before the meth pass, this with just ice in the tank, no meth.

It will be nice to see what the real results end up being when I go to the track again soon.

So far so good, I'm happy with it thus far.

GM_Lover

Hey jmb614,

How is this holding up? In particular, what kind of gains did you see at the strip with the meth?

Also, how's your MAP sensor holding up? In this thread from June 2011 (https://mbworld.org/forums/w211-amg/...locations.html), sneakyneon said he moved his post-IC nozzle because he'd "gone through 2 map sensors in a years time frame".

Thanks.