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Trying to get meth dialed in... Issues
- Thread starter JCam550
- Start date
.AJP turbo said:Targeting .90 may be worse...its already trying to pull as much fuel as the ecu allows..the fuel model is wrong. Trying to make it leaner becuase its too rich is a bad bandaid in tuning
Well, yeah and if you have a meth failure engine is surely doomed.
So how do you adjust for it in the tune then?
Wouldn't smaller nozzles be the first step?
JCam550 said:Is it me or does it seem that each one of these engines seem to react to tuning very differently?
I wouldnt say very....but different yeah
Sinister-CO
New member
Wow, maybe I'm just being too simple about this but it seems to me you guys are just running way too much meth. Meth shouldn't be your primary fuel, it's meant for detonation suppression and a little extra octane. You shouldn't be pulling fuel to compensate for too much meth, that's not how it's supposed to be used.
Put in the smaller nozzles and see where you are at then. If these are snow kits, isn't there a screw on the top of the pump to adjust the pressure down? That's how mine is on my GN. I run the smaller nozzle and I have the pressure turned down. Why?...because it was injecting too much meth, the engine was way rich and I was getting knock. I know that sounds backwards but meth should complement your primary fuel, not replace it.
But then again, what do I know.
Put in the smaller nozzles and see where you are at then. If these are snow kits, isn't there a screw on the top of the pump to adjust the pressure down? That's how mine is on my GN. I run the smaller nozzle and I have the pressure turned down. Why?...because it was injecting too much meth, the engine was way rich and I was getting knock. I know that sounds backwards but meth should complement your primary fuel, not replace it.
But then again, what do I know.
Sounds perfectly reasonable to me.Sinister-CO said:Wow, maybe I'm just being too simple about this but it seems to me you guys are just running way too much meth. Meth shouldn't be your primary fuel, it's meant for detonation suppression and a little extra octane. You shouldn't be pulling fuel to compensate for too much meth, that's not how it's supposed to be used.
Put in the smaller nozzles and see where you are at then. If these are snow kits, isn't there a screw on the top of the pump to adjust the pressure down? That's how mine is on my GN. I run the smaller nozzle and I have the pressure turned down. Why?...because it was injecting too much meth, the engine was way rich and I was getting knock. I know that sounds backwards but meth should complement your primary fuel, not replace it.
But then again, what do I know.
FoMoCoSHO said:.AJP turbo said:Targeting .90 may be worse...its already trying to pull as much fuel as the ecu allows..the fuel model is wrong. Trying to make it leaner becuase its too rich is a bad bandaid in tuning
Well, yeah and if you have a meth failure engine is surely doomed.
So how do you adjust for it in the tune then?
Wouldn't smaller nozzles be the first step?
You basically have to lie to the ecu...change the airflow model...tell the ecu that there is actually less airflow then it will dial back injector pulse width...the airflow model would actually look jacked up..the problem is that there is fuel being introduced from an external source....the ecu is not in the know....kinda like a mass airflow tuned car...when there is unmetered air introduced its creates a problem
I would try a different nozzle to have LESS of the 80 mix or same nozzle but with 50/50.
Just a theory but like fomo also said...too much fuel may be bad as well for knock...just like port injection...you have introduced a fuel mix in the chamber waiting to pre ignite....with normal DI the fuel is sprayed in much later so there is really nothing to self ignite
Sinister-CO
New member
I'm with you AJP, but I think we all agree they're spraying too much meth. They should either try the smaller nozzles, turn down the pressure or a combination of the two.
Just because everyone else is using the bigger nozzle doesn't mean you have to. We've already seen another person that is running rich as well.
Just because everyone else is using the bigger nozzle doesn't mean you have to. We've already seen another person that is running rich as well.
It actually is being used for the extra fuel. Not saying a smaller nozzle is not the answer but Torrie has tuned plenty of these engines on meth, I'm sure he would have already came to the same conclusion. This is the first meth log I have seen with knock so it's not the norm.Sinister-CO said:I'm with you AJP, but I think we all agree they're spraying too much meth. They should either try the smaller nozzles, turn down the pressure or a combination of the two.
Just because everyone else is using the bigger nozzle doesn't mean you have to. We've already seen another person that is running rich as well.
Another option worth mentioning since you talked about adjusting pump pressure. I don't think that is an option on the new pumps, but the controller varies pressure based on boost by controlling voltage to the pump. Rather than starting at 8psi and full at 10psi, we could start at 8 and full at 20psi, as boost drops in the higher RPM's, as long as its under 20 the controller will lower the voltage to the pump and in turn the pressure, maybe this will reduce the amount of meth and even things out.
AJP turbo said:may have tuned many but having stft's pegged and in the .70's and afr's in the .70's also is less than ideal
Mif i had meth i would want afr in the low .80's and i would attempt to adjust the fuel curves so that stft's got lot closer to 1.0
Yeah I agree, its going to make more power for sure. I will see how the revisions go and if I end up with a final tune and its rich I will see what he thinks about a smaller nozzle or adjusting the controller. We will see, I will share my logs in another thread. If the OP makes changes please let us know.
Sinister-CO
New member
I'm sure your tuner will get it worked out for you. I was merely passing along what I was told by the Snow guys one of my first times out with it at Bandimere. I thought gee, I have a fast car and probably need a lot of meth. Turns out it was way too much.
Oh no, i get ya, and I agree it sure looks that way. We will see what he can do with it, it may be an attempt to error on the side of caution as well. I am by no means an expert on the topic. I would love to see more meth logs from other tuners and with different nozzle sizes!
Sabtaj1 said:Maybe try a diff brand nozzle. I never used my snow ones cause the threads were s--t. I run an alchohol injections nozzle 10gph as torrie recommended. No problems here. Maybe ur nozzle isn't making a good mist. Just a thought
That may be worth a shot. I did see your post about the crap threads on the snow. I considered using a different brand nozzle because of your post but when I got my kit the threads looked good. You bring up a good point, his nozzle may be having issues and not atomizing the meth well, causing wall wetting like another poster had mentioned. 10gph and 625ml/min is essentially the same size, be it a bit smaller, but its ability to better atomize the fuel could make a world of difference. If you don't mind, could you share a log? I would be curious to see what it looks like. Thanks for jumping into the conversation!
Jcam, did you test the controller/nozzle prior to install into the charge pipe? Not likely a problem because you seem to be flowing plenty of meth, but just a thought, maybe pull the nozzle and check the screen. You could also test with water to ensure it is spraying properly.
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