When to meth ?
Dont run 25psi on a ls based motor on 93, you will most likely blow up. I think this person is leaving out a lot of details when he claims 25psi on 93. That is not good advice at all.
Alex
Its all in what the motor wants. Its somewhat conservative on timing but also low compression motor. Its got good head chambers and good sized cam. It all works together not only tune but combo in general
Run a single 15pgh to 600whp, a dual 15 if approaching 1000whp level. Have it tuned for the meth and dont go wot without any meth. Thats pretty much it.
Run a single 15pgh to 600whp, a dual 15 if approaching 1000whp level. Have it tuned for the meth and dont go wot without any meth. Thats pretty much it.
How will my o2 react when it comes on?
What are you "telling" the pcm to do when it sees it come on?
unfortunately, with my stand alone efi setup, i can only adjust it to command a certain AFR at certain throttle (idle,part,wot,boost) positions and the map sensor (ZR1) handles load and boost based on this. I don't know what people are "adjusting" when meth comes on. Almost like different tunes for when your on meth and not. I'm able to understand it but i don't have any experience with HP Tuners or any other software that can manipulate OE software.
Run a single 15pgh to 600whp, a dual 15 if approaching 1000whp level. Have it tuned for the meth and dont go wot without any meth. Thats pretty much it.
He asked when do you need meth? I answered the question. And you are wrong with meth being required based on hp level. That has little to do with it.
You haven’t given us enough information to make any kind of educated guess. The amount of power/boost/ timing that require “X” amount of meth/water will be different for each setup. Describe your setup in detail and we can suggest a good starting point.
When using 100% meth, it’s more like adding octane. (race gas) There is no real limit to how much you can add. Think of it as an additional fuel injector(s) controlled independently. Your ECU has no idea if it’s on/off etc. Anytime the meth inj. is “ON” the AFR will go rich. How rich is determined by the amount U spray. If your ECU can “auto correct” the AFR, you don’t have to do anything. When the meth kicks on the ECU will automatically lean the tune out to maintain your commanded AFR.
When using 50/50 its more complicated. Water cools the CC much better than methanol, but you are limited in the amount you can add. Water has no octane and is not combustible, If you spray too much it will hurt performance and drown out the spark. So you are limited to the amount you can spray. The higher the water percentage the less volume you can inject without performance suffering. Using something like window washer fluid really limits the volume of fluid you can inject.
All of it works, to get it to work well you have to do some research/testing on your setup. 100% meth usually works best because you can dump in a ton of it without any ignition issues.
You haven’t given us enough information to make any kind of educated guess. The amount of power/boost/ timing that require “X” amount of meth/water will be different for each setup. Describe your setup in detail and we can suggest a good starting point.
When using 100% meth, it’s more like adding octane. (race gas) There is no real limit to how much you can add. Think of it as an additional fuel injector(s) controlled independently. Your ECU has no idea if it’s on/off etc. Anytime the meth inj. is “ON” the AFR will go rich. How rich is determined by the amount U spray. If your ECU can “auto correct” the AFR, you don’t have to do anything. When the meth kicks on the ECU will automatically lean the tune out to maintain your commanded AFR.
When using 50/50 its more complicated. Water cools the CC much better than methanol, but you are limited in the amount you can add. Water has no octane and is not combustible, If you spray too much it will hurt performance and drown out the spark. So you are limited to the amount you can spray. The higher the water percentage the less volume you can inject without performance suffering. Using something like window washer fluid really limits the volume of fluid you can inject.
All of it works, to get it to work well you have to do some research/testing on your setup. 100% meth usually works best because you can dump in a ton of it without any ignition issues.
2005 5.3 gen 4 gapped
799 heads with BTR 660 kit
ls9 gaskets , head studs
Tick turbo grind 217 227 637 623 114+4
80lb FIC bosch, 044 pump -8up -6dn
Single On3 76, Precision PW66 gate
Tial Q 50 BOV
2" ID log manifols, 2"y, 4"dp
MSD Atomic LS efi
4l80e auto/man, Jakes D3 brake
lemme know if you need any more info.
Lookin for 7-750rwhp 9.80s-10.20s
this achievable with my setup in my 70 chevelle 3700 race weight?
The Best V8 Stories One Small Block at Time
If you plan on 50/50 2 12gph nozzles are about right for a 5.3 @ 23lbs and 6500 rpm. You need to factor in the pressure VS flow. Nozzles are rated at 100psi. So 2 12gph nozzles at 300psi flow a lot more than 24gph.
Here is the formula to calculate flow rate vs pressure.
Example: 300 psi divided 100 psi = 3
2. Obtain square root with calculator
Example 3 sq-root = 1.732050807568877
3. Multiply result by nozzle size at 100 psi
Example: 1.732050807568877 x 12 = 20.78 GPH
This is the new flow rate for a 12gph nozzle @ 300 psi of pressure.
You also have to look at the pumps capability of flow/pressure. The big re-circulation pumps advertised at “300 PSI” are MAX rated @ 30GPH @ 200psi. They don’t list the flow at 300. I’m assuming that’s because it’s really low! You can’t keep adding nozzles and ignore the pump. Pressure will drop significantly, throwing your flow rates off.
If you plan on 100% meth I’d jump straight into 1 10gph and 1 11gph nozzle @ 200psi. Which is the max most single pumps will support.
Last edited by Forcefed86; May 14, 2015 at 09:23 PM.
Ill check out that turbo,sounds good.
I'm wondering if the TYPE of water/meth system makes a difference on how much gets injected.
For instance, I run the Holley EFI system and their water/meth system. It uses solenoids to inject the water, much like an actual fuel injector. I have a a single 1000cc (~15-16 gal/hr) solenoid and cant really inject more than 10% of total fuel flow, and at that rate my solenoid duty cycle is less than 50%. At 17psi I use about 500lbs/hr of fuel, so another 50 lbs/hr of meth/water is going in with it.
I always wondered how some guys can run 2 15gal/hr nozzles. If I inject 12%-15% I can get the motor to break-up. Is it possible that my system atomizes the mixture better thus requiring less of it??? My AFR is inline as the ECU adjusted for the difference to keep things at 11.5:1.
As far as "when" to use it. It all depends on your current IAT level vs how much more boost and timing do you want to run. Intercooling, and a lower CR will aid in keeping things safe.
If you are getting close to the limit I would say add it. Meth is the cheapest way to keep things safe fuel wise. Snow Performance has different setups for different power levels on their website. I don't think they are a sponser so I won't post up a link, but it is easily found.
As far as "when" to use it. It all depends on your current IAT level vs how much more boost and timing do you want to run. Intercooling, and a lower CR will aid in keeping things safe.
If you are getting close to the limit I would say add it. Meth is the cheapest way to keep things safe fuel wise. Snow Performance has different setups for different power levels on their website. I don't think they are a sponser so I won't post up a link, but it is easily found.
but then again, its not 94 and humid out yet either. Id like to safely turn this sucker up to 18-20 psi at some point soon to see what its got/potential. Been hitting 11-13psi on the street so far. How accurate is doubling atmospheric pressure to doubling HP? More theory than accurate?
I'm wondering if the TYPE of water/meth system makes a difference on how much gets injected.
For instance, I run the Holley EFI system and their water/meth system. It uses solenoids to inject the water, much like an actual fuel injector. I have a a single 1000cc (~15-16 gal/hr) solenoid and cant really inject more than 10% of total fuel flow, and at that rate my solenoid duty cycle is less than 50%. At 17psi I use about 500lbs/hr of fuel, so another 50 lbs/hr of meth/water is going in with it.
I always wondered how some guys can run 2 15gal/hr nozzles. If I inject 12%-15% I can get the motor to break-up. Is it possible that my system atomizes the mixture better thus requiring less of it??? My AFR is inline as the ECU adjusted for the difference to keep things at 11.5:1.
Your ecu will adjust on its own when you spray?
The research I did confirms that my experience is similar with other Holley users...just strange how different these systems act was my point.
The research I did confirms that my experience is similar with other Holley users...just strange how different these systems act was my point.
http://www.alamomotorsports.com/FJO/waterinjection.html
http://www.alamomotorsports.com/FJO/waterinjection.html





