JB4 ISO 27.8 METH SAFETY CHANGES

Hi guys,

Testing out ISO 27.8 which includes some changes and new options to the JB4 meth flow settings.

First a brief overview. Generally speaking methanol is run with map 3 which adjusts boost between a low and a high boost map as a function of methanol flow and the user defined meth additive. The boost scale for the high and low map is posted below. This additive is typically 40 on pump gas (which targets around 17psi) and can go as high as 75 to target up to 20psi. Technically speaking if using the 3.5 bar map sensor it can be raised as high as 100 to provide values higher than the 75 additive.

We've moved the previous non-meth FUB options to FUD. For FUE the option to disable NLS has been replaced by setting menu 9 in dash (the 2STEP RPM) to 0.

This frees up FUE to be dedicated to meth control options (e.g. for those using the FSB), and FUB to be used for meth safety options (which apply to the FSB kits, Aquamist kits, etc).

FUE (MethFlow): They are all self explanatory. You have the option now to allow methanol flow on map 3 only allowing your map 6 or map 7 to be a non-meth map. Not documented below is that we've also removed the meth additive on map 6. It was a good option in theory but caused too much confusion among map 6 users. So users who are using map 6 on meth will want to use one of the other methanol safety options now.

FUB (MethSafety): Due to popular demand we've added some new options here.

Note that all options work with either the FSB based kit or the Aquamist turbine flow sensor kit.

Option 0: The default meth safety mode is the most comprehensive methanol safety in the industry. Boost is raised as a function of methanol flow only raised AFTER methanol is properly flowing as verified by the FSB or turbine flow sensor. This prevents knock during spool up and post shift where it is possible for boost to hit before methanol does.

In addition the JB4 monitors historic knock activity to ensure the fluid being injected is sufficient to prevent knock for the boost/timing curve dialed in. Methanol mixture variances, weather changes, etc, can all effect whether or not a given mixture is sufficient for the tuning. Add in a little too much water one day, use fluid that isn't as potent as it should be, go out on a cold night where air is denser than normal, do a run to 140mph where IAT goes higher than normal, etc, and you can quickly find yourself running in to knock if the fluid isn't up to the task. JB4 owners of course can always monitor timing in dash but I'm sure few do. This safety works full time behind the scenes to protect your engine from this sort of a situation.

But all this safety comes at a price. Waiting for methanol to get up to flow before raising boost up to full target means you sometimes need to delay boost while methanol starts flowing. And sometimes when you are racing you want to keep full boost even with some knock because winning the race is more important to you. So we've got some other options below.


Option 1: This is the same as FUB = 100 previously. Boost increases are mapped on methanol flow but the historic timing activity is ignored. This was previously added prior to the "flatline fix" where timing would drop negative post shift in some cars not due to knock but due to torque management. The JB4 would incorrectly interpret this timing drop as knock and reduce boost accordingly. So this was a way to bypass that system. Today it's used by those who wish to monitor timing directly and for whatever reason do not want boost reduced as a function of low timing. Often by those running E85 + meth.

Option 2: This is a new option, lovingly referred to as "Spray and Pray", and is equivalent Aquamist flash only safety. With this setting the JB4 assumes you have full methanol flow and enough octane to prevent knock and makes no attempt to drop boost unless methanol falls below your user defined scaling value for 1500ms while boost is greater than 12 psi.

If methanol flow does fall below the flow value you define then a map 4 switch is initiated and the SES light will flash 3 times. Technically this implementation is better than the AM kit becuase AM can only open the wastegates which bleed off boost over the course of a couple of seconds, while the JB4 map switch will instantly close the throttle body, reduce timing, and simultaneously open the wastegate. So boost to the engine is reduced faster during a failsafe trigger. And you are alerted in dash to what has happened.

Note that while we don't suggest option 2 due to its non-integrated nature the benefit here is going to be quicker boost response. When you decide not to worry about spool up knock and whether or not your methanol flow is sufficient for the tuning the car can feel more responsive. It's a bit like burring your head in the sand but for those running E85 + meth its less of a risk than those running pump + meth.

Option 3: This allows you to use map 3 in non-meth or non-safety situations. Absolutely no safety is provided and you get the boost curve you set via the meth additive (menu 8 in dash) regardless of methanol flow. It's a useful custom tuning option as you can slide your boost curve between the two curves on the fly. A 75 additive would give the high curve, a 0 additive the low curve, and anything in between blends them. Those wanting something a little stronger than map 7 could go with say a 70 additive and those wanting something a bit weaker than map 7 could go with say a 60 additive. Lots of options here for non-meth users. :)

The new firmware is below along with notes on the new FutureUse settings.