Let's say that you are running two settings, 10 psi and 15 psi, for example.

Do you guys run 2 different fuel maps? Or do you just run fuel for the higher boost all the time?

Problem is the Wolf3d can only store one map...argh!

 

Damn, the wolf can only have one map? That sucks. Even on the s-afc you can have high and low throttle settings.

 

I'm assuming that you are using a seperate boost controller and are using the Wolf3d only for the fuel maps.

I use the Haltech E6K and its maps store fuel injector timing by rpm and boost. This means a sinlge map will work (assuming it is tuned of course) for all boost ranges. You do not require two maps for two boost settings.

The only time you might require 2 seperate maps are if you would like to run different ignition timing for different types of fuel (C16 vs. pump gas for example).

I am not familiar with how the Wolf3D functions but it would be illogical for it to require 2 maps to run 2 boost settings, it wouldn't make any sense at all. Boost is not something that is on or off, it is a variable that must be factored into the fuel equation. There is no way to guarantee a certain boost level at a certain rpm therefore the ECU MUST know what fuel to use at all boost ranges. For example, steady throttle at 6000rpm will not generate any boost (except maybe in 5th gear) but the pedal on the floor in most gears at 6000 rpm will generate boost for sure. The Wolf3D couldn't possibly function without taking this into account.

Bottom line: you don't need 2 maps, just one properly tuned one.

 

Maybe I'm confused or I didn't explain myself correctly....

Lets just say you have your car set up running 10 psi. You tune your fuel map to run that amount of boost safely.

Then, you decided one day that you wanted to up the boost, either with a controller, or a different spring in your wastegate etc. to 15 psi.

Would you not have to change the fuel map (ie add fuel by increasing injector time) to compensate for the higher boost, at least for full boost under high load...????

I'm assuming that you do.

So, according to my assumption, when using a boost controller you could either:

1. run a fuel map with enough fuel to safely run 15psi all the time, even if you're only running 10psi most of the time.

2. have 2 maps. one map for when you're at 10psi, the other for when you are at 15psi.

3. I'm missing something here, and I'm talking out of my ***

 

Well what I think Crazy is saying is that you don't "set" fuel maps really. You don't run a map and you get that "set" amount of fuel no matter how much gas you give it or how much boost your running. Your car still adjusts some(right?). I mean the only way I'd really run 2 maps is 1 for my high boost setting and 1 for the best possible gas mileage.

 

Not exactly. The fuel injector time is determined by two variables in the map: rpm and pressure. You will have to tune your map to accomodate 15lbs. of boost but this will not require a second map. The changes you make to the map you use at 10lbs. of boost will not be lost as your are changing a different range on the map, not the one that is used at 10lbs. of boost.

Keep in mind that I am basing my suggestions on functionnality that I know is part of the Haltech and I assume is available on the Wolf3D.

This is correct, but it doesn't mean that your car will run the same fuel at 10 psi and 15psi. If that were the case, I can assure you your car would be undrivable.

Just remember that your Wolf3D will simply meter the fuel by selecting the time associated to a specific boost/rpm combination. I'm not sure if I'm making sense, if I only I could draw in here...

 

Generally, when you tune in a fuel computer, you can think of it like an X/Y axis graph. Going across is RPM, and going down is boost. Let's say RPM goes from 0-9000 RPM, and boost goes from full vacuum to, oh, 1.5 bar. Well, when you're at say 5000 RPM at 10psi, it looks up the coordinates on the graph to find out how much fuel to inject. By the same token, at 5000 RPM at 15psi, you would be down a few more boxes on the graph and there you would find a different (richer) fuel value to compensate for the extra air you're shoving in the motor.

So, you have 2 boost settings, and one big fuel map.

Dale

 

Ahhhh, yes!
The haze is clearing now. I'm beginning to understand!!!

Thanks Crazy and Dale!