Hi All,

As part of my next round of patches (v5) I will be including the ability to swap boost maps along with the fuel+timing maps.

Now to keep this as simple as possible we need to follow some kind of standard for boost maps - given the recent mods done by MrFred I wanted to ask what the best method for boost control is?

Best being most reliable + most common.

Now I may be getting ahead of myself here, as the control maps that need to be swapped might be the same amongst the different BCS control methods.

Anyone car to comment?

Cheers
D.

 

I tune a ton of evos with ecu-boost. About 3-4 or so a week.

I would say that the normal (stock style) load-based method is the most common, mainly because of the cost associated with going to psi-target based. Set up correctly and changing the boost to follow 2byte fuel/timing load instead of it's own boost load makes for a very consistant boost control system while still using load from my experience.

I would be very very happy with switchable boost maps that still use load-based boost.

This would mean:

BDEL
WGDC

maps be switchable

BCLO and error correction can stay the same between most boost levels if you set the BCLO to something that would work with both boost levels (something like 200)

This would also keep the ability to use most boost solenoids (stock and aftermarket 3port)

 

I believe the jcsbanks' real time tuning method uses a single timing map for the IX instead of 3 separate ones. I'd suggest the same approach for boost control if it's possible. Compress all of the BDEL maps in to one .. the same for WGDC maps.

I agree that only the BDEL and WGDC maps need to be switchable. I personally use the BCLO map for running race gas, but that could easily be avoided with a different tuning method as razorlab said. Just increase the BCLO map to a value that works with both desired boost levels.

 

Yes well my altmap patch does 1 timing map as well.

I will be doing the same for the boost maps...

 

Using WGDC# (IMHO) would be the best and simplest way of controlling boost, increase and decrease boost as pre-desired, less variables.

You could also tune the timing maps to cover low boost (load) and high boost (load) accordingly, keep things simple...

SK

 

Many people still use error correction for ECU boost control, so this method wouldn't exactly work. With error correction enabled, you would need to adjust the BDEL tables as well as WGDC since the ECU will adjust WGDC to meet the desired BDEL. It would be possible to switch only WGDC and BCLO and still use error correction ... but not WGDC alone.

 

I concur with razorlab and touringbubble

 

As well as the best boost control method, it is worth thinking at this stage how we want to switch maps - ie programatically...

The boost stuff is not as it stands part of the map switching system the ECU already has in place, so one method is just to use pointers in RAM and update them as we go along to map switch. This would probably be a better way of switching all the maps since it works for anything, even 1d values like RPM limit, launch limiter etc.

If we can settle on a structure in RAM that we use to store all the map locations (that can point to ROM or RAM), then we can start to converge all these patches together, I can bolt DMA logging and editing of RAM into Tephra's stuff. That way he can put ROM or RAM maps wherever he likes and I can edit them.

There must be some checking for valid RAM data - whether that be pointers or maps. This and getting organised are our more demanding tasks.

 

The psi-based method looks up the same tables used by the load-based method, so if map switching works for the load-based method, it will also work for the psi-based method. :-)

BDEL and Baseline WGDC sound good enough to me too.

 

Hey John,

Well the boost maps aren't like the fuel/timing maps, ie they are pointers to maps but rather maps themselves. Hard to explain.

What I was going todo was overwrite the calls to the readmap funciton with my own sub...

Anyways the short of it is, because its a bit different, I just want to get it going, then we can worry about getting it going as best we can... if you know what I mean

D.