darrenjlobb's Adaptronic Managed Compound Blown Derv Bus Build

[darrenjlobb]

Thanks guys, feels great having it on the road, certainly a big moment for me and the car!

Now begins the tuning of another variety, due to limited workshop facilities / time and money at the moment, the engine tuning is somewhat on hold, although I am working on a new flow bench to enable me to calibrate and flow test CR injectors, so I am able to build my own injectors and get accurate calibration data, as I have given up trying to get any other company to do this for me now and no more money is being thrown at people wasting my time....

So now its time to get the car setup a bit, and dial the engine in to the chassis somewhat.

First big project has been getting the low / mid range fuel control more useable. The dyno makes tuning WOT very easy, but there is still alot of work to be done in the midrange, not so much in terms of fuel tuning, as this has already been setup on the dyno, but actually at logic level to make the car drivable.

Because I have re-wrote the ECU logic / software from scratch, it has started in a very basic form, and has become more and more advanced over time (13 ECU pages so far!). But now its on the road, it has instantly became clear I needed more logic to give some form of governor / engine stability control. In basic terms, the way it was setup, was largely as I call "direct rack control" where I am referring to the throttle cable being directly connected to the fuel rack in a P pump, or if you like, directly to the control collar in a VE rotary pump. Altho this is great for WOT etc, the second you try to "drive" the car, it becomes extremely hard, as soon as the engine gets unloaded / at light load, you will find it wants to "hunt" / "judder" like crazy as its coming on / off the fuel demand. A simple spring in the VE governor is all thats required to smooth this out in a mech pump, but its quite amazing how hard it is to replicate this simple spring in software / logic. However after quite alot of work, I am now getting somewhere, and the car is now largely drivable across most of the useable rev range, really just needing some extra dampening / control logic at very specific conditions where there are still issues, but we are making good progress and its already 10 x better than it was a week ago.

Another thing that has also become noticeable is the need for VSS / vehicle speed input into the ECU to allow me to create some tables for speed vs mm3. Predictably, it is impossible to put this much power down in first, and second gear at times even with the LSD an dry weather. I have got some basic control to get it away from a dig now using a button I have mounted on the gearstick connected to an aux input, which then switches some logic I have wrote for some basic launch control, which basically brings in an secondary 2 step at x RPM where I find it launches best with most traction. it also adds a late post injection to build EGT and spool the turbos, which is working very well, and will really get up and move now, but the problem is the second you let go of the button, it just tears the front end loose and wraps around to the 6k hard cut. So plan is going to be get some vehicle speed sensors hooked up on back wheels, so that I can limit torque / mm3 based on speed, then should be able to get the car dialed in to come off the line hard every time... In theory anyway! Have toyed with connecting all four VSS inputs and actually implementing traction control, but think this is likely to be a project for the future!

Bit of a boring update, but there isn't really alot to show for the recent work, but it has made some big leaps forward. And I am learning all the time!!!

Thanks for reading and supporting as always