How do I edit the AFR tables in Tunerstudio?

[boxertwin]

Hi, I am not a complete newbie to Microsquirt, and before this project had successfully fuel injected a 400cc two stroke twin with a V2 Microsquirt tuned using Megatune V2.25. (It has now done almost 7000 miles!)

My current project is a 700cc 4 stroke boxer twin fitted to a car! (just a very small car!). It is a ‘sport’ spec naturally aspirated engine, with 10:1 compression, modified GV650 throttle bodies and injectors, a Honda VFR800 fuel pump, with crank sensing via a tooth wheel milled into the flywheel. The camshaft is, by modern standards, VERY hairy and has about 90 degrees of overlap, but with lazy opening ramps. The engine is fitted with an Innovate LC1 and a broadband sensor in one of the down pipes at the ‘cross pipe position’. The engine should produce about 55+bhp at 6500 to 7000 rpm (red line is 7500). I want to use close loop feedback control with Flash up-date in the Microsquirt using the LC1. A Microsquirt V2 (whoopee it has everything built into one box and has no interference problems! – just keep the ignition and sensor wires apart!) is programmed as a wasted spark configuration with no cam sensor, so I get 2 injections per cycle. Both Ignition wires are connected together to a single Honda motorcycle wasted spark coil with 4.5ms dwell. (I am also using a coil condenser). Since Megatune wouldn’t handle the V3.XXX code in the Microsquirt, I had to use Tunerstudio (I have paid for registration and my laptop shows a message of “Registered to” at the top), and I set up the basic tables as I thought they should be. Everything was set up on the bench using a JimStim V3, and as soon as the complete installation was cranked over while I primed the fuel system – it just simply wanted to ‘go’. Once running with the laptop connected, I used Tunerstudio and immediately found that the engine produced – surprise surprise! - Very Very little manifold vacuum. Simple - I changed to Alpha/N tuning and set up the Alpha N and VE tables appropriately – I had used Alpha N before on the twostroke and found it really easy to use (but the twostroke required continuous adjustment for about 4000 miles until the engine broke in – another of the reasons I had intended to use closed loop control on the boxer twin.)
Once converted, several minutes blipping the throttle allowed VE analyse to get on top of the mixture – not completely, but near enough to drive the car! When taken for a drive I found on a couple of occasions that Tunerstudio froze. I think that this was due to the closed loop control in Microsquirt over-riding VE analyse – solution – just allow the closed loop control to do its thing with no lab top connected.

After 100 miles the VE map was well sorted using the on-board closed loop control with Flash update, and the engine really does run VERY well. I still probably need some more cold and hot cranking fuel and I can’t re-start the engine if it stalls without turning the ignition on and off! But really it does FLY! - and drives well.

Now for the big BUT, I have a couple of driveability problems – at very light load and low to medium revs – an area where ‘Lumpy’ cams are notorious – solution - make the mixture richer at these points. Big problem is HOW? I can use the 3D map in VE analyse in Tunerstudio to do so, but DOES THIS CHANGE THE AFR MAP AS WELL? If it doesn’t the closed loop control within the Microsquirt will lean the engine back to it’s original setting with time – pretty pointless!!!!!!!!!.

If I look in Tunerstudio, (remembering that I think that I have a registered copy) and try and find the AFR table, it is ‘ghosted out’ and I cannot open it. Simple question – IN TUNER STUDUIO - HOW DO I GET INTO THE AFR MAP TO CHANGE IT SO THAT I CAN USE CLOSED LOOP CONTROL (in the Microsquirt) WHICH IS PARTICULARLY IMPORTANT WITH ALPHA/N TUNING?

I am really scratching my head with this one since I really cant find anything in the manuals about this. They only deal with the AFR tables on initial set up!

I am gobsmacked that the car is running so well after all of the problems with the 2 stroke, but remember, I am not a professional using these softwares every day. I don’t have a rolling road, and have to get some of the basic problems sorted and the engine broken in BEFORE it goes to a rolling road! – and then perhaps stop the closed loop Flash up-date!

Perhaps one final point is that I have always found that the engine set up systems do not work well for small engines, (I admit that I am playing at an extreme!) and have to use experience and my own calculations to do so. This means that I have had to override the settings that Megatune and Tunerstudio have wanted to set since I can tell from looking at them that they simply won’t work with the configurations I have used.

And Finally – sorry for the length of the entry!

[LT401Vette]

DOES THIS CHANGE THE AFR MAP AS WELL? If it doesn’t the closed loop control within the Microsquirt will lean the engine back to it’s original setting with time – pretty pointless!!!!!!!!!.

Nope, as you suspect it does not change the target AFR.

If the AFR tables are greyed out, it should mean it is set to not use them.

Can you post an msq? Then I can see what setting is greying out the AFR tables.

[boxertwin]

Hi,

OK, I am using Tunerstudio V2.0.6, and it has a " Registered to" at the top. I am using a very classic display - like the Megatune one, with drop downs in the top tool bar. In 'Basic Tables' everything is greyed out, so I cant open any Tables. In 'Tuning' RTD, Warmup Wizard, and Acceleration Wizard are useable - everything in the middle is greyed out. I am using a pure Alpha/N tuning, and in 'Other Tables' TTV, AlphaN and Baro are accessible - everything else is greyed out.

If I go into VE Analyse, I do have a VE table, and I can change the values, and it will work in 'live' mode. If I go into 'advanced Settings' in VE Analyse, then at the right bottom, click AFR Target, I get 3 selections The top one has a tick in the selection box, if I click on the legend beside it - 'Edit/View AFR table - I get an AFR table that looks a bit like it should!!!

But where, Oh, where, is the Ignition Table???

All of this looks very odd with none of the drop down tables from the tool bar not working!

John

Reasonably recent MSQ: -

[LT401Vette]

Ah... There is a bit of a settings conflict.
In Project Properties, MAP Baro is on, but in the "Other fuel Settings dialog" it is set to "Use MAP only"

These 2 settings need to match or all your tables will be greyed out.

If you are not intending to use MAP Baro:
- Open "Project Properties", either from the File menu or press CTRL+P
- Click on the Settings Tab
- Change MAP Baro to "MAP Baro off (Default)"
- Click Ok

If you do want to use MAP Baro:
Open the dialog:
"Other Fuel Set-Up" --> "Other Fuel Settings"
- Change "VE/SPK/AFR table index" to "Adjust MAP for Baro"

Changing either of those will re-enable your tables.

[boxertwin]

Many Thanks.

I had got somewhere near there about 10 mins ago - earlier I had been digging about in MSQ files to attach one. I originally set up the Ecu about 6 months ago (I was still restoring the car - a 1963 BMW 700 CS Coupe!) As soon as I started to run the car I found with 90 of cam over lap and only 2 cylinders the minimum MAP was 90 on a naturally aspirated engine! so I immediately changed across to pure Alpha/N control. With feedback mixture control any changes in the engine would be continuously mapped out.

When I was digging about I found what I think were the original msq project files I set up - and when I loaded that project I got the tables back. Will go back and sort out the properties (and also sort out a TPS/Baro range problem between the Alpha N table and the VE/AFR tables!) Think that the 'Properties' must have got corrupted somewhere in the TPS/MAP control conversion!! I hate to think of how much time that corruption has cost!

Many Thanks for your help,

John.

(by the way, the 400cc twostroke twin also uses an LC1 - the sensor lasted over 5000 miles before it failed!)

[R100RT]

What is the engine that you are using (perchance a BMW?)
Any photos of the project?

[boxertwin]

Hi,

I am using the original BMW 700 engine which is a derivative of the R69 motorbike engine, but with a dynastart and fan cooling. I suppose that one way of looking at it is as a two 300cc Isetta engines with a common crank, but 350cc barrels on each! Crank is the built up roller bearing type with large ball races at the front and rear. It drives through a custom BMW transaxle used only on the BMW 600 and 700, with the engine and drive in the rear of the car.

The Engine is very much a 'sport' spec one so should produce significantly more than the 'straight from the production line ones. There weren't very many coupes made, and the early ones appear to have been light weights and were extensively used for club racing in the late 50s and early 60s in Germany. Mine is one of the original UK RHD imports - there are reconned to have been about 120 imported in total to the UK - they just would not sell because they were so expensive. There were also about 280 RHD short wheelbase and long wheelbase saloons imported.

Will see if I can dig out a photo

[R100RT]

Thought I sent a reply and it vaporized
As you can tell from my signature, I'm no stranger to the boxers as well. My engine is a slightly larger 980cc twin, and has much less valve overlap. I am going to chart valve train travel per crank rotation to confirm if my intakes open @ 16BTDC, which may be providing me a tad of backfire up the intake when on boost, due to wasted spark. If confirmed (right now I am just assuming cam spec as per build data) I will be adding a cam sensor and loosing wasted spark for sequential ingnition.
I've continued using Map for throttle control, as @ idle I pull a pretty calm 65ish. That of course is conditioned via the popular "orificed buffer" chamber that is fed from a tee'd feed from both inlets.
Do you have any photos of your engine residing under the bonnet?
Lorne.

[boxertwin]

engine.jpg

The engine bay, the Microsquirt is out of shot on the right hidden inside a rear brace, ans there is a home made aluminium swirl pot on the opposite side that holsa about 0.75 litre of fuel and the Honda VFR high pressure pump. This is filled using a little Facet pump at the front by the tank, controlled by a 2-strok oil tank level switch and a relay!

(63.08 KiB) Not downloaded yet

Cams real.xls

Measures these with my rotary mill table on its side and the digital read-out on my little drill/mill!

(71 KiB) Downloaded 101 times

FYI, A comparison of the camshafts I had available for the engine, The Racing cam is the one I bought from Germany and gives a lot of extra lift (it is also set with a bit of extra valve clearance in the calcs), The Sport cam is the standard factory CS cam, and Saloon cam is the cooking cam. The CS engine was meant to produce 40BhP at about 5650 rpm, and the saloon about 32 bhp at about 5200 rpm. The principle difference between the CS and saloon engine is a) higher compression - claimed 9:1 in reality actually about 8.2:1, the higher lift cam with more inlet lift, and twin carbs with short inlets. The saloon had a single carb with long bits of tube to get to each head. The Factory would also supply coupes with 'SPORT' engines (and a pretty 'Sport' badge on the back panel!), these had raised compression up to 10:1 (actually?) with high compression pistons, a bit if gas flowing and then a variety of special cams depending on how much power you wanted! (as far as i can tell). Oh, Yes, all of the engines used the same valves - 38mm inlet and 34mm exhaust - that is really the limit that the hemi chambers will take, but they do have a very lazy squish band around the outside of the chamber, (I went back to my 2-stroke tuning principles and changed this from about 3mm down to about 1.5mm so that the squish would pump better and give me better mixture preparation). My throttle bodies were designed to be a direct replacement for the original Solex carbs, so I still use the original air cleaner rather than the 'racing' filters that were fitted on the highly tuned engines - I am also using a standard aftermarket replica Arbarth Silencer - (not complete racing exhaust system)

There is a period motor magazine test of one of these 'special' CS's and when the factory was asked by the tester they simply said - dont take it over 7500 in top! (for those that like these things that represented well over 105 mph! remembering that it has only got 700 cc and it is a car!)

Rumours are that the factory could supply engines with over 75 bhp for those who were serious club racers and had a deep enough pockets.

The engine spec I am using is above, runs very nicely, but there is no MAP reference, I haven't tried a vacuum pot - I have used pure Alph N before and it works very well it also allows you to mimic good Map variation at small throttle openings. Where am I up to? well it needs a lot of hot and cold cranking fuel because of the high overlap and the comparatively large throttle opening that is therefore needed at tickover. Engine pulls well even from low revs, it will pull without snatch (or poping back) from about 1500 rpm in top, Engine starts to pull quite strongly from about 2000, is cooking on gas at 2500, and then starts to fly from 3000 - it just keeps on pulling to way over 6500 without anything more than a cooking set of non-optomised maps. On the road it will cruise with a hint of throttle at 75, ACCELERATE to 85 for overtaking, and go up a very long 1:10 hill at over 50! On the other had it does seem to be able to puddle about happily at under 25 in top! Biggest down side is that I get a very slight hesitation as I start to give a small amount of throttle between about 2500 and 3500, when cruising in top. Think that this can easily be cured by delaying the cruise lean a bit and richening the 0 throttle mixture. Clutch isn't right and I will need to pull it, and also richen the low rev mixture, since the engine with 'die' too easily when you do a standing start - the car has got the 'factory' 3.22:1 first gear close ratio gearbox.

[R100RT]

Very interesting. I spoke with the BMW shop I deal with here at the West Coast (near Vancouver) "Shails" and he mentioned there was around 3 or 4 "Isetta's" locally that guys would come to him looking for engine parts. He said that engine was rather specialized and not too many items would fit or swap over from motorbike engines.
Good luck on your project.