Thunderace EFI - Day 2 using MSExtra 3.0.3s

Finally a day off work, and a little play again, as I needed to sort out the irregular slightly lumpy idle. Once I reloaded the MicroSquirt with the last running settings from Day 1 few weeks ago, I managed a start, but I need to tweak the cranking pulses, as it took a little bit of brake cleaner to get it going.

Once I did and after the passage of time, I began to think the idle fault was an air leak in the induction system. The quickest way to test this, is to put your hand over each throttle body and choke the engine, if they all die at the same rate, it's unlikely to be one, but on doing cylinder 2, I got a hissing sound.

Further investigation showed it had no pilot or idle screw, as it had been used as a sample perhaps for the new batch that were made, as part of my idle screw replacement kit. It was close on three years ago...that's my excuse! 

Once I got the engine warm, I realised the air temperature and coolant sensing had switched, so it was affecting the fuelling and advance, so no wonder I had problems with the timing light. It is a software fault with the alpha code I am using, that I was not aware of, so hopefully it won't be there when I upgrade to 3.0.3t. Once I had eliminated all the temperature corrections, I balanced the throttle bodies, because I had replaced the idle screw now, and I found 1 & 2 were out with respect to 3 & 4.

I have now got the bike running nicely (on the centre stand) using "untimed injection" (or batch injection), and "semi sequential". Both of these do not need a cam sensor, but have different fuelling algorithms. The bike sounds good and revs nicely in "untimed injection" mode, but the "semi sequential" mode needs a little more work, and it looks like I might be altering the OEM advance degrees...the figures in the black box, as you can hear a roughness at around 4K, although it's only revving to 6500 in this test on part throttle. There is another bug with this mode which is apparently a double fuelling glitch, but it seems I also have to alter the Acceleration Wizard quite a bit in semi sequential, and I now have to do some more reading to understand this, and the bug symptoms.

Thunderace Running Day 2

I am well impressed with the Thunderace conversion so far, it's just unfortunate the neighbours are too close, and I am working tomorrow, otherwise I would be further down the line, by the end of the weekend, although I have uploaded the latest Alpha, 3.0.3t, into the MicroSquirt and started looking at the settings some more.

Thunderace vs GTS1000 Dyno Graphs

These Thunderace HP dyno graphs look promising...

Thunderace EFI - Day 1 using cased MicroSquirt


Today is the end of one journey and the start of another, as finally the Thunderace engined GTS1000, which is connected to a cased MicroSquirt using the stock wiring loom and ancillaries started to idle. It was a little lumpy, but as it's only day 1, but first impressions are it seems snappier on part throttle looking at the video, which suggest it will be quicker revving. The engine also has a higher compression, so the maximum torque figure should be higher, but as to what the cam timing, port differences and the EFI do, it's just guesswork.

There are a couple of videos, one is 20MB, the other 11.5MB, and you’ll need Quicktime

The ignition timing needs tweaking, and for some reason the coolant temp is too low and the air temp too high, so I am going to load the latest alpha 3.0.3t, which fixes a few things. Also the injection event is slightly off, or at least it sounds like it is, with that lumpy idle, but again I am running tired stock coils to create an electrically noisy environment, which is not ideal. I will be fitting my R6 stick coil conversion once I get smooth idle, and nice throttle response (unloaded, until I dyno or go down the road)

There is no lambda or O2 sensor in the exhaust yet, which needs tweaking (more upswept) too, before I can go down the road, but I will be fitting an Innovate LC1 wideband, once I put in the bung.

The bike is going to go to the this years European Treffen at Harz, but it's a friends hack bike (that had a rattly GTS engine) with my engine fitted. This means it has to be rebuilt properly to pass its MOT, before it is taxed to go down the road. He also needs to upgrade a lot of the tired metal and plastics, swap the shocks for Öhlins, different seat, swap to Krauser panniers and higher windshield for touring.

When the bike is roadworthy, I am sure it will bring a smile to our faces, dispel a few myths about the GTS engine superiority, and give others the opportunity to explore this conversion, if they want too. It won't stop there for me, as I will be fitting different throttle bodies and injectors later.