Tiny said:Fahrenheit , with degrees of accuracy delivered via China,
I gave up with the A/F monitoring using an Innovate Motorsports Digital MTX-L Air/Fuel Ratio Gauge, with a Bosch lsu 4.2 02 sensor, set to read stoich, with 6.4 being the target.
I was getting reliable readings of 6 to 7 @ high idle, but usually got an error code after opening the can of whoopass.
Quote from Innovate-----
" because methanol has a very high latent heat value compared to gasoline.
On a cold engine only part of the inducted or injected methanol even vaporizes and takes part in the combustion.
The rest runs out of the exh. ports still in liquid droplet form. Innovate seem to forget that a byproduct of methanol burning is water !
This can be seen on the exhaust ports that show traces of liquid methanol running out.
This liquid methanol can kill the sensor by heat shock (high latent heat, as said), just as water can.
"In addition the EGTs of methanol are typically much lower than on a gasoline engine, while the exhaust gas volume is higher.
This causes the sensor heater to not be able to keep the sensor at operating temperature and it will error out.
Even higher supply voltage will not help because the sensor heater has a limit to how much wattage can be supplied to it. After all,
these sensors are designed for production cars with much lower power than a methanol fueled dragster.
Using a double height bung so the sensor is out of the direct exhaust stream will help the sensor heater to keep the sensor
in its operating temperature range."
Innovate make shit, and lie about their capabilities !
It turns out, when running a filthy rich A/F mixture, some of the methanol gets thru the engine without burning, carrying with it Oxygen, this tricks the gauge into thinking the mixture is lean, when , in fact, the opposite is true.
The idea of using an 02 sensor & gauge was to help the tuning process, it didn't ,,,,although when the mixture is sorted, the gauge will read accurately, I prefer to read the pugs, 02 gauges are best left to monitor petrol a/f ratios, unless I spent $US1000 on a sensor with alcohol capabilities..
Tiny
Project CBR250RRi
3
Its about time I stuck a thread up on this. I'm hoping that having something like this to keep updated will give me the motivation to push on and get it done.
The idea has been in my head to do an EFI conversion on a CBR250 ever since I read the feral injection website. I always thought I didnt have the know-how to do it what with building an ecu and designing the software to control the injectors. At least that was until I found out about megasquirt.
The megasquirt ecu did away with the need to be able to assemble complex enough electronics and design base software so brought it all back within reach. The idea got put on the back burner for a while until last summer when I started seriously researching it again and one thing led to another and now I hope Im in far enough to have to finish it. Actually finishing it within 2012 is my new years resolution!
Theres a few things to get and do before I start doing anything to the bike.
The easiest bit is the ECU. I'm going to use the microsquirt ECU from Bowling & Grippo. The tuning software for it is free and it supports both fuel control and ignition control. If a wideband oxygen sensor is plugged into the ECU, it allows for datalogging and closed loop injection if needed.
I have chosen my throttle bodies already. I'm going to use GSR400 throttle bodies. The reason is because the OD of the intake stubs is the same as the CBR carbs so there will be no need to make up reducers to fit the throttle bodies to the engine. Also, having the same diameter bores will make for the best throttle control across the range. The problem with having too big bores is you end up with effective 100% throttle happening too early and losing some control over the throttle. Besides, bigger throttle bodies just wont fit in between the frame rails of the CBR.
The GSR throttle bodies will need to be modified though to suit the spacing of the CBR intakes. The spacing between #1-#2 and #2-#3 will need to be reduced while the spacing between #3-#4 will need to be increased. And with that, I'll need to get completely new butterfly valve rods made up to suit the new spacing.
The throttle bodies got bought from yahoo auctions japan and hopefully I'll have the gen soon enough to send them off to a machine shop to get the work done on them.
Here they are stripped down with most parts removed:
![]()
![]()
I picked up a set of GSXR750 injectors over the weekend that will hopefully fit the GSR TBs. They are a higher flow rate than I have calculated I'll need for the CBR but I got them for nothing so if they dont work I've lost nothing. If they are too big it will be obvious straight away when trying to tune the idle.
The GSXR TBs have a few other bits that will be handy aswel. I'll be able to use the MAP sensor off them and the way the fuel rail is structured it should be handy enough to modify the spacing. I havent got a chance to pull them apart yet to see how they go together.
![]()
The fuel pump is the part thats bugging me at the moment. I can either go with an external pump or in-tank pump/filter/regulator assembly.
I want to make this conversion in such a way that I can easily revert back to stock carbs at any time. From that perspective the external pump works best as all I'll need to change is to tap in a return line fitting into the tank and that could be blocked up easily enough.
The disadvantage of the external plumbing is space. Where to mount the pump, regulator and filter and route the plumbing so it all stays tidy and servicable. Thats where the in-tank assembly comes up trumps. If I can get hold of a spare petrol tank for handy money it will be worth modifying it to accept the internal pump assembly. It would tidy up things a lot what with only having the one fuel line running from the tank to the fuel rail. I would lose fuel capacity but I think that will be a small price to pay.
Thats about all for now. The next steps are to make up drawings for the machine shop to modify the TBs and make up new throttle rods and also to see about getting hold of a spare tank.
Watch this space.
I'm hoping that having something like this to keep updated will give me the motivation to push on and get it done.The idea has been in my head to do an EFI conversion on a CBR250 ever since I read the feral injection website. I always thought I didnt have the know-how to do it what with building an ecu and designing the software to control the injectors. At least that was until I found out about megasquirt.
The megasquirt ecu did away with the need to be able to assemble complex enough electronics and design base software so brought it all back within reach. The idea got put on the back burner for a while until last summer when I started seriously researching it again and one thing led to another and now I hope Im in far enough to have to finish it. Actually finishing it within 2012 is my new years resolution!
Theres a few things to get and do before I start doing anything to the bike.
- Throttle bodies sized and spaced
- Injector selection
- Sensors. Coolant temp, intake air temp, MAP
- Fuel Pump
- Fuel filter and pressure regulator
- Air filter / airbox
- ECU
The easiest bit is the ECU. I'm going to use the microsquirt ECU from Bowling & Grippo. The tuning software for it is free and it supports both fuel control and ignition control. If a wideband oxygen sensor is plugged into the ECU, it allows for datalogging and closed loop injection if needed.
I have chosen my throttle bodies already. I'm going to use GSR400 throttle bodies. The reason is because the OD of the intake stubs is the same as the CBR carbs so there will be no need to make up reducers to fit the throttle bodies to the engine. Also, having the same diameter bores will make for the best throttle control across the range. The problem with having too big bores is you end up with effective 100% throttle happening too early and losing some control over the throttle. Besides, bigger throttle bodies just wont fit in between the frame rails of the CBR.
The GSR throttle bodies will need to be modified though to suit the spacing of the CBR intakes. The spacing between #1-#2 and #2-#3 will need to be reduced while the spacing between #3-#4 will need to be increased. And with that, I'll need to get completely new butterfly valve rods made up to suit the new spacing.
The throttle bodies got bought from yahoo auctions japan and hopefully I'll have the gen soon enough to send them off to a machine shop to get the work done on them.
Here they are stripped down with most parts removed:
I picked up a set of GSXR750 injectors over the weekend that will hopefully fit the GSR TBs. They are a higher flow rate than I have calculated I'll need for the CBR but I got them for nothing so if they dont work I've lost nothing. If they are too big it will be obvious straight away when trying to tune the idle.
The GSXR TBs have a few other bits that will be handy aswel. I'll be able to use the MAP sensor off them and the way the fuel rail is structured it should be handy enough to modify the spacing. I havent got a chance to pull them apart yet to see how they go together.
The fuel pump is the part thats bugging me at the moment. I can either go with an external pump or in-tank pump/filter/regulator assembly.
I want to make this conversion in such a way that I can easily revert back to stock carbs at any time. From that perspective the external pump works best as all I'll need to change is to tap in a return line fitting into the tank and that could be blocked up easily enough.
The disadvantage of the external plumbing is space. Where to mount the pump, regulator and filter and route the plumbing so it all stays tidy and servicable. Thats where the in-tank assembly comes up trumps. If I can get hold of a spare petrol tank for handy money it will be worth modifying it to accept the internal pump assembly. It would tidy up things a lot what with only having the one fuel line running from the tank to the fuel rail. I would lose fuel capacity but I think that will be a small price to pay.
Thats about all for now. The next steps are to make up drawings for the machine shop to modify the TBs and make up new throttle rods and also to see about getting hold of a spare tank.
Watch this space.
281 - 296 of 296 Posts
Innovate do make sh*t, I agree with that but they just use a Bosch sensor and the sensor failing is more likely, as you described, the non-ideal running conditions in Methanol. Without a more sophisticated control on the fuelling, you are probably firing a lot of unburned fuel out the exhaust along with some condensed water at least until the system gets up to temperature. Have you tried warming up the bike and then fitting the lambda sensor? You don't care about lambda during warmup do you?Fahrenheit , with degrees of accuracy delivered via China
I gave up with the A/F monitoring using an Innovate Motorsports Digital MTX-L Air/Fuel Ratio Gauge, with a Bosch lsu 4.2 02 sensor, set to read stoich, with 6.4 being the target.
I was getting reliable readings of 6 to 7 @ high idle, but usually got an error code after opening the can of whoopass.
Quote from Innovate-----
" because methanol has a very high latent heat value compared to gasoline.
On a cold engine only part of the inducted or injected methanol even vaporizes and takes part in the combustion.
The rest runs out of the exh. ports still in liquid droplet form. Innovate seem to forget that a byproduct of methanol burning is water !
This can be seen on the exhaust ports that show traces of liquid methanol running out.
This liquid methanol can kill the sensor by heat shock (high latent heat, as said), just as water can.
"In addition the EGTs of methanol are typically much lower than on a gasoline engine, while the exhaust gas volume is higher.
This causes the sensor heater to not be able to keep the sensor at operating temperature and it will error out.
Even higher supply voltage will not help because the sensor heater has a limit to how much wattage can be supplied to it. After all,
these sensors are designed for production cars with much lower power than a methanol fueled dragster.
Using a double height bung so the sensor is out of the direct exhaust stream will help the sensor heater to keep the sensor
in its operating temperature range."
Innovate make shit, and lie about their capabilities !
It turns out, when running a filthy rich A/F mixture, some of the methanol gets thru the engine without burning, carrying with it Oxygen, this tricks the gauge into thinking the mixture is lean, when , in fact, the opposite is true.
The idea of using an 02 sensor & gauge was to help the tuning process, it didn't ,,,,although when the mixture is sorted, the gauge will read accurately, I prefer to read the pugs, 02 gauges are best left to monitor petrol a/f ratios, unless I spent $US1000 on a sensor with alcohol capabilities..
Tiny
I have found that because I have fitted the lambda sensor in the bottom of the pipe, if I start the engine cold with the sensor installed, the condensing water vapour from the cold engine collects in the sensor head and kills it. Since I am happy with my cold start & warmup performance, I now only fit the lambda sensor to a fully warmed up engine when I need it.
2
So it has been a few months since my last proper update. In that time, I haven’t done a lot more with the EFI side of things other than improve the cold starts.
I’ve ended up doing 2 more track days on the bike which were in the dry so I could really see the areas which needed improving on the bike.
The first track session was carried out with the same setup as I had run in Mallory Park in February. This session highlighted that the back shock was way underdamped and also a little undersprung. (not that I didn't know that already) I also felt I lacked just a little bit of drive out of corners but felt that was mostly my own fault for not being spot on with my gears.
After that first track session, I made the following changes to the setup
1.Installed new custom rear shock
2.Set up front and rear preload to my weight with the new shock
3.Installed 54T rear sprocket for slightly shorter gearing
I had posted in this thread a few years back when I bought a Nitron rear shock supposedly designed to fit the mc22. When I came to fit it, it became clear the top mount was too large and fouled the frame. Nitron advised the frame would need to be ground down to make the shock fit which I was not willing to do. I made several enquiries in the years that followed to try and find a proper replacement shock for the basic and now tired stock unit. Penske were the only other company that listed a shock to fit the mc22 but that had the same issue as the Nitron. Actually it was worse as their top mount was larger and so would need even more material ground from the frame. I approached BG Motorsport, my local Ohlins dealer, some time back about building a custom shock specifically to fit the mc22 with my requirements built in. They were quite happy to relieve me of some cash and build a unit and I ended up getting Hunkipunky from the site involved aswel to at least take the sting out of the cost.
The shock was completed at the end of June and I must say I was very happy with how the whole package turned out. The entire assembly including the remote reservoir fits nicely under the stock fairings making it quite discreet.
![]()
![]()
From the get-go, the improvement the shock made to the handling was obvious. Even without making any adjustments, the bike tracked the road very well and felt much more stable on the road compared to the stock unit.
After setting the preload on the front & rear to my weight, this improvement just got bigger.
I also installed a 54T rear sprocket on the bike to get slightly shorter gearing. This was the shortest I could go while sticking with the standard 428 pitch chain. I may look into the 520 conversion in the future to give me more gearing options.
On the 2[SUP]nd[/SUP] track session after the above adjustments were made, the difference in handling was night and day. I am extremely happy with the way the bike handles now compared to the stock setup. I do have a few more items on the wishlist but these are things that will get done over time.
Some have you have asked for a video a while back so here is one now. I played around a bit with some software that overlays data from the ECU onto the video which I think works quite nicely. The GPS data was captured from a smartphone so it is not very accurate and lags a bit. That just affects the track map and lap times really. Still it makes it very handy to review the video and get an idea of what the bike was doing when.
I’ve ended up doing 2 more track days on the bike which were in the dry so I could really see the areas which needed improving on the bike.
The first track session was carried out with the same setup as I had run in Mallory Park in February. This session highlighted that the back shock was way underdamped and also a little undersprung. (not that I didn't know that already) I also felt I lacked just a little bit of drive out of corners but felt that was mostly my own fault for not being spot on with my gears.
After that first track session, I made the following changes to the setup
1.Installed new custom rear shock
2.Set up front and rear preload to my weight with the new shock
3.Installed 54T rear sprocket for slightly shorter gearing
I had posted in this thread a few years back when I bought a Nitron rear shock supposedly designed to fit the mc22. When I came to fit it, it became clear the top mount was too large and fouled the frame. Nitron advised the frame would need to be ground down to make the shock fit which I was not willing to do. I made several enquiries in the years that followed to try and find a proper replacement shock for the basic and now tired stock unit. Penske were the only other company that listed a shock to fit the mc22 but that had the same issue as the Nitron. Actually it was worse as their top mount was larger and so would need even more material ground from the frame. I approached BG Motorsport, my local Ohlins dealer, some time back about building a custom shock specifically to fit the mc22 with my requirements built in. They were quite happy to relieve me of some cash and build a unit and I ended up getting Hunkipunky from the site involved aswel to at least take the sting out of the cost.
The shock was completed at the end of June and I must say I was very happy with how the whole package turned out. The entire assembly including the remote reservoir fits nicely under the stock fairings making it quite discreet.
From the get-go, the improvement the shock made to the handling was obvious. Even without making any adjustments, the bike tracked the road very well and felt much more stable on the road compared to the stock unit.
After setting the preload on the front & rear to my weight, this improvement just got bigger.
I also installed a 54T rear sprocket on the bike to get slightly shorter gearing. This was the shortest I could go while sticking with the standard 428 pitch chain. I may look into the 520 conversion in the future to give me more gearing options.
On the 2[SUP]nd[/SUP] track session after the above adjustments were made, the difference in handling was night and day. I am extremely happy with the way the bike handles now compared to the stock setup. I do have a few more items on the wishlist but these are things that will get done over time.
Some have you have asked for a video a while back so here is one now. I played around a bit with some software that overlays data from the ECU onto the video which I think works quite nicely. The GPS data was captured from a smartphone so it is not very accurate and lags a bit. That just affects the track map and lap times really. Still it makes it very handy to review the video and get an idea of what the bike was doing when.
Thomas, nice touch with the header flanges
No updates since I'm afraid lad. The exhaust end can centre dropped out of the TSR can during that last track day and I haven't got around to replacing it yet. There will be the usual winter maintenance to be done but really I consider the EFI installation 90% done at this stage. There are parts that I would like to tidy up over time but the bike rides well with the current setup so only small changes will be made from now on.
I have also moved on to a new more exciting project which means my poor 250 will take a backseat for the next year or so.
281 - 296 of 296 Posts
