calling all knowledgeable 2smokers, brace your self .. 3d ignition questions!

The main reasons to avoid a home built EFI for a 2T bike to be used seriously, are firstly cost, and secondly the level of complication which will drastically reduce reliability. If high cost ($3-5K inc development) and less reliability, are not a big problem then I wish you the best of luck, but if I had that money to spend on improving a bike I certainly wouldnt be looking at EFI (the only EFI bike I have ridden works well, but the system certainly doesnt mean its $3-5k better than a carb bike).

The efi system may be home asembled but the parts are not home built. The ecu is made to work with all the sensors i mentiond. There are no reliability issues with morden efi, not even water will be an issue.

2trally the bigest two problems with 2t dfi is that to power the pump you are going to need a big stator, my system will suck aproximitly 70Watt and the second problem would be weight, but i guss on an adv bike a few extra kilos would do no harm.

it would cost just as much to inject a 4t as it would a 2t. The parts used are the same, the testing method's are the same and dyno time would be the same.

I think you will find the time it takes to development an indirect home built EFI system for a 2T motor, will be considerably longer than anything related to 4T.

Reasons for this is due to the difficulty of accurately measuring the negative/positive pressures in a 2T crankcase, which are linked directly to atmospheric conditions and temperature, and is the main reason nearly all commercial 2T EFI systems are direct injection, even though this is much more complicated and costs more than port injection.

I am going to use a method called alpha-N blending where load is determined by a tps not a map sensor.

4t without vtt that use very large valve overlap would display the same weak map reading at idle(like a 2t), but fuel injection is still used on them quite efectivly. There is a way to stabilize the map reading at idle.

Wish you the best of luck, but get the feeling that the final results are likely to a lot less effective than what you are looking for?

I found something that can do all i want fuel wise and its simple, but not cheap at the moment. The price will halve next year when they start diecasting.

Here's a link to a discussion and customer reviews about the carb.

http://www.gasgasrider.org/forum/showthread.php?t=13471

Link to there website.

https://secure.powerapt.com/index.php

Here is the carb. Mmmm me likey.:eek1



But i am still going to do the 3D ignition.

You have an real experience with EFI? What exactly will reduce reliability?

I can be done for under $1000. And done well. Instead of using the kit this may be cheaper and easier to use. It will even autotune E85 with a sensor. If you look around the 'net there is tons of good info on homebuilt EFI.

That is what I have been saying, efi is not as complicated as most people think.

I revered him to this video http://www.youtube.com/watch?v=Y91Jms6MyCY , but he wont beleve anything until he rides the bike.

Cool project. I very much hope it works well and that mfg's start making FI 2strokes available widely. Only think that's annoying about my CR250R is that it's impossible to have it jetted right for an entire ride when a ride might go from 6k' to 12k' and 30 deg to 90 deg over the course of a day. I think the folks who don't see the value in FI probably don't ride in the mountains.

Thanks man.

most of the guys that say it isn't an improvement, its a waste of time, my carb works just as well, my carb can be made to work just as well etc are trail riders.

I understand why they say that, i watched a lot of youtube to see that they don't use their engine enough for the efi to be any benefit to them.

But where i live we don't ride trails, we ride dunes, enduro loops, motocross, and short adventure rides with the same bike.

But if i spend money on aftermarket ignition and all the carb mods to almost meet my objectives. I would have spent more money than my proposed efi system.

Been tuning EFI via the dyno for almost 20 years and I cringe when I have to do a carbed bike now. CV carbs are the best for all around use but will never touch EFI. lemme know if I can help ya. Just shoot me a PM and we'll see what we can do.

Thanks, I will keep you on my short list of experts to contact. The project is still ways off at the moment, engineering students don't have a lot of money. But i will see if i can't buy most of the sensors next year.

Like i said its going to be another 3 to 4 years until i have all the parts.

No problem. I don't plan on returning to the Home Planet for a while.

Haha. Everyone i know thinks i am insane, but in a good way.