Custom fuel injection conversoin for RX1 ideas... questions.

[Ski-Dooin' it]

So I find myself pleasently happy with the ridability of turbo carbs, BUT, the one thing I do hate is the rolling and hard to start issues related to parking in steep spots. the carbs are just to sensetive. I also get stuck and roll LOTS and the whole killing the battery thing when cranking it over is pretty much as dumb as it gets. SO, I am interested in the idea of doing one of the DIY fuel systems, mainly looking at SDS, as they look like a really good alternative. My thought is the stock rx1 ignition system is more then fine for me, I really have no true interest in the timing control, it would be cool, but I am just interested mainly in fueling that isnt gonna SUCK when I roll or hit steep stuff.

anyone done anything like this. also, just curious if you could leave the stock stuff in place, and just add a fueling system.. Im ignorant of this stuff, so anyone interested in discussion, or who knows anything about it would be awsome to hear about.

 

[TurboMatt]

I really with I had more knowledge of EFI controll that I do, I mean I know some stuff, but not the real technical stuff.

If I did I would be using this without a doubt:http://www.microsquirt.info/indexright.htm
I have setup a couple systems on cars, but those where prebuilt, mostly programmed units. I don't have the knowhow or time to start from scratch.
Maybe, we'll see. It's an option, I just don't have a whole season to waist getting my sled running.

 

[Ski-Dooin' it]

I am still leaning heavily towards the sds systems for 1 big reason, they offer the injector housings and can supply injectors as well. this would make my setup rather simple as far as fab work goes. and their tuning seems to be just way to simple with there box. I have a laptop and can tune with it, just not something I want to be dragging around and playing with on the hill. Also, I would most likely be doing tuning in town ridding it around in fields for right now to get basic fueling down. get little stuff worked out. I will see what goes down, I should know within the next month, I just know that I have other financial goals right now, and its a bit of coin to drop on something that isnt just throw on and go.

 

[Mtn-Track]

Supposedly MPI was working on a EFI conversion kit last Fall for the RX1. You might give them a call and see what they say.

 

[mulot30th]

I have a SDS EFI on a rx1 engine.

works fine, why not use the timing/ignition at same time?


Only problem I found so far... its a waste spark system, so I must find a way to cope with that to avoid backfires at higher boost levels

 

[HURRICANE]

We already have a injection conversion kit for the RX1.The kit is simple.We have adaptors to bolt to the head so that you can use stock Apex throttle bodies.We also resize the Apex injectors for the proper boost volume in order to get the duty cycle right .We have a RX1 engine running on Hurricane complete stand alone system but if your only looking for fuel management,then Mountain Performance has a system that will work for your fueling.

 

[mulot30th]

Hurricane, tell me more about your hurricane stand alone....

 

[kinger]

I dont think ski dooinit can afford the $6K + hurricane system. The SDS do it yourself kit is around $1500. That said you may have a lot more in it before you get the sled running right, where the hurricane set up I bet will bolt on and be fairly close out of the box.

 

[mulot30th]

With sds, you still need the fuel rail/ injectors fabricated

Fuel pump, fuel pressure regulator

You need to fabricate a trigger magnet wheel (On my supercharged sled, was pretty easy, just installed the trigger magnets on the SC pulley)

Need to fabricate the hall sensor bracket.

Need to properly integrate the sds wiring with the stock wiring harness (I did this to keep the stock ecu 'think' it still ignite the engine so the dash and controls remain fully functionnal and keep stock appearance.


Not any harder than any other standalone system, in fact sds is easier to program (much simpler) but more limited too... (no decent datalogging, no 3d ignition/fueling tables)

 

[Ski-Dooin' it]

well, thanks for al lthe info guys.. glad to come home to a bigger thread. as far as fuel rail... etc etc. SDS now offers billet injector housings you basically run a large main hose with T's off of it to each housing, sort of a poor mans rail, but works great, and you just weld the injector housing into your intake runner. as far as not using ignition, for the boost levels I am looking at, its NOT an issue and I have truely no interest to mess with timing etc.. its cool, just more then I want.

My sled is already turbo'd and I have a pump capabable of 80+ psi with still plenty of fuel to run it.. smae one everyone runs on the high boost apex's and such. also have a nice fuel reg, I just have to put the stiffer spring back in it for fuel injection, i have a weak one for carb right now. so lots of things that cost like $100+ apeice, I already have.


Also, I was thinking of converting to a midmount with a custom tank, and doing a single throttle body that I have off of my old doo 100 motor. the hting is 2.25 ID.. so just as large as the charge tube. it also has a TPS in it I can run to keep the SDS system happy. I have lots of odds and ends to keep my cost down, I dont want to spend a fortune, and im not the kinda guy that buys something someone else did. I might take ideas from it, I just like trying new things.

mulot, glad to hear you have it, I would really like some feedback on how tuning with the little sds box is. it seems relatively simple, again thought, like you said, nothing to crazy. I dont need this thing to be spot on making the most power, I just KNOW mine had a lot of issues with fueling with my current carb setup, and I know there is a lot more left on the table and would like the throttle response of a midmount and an EFI.. i have talked to plenty of people who can attest to the gains being there. I honestly am pretty happy with my carbs, I am just used to carbed and efi 2 strokes, if you roll em, hold em wide open, pull 2-3 times and your running again, with mine, crank it and risk running the battery dead, which happend WAY to many times this season to make me very mad a LOT.. runing a few days and had to spend lots of time working out a charger and still messing with that to charge em off another sled. Ijust want to be able to roll, crank on it and BAM, ride.

I really appreciate any inpute.. mulot, you opened your mouth, your gonna get your eyes typed out now with all the question I have, and if I get going on it.. I almost feel bad!! I do really like being able to ask someone who has done a similar thing first htought, I dont want to get into a total cluster f00k and have a sled that doesnt run.

I also just looked into there spark systems as well.. so your saying you can basically controll the stock packs with the sds setup?? if so that is pretty cool, kinda makes me interested, what kinda options do you get with it??

 

[mulot30th]

Just take the time to ask a couple thing at a time and I'll help you.

I've done it last summer so its still fresh in memory.

 

[Ski-Dooin' it]

oh boy... right now I need to figure out if im truely interested.

overal how is tuning using the box they run?? seems pretty intuitive. and being some what computer inclined, it doesnt seem to terribly bad to use.

once "close" to a good map has been generated, how often to you find yourself adjusting it to keep the sled running well in the given conditions??

converting to efi one big thing I am after is nice clean throttle response. you have an apex and a rx1... how does each compare for running then?? I dont want to spend all this time and money on a sled that runs a "little" better, If im gonna dump money im looking for something that will run good day in and day out. I dont mind stopping to punch a few buttons to clean it up if the weather changes a bunch, or major elevation swings.

as far as the little knob deal... does it work or is it more of a joke?? seems like a good idea for tuning slight changes in the weather once a good map is produced

thanks a TON for any help, this is really going to help me descide if its worth my time and money.

 

[mulot30th]

The knob really works

you want to tune it properly and usually use the knob only to quikcly test if it like more or less fuel, pretty easy.

give you an example: tune it with know set to ZERO, to 13-1 air fuel... then you can easily go down to 9-1 air fuel or 18-1 air fuel only by using that knob... it does have a huge range.


The system is pretty easy to tune. in fact this is the easiest system to tune.

tuning is realtime, you change the fuel / timing numbers while engine is running, will take effect as soon as you change it.


for throttle response, SDS allow you tu fine tune throttle snap from idle and throttle snap from cruising rpms... (two different accel pump values) I have absolutely no problem with throttle response.

 

[Jabakanada]

If starting the engine after rolling down the hill is the issue... Do you have on/off switch for fuel pump?

I have on/off switch for fuel pump. When I will roll sled over I will turn off fuel pump and start engine within few seconds and ride without electric fuel pump for a moment. After that I will turn on that pump and no problem.

Seems to me that you have decided to go EFI but this is worth of trying.

 

[mulot30th]

If starting the engine after rolling down the hill is the issue... Do you have on/off switch for fuel pump?

I have on/off switch for fuel pump. When I will roll sled over I will turn off fuel pump and start engine within few seconds and ride without electric fuel pump for a moment. After that I will turn on that pump and no problem.

Seems to me that you have decided to go EFI but this is worth of trying.

When my rx1 mtn was still carbureted, same thing here... fuel pump was not the problem, the floats emptied all of themselves with into intake ports.... so re-starting was a PITA each and everytime...

EFi, means no more of this... worth it if you ask me.