dgeesaman

iTrader: (7)

I don't think so, it's a stepper motor and the ECU monitors the position sensors of the stepper. The ecu is looking for a signal that alternates with the speed of the pump motor and that's not going to be as simple as a resistor.

On a stock car, I would put premix in the fuel in addition to the existing OMP system.

Dave

RotaryEvolution

iTrader: (30)

possibly but the signal can still be copied. even with the OMP off the engine the ECU doesn't seem to mind that the motor is not turning. if i only had the time and an experiment car i'm sure i could figure it out without too much trouble, possibly in the future when i delete the OMP on the gf's S5 since my S4 never had an electric OMP i never worried about it.

Banzai-Racing

iTrader: (11)

I agree completely. It is a lot of R&D for what? To avoid installing a PFC, which gives you complete tune-ability and the option of further mods. Just doesn't make any sense.

On another note that has not been brought up in this thread.....For those people running 3mm apex seals, you really need to be premixing. We get 3mm engines in all the time with low compression due to warped/sagged seals, this is a direct result of improper lubrication. The ECU & OMP are not aware that you have increased the thickness of the seals by 50%. The additional friction needs more oil, couple this with the issue I previously mentioned regarding the larger injectors and you have a recipe for disaster when only using the OMP.

OneRotor

iTrader: (3)

To Howard:

Thanks for the info. What do you think of the Richard Sohn 2-stroke OMP adapter? I will be running it in my S3 GS (12a, carb'ed, oil injected in the carb., not through oil injectors like in a FD)? Will this provide adequate lubrication for apex seals, while slowing/reversing the carbon buildup issue?

I only ask this because of the mention of the oil injectors on the 13b-rew that only hit the apex seals, not the incoming air/fuel mix, and I will be mixing the 2-stroke in my carb, via the OMP.

1982 GS
MSD Blaster 2 coils
RB SP (non-collected header, exhaust merges in front of rear axle) exhaust
DD during the summer, about 10k miles/year, redline is hit daily.
Run 20W50 normally, either Royal Purple or Valvoline VR1 (high zinc content).
Current oil change: Mobil1 10w40

scotty305

iTrader: (2)

For what it's worth, I agree with Banzai and Mahjik and the others who have suggested that eliminating the OMP and keeping the stock ECU happy is going to be difficult at the least.

There are 7 wires between the stock ECU and the OMP.
(arghx from these forums would insert an appropriate FSM screenshot right about here. I'm lazier than he is).

4 of these wires go to a stepper motor which operates a flow control valve, similar to the stepper idle control valves found in many GM, Toyota, and DSM/Mitsubishi vehicles. When the ECU wants to move the valve, it switches the polarity on some of the 12V/GND signals to the stepper valve to 'step' the valve, one step at a time. Google 'stepper motor' if you're really interested in how they work, howstuffworks.com may have a good article about it. In theory, it would be possible to add resistors and fool the stock ECU into thinking that the stepper motor was still connected to the ECU. Unfortunately there are still 3 more wires that we haven't talked about, and those are going to be the most problematic in this instance.


The other 3 wires on the OMP are for a position sensor, telling the ECU the current valve position. Think of it like a throttle position sensor for the OMP. When the stock ECU decides the OMP valve should be in a certain position, it not only moves the stepper motor a certain amount of steps but it also checks the valve to verify that the valve has moved to the correct position. While it wouldn't be impossible to build an electronic device to trick the stock ECU into thinking the valve has moved, designing something like this would take time and money, and the final product would be quite a bit more expensive than splicing diodes, resistors, or relays into the harness. Are there really that many people running the stock ECU who are that interested in completely removing the OMP?

I think it would be simpler to block the OMP or disable it but leave the electronics connected to the stock ECU. The valve will still move, the position sensor will still tell the stock ECU that the valve has moved, and the stock ECU will be happy.

MOBEONER

iTrader: (18)

Wouldn't it be easier to spend $90 on this adapter and be done with it? no hassle with the ecu or oil spills or even oily fingers pouring bottles down your gas tank?

Banzai-Racing

iTrader: (11)

The adapters are very nice pieces. However, the OMP and ECU are still being used to distribute the oil. This does not solve the issue of pump failure with the PFC or the need for additional lubrication.

The best way to insure that the 2 cycle is actually making it into the engine is by pouring it into the gas tank and allowing the injectors to be the distribution method.

Battle Cat

iTrader: (78)

Im sold on the premix!!

KaiFD3S

iTrader: (37)

Looks like I got something to do, been wanting to do this since I have been premixing already...So my question is, for the meantime can I just cap the 2 lines to the oil injectors till I can get in there and remove it completely and block it off with the screw?

TpCpLaYa

iTrader: (10)

Question...by running premix and thus using the fuel injectors to play the role...how does this effect the injectors over time? It seems that if a car sits for a period of time (ie winter) there could be the possibility of the injectors gumming up.

On the same note, how does premix affect actual fuel delivery. To me it seems if there is a specific injector duty delivering X amount of needed fuel, then by running premix wouldn't there now be less than X amount of actual fuel being delivered because now there is oil in that X amount?

I understand the amount of oil could be minimal as to not have a great affect but fuel delivery seems to be very important when dealing with a boosted rotary.

grimple1

iTrader: (1)

I'll throw a word of caution to single turbo users in that there have been several folks with clearance issues and the RA adapters.

Captain_Panic

iTrader: (15)

Since the 2 cycle premix is completely (or close to it) combustable, I imagine the delta from a premix spray in the injectors vs a straight gasoline spray is minimal to untraceable in AFR ratios under boost etc.

I haven't proven this, so don't take my word for it.

Also, as best I know, and perhaps other experts out there can elaborate further, the only thing to concern yourself with running premix is maybe the fuel filter should be changed out a little more frequently.

Outside of that premix is the way to go. I have yet to remove my OMP, but that will be added to the list as I have already been premixing.

Howard Coleman

iTrader: (6)

"What do you think of the Richard Sohn 2-stroke OMP adapter? " i am not familar but guess it feeds oil into the carb throat. i like the premix idea.

thanks scotty305 and also for the humor:
"(arghx from these forums would insert an appropriate FSM screenshot right about here. I'm lazier than he is)."

"The best way to insure that the 2 cycle is actually making it into the engine is by pouring it into the gas tank and allowing the injectors to be the distribution method."

yup

"can I just cap the 2 lines "

nope. read the above posts...

"by running premix and thus using the fuel injectors to play the role...how does this effect the injectors over time?"

reasonable question. don't know the answer other than as i said i have been premixing since 99 and all is well.

howard

BonesZ33

iTrader: (5)

As always, thanks for the useful info you guys. Can't get this stuff anywhere else.

scotty305

iTrader: (2)

While on the subject, does anyone have data, theories, or interesting stories about how premixing might help or hurt emissions? If it leaves fewer carbon deposits, does that also mean there may be fewer pollutants out the tailpipe during a smog test?

DaveW

This is an educated guess, but...

IMO, the premix will do nothing bad, and may even extend the injector life by lubricating them. And, IIRC, good 2-cycle oil is formulated to not turn into varnish and plug things, which (varnish formation) could cause problems.

CharlieUK

Yeah, I would like to know the answer to this aswell. Premixing is surely the way to go, but I am also interested to know if it would help me pass the smog tests.
So, until I can afford an aftermarket ecu, is it best to remove the oil pump and block it off with the kit from Bonzai Racing and just leave the oil pump hanging whilst putting 2 cycle oil in the petrol tank?

Banzai-Racing

iTrader: (11)

The emissions issue is a tough one. We do not have smog testing in our state or in many of the surrounding on vehicles older then 95, this makes the FD in the US exempt leaving owners free to modify their cars as they see fit.

Intuitively you would think that burning 2-cycle would be cleaner and produce few carbon emissions. The rotary has never been known for it's "eco-friendly" status and this may be in part as a result of burning the crank case oil. However, this is directly effected by the mix ratio being used.

We never recommend just leaving anything hanging in the engine bay. With the stock ECU you are better off just keeping it in place until you can afford an aftermarket EMS which will allow the car to be modified correctly. If you are concerned with it failing the ECU will go into limp mode to prevent engine damage. If you are concerned with carbon build up, depending on your mileage and driving style, it is already there.

CharlieUK

WOW, no emissions test....you guys are sooo lucky, there have been emissions tests in the UK since I can remember and I'm 31!

I probably wont pass the UK emissions test with the car the way it is what to do

If I leave the set up as standard with the pump still using crankcase oil, would it be ok and still benefit the motor if I premix aswell?

MOBEONER

iTrader: (18)

Did anyone premixing from the gas tank have any issues with the fuel filter due to the oil?
or does the gasoline act like a thinner braking down the oil making it flow through the fuel filter like liquid?

DaleClark

iTrader: (55)

Howard, as always, an excellent post and it's made a good tech discussion. The FD needs more "idea" threads like this!

One thing I've been wondering about is similar to Mobeoner. Fuel filter and fuel PUMP life. You're asking the fuel pump to pump something that's not gas, albeit in small amounts. I seem to remember that someone had a fuel pump prematurely die on a car that didn't run often - the premix settled to the bottom, and the fuel pump choked on it. Now, the car could have sat for years, the owner could have been dumping whole gallons of two-stroke in the tank, who knows.

This is something I've thought about doing on my car down the road. I've been spending truckloads on the car recently trying to get the paint and body where it should be (car runs like a champ, and now is starting to look like it runs ).

Also, one thing I've been wondering and this may be better for the AI forum - is there a simple, reasonably priced, AI kit out there that will give extra insurance? I do want to add AI in the future, but I don't want to tune around the kit, just an additional spray to help keep the motor and intake temps happy.

Dale

Captain_Panic

iTrader: (15)

Illinois passed a rule that any car pre - ODBII doesn't need to be smogged due to excess cost to the state. So effectively any pre '96 car is exempt. One of the few reasons I love Illinois!

tech b

Yes. I used to run 2/3 oz per tank with the OMP. I am now full premix since my new engine/single turbo system though. It is a little bit of a pain, but much better my engine builder showed me.

n2o4fun

Would "ashless" oil ie. oil designed for diesel engines, eliminate most of the problems you speak of Howard?

Howard Coleman

iTrader: (6)

"Fuel filter and fuel PUMP life." w premix...

1/2 oz per gallon is 1 oz 2 cycle to 256 oz gasoline.

i have run the same fuel pump (cosmo) since 1999. about 60,000 miles. i digitally log fuel pressure thru my Datalogit so i KNOW what my fuel pressure is at 8000 rpm and 20 psi boost. all is well. (of course i juice my pump w one of my fav mods. a Kenne Bell Boost A Pump set on 20% V gain under boost).

i will change my filters when/if i get any downtick in pressure.

so i would say, no problem w the pump/filter w the tiny amount of 2 cycle.

since the title of this thread is Save Your Motor, and the whales, i mention AI briefly:

if you are 300 rwhp or less running the stock turbos and are looking for lots of CCP cooling go w a 300 CC/Min nozzle and just run a simple system.

above that go for 500 CC/Min. until you get up around 450 and then do your homework.

Coolingmist has supported our community and makes a range of good product. ditto Aquamist. SnowPerformance makes a good product and AEM is new to the space but is being installed on a number of FDs. DevilsOwn is also worth a look. 'just a quick summary.

BTW, you guys not running PFCs... have you checked the classifieds lately? prices are friendly and i LOVE, repeat LOVE my PFC. i think i own the 15th in the country. bought in 99. works perfectly and provides a major uptick in drive-ability as well as tuning at almost any level.

"ashless" oil... 'don't know but half of the problem would remain which is the huge amount of carbon absorbed by the oil.



howard