DaveW

Dale, while I'm not a chemist, or lube expert, I have some knowledge gained from experience and working as an engineer in a rubber/chemical lab (Bridgestone Research) for 37 years, so:

1. If a fuel pump/filter can withstand gasoline and its additives, it will easily withstand a small amount of oil dissolved in it. Polymers that can stand to be submersed in gas almost never have problems with oil. The opposite is not necessarily true - silicone RTV is an example - works well with oils, but deteriorates in gasoline.

2. A high-quality 2-cycle oil should never separate. These oils are designed to be thoroughly miscible (able to be easily dissolved and stay dissolved) in gasoline, and will stay suspended for years, assuming that the gasoline, itself, is not so old that it turned to varnish due to the presence of oxygen.

CharlieUK

[QUOTE]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.[/QUOTE


I just saw on ebay an Apexi FC and commander for £450 which is about $750, is that good?

Plus I have no idea how to use one...

Banzai-Racing

iTrader: (11)

The PFC just plugs directly into the stock engine harness, eliminating the OEM ECU. If your car is as stock as it sounds then the base map will be okay for you. There is an entire Power FC section of this forum, with years of accumulated knowledge.

When buying a used PFC be aware that there are people willing to sell fried units. Also be aware there are 3 different versions for the FD, so you need to make sure that you are buying the correct year. There is S6, S7 and S8, they are NOT interchangeable. Make sure it comes with the Commander as this is a very handy tool to monitor up to 8 engine functions at once.

$750 is not overly great for a used PFC, but they do retain their value.

I have come to consider installation of the PFC a reliability mod, just as important as upgrading the radiator, AST, DP, etc. Installing one sooner rather than later can only help prolong your engine life. This would be one of the reasons I developed an adapter to allow installation into the automatic FD and both series FCs.

MOBEONER

iTrader: (18)

I have a (Richard Sohn 2-stroke OMP adapter) besides the OMP malfunctioning how is this adapter not better than running oil in the tank?

and i ask again. does the oil mix and spreads withing the fuel in the fuel tank or does it fall down to the bottom. Although i am not an expert on this stuff,i don't see how one can monitor where the oil goes in the tank or the amount the fuel pump pulls or if it just falls down to the bottom. I assume that the oil is much heavier than gasoline.

I understand that the rotors are super clean but if there is no oil to burn then you will not see any carbon build up. I am just wondering not arguing this mod..

RotaryEvolution

iTrader: (30)

minimal is an understatement.

at 1 ounce of oil per gallon of fuel it is less than 1% of 2 stroke oil versus fuel entering the engine.

in AFR terms, it is ~ a .1 AFR difference which is barely noticable.

the OMP only sprays a small portion of the apex seal/slot as you can see where the injector is located in the rotor housing, it has no time to mix and lubricate thoroughly before it is combusted and the majority exits the engine

2 stroke oil doesn't seperate in the tank like conventional oil will. i have let premix sit in containers undisturbed for close to a year and it remained fully suspended and did not seperate.

CharlieUK

I read on here somewhere it was 1/2 oz of 2 cycle oil per gallon of gas, now I'm confused, which is it??

zammm

iTrader: (6)

The first post says 1/2oz of 2-cycle per gallon of gasoline.. If you are at the track or dyno then 1oz of 2-cycle per gallon of gasoline.

But on Pettit Racing's bottles of Protek-r it says add 4oz of protek-r per 12 gallons of gasoline..

DaveW

The key to premixing is to put the oil in the tank when it is close to, but not completely, empty. Then immediately fill the tank. The turbulence of filling will distribute the premix pretty well. Oil and gasoline are not very different in specific gravity, and once mixed, should stay mixed. 2-cycle folks do essentially this all the time.

Dave

alexdimen

iTrader: (13)

I have also seen evidence that backs up this idea. FC rebuilt by myself and premixed since rebuild. Driven by my father on the highway to the tune of 24 mpg. (He gets 35 from his 850 volvo wagon, some weird techniques). So, no high revs and a light foot.

It is a mechanical OMP and 128:1 premixed TCW3 2-stroke oil. 1 ounce : 1 gal.

I've had the exhaust mani off that FC on several occasions after 20k miles and the rotor surfaces and seals were spotless and had an even film of oil on them. Compression has always been around 120 psi as well.

Unfortunately.... It's not $80 and done.

A. You can not use these with the stock turbos. Some people will tell you that you can do so with a modification, but I challenge them to demonstrate that without hacking the pump's electrical connector and making it unreliable. This is due to clearance issues with the oil return pipe. (on second thought, maybe a flexible return pipe would work)
B. You need lines, a resevoir, and an empty resevoir warning indicator (from a snowmobile, i have a this from a polaris brand new if anyone is interested).

The best part about supplemental pre-mix is the safety of having two seal lubrication methods... double redundancy cuts the chance of failure in half and you still have lube if you forget to mix it or use the wrong ratio.

Banzai-Racing

iTrader: (11)

Actually you can't use the adapter on the FD with "most" aftermarket turbo setups either. Many of the manifold designs currently on the market come dangerously close to the OMP as it is.

As I have already mentioned in this thread there are no adjustments in the PFC and I have yet to see any documentation that the PFC increases OMP flow based off injector sizing.

For example if the OMP flows 1 oz/ per gallon of fuel with stock 850/550 injectors, then you increase the injector sizing to 1680/850 you have potentially decreased the mix ratio by nearly half.

Again, the best way to ensure that the mix ratio stays constant is to pre-mix in the fuel. This turns each fuel injector into an oil injector, the more fuel that is in injected carries with it more lubrication. The OMP (with or without the 2 cycle adapter) cannot do this.

As Karack has found, I too have premixed fuel sitting in containers in my shed for my weed whacker that has never separated, even with long periods of sitting through the winter.

And for those questioning mix ratio, we run 1oz/ga all the time, regardless of street or dyno. As DaveW has said pour the 2-cycle in prior to pumping the fuel, then adjust as need. Say you pour in 12 oz, then pump 14 gallons, just add 2 more oz. The FD is a recirculation fuel system, which means it has a return line, so it is always remixing the fuel for you. So even if you were to pour all the oil in on top of the fuel, it will be thoroughly mixed in a matter of minutes anyway.

zammm

iTrader: (6)

Why does pettit racing only recommend 4oz:12gallon ratio for street driving with protek-r?

Banzai-Racing

iTrader: (11)

The protek is for supplementary protection, when the OMP is still in place.

Drifter288

iTrader: (3)

So does this mean on a stock RX-7 with the stock turbos even getting the adaptor and the mechanical motor would be a waste of time and a better method would be to just remove the EOP?

I would like to just keep the EOP in its place and have it pulled from a resevoir but it seems impossible huh?

Scrub

iTrader: (25)

Howard, we've got something on the way (maybe a month and a half out) that will address this exact problem It's a big concern of mine as well and premix is the only "easy" solution at the moment. I'll get some pics up as soon as it's done

dagoof

This is a good thread.

It sound's like I'm going to have to plan on the PFC sooner than I thought.

I'm all for getting rid of one more system on this car. If I can eliminate the OMP and make the car more reliable (and use less oil) that sounds like a good idea to me.

K-Tune

iTrader: (26)

did the engine with the clean rotor have water/meth injection? i'm sure that plays a large part in cleaning the carbon away.

MOBEONER

iTrader: (18)

Scrub

spill the beans....or at least PM me some info.

GoodfellaFD3S

iTrader: (213)

As Banzai mentioned, the Protek-r is just a supplement to a properly working OMP, and I'm pretty positive it's just very expensive rebadged 2 cycle oil.

The 1/2 and 1 oz per gallon recommendations are based on having a deleted OMP.

I personally still run my OMP, and supplement it 8-10 oz of Idemitsu rotary-specific premix. I'm running the RA 2mm super seals, along with 870/1680 injectors, and like the double protection of the OMP and premix.

(Link to a source for Idemitsu: http://www.rx7.com/store/rx7/fdengine_maintenance.html)

I'm also using water injection so am not concerned about excessive carbon buildup. I may have pictures of my old engine rotors, I'll dig around and see if I can find them.

at IRP we recommend premix for all customers, usually in addition to the OMP. We'll delete it if the customer requests it, but it isn't something I feel is 100% necessary. Keep in mind we also like water injection for all performance builds

RotaryEvolution

iTrader: (30)

i never ran an AI kit on mine prior to the first tear down on premix and it showed the same results.

running the OMP and premixing as well should clear up the issue for those that are concerned that the OMP is solely to blame for carbon deposits and have no easy way of removing it(but plugging the lines does work too). there is always a small amount of oil being combusted anyways, especially at higher boost and RPM levels.

jkstill

iTrader: (11)

I bought a 1989 GXL a year ago that looked really great - perfect interior, only some rock chips on the exterior.

The engine bay was spotless.

Unfortunately the car had never been driven hard enough to open the secondary ports.

All manifolds etc, were removed to clean up carbon.

The rods that actuate the ports were so carboned up that it required soaking the manifold for 3 days in PB blaster, and then using a sledge to drive the rods out.

And yes, that one owner was a female that never, ever, put her foot into the gas far enough to open those ports.

Though the FD doesn't have these aux ports, it still has to be driven like it was meant to be.

GoodfellaFD3S

iTrader: (213)

jkstill, I had the same issue with the FC vert I bought. I had forgotten about it, but it took me many hours to get all the gunk removed during an engine rebuild.

grimple1

iTrader: (1)

I think that people that don't premix with a working OMP are just asking for an engine rebuild should that stupid thing stop working. The bottom line is that with or without the OMP premix is a must.

Also, it boggles my mind that people complain about premixing. I keep a small funnel and a quart of 2-cycle oil in the car at all times. It just pours right in and is no more messy than normally pumping fuel. Just shove a rag in the funnel after you're done and toss it in the trunk.


Besides if you're afraid of getting dirty, then perhaps a FD isn't the right vehicle. There's nothing clean about owning a FD.

RotaryEvolution

iTrader: (30)

this is generally what i tell people, if they can't even change their oil then they shouldn't own a sports car and premixing is no worse than changing your oil is(cleaner on your hands and no rolling around in the dirt) but does have to be done about every 300 miles vs 3k.

Double_J

iTrader: (28)

For those that think it is messy here is what I did. I poured the oil in to a clear bottle. I marked the sides of the bottle with graduated marks so I know how much I am putting in.

The cap is like this one http://www.totalmotorcycle.com/pics/...veOriginal.jpg

Pop up the cap, push it in the tank and squeeze till you get to the appropriate line.

It is obviously cheap, needs no funnel, and easy.

alexdimen

iTrader: (13)

That's what i wanted to do as well when i rebuilt this fd.

What i discovered is that with the stock ECU and stock turbos it is a pain to use the adapter or to remove the pump.

From my experience with supplemental mixing the fc and other member's good results from doing the same, I decided the easiest and most effective solution was to supplemental pre-mix.

Another thing... I was planning on pre-mixing regardless of having an OMP because I believe it provides more even lubrication.

So, I figured it was a waste of time and money. Why buy a PFC before I need it and hack up the pump/oil return lines if I can get excellent results the way it is.