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-   -   MOP Adjustments (https://www.rx8club.com/series-i-major-horsepower-upgrades-93/mop-adjustments-120276/)

Delmeister 07-30-2007 07:50 AM


Originally Posted by Jax_RX8 (Post 1991830)
Someone else can try moving the stop screw to see if this would add any flow as right now, I am tired of messing with my OMP for while. I am beginning to think that the ECU is going to compensate for whatever we do here, so modifying the needles or an actual ECU program change may be the only way to actually increase OMP flow.

Don't forget that one of the possibilities that I believe even you suggested earlier was that this sensor could be just a check on the approximate position of the stepping motor.

I still believe that there is no way the ECU can know that it has been duped into delivering more oil if both the mechanical stop and sensor are 'rotated' the same amount in the same direction.

If this is the case, the obvious question then becomes: How much extra oil will flow for a given amount of adjustment?

Jax_RX8 07-30-2007 02:46 PM


Originally Posted by Delmeister (Post 1992655)
I still believe that there is no way the ECU can know that it has been duped into delivering more oil if both the mechanical stop and sensor are 'rotated' the same amount in the same direction.

Yes, this is possible, but I am not adventurous enough right now to pull the position sensor and the cover off of my OMP (on the car) to get to the stop screw. But, even if you moved both, the ECU still might know that you moved the starting point to position 2 or so and either compensate for it or throw a CEL, putting you in limp mode again.

It would be nice if this new "Cobb" ECU programmer I am reading about would provide access to the OMP maps as well when it is available - If it did, I would buy it for that reason alone.

Or, maybe we could get RB to include a flat percent OMP increase (pick your percent) as an option to their flash updates - that would entice me to get the RB flash as well.

Otherwise, replacing/modifying the flow needles may be the only way.

Delmeister 08-03-2007 10:17 AM


Originally Posted by Charles R. Hill (Post 1992722)
I still like the idea of modifying the needles.


Originally Posted by Jax_RX8 (Post 1993258)
Otherwise, replacing/modifying the flow needles may be the only way.

Gentlemen, methinks you give up too easily. Jax, you think the PCM beat you in that mind game you were playing with it but just the opposite is true. You found out some key pieces of information about it’s inner workings, which is that you can easily quiet down that sensor when it balks, and that it is more of a warning rather than a control of actual flow.

It doesn’t really matter too much what it was doing when you played with the sensor but it could be this. You moved it a bunch ccw, It threw a CEL. You moved it back some, it was OK. You turned it a bunch back cw and it threw a CEL. You moved it a bit toward center and it went quiet again. It could be you went past 60, brought it below, brought it below 53, brought it back up.


The combined stopscrew/sensor adjustment could potentially be the most elegant way of making this pump flow more oil. If anyone is interested in being the first to do this, you may be interested in these scribblings which are just based on ruler and such measurements of the pictures on the screen.


Angular range of sector gear: About 80 degrees using a protractor.

Motor rotations for full range of sector gear: Approximately two, by counting the gear teeth (and assuming the pinion is directly connected to the stepper).

Where is step 60?: The winding configuration suggests this is a unipolar stepping motor. Typically, the largest step is 30 degrees for a motor of this type, or 12 steps per revolution. It would thus take only about 24 steps to go through the full range of the sector gear –clearly not the case. The next finer step size is half this, again too course. A motor with the next finer, 7.5 degrees per step, appears to be the most reasonable at 96 steps for the full range. If this is the case, then step 60 is approximately 60% (about 50 degrees) of the maximum angular displacement of the sector gear. Assuming it does not travel beyond step 60, this leaves about 30 degrees for sensor/stop adjustment.

What is the angular range of the sensor?: From the picture, if the lock screws are a distance r from the shaft center, the range of movement of the sensor appears to be about a third of this. Thus the angular range is approximately 360*(r/3)/(2*pi*r) = 19 degrees.

What movement of the stop screw?: The stop screw appears to be about 60% of the distance of the sensor locking screws from the shaft center. This means it would be screwed down about 60% of the linear movement of the sensor slot to effect the same angular displacement.

Jax_RX8 08-03-2007 12:26 PM


Originally Posted by Delmeister (Post 1999251)
The combined stopscrew/sensor adjustment could potentially be the most elegant way of making this pump flow more oil.

I agree this may work - my concern is that it is a royal pain to get in there and take it apart to move the stop screw.

If I could do it once and I knew for sure it would work, it would be worth it - but I suspect I would have to adjust it multiple times to get it where the ECU is happy, and it still might not add much flow.

If we knew for sure, then I might take a shot at it - any way we could find out?

olddragger 08-05-2007 12:05 PM

I agree Ray!---Not knocking analytical minds---but come on bulldogs--maybe time to let go and chew on something else--like what kind of needles to use etc
olddragger

dznutzuk 08-06-2007 04:11 AM

Wouldn't it be great if someone could actually make a seperate controller just for the oil metering pump and injectors. I was always thinking of something like a 5th injector controller-for those who never heard of this it's kind of like a band-aid that people use to use a long time ago for people who turbo'd their car and couldn't afford real programs and new ecu's. You may have also seen them as water injector kits like the aquamist that has it's mf2 controller. Couldn't we use this with an appropriately sized inector for oil since it's variable and sprays accordingly to fuel injectors? I'm really sick of all this shit with the damned omp as I had this same problem with my FD, that is until they came out with ecu's with oil maps. Any insights?

Delmeister 08-09-2007 03:57 PM


Originally Posted by Jax_RX8 (Post 1999498)
I agree this may work - my concern is that it is a royal pain to get in there and take it apart to move the stop screw.

If I could do it once and I knew for sure it would work, it would be worth it - but I suspect I would have to adjust it multiple times to get it where the ECU is happy, and it still might not add much flow.

If we knew for sure, then I might take a shot at it - any way we could find out?

OK Jax, just hold everything. Even though I don't intend making this mod on my car, I have decided to buy a pump and try to prove this will work -- as a matter of curiosity more than anything.

So here is what I intend to do once I get the pump:

Phase 1: Bring the pump into the passenger compartment and observe the behavior of the sector gear under different driving conditions. If I am satisfied that there is a good chance an adjustment of the stop screw and sensor will result in increased flow then
Phase 2: Make the adjustment. The sector gear should behave exactly the same but with a constant angular offset. If this is successful then
Phase 3: Determine how engine speed and sector gear position influence oil flow

Nothing is for sure in this life Jax. You do all the analysis (oops olddragger, didn't mean to use a word that suggested analytical minds were at work) you can, any pretesting that's possible, and then grap your balls, jump in, and hope you're somewhat intact when you come out the other end.

I'll keep you informed.

olddragger 08-09-2007 05:25 PM

they just wont stoppppppp!
I love it.:)
olddragger

TeamRX8 08-09-2007 06:48 PM

Somebody pointed out that the Racing Beat MOP mod is no longer listed on their sire. Not sure if it was accidental or intentional ...

secret8gent 08-09-2007 10:44 PM

it is still listed on mazdaparts.com (not that that means anything...)
http://www.mazdaparts.com/ProductDet...000-1151625435

whoneedspistons 08-10-2007 05:36 AM

may i ask.... i have been reading this thread for a while and i was thinking of calling rb and asking them to do the mod and bore out the lower hole and use the top piston for it... to me this seems as if it would be a logical step... do you think i would loose octane due to the additional oil in the motor?

dannobre 08-10-2007 06:34 AM

According to RB...the Renesis gain HP with a stupidly rich oil ratio......The octane wouldn't be a problem...but your CAT wouldn't like all the oil :D:

whoneedspistons 08-10-2007 07:08 AM

hmm now only if i had a cat... lol...

rotorocks 08-10-2007 08:51 AM


Originally Posted by dannobre (Post 2008451)
According to RB...the Renesis gain HP with a stupidly rich oil ratio......The octane wouldn't be a problem...but your CAT wouldn't like all the oil :D:

So you saying that if I premix more, there'll be more HP?
It makes sense, oil provides better sealing. What is their suggested ratio?

dannobre 08-10-2007 12:38 PM

Quote thanks to Shaun:

Racing Beat Tech Tips on oil cooling and lubrication:
"While undertaking development work on the RX-8 Renesis engine for SCCA T2/T3 use, we decided to introduce extra oil into the fuel to monitor the effect. to our surprise, this additional oil increased power! Further dyno testing found that by adding 10 oz. of Royal Purple 2-stroke oil to 6 gallons of fuel, we gained an average of 1.7 hp from 2000-9000 RPM, along with an increase in peak power of 4 hp. We validated this increase by changing back to a "non-oiled" fuel - and the power returned to the previous level. Later, we tried the same test with another brand of synthetic oil with nearly the same results. For racing applications, the addition of a high quality synthetic oil increases power and most certainly decreases wear. The only negatives are the cost of the oil and an increase in the tendency to foul the spark plugs. (Note: we have not performed these test on non RX-8 engines yet, these results are unknown.)"


Now that's RICH :D:

MazdaManiac 08-10-2007 10:45 PM


Originally Posted by Charles R. Hill (Post 2009442)
Would that also somewhat validate Pettit's claim regarding use of their Pro-Tek R?

Only if you use 3 bottles of it at a time.

paulmasoner 08-11-2007 07:56 PM


Originally Posted by MazdaManiac (Post 2009655)
Only if you use 3 bottles of it at a time.

:rofl:

rotorocks 08-11-2007 09:46 PM

10oz to 6 gal
would amount to around 25 oz per tank. That's a shit load of oil.
That's Extreme Premixing.

Extreme Premixing: Adding fuel in to the oil instead of the other way around.

LOL

whoneedspistons 08-13-2007 11:55 AM

well i just called racingbeat and they indeed do not do the omp mod anymore...

olddragger 08-13-2007 01:36 PM

well for those that run a mid pipe at the track---pour the oil in! for simple sake just use 1 oz a gallon--should give you something. Then when you get home--change the fuel pump?
olddragger

whoneedspistons 08-13-2007 05:44 PM

lol.... nice

olddragger 08-13-2007 07:58 PM

it has gotten more clarification just today. As far as i am concerned anyway. i finally got a symptomatic fuel pump i could dissect this past w/e.
So approx 1 hr ago i finally got the actual filter out of the pump assembly. It wasnt easy.
The size of the filter is approx 1 1/2"tall and approx 3/4" thick that goes around the approx 5 "diameter fuel pump base. It is a fairly large filter in totality. The sock on this pump was what we have typically seen on a car with fuel starvation issues. Dirty and oily. This pump by the way has been out of the car for a few months. In a sealed box.
To sum it up I don't understand how the car was running. The filter was extremely dirty. It was black in color and oily to the feel and oily on a cloth i used to wipe some. this was verified by my wife......:)
When I separated some of the pleats I could not even see the large shed light through it. I mean this thing was unbelievable. This pump was out of a car that had some pre mixing history. It has less than 45K on it.
I am totally convinced as of this moment that premixing will accelerate occlusion of the fuel filter---leading to reduction of pump output. If you premix just add replacing the fuel pump to your maintenance list. If you FI then balance out your risks!
Someone needs to design a return less system with a separate filter than maintain our pressure and volume need.
I think the 7's dont have this problem because of a difference in design of tank etc. But I am not really sure.
olddragger
olddragger

olddragger 08-13-2007 08:35 PM

that was the summation---but not for me anymore.
OD

TeamRX8 08-13-2007 09:51 PM

acute scientific skills FTW!1111

MazdaManiac 08-14-2007 01:49 AM


Originally Posted by TeamRX8 (Post 2013157)
acute scientific skills FTW!1111

For those paying attention:

OD used a pump supplied to him.
I actually took mine out and apart on Thursday. It was pristine.
I pre-mix more than most (8 to 12 oz per tank).


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