kevink0000

For anyone interested in more examples of peak OMP output:

Quote:

Originally Posted by Steve@VersaTune

We did well over a hundred pulls over several days consuming more than 15 gallons of fuel and over a quart of oil.

Quote:

Originally Posted by Steve@VersaTune

We paid careful attention to ambient temp, intake air temp, and coolant temp so that things are repeatable. Pulls were done at 80C ECT and 20C IAT. When we came to the conclusion that any given tune was done, we did multiple pulls to confirm repeatability. We did about 10 pulls on the final tune that we published to be sure that it was repeatable. This ECU/engine is very sensitive to heat. It dumps fuel when it gets hot. It's important to keep temps under control to see consistent top performance.

Red line envy

Hey team is there a way to jump the wires going to the Omp with resistors or something to trick the ecu into thinking it's there. (I doubt it). I have two Omp and either one fixed my problem. I know it's proly the wires further up the harness or something but I would still love to ditch the Omp all together. Standalone ecu proly the only way to do that though.

TeamRX8

iTrader: (25)

the only solution I know of would be the Adaptronic Modular ECU, but they’re recently discontinued/sold out and not going to pass emissions compliance depending on where you live and if that matters. The only other thing is maybe advancing the position sensor just slightly CCW to make sure that it’s not the issue. If the sensor position was right on the edge or has worn some to place it there, then moving it slightly might help.

I was having AC issues on my Civic Si and the shop wanted to install a new compressor for $600. It would work fine when cool, but drop off when hot. It seemed more like the magnetic clutch was the issue. Because the AC was super cold on first start up or when cooler at night, but then kick out the hotter it was.

It turned out that taking the AC pulley clutch cover off to remove a 0.4mm (0.016”) thick shim underneath it solved the issue. Bringing the clutch cover just only that much closer to the magnetic coil was enough for it to pull in and stay engaged, and now it can run all day in this crazy 100°F+ heat without issue. As a number of us have found, having the MOP sensor switch just barely off from the ideal position will make the difference between limp mode or not. In my case it was just bolting it on to a rebuilt motor resulted in limp mode, small position turn of the sensor and never a problem again. So maybe try that.


so I might as well go full off the rails then; if a Sohn provides so much more oil to the engine, yet provides no more durability, because again people racing many, many of these engines over many seasons/years ran a lot less oil premixed without issue, and all the pro builders, race series organizer, and racers all know about but don’t choose to use a Sohn, then how does that prove anything other than it’s a waste of money? Instead of pouring it in with the fuel you pour it into a tank that needs to be monitored. I’ll never have a Sohn and the only reason I have the MOP is due to rules requirements.
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SleepeR1st

iTrader: (2)

If the plugs foul up from too much oil injection or premix, do they foul up so badly that they get so impregnated with combustion byproducts that cleaning doesn't help and they need to be replaced? When I had my first 8 I didn't premix back then but I would regularly clean the plugs as part of my oil change routine.

I wonder if the IGN-1A coils can provide a better spark that can overcome higher premix levels without fouling the plugs as easy. I guess ultimately up to a certain point it doesn't matter due to the oil blowby issue at higher levels of injection and reduced octane rating. Too much of a good thing ultimately isn't good.

TeamRX8

iTrader: (25)

just owning up to and admitting my error; since the edit correcting my misjudgment and refuting my false accusation may not be seen by some:

kevink0000

It takes a lot of 2 stroke to foul the stock heat range plugs with good coils and wires. You probably only have a minute or minute and a half after a dead cold start in winter to foul a plug, even with mondo oil usage. Ask me how I know. If you want to clean them, 2 stroke ash is much easier to remove than motor oil ash.

kevink0000

No judgement at all. Your contributions are many, and errors are expected at the level of inquiry you are at.

It is no reflection on your person or character to have made a mistake. At all.

kevink0000

The OMP "switch" is kind of a PITA. I have a couple around I was messing with to find out how to fix them when they fail. I never got far, I found one that works and wanted to drive again. I would say to double check the resistance values, you may have a bad switch, I chased what I thought was a improper alignment of the switch for a lonnnnng time until I found the switch was intermittent. Its values change with temp, which makes it even more fun, since it is a carbon track pot, not really a switch.

I may have time tomorrow to look at them and see what causes outright failure, in case that is your issue.

BigCajun

iTrader: (1)

To be clear, are you saying because you are NOT using the OMP your 8 is in limp mode?

Red line envy

No I have it blocked but still plugged in. If only the car knew it didn't need it. I'm in limp mode because of Omp even though it is not active. Is that irony?

TeamRX8

iTrader: (25)

just fix it already; did you try adjusting the sensor switch yet?

somebody had an issue with water in the connector as well. The ECU has to verify the position on startup. If anything interferes with this it will execute Limp mode.

Red line envy

I Have checked everything but rest of the wires going to the Omp. I only opened about six inches of the harness last time and found a bare spot on a wire.

The car is half apart now anyways cause I'm just gonna do all the things I neglected to do because I just wanted to drive it lol.
1 exhaust leak between manifold and engine do to broken bolt
2 air pump delete since the manifold will be out (no I don't have a cat)
3 Omp is getting mounted where air pump once was.
4 clean clean clean and maybe paint some things in the bay.
5 heat wrap exhaust manifold or lower intake manifold

TeamRX8

iTrader: (25)

are you getting any cel codes for it?

otherwise maybe review this post to pull the sensor and verify the shaft end to it is cycling when the key is turned on

https://www.rx8club.com/series-i-tec...6/#post4919746

worst case I have several low mileage ones and can send one to try and see if that corrects it. The biggest issue with these is if the sensor goes bad they don’t sell a replacement. It requires purchasing a new MOP to get the sensor. Likely because you technically can’t calibrate it, but most of us have figured out that just moving the sensor to the point the slack is taken up is close enough. In your case it doesn’t even matter since the MOP is off to the side.
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kevink0000

One of the manufacturers that in my opinion is still engineering 2 strokes (although they no longer make Evinrude 2t) very well in these modern times, is BRP. Here is an example from Car and Driver, of all places, of snowmobiles. Fortunately, C/D logged both fuel and oil consumption. This with the E-TEC engine which is designed to be very fuel efficient, and more "green" with lower oil usage and lower emissions. It also has a power density just a bit lower than the Renesis. Maybe Snox can chime in on this, as he probably has seen these up close or even worked on them.

In their test it gave 17mpg fuel and the oil usage ratio amounted to 26:1. It a pretty advanced engine, with an ECU controlled metering pump.

I will try to attach document later, I am having connectivity problems.

Here is link:

https://hmg-prod.s3.amazonaws.com/fi...1544205392.pdf

TeamRX8

iTrader: (25)

too bad they aren’t wankel engines, then there might be some actual rather than assumed relevance.
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kevink0000

That's what we're here to discuss.

The relevance is the factory OMP settings in the RX8 provide significantly more oil at full throttle than is commonly noted and recognized, in line with, perhaps even exceeding at times the ratio % BRP has specified in this engine.

SleepeR1st

iTrader: (2)

Does Skidoo put catalytic converters on their e-tecs?

kevink0000

No, not that I could find.

TeamRX8

iTrader: (25)

when I recently tried to imply to someone on here that a wankel and a 2-stroke are significantly different on many levels all I got in return was an ironically clueless reply about how I was unable to respond in anything meaningful way. You can’t make that level of no-understanding up.

it wouldn’t be any different trying to point out that unlike a street engine in somebody’s car, FAA regulations mandate engine rebuilds after so many operating hours regardless. We could discuss a lot of other variances too, except my advice to someone more open-minded is not to waste time on it.

because this unresolved topic is decades old and the equivalent searching for the Holy Rotary Grail that simply doesn’t exist. Being fixated on the wrong thing is never a good thing, but some people are destined to do just that. Suffer it to be so.
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kevink0000

I will add this now, I was going to wait for more mileage to accrue but that will likely take a while since I am driving a different 8 now.

It is no way meant to be conclusive, but the 8 my son bought from Smutterbutter 4 years ago that then I bought from my son and used as a DD, has about 78k miles on Smutter's home rebuild.

Shortly after the car arrived here, I did a compression test, which was about 10-11k after the engine had been assembled.

I did another compression test recently, about 66-67k after the first one I did. The starter was a lot slower (40-45 rpm slower) but the engine showed exactly the same compression when adjusted for rpm.

Both rotors has the same relationship, with the rear being lower. 118/121 psi. This was with the same non-rotary gauge, tested the same way it was before. (Valve out, take video, then peak hold)

This is not enough mileage to get excited about for sure, but the fact that there was no degradation at all, might prove to be significant in the long run.

The OMP mods in this thread were put into use when we first got this car, in addition to premix. The combined ratio was about 60:1 for normal driving, then would get a lot lower than that if the pedal was pushed down.

Smutterbutter built this engine with used housings, also. The irons were resurfaced.

kevink0000

Of course, I disagree. I think when you say "open-mindedness" and "decades old" in the same statement you are actually making a case for close-mindedness.

Both the 2 stroke and the Wankel use a total loss system for top end lubrication. shut that system off, and both engines would fail quickly. Of course there are similarities. Similarities that bear exploration.

ThreeTreeDog

How Is this engine now?

TeamRX8

iTrader: (25)

I’m not open-minded because I accept that there’s no such thing as a perpetual motion device? There’s a point where a person crosses over to being foolish in refusing to accept established realities.

I believe in common sense over being foolish as much as being straight up rather than engaging in nonsensical word games that only deceive and ensnare other foolish people.
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kevink0000

We differ. To each his own.

kevink0000

Which engine are you referring to?