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what is premixing and the benefits

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Old Apr 26, 2010 | 08:09 PM
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what is premixing and the benefits

hey guys just read a post that mentioned premixing. can someone explain this to me? thanx
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Old Apr 26, 2010 | 09:22 PM
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Mixing 2-stroke oil into your gas tank and disabling the metering oil pump. Benefits? Basically nothing. If you're adding more oil than the OMP would normally add, you could theoretically be reducing any potential seal/housing wear. However, you can also introduce some smoking from the exhaust due to all the excess oil burning off. I've done it, and it was a pain in the ***. I ended up hooking the pump, lines and injectors back up soon after. A working oil metering system is far superior, except in the case of S5s, which often have the electric pump fail. The Rtek for S5s disables the OMP and allows premixing instead. This is a much cheaper route than going with new electric OMPs.
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Old Apr 26, 2010 | 09:45 PM
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well i premix on both my 1st gens and i dont have a problem with it at all as far as it being a "pain in the ***".. crank case oil does not burn as good/clean as 2stroke oil period... check this thread out and make your own decision bro good luck https://www.rx7club.com/showthread.p...ight=premixing
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Old Apr 26, 2010 | 10:27 PM
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Originally Posted by intorx7s
... crank case oil does not burn as good/clean as 2stroke oil period..
The difference is insignificant. The lubricating components in your average mulit-viscosity conventional oil are essentially identical to what's found in 2-stroke oil. The only real difference is the viscosity index improvers, which are high molecular weight polymers. It all contains carbon chains, so while the OMP system burns very little oil under most conditions (throttle controlled), a premixed car will burn lots of oil at all times. You're going to end up with the same or MORE carbon byproducts from the combustion process.
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Old Apr 27, 2010 | 07:51 PM
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introrx7s thanks for the link....and i know about the s5 omp just bought a used omp and ecu do to them both failing....rotoryrocket u sure you aint a scientist lol....really guys thanx for the input
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Old Apr 27, 2010 | 11:04 PM
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Originally Posted by MR. ROTARY
rotoryrocket u sure you aint a scientist lol.
Actually, I am a chemist by profession.
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Old Apr 29, 2010 | 03:39 PM
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There is no significant advantage to premixing for "daily driver" vehicles. The main use for it is on track because it reduces the wear on the seals (because noone wants a broken seal on a rotary.)
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Old May 13, 2010 | 04:06 AM
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as rotaryrocket said when you premix you don't get the controlled amount of oil as you would get from using the omp. Another disadvantage of running premix is that it reduces the octane of your fuel ever so slightly.

Last edited by RotaryRocket88; May 13, 2010 at 09:52 AM.
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Old May 23, 2010 | 05:50 AM
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I've never had a problem letting the OMP do the work, some uk owners premix and use the metering pump as well.... seems like overkill to me, especially in a normal roadcar
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Old May 23, 2010 | 11:40 PM
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I think i'm going to try running both, if you look at pettit racing's website they love premixing regardless. And since you can't get there premix should i use mmo or idemitsu?
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Old May 24, 2010 | 10:13 AM
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Running both the metering oil pump and premix will just waste money and foul spark plugs. The only time you'd want to premix a little with the stock metering oil pump is for track driving.
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