Some questions for my build

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Feb 7, 2019 | 08:37 PM

BTNH-LC

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From: Las Cruces, NM

Some questions for my build

So I just got back in the RX7 game after 10 years away and had some quick and probably stupid questions. First off I'm building a S4 TII. The motor will be half bridge port, fully studded, lightened and clearenced rotors, with the RX8 oil upgrades and all balanced. So my first stupid question is on what oil to use. I'm using the OMP and will also premix. I used to use cheap 20W50 but with how much money I'm dropping on the engine, I feel like I should use something better. I've heard in the past that full synthetic was bad for rotaries but now that I'm more experienced, that doesn't make sense. So suggestions would be appreciated.
Second question: I was running RC 550cc primaries and RC 750cc secondaries but I'll be going for more power. I was thinking of keeping the primaries the same and upgrading to 1200cc secondaries but I would like opinions on the matter. My goal is 450 to 500 WHP.
Also other suggestions for this build are welcome. I am an mechanic by trade but that's all piston stuff and I'm somewhat inexperienced with rotary performance choices. I'm sure I'll have plenty more questions for those willing to help. Thanks

Feb 8, 2019 | 03:43 AM

Sgtblue

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Oil question: There are valid arguments for and against synthetic oil...in the final analysis it's up to you. I will tell you what I do...My car still has the stock twin turbos and I run full synthetic with a working OMP and premix at about half-rate (.05 oz. @ gallon). I’ve used synthetic for the 16 years I’ve owned the car and premixed with the OMP for the past 12 years. Anecdotal, but those are the original turbos, now with about 130k. They don’t smoke or leak and still boost just fine. Still, it’s at least as important, especially with your engine mods, to be moving the change intervals closer regardless of the type of oil used.
I also have a simple Water Injection system so carbon deposits aren't a big concern. Since you also get knock suppression and cooling with WI, it...or Auxiliary Injection, is something else you could consider down the line since you're forced induction. There's a sub-forum for it with several evenings worth of good ‘Sticky’ reading.

Last edited by Sgtblue; Feb 8, 2019 at 06:57 AM.

Feb 8, 2019 | 09:24 PM