Rotary help. 2010 series 2 RX8

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Originally Posted by d00df00d
Originally Posted by TinyVoices
I have the cat, I have just heard from all the forums that they fail easily and get blocked up and cause a ton of issues, hence everyone running cat deletes. If that isn't true, i'll throw it back in.

Oh, it's true alright. But mainly because people flood their engines, drive way too long with their engines running like crap, and then keep driving after their cats have clogged up. Often they don't stop until the cat glows after short drives or the engine just won't run. By that time it's far too late.

S2s are less susceptible to flooding and poor running, and the S2 cat is bigger. Plus, the symptoms of a bad cat are pretty obivious once you know what they are; the car basically just runs out of breath at high RPMs. If you stay on top of things, you'll be fine. Even if the cat does fail, you can catch it and fix it long before it takes anything else with it.

My R3's cat failed at ~54k miles. The failure appeared literally within hours of when I picked the car up from an incompetent dealership (airbag recall). Then I drove on it for like 2k miles while trying various troubleshooting steps because I wasn't getting a CEL and didn't know better. The engine ran another 20k miles before compression fell below Mazda's spec for warranty replacement -- but it never got bad enough to cause any starting or running problems. And I know for a fact that compression wasn't the best when I bought the car at 21k miles -- probably because the car had been a dealer demo or something for like a year and a half before it was sold.

But yeah, it is a possibility. You just have to weigh that against the toxic crap you're spewing without a cat. For me, it was a no-brainer. I refuse to be "that guy". But it's your call.


I likely will throw it on. The PO said the cat was removed at like 14k miles and never reinstalled so its likely that it'll last me a while before failing. I'll probably throw it back in considering its a quick and easy job.
 
Originally Posted by TinyVoices
I likely will throw it on. The PO said the cat was removed at like 14k miles and never reinstalled so its likely that it'll last me a while before failing. I'll probably throw it back in considering its a quick and easy job.

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Maybe you can trade the decat pipe for someone else's good used cat. Wouldn't suck to have an extra around.
 
Originally Posted by d00df00d
Originally Posted by TinyVoices
I likely will throw it on. The PO said the cat was removed at like 14k miles and never reinstalled so its likely that it'll last me a while before failing. I'll probably throw it back in considering its a quick and easy job.

thumbsup2.gif


Maybe you can trade the decat pipe for someone else's good used cat. Wouldn't suck to have an extra around.


Thanks again. You seem to know a lot about these cars/motors. 5w20 sounds scary and thin but if its what people run, I'll do it. Haha
 
I like the rotary engine for the design and out of the box thinking. By why would anyone own a car that has so many caveats? I don't mean to knock the car at all, just curious.
 
Originally Posted by JoelB
I like the rotary engine for the design and out of the box thinking. By why would anyone own a car that has so many caveats? I don't mean to knock the car at all, just curious.


I mean it has a lot less moving parts than a piston engine and when well maintained, they make phenomenal power for their displacement. As long as you expect the engine will have to be rebuilt eventually, there aren't really any real issues. Keep oil in it, standard maintenance, high octane gas, and go. Things like needing ignition coils replaced or catalytic converters failing are common to many cars, not just rotaries. Plus there is something satisfying about knowing you are SUPPOSED to redline the engine often, as stated by the manufacturer. Confidence to drive the [censored] out of the car, as it was intended.
 
Originally Posted by TinyVoices

Should I get an intake more similar to the other common design for these cars like this:
[Linked Image]


Yea. This one. Right out in front to catch all the dirt, rocks, bugs, road kill and rain water.
 
Originally Posted by d00df00d
I had a 2011 R3 until just this past October. I researched the crap out of this and cut through a lot of BS.

To make a long story short, there only seem to be two worthwhile engine oil options for this car:

1. Idemitsu Racing Rotary Engine Oil 10W-30
2. Any GF-5 5W-20 non-synthetic.

As far as I can tell, the problem with synthetics isn't with the basestocks per se; it's the combination of certain synthetic basestocks with certain additive packages. Running a GF-5 5W-20 non-synthetic is a really easy way to avoid all that, which is probably one reason why Mazda insists on it.

Idemitsu was Mazda's lubrication partner for the rotary-powered 787B race car, and they've published some of the definitive papers on Wankel engine lubrication. They know more about this than anyone other than Mazda. Their rotary engine oil is a full synthetic, but with a lot of ester content, which should provide good self-cleaning. What really separates it from other oils is its additive pack. It uses a lot of anti-wear additive and a fat slug of friction modifier (moly), but doesn't go overboard on detergents/dispersants. That allows it to keep ash levels low when it's burned, and ensures that the detergent/dispersant additives don't interfere so much with the AW/FM, while retaining enough cleaning ability for short-to-moderate OCIs. Most oils are the opposite: they have tons of detergent/dispersant for medium-to-long OCIs, and then manage ash levels by lowering AW/FM. Or they just have a lot of everything, and form a lot of ash as a result. That's a lot more likely to be true of a synthetic oil, which is probably another reason why Mazda insists against them.

The only problem with that Idemitsu stuff is is that it's expensive. Compared to a GF-5 5W-20 non-synthetic with shorter OCIs, I figured it'd have to extend the life of the engine by 20-40% to be worth the money. That seems like a bit of a stretch.

The idea to use heavy oil seems mainly to come from a desire to protect the gears and bearings better than a thinner oil can. There's some merit to that idea. But try asking someone who advocates thicker oil whether they have any evidence that it does what really counts, i.e. make the engine last longer between rebuilds. If you get an answer, let me know. I've tried that many times and gotten nothing.

The stock oiling system, including the MOP, was designed for xW-20 and xW-30 oils. Mazda's own Renesis-specific oil, sold only in Japan, is a 0W-30. Japanese dealers put 0W-20 in it all day. In Europe, Mazda recommends an ACEA A5-rated 5W-30 -- but there's no indication that that's for any reason other than to cope with longer OCIs.

There should be plenty of xW-20 and xW-30 synthetics that'll work in this car. I've just never found enough evidence that they'd be worth the money over a good GF-5 5W-20 non-synthetic.


Would oil blends that use non-metallic or metallic friction modifiers be ideal then?

poking at valvoline conventional and maxlife as a non-metallic represenative:
http://pqiadata.org/Valvoline_5W20.html
http://pqiadata.org/Valvoline_MaxLife_5W30.html

poking at Quaker State as a metallic represenative:
http://pqiadata.org/QuakerState_Defy_HM_5W30.html
[note that this is SN, not SN plus, which ought have less Ca now]

I'm curious if Boron additives might help for this application..
 
Originally Posted by JoelB
I like the rotary engine for the design and out of the box thinking. By why would anyone own a car that has so many caveats? I don't mean to knock the car at all, just curious.

I can only speak for myself, but here's what it came down to for me: There is no car with equal-or-bigger back seats that handles better in stock form or mod-for-mod, at any price, ever.

The engine is a major reason for that. It's light and extremely compact, so it can be mounted really low and behind the front wheels, and it leaves a lot of room around it for a rigid structure and good suspension.

I actually agree that the RX-8 is a terrible car for most people, just because most people don't value handling enough to put up with the downsides. But for those few of us who do, it's very hard to do better unless you're willing to give up the back seats.
 
Originally Posted by Brian553
Would oil blends that use non-metallic or metallic friction modifiers be ideal then?

poking at valvoline conventional and maxlife as a non-metallic represenative:
http://pqiadata.org/Valvoline_5W20.html
http://pqiadata.org/Valvoline_MaxLife_5W30.html

poking at Quaker State as a metallic represenative:
http://pqiadata.org/QuakerState_Defy_HM_5W30.html
[note that this is SN, not SN plus, which ought have less Ca now]

I'm curious if Boron additives might help for this application..

Good question. I don't know enough to even guess.
 
I have plenty of experience with Rotaries. Just run a decent synthetic Xw30/40 or conventional 10w40 or 10w30. 5w20 is too thin when hot. My brother has been running synthetic 10w50 in his old 13b in his 86 rx7 and is currently at 180k miles on the original engine. Synthetic is nothing like what it used to be and burns perfectly fine. I personally run Castrol edge 5w40 in mine and it is happy as can be. My friend with an rx8 is sitting at 140k on the original motor and has run autozone housebrand/stp 10w40 since he bought it at 50k miles.
 
Originally Posted by d00df00d
Originally Posted by JoelB
I like the rotary engine for the design and out of the box thinking. By why would anyone own a car that has so many caveats? I don't mean to knock the car at all, just curious.

There is no car with equal-or-bigger back seats that handles better in stock form or mod-for-mod, at any price, ever.



This is what it was for me.
 
Originally Posted by TinyVoices
Originally Posted by d00df00d
Originally Posted by JoelB
I like the rotary engine for the design and out of the box thinking. By why would anyone own a car that has so many caveats? I don't mean to knock the car at all, just curious.

There is no car with equal-or-bigger back seats that handles better in stock form or mod-for-mod, at any price, ever.



This is what it was for me.

Hooray! Someone who gets it!
cheers3.gif
 
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