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I just got a 2005 manual RX-8 70k original miles absolutely clean. Only 1 owner who drove it barely 10k a year. Kept it in a garage for a long time. Had a minor issue and decided to auction it. Dealership got it from the auction, they fixed the issue, then I got it from them. I made sure it would cold start and hot start. Clutch is smooth so gears are great. Suspension might need a look over, but rough. It doesn't veer when driving it's solid. Ac, windows, radio, sunroof everything works. I think I got really lucky. But I do want to take really good care of it. What oil should I put in it? Should I put premium gas in it every time, should I put an aftermarket air filter in it? Just want some advice. Please and thank you all.
5W30 non-synthetic oil use and use high quality oil filters. To prevent engine knocking- use premium fuel. Did you have the engine compression tested with a rotary-specific engine tester for both rotors?
5W30 non-synthetic oil use and use high quality oil filters. To prevent engine knocking- use premium fuel. Did you have the engine compression tested with a rotary-specific engine tester for both rotors?
No, I haven't gotten a compression test done yet. I just bought it 2 days ago. So I have to go to a mazda dealership for that? How much would it be to just buy my own compression test kit for a rotary? My dad's a master mechanic but has never worked on a rotary.
Unfortunately the owner of rx8help.com seems to have vanished, but if it ever comes back it's a great summary from that thread.
You can do the comp test at a dealer or at a rotary specialist if there is one near. Where are you? You can buy or build a tester, but it should be 1.5 hours of work max at the dealer, a tester is about $300.
Always premium gas. Not just for knock but for detergents and overall system cleanliness.
The number one killer of engines is ignition coils. Replace preemptively.
Air filter: the filter sure, why not, the intake itself can't really be improved, and can easily be made worse with aftermarket stuff, so keep that stock.
Unfortunately the owner of rx8help.com seems to have vanished, but if it ever comes back it's a great summary from that thread.
You can do the comp test at a dealer or at a rotary specialist if there is one near. Where are you? You can buy or build a tester, but it should be 1.5 hours of work max at the dealer, a tester is about $300.
Always premium gas. Not just for knock but for detergents and overall system cleanliness.
The number one killer of engines is ignition coils. Replace preemptively.
Air filter: the filter sure, why not, the intake itself can't really be improved, and can easily be made worse with aftermarket stuff, so keep that stock.
ok I'll do that! Thanks for the info! I live kind of central indiana little north. By Kokomo. Little town called Peru.
I’ve had my rx8 now for 17 years what I can tell you right now is yes use premium gas. Your catalytic converter is very particular and using unleaded. Gas can cause clogs in your catalytic converter. Your rotary engine will throw a small amount of gas out of the exhaust, it doesn’t burn every bit of it. It does have a fair bit of a how do you say backfire which causes problems with the Cadillac converters so you’ll have to watch the catalytic converter also if you have stock coils in your engine, you’re gonna have to change those out. I suggest getting a LS coil kit and changing that out that will actually help because your coils stock coils will give out and the LS cools will not give out and they will also give you better performance and also higher combustion. I would also suggest cooling mods. You’ll always have to watch cooling keep an eye on your reservoir sensor because the reservoir tank sensor tends to go out and when it goes out, you’re constantly seeing your reservoir light pop on and then I’ll turn off pop on turn off. It’s not a problem really but it’s an annoyance. Also get a Sohn adapter Your engine will burn a lot of oil. It sends oil into the engine to burn that’s nature of a rotary it mixes, gas and oil so your engine will consume a lot of oil so if you get a Sohn adaptor with a reservoir you avoid burning all the oil in your old pan. Also, make sure to get new aftermarket oil coolers. The ones that you have stock which if you have a manual, you have and the stock ones are not very good. You’re gonna need to change those out to essentially upgrade. You don’t really need to pre-mix if you have sohn adapter if you do not have a Sohn adapter, I would say not every tank of gas the premix, but at least once a month premix but like I said your main problems that you’re going to have with the vehicle are going to be your coils and your Cadillac converter, but as long as you keep taking care of those to your car might be somewhat reliable. They’ve been the cause of every breakdown I’ve had so far I’ve caused every problem I’ve ever had even the expensive problems I’ve ever had. I’ve been caused by misfires and Cadillac converter failures
I’ve had my rx8 now for 17 years what I can tell you right now is yes use premium gas. Your catalytic converter is very particular and using unleaded. Gas can cause clogs in your catalytic converter. Your rotary engine will throw a small amount of gas out of the exhaust, it doesn’t burn every bit of it. It does have a fair bit of a how do you say backfire which causes problems with the Cadillac converters so you’ll have to watch the catalytic converter also if you have stock coils in your engine, you’re gonna have to change those out. I suggest getting a LS coil kit and changing that out that will actually help because your coils stock coils will give out and the LS cools will not give out and they will also give you better performance and also higher combustion. I would also suggest cooling mods. You’ll always have to watch cooling keep an eye on your reservoir sensor because the reservoir tank sensor tends to go out and when it goes out, you’re constantly seeing your reservoir light pop on and then I’ll turn off pop on turn off. It’s not a problem really but it’s an annoyance. Also get a Sohn adapter Your engine will burn a lot of oil. It sends oil into the engine to burn that’s nature of a rotary it mixes, gas and oil so your engine will consume a lot of oil so if you get a Sohn adaptor with a reservoir you avoid burning all the oil in your old pan. Also, make sure to get new aftermarket oil coolers. The ones that you have stock which if you have a manual, you have and the stock ones are not very good. You’re gonna need to change those out to essentially upgrade. You don’t really need to pre-mix if you have sohn adapter if you do not have a Sohn adapter, I would say not every tank of gas the premix, but at least once a month premix but like I said your main problems that you’re going to have with the vehicle are going to be your coils and your Cadillac converter, but as long as you keep taking care of those to your car might be somewhat reliable. They’ve been the cause of every breakdown I’ve had so far I’ve caused every problem I’ve ever had even the expensive problems I’ve ever had. I’ve been caused by misfires and Cadillac converter failures
ok I'll check into all that! Thanks for the advice!
I would leave the oil coolers well enough alone. They're plenty for normal climates (again, location). Maybe straighten the fins and put a mesh in from of them for protection. Racing Beat sells a kit. You could plan for radiator replacement though, if it's still the original 20 year old plastic in there. CSF or Koyo are great.
Premixing sometimes doesn't make sense, you need a constant supply of oil if you're going to do it, not an occasional bump. Look into the Sohn, but I would also premix. The Sohn solves the problem of supplying more appropriate oil, while premix solves the problem of delivering oil to more places.
Straightening the fins is FREE and really easy with two toothpicks. You just pull the toothpicks away from each other towards the top and bottom of the cooler while between fins.
Premixing just 100% guarantees you are lubricating the combustion chamber. However remember there is fuel cut when you are off throttle, so no premix will be in the chamber during that time. The sohn kits allow you to make your oil injection pull from a clean separate tank. Is it necessary.....not really if you check your oil regularly. However it allows you to run synthetic in the engine and a 2cycle for the injection system that you can monitor easier.
Rotarycompressiontester.com does sales all the time, usually posting on the forums. If you plan on keeping the rx8 long term I would just buy one. Otherwise just remember that 90% of hot starting issues are caused by compression.
typical items I would replace on any new rx8:
radiator(go all aluminum) + coolant tubing(autobahn88 sells multiple silicone kits that you must figure out which ones you need)
Battery (optima red tops suck ***, I use antigrav from sakebomb. However I was recently impressed by my buddies cheap as **** everstart..... 3 years old and it turned over his car 25+ times.)
Ignition coils+wires+plugs, stock coils tend to fail and weak ignition leads to cat failure. Teamrx8 has a good thread on testing coils.
Starter, there is an upgraded starter available for around 70$ on amazon. The faster you can spin the engine, the more compression it gets to help start.
Many rotary guys also ditch the cat as it is a major failure point, but that is up to you as it may be illegal. A good exhaust combo I found is the Racingbeat dual res midpipe+turboXS catback. Basically at the sweetspot of no drone, but isn't weak and raspy.
However remember there is fuel cut when you are off throttle, so no premix will be in the chamber during that time.
This is off topic, but at least in the S2s, fuel isn't cut completely when off throttle. I have mine set up with some instrumentation, and live up in the mountains above Denver. I regularly go down long stretches off throttle. I noticed that the calculated instantaneous fuel economy is higher coasting in neutral than in gear at higher RPM. Throttle is closed either way, so the difference is RPM. The difference in fuel economy is fairly substantial. It's not cutting fuel off throttle.
