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Mazda RX-8

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  • As far as I am aware, you can order satellite radio when you order your car, if you do a special order like I did. I'm not getting satellite radio so I didn't pay a lot of attention. I saw on the pricing guide they had a price listed for fender strakes as being a port installed option. However, it wasn't available when I placed my order. As far as I know, to get a good deal on the strakes, you would have to buy them at the time you buy your car, i.e. sign the papers and pick it up. Even then I think it is up to dealer discretion since it is basically an extra accessory for the car. When I did my order I told them I wanted the strakes and wanted to have them already installed on my car when I get it. I was told they almost always have at least one set in stock, but to double check with them when they notify me it is "released from port" since it would take a week to get them in if they didn't have some in already. (There is always the option of taking their's from the display case if nothing else).

    It appears my ETA is April 17 due to an electronic parts availability issue (they ran out of something) I think that had to do with my Navigation. This is fine by me since my work cut my pay down to $9 an hour from $25 an hour and I can't afford my car on that salary let alone anything other expenses (was told a few months ago the work slow down and shortage was just temporary; it's not and they cut my pay, too). Fortunately, I have a job interview for a new job in the same field at another hospital so I am thinking it is highly likely I am getting it. The position has been available since at least the beginning of December and is listed as "critical to fill" with hiring bonuses. I have the interview next week. They called me within two days of sending my application in. I will still keep my current crap job for a few months part time to get a little cash built up to pay down some other bills so I won't have to work so much to afford everything. I will have to drive to the new job, though, so I will really need my car!!! Currently I work at home.
  • pathstar1pathstar1 Posts: 1,015
    My understanding of the manual recommendation is they (engineers) figured there was fuel "pooling" inside the engine when the engine was cold. If you shut it down at idle the fuel just stays there. If you rev. it up it disturbs the pooled fuel and it gets exhausted from the engine. I'm not sure why they don't recommend shutting off at 3000 RPM - perhaps they were worried some would "pop" the clutch and loose control of the car. As I said, it's better than doing nothing and I haven't seen any problems caused by doing it. It has been my operating procedure even with a warm engine.

    As far as warmup, as soon as the oil pressure is up you could drive away. Just don't use a lot of throttle. This isn't peculiar to rotaries, it applies to any high performance engine - any engine even. When the engine is cold the parts haven't expanded to their final size and high power output can cause the parts to wear faster. After a few minutes of driving the engine is at "operating temperature" (the metal parts), and after about five minutes the coolant should be at its' control temperature.

    Another way to look at it is when the temp. gauge is off the cold "pin" about 1/4" you can safely shut off the engine (safely re flooding). If you want to warm up a cold engine I find running it at 2000 to 3000 RPM cuts the time down a lot. Of course it also uses more fuel - tnstaafl (there's no such thing as a free lunch). ;)
  • mdw1000mdw1000 Posts: 171
    Tripsec,

    Did your RX-8 come with the "driver's guide" or did they just start including that recently? That is where they talk about needing to do it for an engine that is not warmed up. I know the service guys in the department at my dealer have been to the special rotary school that mazda has, and the depts opinion seems to be only do it when you haven't been able to properly warm up the engine.
  • plektoplekto Posts: 3,706
    The problem is identical to my old Mercedes, though it will start reguardless since it's an inline-6. :)

    The engine uses oil during operation. The real problem isn't fuel, which mostly evaporates and is easily and almost insteantly burned off, but oil that seeps in and pools over a few hours. So you need to drive it and/or rev it a bit to "blow out" the excess oil in the cylinders.

    My trick is to start it, let it idle until the temp gauge *just* starts to come off of the bottom(about a minute or so), then drive it gently until it gets warm. Works like a charm and no vapor-lock(got carbs that are a bit famous for this, actually), either. Cold oil sits there, pretty much, while warm oil is easy to get rid or or spread around the cylinders. If the injectors or plugs get clogged with gummy oil sediment... oops.

    That said, my car runs like junk for the first 2-3 minutes until all fo the excess oil and crud is gone. Then it's fine all the rest of the day. I suspect this is happening with the RX-8, though it should clear up much faster due to fuel injection and computers. Maybe a minute of bad behavior on really cold days.
  • trispectrispec Posts: 305
    No "driver's guide" in mine. The advice on the 3000RPM shut down is from experienced rotary owners and engineers who've had long experience with rotary engines going back over the decades.

    My RX-8 has never needed more than 2 or 3 seconds to fire up even on 10F degree mornings. I just started to test another shut down procedure to see if the fire up time remains the same.
  • trispectrispec Posts: 305
    My new shut down procedure is very similar to the 3000RPM rev for 10 seconds then immediate cut the switch.

    The new procedure is 3000RPM for 10 seconds, then take my foot off the throttle for half a second, then cut the switch.

    The theory being, that by being letting off the gas first, that a even more of the remaining gas will burn up because for half a second the spark plugs will still being flashing. This probably happened anyway at times under my old procedure just from the random chance that my foot came of the gas before the switch off happen. So I'm not risking any thing new here.

    As time goes on, I should be able to increase the time delay before switch off and then correlate this with the next start up time. If the start up starts to creep up, then I can theorize that any remaining gas is increasing and a finally theory can be published.

    Silly, I know, I know, but college statistical training needs some manner of expression, otherwise why was I pounding that useless knowledge in my head all the years.
  • pathstar1pathstar1 Posts: 1,015
    In the rotary engine it isn't oil, it really is fuel (gasoline). In a piston engine excess fuel in the combustion chambers can "leak down" to the oil pan past the rings when the engine isn't running. In a rotary this isn't possible. The path to the oil pan is "up" - that is, into the oil inside the rotor. There is no open path to the oil pan below the rotor housing.

    If you have gasoline inside a cold rotary engine, there is no way for it to evaporate, as there is nowhere for the vapour to go. In winter it wouldn't evaporate anyway, as the temperature is too low. When you try to start the cold engine with excess fuel inside the fuel soaks the spark plugs and they don't fire well if at all. Then the engine starts firing in lots more fuel (because it's in choke mode as it's cold). Now you have a flood. The only way out is to:-
    1. stop the fuel injectors from adding more fuel, (one of Mazda's fixes delayed the fuel injector firing during cold start)
    2. crank the engine to exhaust the fuel already in there, and
    3. fix the spark plug problem.

    The fixes are:
    1. hold the throttle pedal to the floor - this engages a "fuel shutdown" mode that shuts off the injectors.
    2. crank for 30 sec. at a time and let the starter rest (cool off) for a minute between. Hold the throttle to the floor throughout this procedure, otherwise you will end up with still more fuel inside! If you add a cc or so of oil to each rotor housing the pumping out works much better as the oil "finishes" the sealing in the housing. Because #3 requires removal of the spark plugs you can remove them now and add the oil in there - leave them out and you have an extra escape route for the fuel (and excess oil if you added too much).
    3. Clean or replace the spark plugs once you think you have pumped out the excess fuel.

    A flooded rotary will eventually start, be patient, it really will. It will also emit copious amounts of smoke for a few seconds (the excess fuel and oil if you added it will burn).
    In "the old days" we used to use auto transmission fluid, and it REALLY smokes!
  • I'm 6' 215 lbs. Felt very confined in the RX-8. Even my kids felt boxed into the back seats. This car seems to be for smaller drivers. I liked the styling tho. Not the confinement.
  • mdw1000mdw1000 Posts: 171
    I'm actually 5'9" 205 lbs and feel good in the car. However, if I were much taller I don't think I'd have hardly any headroom, so I can see your point. For a 6 footer to fit I would imagine you would have to lean the seatback a bit more.

    I actually fit in this car much better than the Acura TSX, which is a bigger car. The TSX was too narrow for me in the knee area, but the RX-8 fits me great there.
  • mdw1000mdw1000 Posts: 171
    trispec,

    "Silly, I know, I know, but college statistical training needs some manner of expression, otherwise why was I pounding that useless knowledge in my head all the years."

    Ha! This gave me a good laugh! I had a year of statistics in college that I have yet to use...

    Your new procedure sounds basically the same as the "driver's guide" procedure with the exception that you do it every time. Right now I am doing the same thing if I run the car for less than 10 or 15 minutes. Will see how that goes and let you know. So far no problems, and its been in the 30s and 40s F here since i've got the car. Not the coldest weather, but not the warmest either.

    I do notice that in this weather the car warms up quick. Probably won't be quite as quick on those 0 degree F days :)
  • mdw1000mdw1000 Posts: 171
    After having my RX-8 for a couple days and loving it, I'm starting to think about adding a couple things. I'm wondering if anyone has bought the mazda splashguards and if so, how they look on the car. I've noticed that these big tires seem to kick up a lot of stuff on the underside of the car - keep hearing little pieces of gravel, etc. Plus I've had dry roads and have still noticed a bit of "splash" dirt behind the front wheel wells.

    Also, anyone bought the maza all-season floormats?

    Thanks!
  • plektoplekto Posts: 3,706
    Nice info about the engine - so it's doing what my old car does with oil in the cylinders(at 39 years old, she can be given some slack - still drives better than a new Corolla), but with gas.

    Wouldn't a proper fix be to just partially open the valves when it's shut off? If the gas could evaporate, it would solve the problem, or at least most of it. I was also wondering - would changing to those multi-prong plugs help at all? Not the dent on the in the center type, but the ones that I've seen with four prongs coming in from the edges. That seems pretty near impossible to "get wet". I'd also suspect that platinum plugs with their small resistor surface in the center would fare worse as well.
  • duke15duke15 Posts: 161
    I was sorry to hear about your job bunnygirl. My wife is a nurse and has worked at several hospitals and most of them seem to do money things like that in one way or another.

    I called the Costco dealer on Tuesday, and left him a message saying that I wanted to order a car this week. He hasn't returned my call yet. I left him another message today. I never thought I'd see the day when I contacted a car salesman and said that I want to buy a car this week, and have been ignored. Maybe I'll phone him tomorrow and say, "What do I have to do to get me into a car today?". If I don't hear anything by Monday, I'll just go to another dealer, tell them what I get from the Costco program, and ask them to match it.

    Good luck on getting the new job!
  • rorrrorr Posts: 3,630
    "Wouldn't a proper fix be to just partially open the valves when it's shut off?"

    Rotaries have no valvetrain and hence, no valves.
  • trispectrispec Posts: 305
    I'm 6'1" 220lb. My wife and 7 year old son spend 16 hours over two days on a 1000 mile trip (2000 round trip) in my new RX-8. We practiced several smaller, shorter trips before, but we had absolutely no problem with the space in the RX-8.

    In fact, I can say, with experience driving Mini-Vans, four door sedans, and wagons over the same 16 hour 1000 mile route, the RX-8 blows the other vehicles away because:

    1) The RX-8 is way way easier to drive at high speed for passing and cruising. Need to get the job done in any other vehicle, you gotta work hard just to keep things on the road.

    2) The RX-8 seats, are stunningly comfortable over very long periods. Other vehicles just don't support you.

    3) The RX-8 is very easy to pack because of those suicide doors. Other vehicle might hold more, but then crap goes flying around alot too.

    4) The RX-8 is plain fun to drive over the whole trip. Other vehicle are just mind crushingly boring to drive even 10 miles.

    5) Put a golf glove on one hand then put an oven mit on the other. Which one is more comfortable?
  • trispectrispec Posts: 305
    Yep, it' now closer to the manual's procedure, but the half second with my foot off the gas is not really long enough for the 3000RPM to drop much so the pumping action of the rotors is pretty much the same as before. But more gas is definitely being burned up in that half second.

    Having done this modified shut down procedure a dozen times now, I can definitely say, that start up is much smoother and quicker with 1 second crank times every time. There must have been a very small bit of gas left before, because there was a little bit of a jerk to most startup. Now, it's like turning on an electric motor
  • plektoplekto Posts: 3,706
    Rotaries have no valvetrain and hence, no valves.

    That was my point, too - perhaps a device that opens up the intake ports or maybe even a couple of purge-valves(or simmilar) when it's off? Let some air into the engine. When the key is put in the ignition, they close click shut/back into position When the key is removed, they open up.
  • nikkonikko Posts: 3
    I'm 6'3" 195 lbs and fit fine in my RX8. I even have a sunroof.
  • rorrrorr Posts: 3,630
    "That was my point, too - perhaps a device that opens up the intake ports or maybe even a couple of purge-valves(or simmilar) when it's off?"

    As I understand rotaries, the intake ports are ALWAYS open. They 'open' and 'close' as the rotor spins in the housing and the face of the rotor alternately covers up and then uncovers the ports (same for the exhaust side). The portion of the housing containing the spark plugs is located in a separate part of the housing from the intake. In other words, any fuel remaining in the portion of the housing containing the spark plugs is physically seperated from that part of the housing containing either the intake or exhaust ports.

    Yes, I suppose that if the problem were severe enough, purge valves could be installed so that fuel remaining in the chamber with the plugs would have a means to escape. Personally, I don't think the problem is severe enough.
  • pathstar1pathstar1 Posts: 1,015
    The liquid fuel runs to the bottom of the rotor housing, where it can sit for days (from experience, ours and others). When you try to start the engine some of it is swept up past the spark plugs. They are set deep in the rotor housing, with small holes that allow the spark created flame front to advance into the "combustion chamber" (the three "bathtub" like structures machined/cast into the rotor faces). Some liquid fuel enters through the small hole and soaks the spark plug, resulting in little or no spark.

    Even though the "intake ports" are always open, they are low in the engine assembly, and gas vapour is heavier than air. It stays in the engine as it forms an equilibrium of condensation and evaporation. A warm or hot engine has no problem evaporating any liquid fuel left inside, hence it's hard to flood a warm engine. In this case the heat forces the fuel vapour out into the air box as well as into the carbon canister. It also helps to have warm spark plugs - any fuel touching them will evaporate rather than soak into the ceramic.

    The solution is very simple. Don't start a cold engine and then shut it down before it warms up a bit. Don't think this problem is restricted to rotaries. It isn't. Piston engines resist the problem of no start because in most cases the spark plugs are high (don't get exposed to any liquid fuel) and any liquid fuel left in the combustion chambers runs past the piston rings into the oil in the crankcase. As long as the spark plugs fire they will recover from a flood condition. Have you never noticed that sometimes a piston engine will start up and emit a lot of carbon dust? It was flooded!
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