screw em all...bastards.

 

ok u guys you dont want you car to do that its so bad for the cars thats just mazdas way to heat up the main cat to pass emmisions

 

Like I said before "PROVE" that this is bad for a rotary engine! I haven't heard any valid explanations yet. I've already explained the differances in stress the bearings go through when you compare a rotary to a piston engine. The stationary gears support the majority of the rotors weight not the bearings & e-shaft. We need proof not hear say. IMHO this is just like the 3 mod rule. That has been proven to be wrong.

Hell I'm staring to think that we need a "Myth Busters" section on this forum.

 

RXJoey just tell the dealer that the "Accelerated Warm-Up System" (AWS) is no longer functioning.

 

This is like arguing with a contrarian adolescent. Talk less and listen more.

 

Holy ****, that's funny!

If that's the case, how do you explain the pre-cat, or the plastic AST, etc., etc. Mazda did a lot of things not conducive to long-term reliability just to get the car on these shores.

I think only someone completely ignorant about cars or physics in general would argue that a 3k rpm warm-up causes no more wear than a 1500 rpm warm-up.

 

This thread deserves an Acadummy Award.

 

True but we need to think outside the box especially when dealing with a rotary. What may be common knowlege with a piston engine may be completely differant with a rotary. The rotors travel at 1/3 the speed of the e-shaft. The rotors are only turning at 1k rpm's in warm-up mode. Anyways ignorant or not no one has "PROVED" my point yet. Thats my whole argument!

 

The precat was a quick solution to an emissions problem they were facing in the US at that time period. Mazda isn't completely bumb when it comes to engineering stuff. However they did do some things that could have easily been done better. Look at the poor design of the rats nest. At least it was eventually improved after about 4 years. Also we gotta give Mazda some credit for putting in a low coolant level buzzer that sounds off when that plastic AST leaks. There are alot of cars on the road today that don't have that feature.

 

You agree that cold start at 3k rpm causes more wear than 1.5k rpm, right? You agree that the AWS is only for start-up emissions, right? Regardless of whether the 3k startup will cause enough damage to shorten the motor's life, it causes more wear and is completely unnecessary. Therefore, there is no point to ever letting it happen.

BTW, Mazda DID go through an elaborate process to make sure you didn't get full power until the engine was warmed up (double-throttle system). Why do you think they did that?

The AWS and pre-cat were the only way Mazda was going to be able to import the FD, they did what they had to do. I seriously doubt that the Mazda engineers didn't know that pre-cats would die in 60k miles. But they put them in anyway, because that's what they had to do to pass emissions. I don't think it's a big leap to assume the AWS was in the same boat -- potentially harmful to longterm reliability but necessary to sell the car here.

 

I do agree with the idea that any higher rpm's on any engine (piston or rotary)will cause a little more wear but, for some people to insinuate that this is "REALLY" bad for a rotary engine is way out of line. I feel that you could allow the engine to warm-up in it's normal manor (3K mode) and it would still last and be a every reliable engine in the long run. The stresses on this engine (cold or hot) in the 3k range are so low you can't compare it to a piston engine.

Anyways like I said before, I think it does have another benefit. Our engines dump alot of fuel in during start-up. Anyone with vast rotary engine knowledge will tell you that the rotary's cumbustion chamber is terribly un-efficiant in cumbusting the fuel air mixture. Letting the engine run at this measly 3k during start-up can and will burn off any unburned fuel. This un-burned fuel is one of the main reasons these engines flood so easily during start-up and a quick shut down. This will help keep carbon build-up down. We all know that carbon is another thing that will kill these engines because of stuck seals. Lastly I feel the engine will die of coolant seals failer or stuck seals from carbon well before any damage occures to the bearings from the 3k warm-up mode.

 

Bah, my motor at 85k was pretty clean inside and no use of AWS here....

Or more likely an apex seal breaking, but I agree....

 

Ryan not everyone drives their car the way you do. There are other things that can be done to keep carbon build-up down. Odviously you drove your engine the way it needed to be driven to keep the carbon build-up down for those 85k miles. This means you drove the engine fairly hard on some occasions to get things hot enough so the mixture burns completely. After all you do track your car on occasions right? This kind of driving isn't going to happen with your average Rx7 owner who drives their car on the street. So my point here is allowing the engine to rev in the lower rpm band will introduce more carbon build-up due to less efficiant cumbustion. Blipping the throttle to kill the AWS feature will do the same.

 

Damn guys I just though of something. If your engine dies from bearing failer, the repair really would be no where as expensive than if the engine blew because of carbon lock(which I have experianced). A carbon locked engine can break a seal and cause rotor and housing damage where as a bearing failer would be nothing by comparison. Bearings only cost about $18.00. You compare that to a new housing and rotor. Yep AWS isn't that bad after all guys.

 

3k rpms is not like 6k rpms. If you say it's bad for pistons motors then many new high performance motorcycles warm up at 3k rpms.

The bearing wear at 3k rpms may be infintismal more than at 1.5k rpms. I bet installing a cat-back exhuast will wear out your engine faster than the AWS.

The double throttle system is different. At 3k rpms at idle the force on the bearing will be much different than at 3k rpms at 50% throttle and 5psi.

I'm with T-von on this one.. Show me the proof that it's harmful for the engine.

 

I wasn't aware that FCs had the AWS, but 1st gens did not (hell, they had a fricking manual choke). And other than North America, FDs didn't have the AWS either.

And a motorcycle engine ain't a car engine either. How many motorcycle engines have you seen hit 100k miles without a rebuild, for that matter?

MAY BE being the operative words there, the point is, you don't know how much more wear there is.

Show me the proof it isn't. I have an opinion based on the facts as I see them, you and T-von have another opinion based on the facts as you see them. Neither has been proven. The difference is, my opinion results in a safer condition (even if infinitesimal).

Why are you guys arguing this anyway? The car warms up just fine at 1500 rpm, there is simply no reason to ever let the AWS kick-in. Personally, I don't buy the whole carbon build-up theory. There is either something wrong with your car or you need to stop driving like an 80-year old grandma if your engine is carboned up severely enough to damage seals.

 

whoa... I just got done reading this whole thread. Lots of good points for both sides. But I'm still stuck with, "Should I let the AWS kick in or bypass it? (start in 1st or blip)". My engine has 60K in it and has been ALWAYS doing the AWS with no issues. BUT I would like to point out that if the verdict is that it causes more wear, then I obviously want to stop. Can the other gurus step in here with their opinions, please?

 

I dont understand what the big issue is hear. My Rx7 usually hits 3rpm starts and my motor has 14,000 miles on it everything almost and ignition has been replaced. My two other friends Rx7s I drove started off with 3rpm warm ups. If my car has already been properly warmed up turned off and turned back up it wont do this. This is a healthy warm up motor start. You can put it in gear or tap the throttle if you want the rpms to drop.

 

Well i'm no rotary expert, but I think the bearing wear probably isn't hardly any IF any moreso than 1500rpm, I mean being a cautious maintence guy and overall down for mechanical sympathy, I shift @ 3k till it's fully warm anyway, is that really any better? Should we just shift @ 1500rpm cold too

I don't think it's a big issue, the increased rpm would make the oil flow faster anyway wouldn't it?

I think the issue is parts moving BEFORE oil coats them, 3000rpm isn't "racing" the engine

 

If its so damn good for the motor then why does it cut off well before the motor is warm? Use common sense here people. This thread is emabarassing.

 

It's not about having common sense. Open up your mind a little more and think about whats going on inside the engine. AWS was on the 2nd gen (my 91 vert does it). Emissions weren't that strick in the late 80's but they still had the feature. Why? There has to be another reason! We all know that the precat isn't going to warm-up that fast in only 15secs. AWS odviously serves an added purpose. Now I'm starting to believe that it's to help burn off the additional fuel these engines get during a cold start-up.

Ryan, the 12a's never had it because they were not fuel injected( I owned 2 12A's). I don't know about the fuel injected GSL-SE's?

Anyways like I said before, these engines are un-efficiant in fully cumbusting the fuel air mixture(especially in the lower rpm range). The quick jump to 3k on a cold engine will burn off the extra fuel that gets dumped in during start-up. Tapping the throttle and lowering the start-up rpm will cause any un-burned fuel to be left behind on the rotor faces turning into carbon. In a cold engine fuel sticks to the rotor faces more so than on a fully warmed engine. Thats why these engines flood so easily after a quick shut down. Think about what happens when the fuel burns on the rotor face? Fuel burning on the rotor face will introduce more carbon on the rotor face. This is why I believe carbon will eventually kill this engine due to stuck seals and compression loss well before any bearing failer. Why do you think these engines gradually loose compression all the time? Why do you think that more than half of the imported JDM engines arrive with little to no compression? It doesn't take much carbon to slow the movment of the internal seals. Too much fuel can sometimes be a bad thing.

Soooo IMHO Mazda uses AWS as another way to fight carbon build-up. Even the emission friendly Rx8 has it. I willing to bet that if the Rx8 owners take advantage of the AWS feature, their engines won't flood nearly as much.

 

It just doesn't bother me, the 3000rpm cold start "sounds" right to me (admittingly a piston guy), but it just sounds and feels right, not too sure on this flooding thing, i've never had a startup problem

i can tell you though when i first looked at this car and it sat for a long time, it smoked heavily of unburnt fuel (fouled plugs) from being repeatadly idled warm (owner thought he was keeping it in good shape this way), they do accumulate carbon quickly, a mixture of 8000rpm shifts and AWS seems to keep mine smoke free and running good

fuel economy is another concern, on short trips this thing gets 12-14mpg :/