RotaMan99

Since I have had my SAFC, its saved me on gas money and from walking to the nearest house to use a phone or to get gas. Usually I notice my fuel is low and I start removing more fuel below 3000 rpm under 30% throttle to about -20 to help me get home.

Well this last time, the fuel gauge was were it usually gets when the engine starts bucking around, so once it started bucking while my Correction was at -18 below 3000 at 30% throttle, I brought it to -20 which helped for a few seconds, then it bucked around again and I brought it -30 which helped for about 1 minute, then I brought it to -40 which at that point it was not liking the very lean condition but it stayed running and I kept it there for the next few hundred feet of road with some hills to get to my house. I Then changed it back to where it was.

The engine wont detonate under 3000 rpm while below 30% throttle so I knew I could go even leaner if I had to untill it would cut out. Which would defeat the purpose which is also why I kept it at -40.

Sometime I just don't know where I would be without my SAFC.

Have any of you had the same experience?

88turbotime

Dude just fill it up with gas sooner!

RotaMan99

Thanks for the idea, I never even thought of that! When you are on a very tight budget and can only fill up on certain days, it gets kinda hard.

I hope you were kidding?

Boost Lee

iTrader: (3)

don't own an rx7 if you're so broke you have to lean out your car just to get home.

spot_skater

Be careful man... don't want to be sucking up ~15 years worth of crap from the bottom of your tank...

RotaMan99

Tank was changed out and I think was cleaned out when it got swapped a few years ago.

I love all these comments. I have had this car for 5 years. Only these past few months I have been broke.

Keep comments such as this to your self.

RotaryEvolution

iTrader: (30)

do you even know what detonation is?

running lean at any RPM can cause detonation and destroy your motor.. thinking leaning it out is perfectly fine to get home is just moronic.

do as the previous posters said and fill up before you get that far down on the fuel level or don't own an RX7. if i hear that you popped a motor because of this i am going to give you SO MUCH crap it will be coming out your eye sockets..

RotaMan99

Its a n/a. Tell me ANYONE that has popped their motor from running lean under 3000 rpm. Please tell me. You will see that it happend to no one with an n/a.

Go ahead. Give me crap but you will never see an N/A blow under 3000 rpm due to a lean condition.

Prove Me Wrong. I dare you. I want to see FACTS!

Are you another one that thinks post count and join date represents the amount of knowledge someone has?

Who are you, my mother? Who the **** you think you are? Did you not see what I posted before?

I have hit financial hard times these past few months but I always come out of them as everyone does. You don't know what goes on financially with me so don't even think for one ******* second that you can give me **** because I have had a hard time recently! **** You *******.

RotaryEvolution

iTrader: (30)

you're giving people bad advice, whether you want to believe it or not, leaning out the air flow reading under light load also gives the ECU the impression that it can advance the timing even further accompanied by a lean condition detonation can occur regardless of whether the car is n/a or not. most people just don't do this as something out of normality, how many people do you hear of leaning out their AFC to try and run a few more blocks on no fuel? n/a engines do pop and more often than not it is due to a fuel system issue not just age of the motor.

why am i giving you a hard time? because as i said before, if you make it sound safe then other people will interpret it as being safe to do when it is not.

if you want to do it then that is fine, just don't come here and be all LOLly about it making it sound like its fun and that everyone should be doing it...

scathcart

There are a couple ways to easily detonate and blow a naturally aspirated car.
One is not enough octane for the compression ratio. With a maximum compression ratio of 10:1 on N/A rotaries, this will never occur, even with 85 octane fuel.
Second is lugging the engine around in low gear. Don't floor the car in 4th gear at 1500 rpm. The car will detonate.
Advanced timing will also cause detonation. There's no need to run above 25 degrees BTDC at WOT, you won't make any morepower.
Preignition will also cause detonation, though I have no idea how'd you'd get your intake charge hot enough to do that on an N/A.
Another possible method is running lean. Although at part throttle, extreme lean conditions typically only cause misfire, but detonation certainly can occur.

Have you ever installed a knock sensor on an N/A rotary? I have, for the purposes of monitroing knock under nitrous injection. Even in naturally aspirated conditions, lugging the engine around and running lean caused detectable knock.
Thirdly... why do you think N/A rotaries ever pop a apex seal? I have taken apart blown 3-piece apex N/A motors plenty of times. Sure, sometimes the seal has simply worn past its limit and v'd the rotor groove, and then popped out of its slot, but what about those motors where the seals spec out fine? How did these seals break? How about broken corner seal on a stock port N/A FC? Know I've seen that a couple times.

Thinking that these engines can not detonate is simply foolish. Sorry to tell you, but the laws of physics still apply to these motors. Running your tank dry is even more foolish... overheating your fuel pump and burning it doesn't save you any money.

Finally, your financial problems are no one's fault but your own. There is no need to resort to swearing and name-calling because your broke *** failed to plan for the future. If you truly cannot afford gas, take the bus. Get a second job. Get a third job. Sell the S-AFC. Sell the car and buy something you can afford. I am sorry if you expected praise for your ability to risk engine and pump damage, but no one is impressed by your lack of an ability to support yourself, and the ensuing risks you place upon yourself and your car.

RotaMan99

Preignition and detonation are the exact same thing. What do you think detonation is? Preignition of the air and fuel mixture.

I was trying to say I wont pop the motor under 3000 rpm for a lean condition. There just is not enough timing, pressure or heat to do so.

Over that yes there is a risk of poping the motor.

What were the miles on these motors? How were they driven? How high were they taken to? This statement shows no proof that they popped because of lean conditions. This shows that the OEM motor poped which happends on every rotor motor once it gets a lot of miles on them. Some pop before other and some pop later.

Sorry but while fuel is still flowing through the fuel pump, its not going to overheat. I never ran the tank "dry".

For you to say this I must have said that my finacial problems were caused by someone else?

No I do plan for the future but I don't always plan on going to the hospital and getting large bills and then loosing a job after I get those bills. I have CC bills as does almost everyone, and I will never say its not my fault. Right now I got another job and im getting my self back up to speed with everything.

I live in the stix, Buses don't come to my house and taxis will be even more then gas when they have to drive 45 min from their station just to get to my house and then 55 min to work.

See this is where I get really pissed off at people that come into threads and by reading the first post, they know everything about the poster and tell them things they have no right to tell them. I had one guy tell me that I don't know this forum and don't know anything about oil because my post count was low and my join date was recent. Even though this is just a new sn and I have been around for many years, but some how the join date represents the days I have been are rotarys and the join date represents how much time I have had to learn about them. Rediculous.

So people that can't support them selfs after their funds are depleted from bills are complete morons and are the scum of the earth? This is basically what you are saying. Thank you very much rich man.

Yes, sell the car for only about 1500 or less, around here you can only get a POS for that much that you need to dump a crap load of money in just to keep it running. Sorry your not from around here and you don't know what the life style is in good old NH of the USA. Now you will probubly say to move to a different location which again costs a lot of money.

I am getting a second job and a third job is rediculous, no time to relax or sleep, very smart and very unhealthy.

I always come out of financial troubles within a short period of time so im not worried about it. If I knew I was going to be in this situation for a year or more, then I would sell what I could to get what I could.

So STFU cause you have no idea about the living conditions around here.

But I know you have more to say because you know all about me and how living is around here. So keep it coming and keep sounding like a complete moron.

RotaryEvolution

iTrader: (30)

sorry, it's just that i get worked up sometimes when i see people giving advice that i don't agree with. IMO it still is a bad idea to put into people's heads.

RotaMan99

Fuel system is all new even the fuel lines going to the tank from the motor. Injectors were sonically cleaned a few years ago. Also, people should never advance their timing to the point where it just might detonate. This means you would have to turn the CAS all the way almost and remove a lot of fuel.

If your timing IS correct, as in timing to stock form or only slightly advanced and not advanced 15 degees because the motor "was" running rich, You will not detonate or harm your motor by leaning out the motor under light load. There is simply just NOT ENOUGH timing to do this under light load EVEN when the ECU advances the timing.

People remove fuel NORMALLY when running a SAFC. I never told anyone to go ahead and do what I do, I never said try it, I never said copy me because it works. If people are stupid enough to try something like I do when they DON'T know what the hell they are doing, they deserve to have their motor pop. Plain and simple. Learning experience for them. You don't **** around with what you don't know. I bet if I posted my correction numbers I run with on a daily basis they would ues them just because it works for me and they OBVEOUSLY don't know how much fuel to remove because they don't know what they are doing. They are stupid and I hope their motor pops.
Since when did I say this is safe? I never used those words. I know what to look for and feel for and hear for in my motor when it starts to act up or run lean or rich. My engine would miss, but it did not detonate.
I never ever ever said it was fun and everyone should be doing it. You ned to re-read my first post and then point out the sentences you got mixed up on and maybe I can clear them up for you.

Very very highly doubtful it will PREIGNITE while flooring in 4th gear at 1500 rpm. ECU sees more air coming in the motor from the AFM and also see the TPS is maxed out and the pressure sensor also has no vacuum. Also your fuel pressure spikes under no vacuum. Engine will not detonate unless you have it timed way wrong or have a ton of fuel removed during heavy throttle which again, if someone does this, they don't know what they are doing and deserve the motor to pop.

scathcart

Detonation and preignition are not the same thing. Preignition is a ignition that occurs before the intended timing. Detonation is an ignition after the intended ignition event.

Its a common mistake, but a mistake none the less.

Again, I have picked up measurable knock on a stock ECU. Go up a hill in fourth gear at 1500 rpm, WOT, and you'll have knock. Starve the fuel pump so the rail pressure drops (to the point where the engine misses and bucks, as you describe) and you'll have knock. Doubt it all you wish, you'll still be wrong.

RotaryEvolution

iTrader: (30)

well since you felt like dredging this back up we can continue.

air and fuel means everything to pre-ignition and detonation as well as the octane of the fuel. leaner mixtures with lower octane fuels while under hard enough loads can cause the mixture to pre-ignite without the use of spark. case-in point is deisel engines, even though they are designed to run without spark and have much higher compression ratios a gasoline engine can very similarly resemble a deisel when enough air with little fuel and high throttle applications are introduced, as RPMs increase and throttle is opened more then your compression numbers rise and with load so does internal temperatures.

RotaMan99

Desiel Engines use glow plugs to ignite the air and fuel. Its not only the compression of air and fuel like some think.

RotaMan99

Desiel Engines use glow plugs to ignite the air and fuel. Its not only the compression of air and fuel like some think.

Your right. I for some reason always thought they were the same. I will say im wrong here.

I need to know why here. Exactly how much knock do you see?

RotaryEvolution

iTrader: (30)

diesels only use glow plugs on cold startups, after a minute the glow plugs shut down and air/fuel/compression are the only thing the engine runs on. ever messed around with a gas powered RC car? same principle, use the glow plug to get the engine started then the engine runs on the heat generated by the combustion as well as the octane of the fuel in conjunction with the compression in the engine.

scathcart

Its literally a time issue. The higher the revs, the less time there is for the fuel mixture to be exposed to higher heat, and begin the detonation reaction. Octane requirements decrease as RPM increases. This is partially the same thing that retarding timing does, as detonation always occurs post-ignition: it gives detonation less time to take place.
The problem with the stock ECU is that it cannot gear count. The timing map is designed for making torque in gears such as first and second, where using such low-rpms are likely, and acceptable, but are far too advanced for the upper gears, when the engine cannot freely rev. On a side note, this is one of the two main reasons why you should not inject nitrous at low rpms when the engine is loaded in a higher gear... always 3000 rpm or higher in 4rth. You can go ahead and inject it near off idle in 1st and 2nd.