tonyge

i have an 87 T2. i have just the cat back exhaust. i was telling my dad that theres a chance that my car may shoot flames after the next mod whatever it may be, rest of the exhaust or vented b.o.v. of course i would get the fcd.my dad is saying that shooting flames from my car would be nothing but fatal or just bad for my car and nothing can come good of it. basically all it is is my car running rich right?for some reason he keeps mentioning something about damage to valves when running rich saying something about back fire also.basically all i see it as something neat but a waste of gas.
he keeps mentioning that i dont care what kinda engine it is either. u cant take it up to redline. nothing can come good of it. well i told him long as i dont do it all the time the rotory can handle it.i even mentioned that there may be benifits to getting on a rotory once in a while.

hornbm

i dont think theres anything REALLY wrong with shooting flames. I can imagine that it would be horrible for your cat if you still have it. Probably would shorten the life of the muffler too, probably not by much tho. Besides flames look cool!

And yes, it is good to take a rotary to redline once in a while to clear out the carbon. It will actually extend the engine life.

Black13B

iTrader: (1)

Don't care what kind of engine? Valves?

Don't worry about it.

It's usually a waste of time to try to explain how the rotary works, especially because your lucky to find some one open minded enough to accept it, let alone actually listen to you.

Don't trust 'advice' from anyone who isn't so inclined..

SleeperZzZ

if its something with the cats, as in you gutting them, the flames were always there, but with the cats gutted its allowing them to escape( i think, correct me if im wrong)


by the way, its hell to replace the valves on our engines, i did it one time, and i had major problems with fitment issues.

mightymouse0x

y do u care what your dad says? i know i dont, hah

Bigretardhead

yeah, tell your dad he's a big retard head, because your engine doesn't have any valves, even though he doesn't care what kind of an engine it is.

the only thing wrong with shooting flames is that if a cop see's it, you'll get pulled over really fast, and then major screwed.

it won't really waste any more gas than not shooting flames(if I understand this right). the reason it shoots flames is because when you let off the gas the throttle plate closes before the fuel stops being injected(just VERY slightly), so there's a bunch of unburned fuel going into the exhaust system. and that, combined with the higher temperatures of the rotaries exhaust creates an explosion which you get to watch out the tail pipe.

oh, and you probably won't be able to shoot flames with a cat, no matter what the rest of your mods are.

tonyge

my dad got pissed with that last post. lol. he said is your head that stuck up your *** you cant explain yourself.dont get pissed with me. its my dad. but please someone go more into detail so i can explain this to him so he doesnt annoy me. and so maybe he can read it himself.

tonyge

i do and i dont care about what i say. for the most part hes a cool guy. just hates to be proven wrong.haha. i love it.plus if anything from this post i can just gain some more knowledge. like they say knowledge is power. i think thats what they say.teh more knowledge i have of my care the smarter choices i make with my car. nothing wrong with that.

mightymouse0x

go and read Bigretardhead post, he just explained what happens, and its non damaging to ur car

Cheers!

when you add an aftermarket bov to your car you are venting the pressurized intake charge between the turbo compressor and your throttle body. The air flow meter reads the amount of air that hte engine sucks in and assumes this is the amount that is present once it is in the intake system.

With an aftermarket bov you realize this metered / measured air and the AFM does not know this. Hence it will inject fuel according to the metered amoutn of air. That is too much fuel, you have no intake charge to ignite with it. Hence you shoot flames. The stock Bov/bypass valve is redirected back into the intake path via the Turbo inlet duct after the AFM. therefore the metered amount of air is correct.

By getting flames the cons are:
-Your back bumper will be coated with carbon or may melt
-you will destroy you catalyic converter, since it will clog up from all thos carbon
-your o2 sensor will not like it
-your spark plugs own't like it either
-cops don't like it
-it gets annoying sometimes.

there are no valves to destroy since a rotary engine has none. It operates essentially like a 2 cycle engine, where in it has ports intead of valves.

if you were running a huge turbo setup and you did not correct for the huge dump of intake charge the massive amount of fuel may stall your engine out. You have to use your EMS to account to subtract XX% of fuel on decel else you will flood the engine out.

If you are running stock boost levels on stock turbo don't worry about it.

Digi7ech

iTrader: (1)

From what I understand.

Our engines have an overlap for a short period where the intake and exhaust are both open.

This make some fuel go directly into the exhaust and with the reason stated above as well(throttleplate one)

It will create flames. Catalytic Converters usually supress these flames but all rotaries except the new Renesis do this naturally.

I took just the main cat off my 88 SE and still had the 2 precats and drove at night once. My friends were scared to drive behind me because every time I shifted the ground light up under my car with flames.

There is no bad effects to the engine itself. I can hurt the mufflers or cat but that's why our cats are made of more durable materials.

We have no valves to hurt. The idea with piston engines and that i think is that cold air can come in and warp the vales or something.

I have heard our cars do not even need exhaust other than to help with exhaust velocity to add a bit of torque.
(I ran straight manifold on my 88 GTU, Can you say NASCAR loud? heheh)

Black13B

iTrader: (1)

Can't wait to be in full control of my fuel delivery..

http://science.howstuffworks.com/rotary-engine4.htm

Josepi

Don't worry about throwing flames with the stock cats in place...even more so with a functional ACV (air control valve) and cats.

Throwing flames isn't going to be bad for spark plugs for any reason for the nature of the combustion process in relation to the workings of the rotary engine.

In a turbo rotary, the ideal exhaust backpressure is none at all...provided there are steps taken to deliver the fuel necessary to sustain such activity.

Cat back only? You won't be seeing any flames. Toss the cats, ACV, and stock bypass valve (BOV) and you'll see some on the stock ECU.

SnowmanSteiner

Everyone is saying with a catback you won't shoot flames. In my case this is false. I have a catback with and a home depot bov and I can shoot flames. I also can sustain a flame at idle, but that is a problem and I'm working on it.

- Steiner

FC3Slider

sweet, i love flames out the tail pipe!

tonyge

whats that line going to the cat. and wheres teh acv located and how would i take that out and what woudl the side effects be. thanks

minclo

a air hose line. it pumps air into the cat for emissions. leave it there if a)you want to be emissions legal b) you want your cat to survive a month

tonyge

a. is no concern. nor b. but i dont want to clog my cat so i guess ill just leave it alone until i replace it. i dont have emissions in nh.

Josepi

With just a catback, he won't shoot flames.

Now read what you typed again. In your case you have an atmosphere vented BOV.

SnowmanSteiner

Yeah I understand the whole point of the open air and that's the reason it runs rich but come on it's a few bucks from home depot and then you can actually hear your BOV. On a side note, I've never seen so many people so avid about shooting flames and do everything possible to make them. I didn't know that my specific car was even capable until apparently on an on ramp I lit one up for about ten seconds and scared the sh*t out of my friend. I view them as a nice bonus. I don't try to make them cause I do have a gutted cat right now and I don't need to make it more restrictive. I don't understand the fascination that everyone has with it and why they would do almost anything possible to have them. just my thoughts.

- Steiner

Evil Aviator

Your dad is right with respect to piston engines. He is also right on the wasting of fuel issue with the rotary engine, but the atmospheric-vented BOV only wastes fuel when shifting, so it will not affect your cruise mpg. Your cruise mpg will most likely increase with that catback exhaust. See the post by Cheers! for the flame issues of a rotary engine.

FYI your engine already comes with a bypass valve (recirculated BOV) that works just fine. If you are running close to the stock boost level, an aftermarket atmospheric-vented BOV will only act as a $200 noisemaker and fuel waster, and your car will be slightly slower during shifts due to the stock ECU-induced rich condition. If your dad thinks an aftermarket BOV is stupid, I don't blame him. If you like the noisemaker regardless of the facts, then I understand that, too.

Your dad is half-way right/wrong on one issue. Some engines, piston and rotary, are intended for high-rpm operation. You don't necessarily need to wrap the engine up to redline constantly, but the engine will stay in good condition if you at least take it up to the shift light on a regular basis. Short-shifting and extensive idling will create deposits in the engine that will shorten its life (see used police cars as an example). If your dad doesn't like the idea of running your engine to redline, just remind him that the rotors have a 3:1 reduction ratio off the "crankshaft", which means that at your 8,000rpm redline the rotors are only running at 2,667rpm. I'm sure that he will consider this safe.
http://www.rotaryengineillustrated.com/RE101.html

My racing partner shoots flames with a catback on his NA. Removal of the air pump usually causes this, and also he is running a Wolf EMS that he can program to make extra big flames, lol.

Um, flames at idle is not good.

SnowmanSteiner

Yeah I know. I installed new injectors, and I think that the injectors seats, seals, whatever it sits on, are either cracked or didn't seal properly. But basically to get the car home I had to set the idle to 3000. Then after screwing with it I took it just for a nice low rpm drive around the block came back, reset the idle slowy back down. I had it idling at 1700, cause it sounded like it was going to lose it and die. Went inside the car to check the throttle position, and rpms. Saw a flash and went to the back and there is a two foot flame emiting from my exhaust so I imediately shut it off. I think the ecu kept the seconadaries on as I slowed the idle down. But the flame had to have been there for thirty seconds. At least I know what my car looks like when I shoot them now though.

- Steiner