I ditched the cats for the rb header and presilencer, with the stock catback. People on here have described the smell of a 7 w/o cats as making them teary-eyed, and very strong. I've bent down behind my car, and I hardly smell anything. Could I be running lean? I have yet to see flames; not like that's a big concern, I just don't know what kind of indication I should be looking for if I'm running lean.

EXHAUST SNIFFER!!! https://www.nopistons.com/forums/pub...IR#>/blink.png

sometimes they dont smell that bad, sometimes it will though



mike

Yeah, mine didn't smell bad at all. It still shot out some nice flames.

I run a RB header, testpipe(no cat/presilencer) N1 dual catback, and I also run premix....I get more people high then the dope dealer down the street. People ask "what the hell kinda gas you run it that thing!?" I just smile and say, "smells like a 2-stroke"

car is set to run rich at idle from the factory, rich mixture stink....

mine makes my eyes water and burn and gives me headaches.. my garage needs to be aired out again hehe

new problem I noticed on the way home...



I was getting on 3rd gear pretty hard, when I just happened to look in my rear view and smoke https://www.nopistons.com/forums/pub..._DIR#>/sad.png



I try to duplicate problem to pinpoint source; results:



(testing in 3rd gear) when I accelerate into the higher rpm's (not redline), and let off the gas, I got a big puff of blue/gray smoke. When I would do the same, but press the clutch while releasing the gas, I couldn't see anything in my mirror. Whenever I get a chance, I'll have someone drive behind me and see if they see more than I (or I drive behind my car...whatever).



https://www.nopistons.com/forums/pub...O_DIR#>/11.gif please tell me this is ok



but don't lie to me!

You sure it isnt just backfiring or blowing flames like some of these guys said? I'd think either that like its running rich or your burning some extra oil.

sounds like oil control rings to me.

Bill says my 1st gen smells like a lawn mower, 12A stock manifold no cats a RB cat back

my car runs so rich at idle, it smells bad with FULL emissions equipment



looks like you might need a rebuild soon

hold up so if you get the RB headers u dont need the cat replacement pipe just the presilencer?. I thought it was the RB header to RB CatPipe To RB Presilencer to RB catback?. But i dont think it will spit out flames unless u push it passed like 6000RPM. Let me know ok



Jazerx7, nyc

rip that sucker apart and bridgeport it!!! https://www.nopistons.com/forums/pub...1047683894.gif

would that cause a big puff of smoke?



I haven't seen it smoke on startup, or when cold, or during normal driving. Only when I would push it high, then let off gas while keeping clutch engaged. Does backfiring and flame-throwing leave a big puff of smoke?

mine smells like crap. i have no cats, downpipe, on cat-back. seriously, everytime in come in from driving my car, people say "you smell like gas". i dont mind it, unless girls are with me in the car, then i feel kind of bad for them. but then i think to myself "i like girls, and i like the smell of my car, why not mix the two together?"



that's rotaries for you, get used to it. i'm sure mine's rich, and it drinks gas like crazy.

also, it never smoked before I did the exhaust mods



and it doesn't smell https://www.nopistons.com/forums/pub...IR#>/smile.png I was just wondering if it should

well since you seem to only have smoke on deceleration / lugging motor off throttle... it would either be oil getting in past the oil control rings or fuel... the cat(s) will do a decent job of supressing this smoke normally, unless it gets excessive.



i'm not sure if the FC in stock form does fuel cut on deceleration, maybe someone else can answer that... if it doesnt it might just be unburned fuel causing the smoke.



my guess is oil control rings though, they will often cause a small puff of smoke when shifting and smoke on deceleration when they start going bad.

damnit i tried to edit my previous post but ran out of time while adding more, here's some more maybe it will be of help:



I think what happens on deceleration with bad oil control rings is your throttle is closed, but the rpm's are still kept high due to being driven by the movement of the car (clutch engaged), so there is a large amount of vacuum in the engine/intake manifolds during this period... this can suck oil from the rotors passed the oil control rings, or it can also help leaky injectors leak by 'sucking' the fuel out of them, though that is less likely since the FPR should be maintaining the pressure difference as a constant even under periods of heavy vacuum....



I don't remember if you removed the pcv stuff/rats nest, there is a mechanism that is supposed to use vacuum to help suck out crankcase gases, it might also help prevent this smoking on deceleration when working properly... since it too should have greater vacuum when the manifolds do, which should help keep the pressure differential between the 'crank case' and the intake manifolds (the intake part of the combustion chamber is basically part of that during the intake period).. you might want to check that out and make sure it's pressent, conected, and working properly.. I'm not sure how significant this is to prevent smoking but it seems plausible. When people remove the rats nest and pcv with it, sometimes they cap the nipples on the filler tube and intermediate housing to find their car smokes all of the time, this is because they are not letting the 'crank case' vent pressure increases caused by blow-by, so then oil is getting forced passed the oil control rings and now theres shitloads of smoke. Your situation sounds similar but it's only on deceleration, which is a period of high vacuum... the pressure difference caused by that is similar to the situation with the capped nipples, so you might be able to find your solution on this route.



just some ideas...



oh btw, a piston head friend mentioned to me once before some product that was used to increase the vacuum applied to the crankcase on piston motors that supposedly improved a number of things... trying to search for this might be a help, maybe it can be used on a rotary to help reduce smoking. Though more vacuum will likely suck in more junk too for your oil to mix with, like gas.. especially if the injectors leak.

Thanks for the info. I did leave my emissions stuff on.

Here's the update:



I had my wife drive my car while I followed behind. I told her to accelerate past 5k rpm, then let off that gas, which she did in 2nd and 3rd gear. I dumped so much smoke that I could hardly see the car. She just let the car deccelerate with the clutch engaged, and it smoked the entire time is was decelerating, albeit a little less with declining speed. It was very thick grey smoke.



Can the oil control rings go bad really quickly? Because like I said before, I never noticed smoke until yesterday, and now it leaves a lingering cloud (when throttle released, clutch engaged).

Damn! I have no clue... I was thinking you had said before that your car was stinky so I figured something triggered it to run rich all of the sudden and when I had rich running issues on a piston car, I would get gray/black smoke on hard accel and high rpm decel....



I hope its not your oil control rings https://www.nopistons.com/forums/pub..._DIR#>/sad.png

with my luck, it probably is...it has well over 144k miles on the car, and I drive it hard



I've kinda got that sinking feeling in my stomach.

i also think oil control rings, it should run forever that way my 86 base went from 75-118k burning oil like that



mike

y----o----u n----e----e----d a R-----E-----B----U----I-----L-----D

i also think oil control rings, it should run forever that way my 86 base went from 75-118k burning oil like that



mike [/quote]

good to know. I'll consider it a self-changing oil system.





s-----h-----o------w m----e the m----o----n----e----y

i also think oil control rings, it should run forever that way my 86 base went from 75-118k burning oil like that



mike [/quote]

wait a second...so when do I know it's gone on too long like that? when is it time for a rebuild?

when you can no longer tolerate constantly adding oil or constantly smoking...

I think I just might start collecting parts to do a kickass n/a...very, very, slowly



maybe collect all the housings and such over 1 or 2 years....



it would be perfect to use my income tax refund, but we decided that we're going to redo some flooring in the house...decisions, decisions...

sell your body for money





im sure you can find plenty of nice women in their 40s that need some side action

what? your mother? just kidding!!

WOW!! https://www.nopistons.com/forums/pub...1047683785.gif https://www.nopistons.com/forums/pub...1047683785.gif https://www.nopistons.com/forums/pub...1047683785.gif