Interesting smells

i am having interesting smells from my cars exhaust. im planning on redoing it. does anyone know if the high-flow cataylistic converters work? it will go with 2.5 in piping cat back.....anyone know? thanks

o and it snowed today, a car's brakes locked i guess and plowed into a city bus....lol

If you jsut put a new cat back on there is often some smells sorta like rubber burning or gasket material burning. Did with mine and did with all 3 of my friends cars that i helped put the exaust on.

oh sucks about hitting the bus.

nope, has stock exhaust on it currently, is a project for when the snow clears...

i said a car hit it, not me, so i was laughing at it. it was at a red light and he couldn't stop....idiots..

are you sure you didn't.........F.A.R.T.?.?.? eWwWwWWwwwWWwWwWwW.....jk :icon16: it could be the muffler in the back because when i still had my stock on and went WOT i could smell something like you're describing too, and after i took it off the smell was gone, or i should say.....i havn't noticed it, yet.....good luck mang whatever you decide to do, ask jayson with the cavalier about 2.5" piping, he yelled at me for having something similiar like that done to my car :frown: 'cry 'cry *tries to find tears icon but cant find it*

the most common bad smell out of an exhaust is a rotten egg smell, and thats usually caused by a bad catlytic converter. Its the Sulfer Dioxide i believe.

is there any thing bad with putting 2.5in piping on my 4 cyclinder? i don't want the rice sound, more of a deep one like hks....but i think id have to get a universal one from them or blitz....

^2.5 would be perfect if you're n/a... if your cat is going, just replace it with a high flow cat or something... they have pretty nice warranties on em'

you have a 2.0 sentra i assume, if your not planning on going boost, then a 2 and a quarter would be perfect. however i've read articules with dyno results that despite the rule, if you go up a quarter size up from the recommended size, you would gain more peak hp.

also high flow cats do work. if they didn't my car wouldn't have passed inspections. and a highflow cat wouldn't do much on a n/a car but if you have a to change it anyway, then might as well put a highflow one since the OEM ones are $800. but the factory is required to warrantee your CAT if it fails before 75K miles or around that ball park. i suggest you dig it up to find out what the exactly mileage is.

Peak power is less important than what is gained below it :)

yes tat, its a B15 high port sr20de 2.0L

the car has like 124k on it..im not counting on it. what brands are good for low to mid tq muffler wise? this is going to be done all in the summer with hot-shot header, high flow cat, with muffler shop straight back system with muffler...i think i might have to add cams to it since its advised to do those with headers(one question)

im also thinking of gettin a safc(i think its called) and raise the rev lmiter on it if it would make a difference on an auto to shift at different points(idk thats y im asking)....

^as long as you don't get a muffler with like a 3 or 4 inch tip, than you won't loose backpressure, so your low end shouldn't change

modern day 4 clyinder engines work off velocity. With a small pipe while the engine is idleing the cars exhaust has a constant stream of velocity. Meaning the exhaust gases have filled the exhaust system, and are moving at a constant rate out. When you get an exhaust system that is to big, what happens is the air moves in burps. It doesnt fill the exhaust pipe all the way, so the exhaust gas gets pushed into the pipe, then it doesnt have enough pressure to get out of the pipe, so it sits there, then another wave of exhaust gas comes and pushes it a littler further and so forth untill its completly out.

The problem is so many people try to apply the fluid dynamics of a V8 to a 4 banger. With a v8 you have the extra cylinders that allow for you to put a large exhaust pipe on it and not lose low end power. They fire so quickly and so much more exhuast that they dont have a problem keeping the exhaust gases moving. Not to mention they are already very torquey.

Putting on an exhaust will give you a little higher peak HP, but your gonna lose a noticeable amount of lowend to gain it. Your going to lose lowend torque, and low end torque is what makes a car fast.

Torque wins races, HP is for braging rights.

Also i have never heard a 4 cylinder with a good sounding exhaust that wasnt raspy. THis does not include exotics and sports cars. With the exhaust it is gonna sound ricey, unless you put a big ass resonator on it.

i dont think so. i've heard some pretty good exhausts that aren't ricey at all from my friends 5 dollar ones from ebay. they have turbo eclipses/lazers, but maybe its because they are turbo....some n/a cars ive heard aren't ricey..i dont think mine will be, all i know is that i dont want the beehive sound, just a little lower sound and ill be pretty happy. i honestly bearly know the difference between the two, a ricey one is always loud, the others are much quieter unless revving higher than 3500rpms... i think everyone i know with the exception of one or two people have the exhaust from ebay with straight piping from the muffler shop, so if anyone has sound clips i think that would be a good idea to help me out here.

remember jayson he does have a SR20DE in his car. so its goin to sound atleast decent. a good brand of high flow cats would be from magnaflow and if you got the dough you can get a random technology one.

I thought HP won races, hp sold cars and torque was what the muscle cars used to have something to brag about :) "i may only have 200hp but i have 500 lb-ft of torque"

I thought HP won races, hp sold cars and torque was what the muscle cars used to have something to brag about :) "i may only have 200hp but i have 500 lb-ft of torque"

HP is a number derived from torque. . .

the formula is actually HP = ( tq x rpm ) / 5252

now the reason why they had so much tq and so little hp is because there wasn't enough revs for the tq to do anything really. so if the tq was spread over a broader area ( more revs ) the hp would be much higher.

case in point. the S2K makes a measly 156lb ft of tq but its spread thru a 9K rev range so thats where the 240hp comes from. the a decent amount of work was done by a small amount of tq becasue the work load was spread out. its like being able to lift 20 lbs 50 times is the same amount work as lifting 100 lbs 10 times.

i am having interesting smells from my cars exhaust. im planning on redoing it. does anyone know if the high-flow cataylistic converters work? it will go with 2.5 in piping cat back.....anyone know? thanks

o and it snowed today, a car's brakes locked i guess and plowed into a city bus....lol


Rotten egg smell is a cat backing up and going bad. Is that what it smells like?

after i go wot, or sometimes just randomly...it happened yesterday after i go fater than 65mph, rpms really dont bring out the sound, but a while back if i held at 3000rpms, i could hear a rattleing sound coming from by the header or so....

Yes i know why the engines made so much torque and so little power. a torque engine is great for towing or moving heavy heviles around or daily driving in low RPM ranges but HP is what counts as torque is work done and horse power is work done in a given ammount of time. Torque can me multiplied through gearing, horsepower cant.

Think of it this way, instead of racing around a track we are racing to boil water to create steam to shoot a steam rocket off. You may have more potential energy (joules) stored up in your fule but if i can get enough energy into the water to get it to boil faster than you can i will win.

Case and point

You use propane where as i use acetelene, however your total ammount of propane has stored more energy than my total ammount of acetelyne. we both need the same number of joules to rais the gien ammount of water to the given temeperature but acetelyne burns quicker and hotter. for examples sake i will say i can burn at 1000j/sec (1000w) and you can burn at 100j/sec (100w), i will be able to boil the water faster.

and what an amazing relation, 746w=1hp and wherethey dont use horsepower figures for engines (companies and countries) they use wattage. Greater watage = Faster down the track.

im not trying to start an argument, stating fact, if you want to argue that point you have little knowledge of physics.

If it's a sweet smell maybe you're luck and it's a head gasket.

oh didnt even think of that....good luck.

sweet smelll?????is always smelled like rotten eggs so i guess bulldog was right, but which one is the question.....

You use propane where as i use acetelene, however your total ammount of propane has stored more energy than my total ammount of acetelyne. we both need the same number of joules to rais the gien ammount of water to the given temeperature but acetelyne burns quicker and hotter. for examples sake i will say i can burn at 1000j/sec (1000w) and you can burn at 100j/sec (100w), i will be able to boil the water faster.

:bs:



acetelyne doesnt burn that hot, oxyacetelyne does :tongue:


but yeah torque= force times torquearm. power is rate in which work can be done. but you still need tq to move the damn thing, u ever seen one of those purpose built cars that can hardly move at low rpms...


This is the reason i think its completely retarded that the honda ridgeline won truck of the year at detroit, the fuckin thing has no tq, thats the only thing that matters in a truck. sure the trunk thing is kinda neat but comon :banghead:

Acetelyne + Oxygen + Potato gun = teh win.

Though i dont reccomend it.

yes tat, its a B15 high port sr20de 2.0L

the car has like 124k on it..im not counting on it. what brands are good for low to mid tq muffler wise? this is going to be done all in the summer with hot-shot header, high flow cat, with muffler shop straight back system with muffler...i think i might have to add cams to it since its advised to do those with headers(one question)

im also thinking of gettin a safc(i think its called) and raise the rev lmiter on it if it would make a difference on an auto to shift at different points(idk thats y im asking)....


the rattling sound from the header might be the heat shield.
which cat went bad? if the precat went bad, ur check engine
light will come on....if the 2nd cat went bad.....
well, u just keep driving....unless u're willing to spend copule hundred $
to save the environment.

I read some articles before, they were saying a high flow average lasts
only 1~2 years. I'm not sure if that's true or not.
and I asked the guy who installed the high flow for me, he just said
"it will last longer than that".....somehow, that answer gives me no confidence.

for an auto, if u r getting new header, make sure it's 4-2-1,
that way u don't lose to much tq.

and for the sound, nothing runs close to stock mufflers.
even though we got different motors, but I don't think their sound
are too far off. after I got the header and muffler(but the resonator
remain stock)....the car gets noisy after 2500 rmp.
so, u r not getting away with sound(or ricey),
u can try to get a deep tone cat back though.....good luck!

the check engine light came on, but after a couple days i got tired of it, WOT and it was gone...this isn't a stable problem, but it happens once in awhile...so idk whats wrong with it....

we had a lil discussion on tq in here obviously, and the saying goes hp sells cars tq wins races. well something interesting in the car&driver i got today

lotus elise vs carrera S

they have the exact same lb per hp. but the carera has a large tq advantage. the porsche killed the lotus in tests, even beat it around road atlanta because of how much faster it accelerated. so i think that test kind of proves the old saying.

but maybe theres something idk? if so id be glad to hear it.

The test is flawed...you proved it through your own statement... more torque but same HP/Lb means it has a flatter power curve...flatter power means better linear acceleration...its power that is making accelerate...not torque...you can have all the torque in the world and still be at 0 RMP... you're not getting anywhere at 0 RPM.

there is alot more that affects acceleration in thoes instances... Lotus has a smaller power band, different gear ratio's, etc.

Let's put it this way...how much torque do you think F1 cars are producing?
Certianly alot less than their mucle car counterparts producing Aprox the same power.
How many cars can beat F1 cars....F1 cars have no traction controll and a skilled driver can put them into low 9's down the track...with a form of traction controll (or in theory) they can run 7's in the 1/4 mile. The muscle car of the same power to weight ratio would run about the same in the 1/4 mile assumeing both have optimal gear ratio's. As far as F1 is concerned their torque is minimal... If torque won races they wouldnt be focousing on 700hp from 3.0l at 20,000 RPM they would be focoused on as much torque as possible at w/e RPM.

like i said... Power is what matter when trying to get something done in the least ammount of time possible.

The test is flawed...you proved it through your own statement... more torque but same HP/Lb means it has a flatter power curve...flatter power means better linear acceleration...its power that is making accelerate...not torque...you can have all the torque in the world and still be at 0 RMP... you're not getting anywhere at 0 RPM.

there is alot more that affects acceleration in thoes instances... Lotus has a smaller power band, different gear ratio's, etc.

Let's put it this way...how much torque do you think F1 cars are producing?
Certianly alot less than their mucle car counterparts producing Aprox the same power.
How many cars can beat F1 cars....F1 cars have no traction controll and a skilled driver can put them into low 9's down the track...with a form of traction controll (or in theory) they can run 7's in the 1/4 mile. The muscle car of the same power to weight ratio would run about the same in the 1/4 mile assumeing both have optimal gear ratio's. As far as F1 is concerned their torque is minimal... If torque won races they wouldnt be focousing on 700hp from 3.0l at 20,000 RPM they would be focoused on as much torque as possible at w/e RPM.

like i said... Power is what matter when trying to get something done in the least ammount of time possible.

but see your proving the point with you statements. power is very important yes, but the same power with more tq makes a faster car. so in that sense the saying works perfectly, and thats exactly what the saying is talking about. the lotus has no tq so it has to wind its rev way up there and peaks out super late. thats a disadvantage to a car with a flatter curve just like you said.

F1 cars are not a fair comparison at all. they are open wheel race cars, basically awesome indy cars, and with the way they are built they could have significantly less power and tq and still beat a lot of cars. not to mention they dont way anything. Also F1 cars definatly do have traction control.

dont worry i took high school physics too i know exactly what your talking about, for christs sake im a physics major. just read your first paragraph, your proving the point for me. shoot i forget the exact number of hp that F1 cars make, its very high though. when juan pablo montoya took jeff gordons car out on the track he was vary impressed with the power. im assuming that the 358cube engine has considerable tq.

i want my car to go at 20,000rpm....tell me how!!!! id be happy to break 10,000

f1 cars don't have traction control, and lastr i heard they were at aroun 800-850hp. next season however will be either 2.3 or 2.5L (don't remeber) v8's so you can expect power to go donw alot from there.

Back to the discussion. with the lotus and the carerra, the carerra had more power more of the time, the torque didn't matter other than to give that superior power. If you took a dyno graph from the elise and the carerra and put them one on top of the other, you'd see that the carerra almost always had more power, except at peak.

f1 cars don't have traction control, and lastr i heard they were at aroun 800-850hp. next season however will be either 2.3 or 2.5L (don't remeber) v8's so you can expect power to go donw alot from there.

Back to the discussion. with the lotus and the carerra, the carerra had more power more of the time, the torque didn't matter other than to give that superior power. If you took a dyno graph from the elise and the carerra and put them one on top of the other, you'd see that the carerra almost always had more power, except at peak.

exactly, and why do you think it has more power most of the time. because it has more ability to make it. or in other words, torque.