Celica Forums General Discussion General Question...

What is the difference between Exhaust and Muffler? Which one is better? thanks

a muffler helps mute the sounds of your engines waste output (fumes). take off your muffler and your car will run much louder (think aftermarket racing exhaust)

an exhaust is just an outlet to release your engines fumes to the rear of the vehicle (obviously so you don't breathe it--very bad)

most car setups have both a muffler and an exhaust. fumes flow through the muffler (muting the sound) and then out through the exhaust.

furthermore, the reason aftermarket performance exhausts and mufflers exist is to mainly lessen backpressure. a high flow muffler allows more fumes to enter and exit more freely..which allows the engine to perform better (and therefore increasing horsepower)

aftermarket performance exhausts work the same way. they have a wider diameter and smoother bends that allow the waste gases to exit more freely...making it easier for your engine to 'push' the gases out. (same as muffler). the easier it is for gases to exit, the more power you will free up.

this is why turbos are more top-end peformance mods. because turbos are run by a turbine driven by exhaust gases, this increases backpressure.

aw man thats much better. thanks for the explaining that. i really had no idea.

neither did i

i hope you dont mind but uuhhh... aaahhhh... can you also tell me what a torque (did i spell that rite?) and rpm is. im pretty new at this stuff. hoping to learn it from you..

no prob, glad i could help

rpm= Revolutions per Minute, and torque is a rating of horsepower.

Ummmm, Actually everything from the exhuast port's in the head to the tip is the exhaust.



The muffler is just that a "noise suppressor".

lol, well i'll try and explain as best i can.

torque is 'pulling power'. it's goes hand-in-hand with acceleration. (a vehicles acceleration curve follows its torque curve perfectly--credit michael artistide for this info). therefore, the more torque you have on tap, the better you will accelerate. so obviously you cannot accelerate without an increase in torque.

and rpm just stands for "rotations per minute" this is usually shown in thousands (1 rpm = 1,000 rpms). this is just measuring how fast your gears are spinning. if you are in 2nd gear and you are at 4rpms, that means your 2nd gear is spinning 4,000 times a minute. obviously the faster you spin the faster you are going. (which is why it's so good to have an 8k redline in the celica gts--most cars usually get around 6).

this is true..the muffler can be considerred part of the exhaust

we usually use exhaust as a separate term though (like we do with headers--technically headers are part of your exhaust as well)

^^ yep an entire exhaust system consist's of many part's all with their own name's

eh, thats kinda hazy "torque is a rating of horsepowr"

the two are VERY related, but they ARE separate. horsepower can be described as "force" while torque can be described as "pulling power derived from this force" thats kinda confusing, if anyone has a better explanation, definately feel free to clarify my remarks.

thanks for the explanation bro. im really learning a lot more than you think. appreciate that bro. Thank you

to go along with what i said earlier about rpm's...

every transmission has a redline. this is a warning to how many rpm's can be safely attained without causing damage to your transmission (like i said..in the celica gts the redline is about 8 thousand rpms--really 7.8. most cars only have a 6 thousand rpm redline).

what this means is that in a celica gts, it is not recommended to go past 8 thousand rpms because the manufacturer (toyota) has deemed it to be unsafe for you transmission to be rotating that fast. this is why fuel cutoffs are evnetually applied. also, if you run into the redline very often for very long..it is very possible your transmission will fall apart (blown transmission)

ohhh.. ok.. so in regards to the redline, how fast can a gt (which i have) stock go? i mean whats the top speed it can go? does it also have a limitation like the RPM. Sorry for being dumb at this...

whats the redline for gt?

the GT model redline i beleive is around 6500 rpms (somebody correct me if i'm wrong). since you have an '01 model, you do not have a rev limiter. but at the same time, you only have 140 bhp, so with a stock gt the redline doesnt really apply in last gear--because you will run out of power before you reach the redline.

i think top speed of a gt is like 125? thats under 'standard conditions' (totally flat, fuel tank half full, no wind, etc--a few other things). so having a slight incline, a wind pushing at your back, less fuel, etc...will help you go faster.

thanks for all the help guys..

well, like i just said..i beleive it is 6500 rpms. since you have this...you can just simply walk out to your car and check and look at your tachometer and see where the redline begins (yes, its an actual red line..hence the term).

wow... so the 6500 rpm should not be passed or do offten? dang good thing you told me...

i just looked at it, how come its on 7000 rpm?

well if you go much into redline you will experience fuel-cutoff so you won't be able to go much higher than the redline.

you can pass the redline occasionaly and for short spurts, that really won't hurt the car. driving just above the redline though (before you hit fuel cutoff) can possibly cause damage though. (and tranny's are NOT cheap to replace).

if the redline starts at 7, then thats where it starts (thats what toyota thought was safe enough to travel at).

for some reason i thought it was 6500.

is there a way to bypass the fuel cutoff?

probably..theres ways to do anything...it's all just what your ecu is programmed to do. but why would you want to? its there as a safety valve so you don't drop your tranny.

last confirmation,if i run the car 1000 rpm to 6900 rpm often, would that create any damage to the car?

i was just wondering... again bro i very, very thankful for all this information. it helped me ALOT. thanks , and sorry for being anoying...

not exactly sure what you mean...but if you do indeed redlie at 7 thousand rpms..then it's safe to drive at 6900 rpm. i still wouldnt drive like that continuously though.

just for the record..its best to run your car (at a constant speed) at rpms of 2.5-4.5 thousand rpms for longest life. obviously when you are accelerating you will push the rpm's more than this (racing included) or when you are driving at very high speeds and that won't hurt your tranny much at all...but when you are just cruising..keep it between 2 1/2 and 4 1/2

thanks bro. Appreciate it alot..

just for the record... sPeEd4tHeNeEd is the MAN!!!

They asnwered the question about the exhaust and muffler. CID said it best. An exhaust system is all the way from the exhaust ports on the block, or even the exhaust cam and valves in the head and the muffler is just the noise suppressor.

As for the torque conversation, check this link out.

http://www.vettenet.org/torquehp.html