hey i just took the muffler off my car and it sounds cool but i feel a huge loss in performace, mainly acceleration. why is this, i thought straight pipes increased horsepower? what can i do so im able to run straight pipes? anythin i can do with cam, valve springs, to help it run better becuase i like the sounds i just wanted to have good performance back. thanks alot

 

2 things 1. taking off muffler should in no way lower hp 2. you cant run str8's in NY either you will get pulled for noise or you def. wont pass inspection.

 

i took my muffler off, and when u do u have next to no back pressure

 

how can i keep the straight pipes on and have backpressure.

 

A lot of your loss in power is in your mind. I bet if you were to put enough mufflers on to make your car almost silent, like a brand new car, you'd think you had more power. It's a phsycological thing. There is the loss in backpressure also, which is where performance mufflers come into play. Most of them will have chambers and things, coupled with a fibreglass-type filling, which blocks out high-pitched noise but keeps the rumbly note. It also increases backpressure, so you get a loud exhaust with no power loss.

 

Oh *** not this again. When will you people learn that backpressure is bad?

 

i now i dont no much and am still learning every day but i alwase thought that u had to atleast have a little back pressure for an engine to run right.

 

Not to offend anyone but straight pipes sounds like ***. Not to mention yours gonna fill your passenger compartment with exhaust fumes since it exits early. Gonna get you pulled over. And sound bad.

I had dual exhaust it was loud as hell. I eventually got so tired of it. My edelbrock headers and hooker catback is much quieter but sounds good. I like it.

Id put a 2 chamber flowmaster catback on it or something

 

NONONONONONONONONONO!

BACKPRESSURE IS BAD! VELOCITY IS GOOD! BACKPRESSURE IS BAD!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

i like my muffler to be loud! whats the loudeset muffler anyone here has heard tha sounded good but kept good performance. with my straight pipes i drive by and send the horses runnin across the field when i rev it, and set car alarms off. what muffler will allow me to do this? i like it to be loud and good performance!

 

Maybe the phenomenon is caused by the fact that the ECM has tailored itself (leaned out to keep it's air:fuel ratio) to a restrictive exhaust (or crappy muffler in this case) thus, the muffler falling has increased exhaust flow causing a now lean condition (the will eventually correct itself mostly) reducing the butt-dyno feel.. just my thought...

 

Old muscle cars did not need back preasure, thats why straight pipes were good. Our newer camaros need some bottled flow, backpreasure if you want to call it that if you dont then dont but you do need some kind of restriction there. I know this by trial and error.

 

WTF, the new ones dont have different needs than older cars. I don't care what anyone has to say, BACKPRESSURE IS BAD! Everyone repeat after me, BACKPRESSURE IS BAD! The same things that worked on the older muscle cars still work on todays cars. People commonly confuse backpressure with velocity. You want to keep velocity high without restricting the flow of gasses out of the engine, aka backpressure. When choosing the proper size exhaust you want to take into consideration the amount of hp you will be making in order to figure out which size will keep the velocity up while reducing backpressure. If you went with 1 3/4 tubing with dual 3 inch piping on an engine that makes 150 hp you will most likely lose hp because the engine isnt pushing out enough gases to need the larger pipes. What you will do though is slow down the exiting gasses and in a way increase backpressure. Any time you put a restriction in the exhaust you will slow it down! When you reduce backpressure you make it easier for the engine to pump out the burnt gasses therfor making more power. BACKPRESSURE IS BAD!!!!!!!!!!!!!!!!!!!!!!

 

Older cars were not equiped with computers. Thats the difference and I did not exactly say backpreasure. I am saying direct airlflow. And 1 3/4 into 3 inch. is pointless for power or performance.

 

Computer controlled or not, it makes no difference. Also, some engines do require the use of 1 3/4 inch primaries with dual 3 inch collectors. It's all in the amount of hp you are making. You have to match the components to your engine.

 

Yeah, I know what you are saying about the backpreasure thing, but I know when I ran my camaro with new headers on it and open after the y pipe where the cat goes, because I left my cat off and could not get to the exhaust shop before it closed. It was like that for a day and the power sucked. After I went to the exhaust shop and put a pipe in place of the cat it was a huge!!!!!!!!!!! difference and it was no mental thing about it.

 

so basically what this boils down to, in order to run straight pipes i just need to put smaller pipes on, right now i have headers into a Y pipe then 2.5 from the cat back. and if this dosnet work whats a good loud muffler that keeps the performance?

 

I second that. When you make a major airflow change (such as removing a muffler or intalling headers) in the engine, it will never run to its potential unless it A/F ratio is tuned. Off idle flat spots, mid range lean outs caused by these changes all contribute to the loss of torque/power notion. Then magically disappear once its correctly tuned. Just look at all the stock eliminator cars running basically stock motors with open headers. Do you think they have a loss of power?

 

ill tell you all the truth , i have straight pipes on my stock 84 trans am with the 305 tpi engine. It sounds awesome . i have the cat on the car and if im in overdrive and a cop is going by or you want the car to be quiet i just let off, and its totally silent, the catalitic converter and having a manifold instead of headers is what does this. I too also lost some low end performance, i used to be able to chirp the tires going into second and now it wont. i really dont car because the car sounds so much better now. I think if you got headers and then ran straight pipes you wouldnt loose any power. i know my dads 77 trans am has a lot more power when he runs his car with the electronic cutouts open. O and no fumes get into my car, cause i had the work done the right way and didnt just cut off the muffler and leave it open. I love how it sounds. just drive the car like it is and youll be fine.

 

heres a pic

 

thats what a MAF is for


tells the motor how much air it is sucking in


now with a speed density that is a little different
car under such and such load is only pulling in this much air
change it and things can go a litle off, but the computer should adapt to it after a while.... part of the reason an O2 is put on is to correct that

most people putting headers, exhuast on htere car don't notice that much of a loss UNLESS things are mismatched as it is

 

Although more adaptable than SD, a MAF is not a magical tuning tool.

 

well no it isn't a super tuning tool

but it is able to sense the changes in airflow

and I don't think that by changing to headers you are going to cause that much of a change to mess with a MAF system



if so just think of the problems those guys with after market heaeds/cam would face.....
sure you can't get too large but a lot of them do ok with just some mild upgraded parts and those easily would make for more of a flow change then a set of headers