[Iwannagofast]

i like the way my dumps sound....not too loud....but i still have the cats also

[CAMN89GT]

Between my blower, my fuel pump .. it really doesn't matter if I had tails or dumps. I currently have tails, but I seem to made more power on the DYNO w/dumps. I can tolerate the smell, I used to run 110 so It didn't bother me... the heat, it's the same amount of heat, its all in ur head. Dumps FTW.

[superbean]

if your going to dump your exhaust, dump it near the rear axle, not right under the drivers seat like most do. I'm a firm believer that a freeflowing full exhaust will move the power band lower in the rpm without sacfricing peak hp.

Dumps sound cool and are ok for a weekend car, but if you drive it more than 50 miles a week, it's annoying and obnoxious.

[CAMN89GT]

Originally Posted by superbean if your going to dump your exhaust, dump it near the rear axle, not right under the drivers seat like most do. I'm a firm believer that a freeflowing full exhaust will move the power band lower in the rpm without sacfricing peak hp. Dumps sound cool and are ok for a weekend car, but if you drive it more than 50 miles a week, it's annoying and obnoxious.

+1 , I actually dumped them toward each of my slicks.. Made them warmer, better traction. I cheet, i know I cheet!

[-Joeyy-]

oh my motor is carb so does that mean i should have straight pipes?

[88Saleen]

Originally Posted by fogged306 Backpressure is not needed on a EFI engine with o2 sensors, it is more of a myth than anything. Proper exhaust scavenging is what you want with a properly tuned exhaust.

can you explain this? i always thought backpressure was very crucial to engine performance

[Hunt_chevs]

Originally Posted by -Joeyy- oh my motor is carb so does that mean i should have straight pipes?

no its makes no difference whether your carbed or not

[Hunt_chevs]

Originally Posted by -Joeyy- I am saying straight pipes produce more back pressure. In less i am wrong?

str8 pipes = zero back pressure

[stangfreak]

i heared you lose some torque without tail pipes but i always go with dumps. always

[Hunt_chevs]

Originally Posted by stangfreak i heared you lose some torque without tail pipes but i always go with dumps. always

PERIOD

[fogged306]

Originally Posted by 88Saleen can you explain this? i always thought backpressure was very crucial to engine performance

It's not how everybody thinks. There are many variables to this... yes there are certain cars that require a certain amount of backpressure, such as some carb'd cars. Some of them used backpressure as a way to keep too much air from getting in the combustion chamber to maintain stoich. If you remove this backpressure, you are allowing more air in to the combustion chamber but still using the same amount of fuel, resulting in a lean condition, burnt valves ect... An EFI car with o2 sensors will not run into this problem because it will sense the mixture going lean and correct it, something that a carb cannot do.

What you want is exhaust scavenging, what it does is essentially create a vaccum in which the exhaust gasses travelling out of one cylinder will "suck" the spent gas out of another, and so on (in conjunction with the piston pushing it out). When you go too big of an exhaust, you can lose scavenging and it can result in a loss of power. You basically want to match your exhaust size to your power level.

[-Joeyy-]

ohh ok but i am still confused i have a carb 351 do i want straight pips or dumps when it comes to wanting more power?

because i was told straight pipes give the back pressure not dumps so i am confused here

[Chris951]

Dude get dumps. I drive my car 300+ miles a week on the highway with 4.10's and dumped Mac flowpaths. You get used to it. I think I might get some tailpipes just to make the car look a little better though. I think Lx's look horrible without tailpipes.

[-Joeyy-]

i mean for power though i dont care at all for the sound as to if it is to loud or not ( my motor can never be TO loud for my ears )

[superbean]

blah blah blah.. backpressure is a myth as far as im concered..

look at any dyno with header and/or exhaust size comparisons..

the bigger exhaust will ALWAYS make more peak power..

now here comes the question.. WHERE do you want your torque band?

a stock exhaust will allow for a sooner power curve in the rpm and net a lower hp..
bigger exhaust will allow for a later power curve and make more tq...

in racing, you want as much tq at the highest rpm possible..

Even if someone builds a 'street' motor, he could still benefit from a larger exhaust..

go big, you can always build a motor to grow into it.

so to answer the dumps question.. it has nothing to do with power, but merely if you can stand the sound of dumps all the time .. nauseating if you ask me.

[fairlane_68]

FWIW, dumps under the car make it louder in the car. Good excuse for an amp and a couple subs.

[superbean]

Originally Posted by fairlane_68 FWIW, dumps under the car make it louder in the car. Good excuse for an amp and a couple subs.

and tear drops for the carbon monoxide.

[-Joeyy-]

so basically there is no performance difference between flowmaster dumps and flowmaster straight pipes?

[flattusmaximus78]

Originally Posted by stangfreak i heared you lose some torque without tail pipes but i always go with dumps. always

The ojly difference with cutting the tail pipes off is sound. That wont affect back pressure in anyway. It's the cutting off of mufflers that will do so.

[-Joeyy-]

ohh ok i got ya, so basically dumps are louder then straight pipes?