Kiff

running a 3.0 and I just did a x-over eliminator, so the pass side now joins down by the o2 sensor. Stripped the cat and put in a new 2.25" exhaust to magnaflow muffler. But the muffler is more of a glass back, it has no baffles. I got the 11225 model as recommend by most on this site.

The truck sounds awesome at idle, and it's fun to open up, but it's too loud for daily driving and I can tell I dont have enough back pressure as I get small backfires when letting off the throttle.

I'm thinking of putting a cherry bomb in where the cat was, but I dont think that will create any more back pressure really. Any ideas? I dont really want to get rid of this $100 muffler. But maybe a flowmaster with baffles would work better?

toytech76

Your 'backfires' arnt from backpressure related issues. My 97 manual trans 4runner used to do that with a flowmaster. The more open it is the more you are gonna hear stuff like that. What you are hearing is extra fuel getting dumped into the exhaust and burning off. Basically a slightly rich condition after letting off the gas. No worries tho, all is ok and is normal for an open exhaust like that

Kiff

ok, that is good to know. Any ideas for making it little more peaceful to drive around town

stormin94

Backpressure= BAD. Period.

You may want to consider putting your cat back on to quiet things down a bit.

or reduce the pipe daimeter to 1.5 inch so you will have more than enough back pressure to ruin your valves faster.

If i was you, I'd only listen to the first and second parts of this post.

Kiff

How is backpressure bad? not enough backpressure will burn out exhaust valves and loose precious low end torque. High revving sports cars want low backpressure because they rev so high and flow the exhaust enough.

stormin94

Ideally, you don't want back pressure. But you do have to find a happy medium with the exhaust diameter to prevent the gasses from cooling down and slowing down the flow, as would likely happen if you were to put a 4 inch exhaust on a 22RE. IF your theory about back pressure is true, then the smaller an exhaust, the more torque you will have. I'll admit that altering the back pressure will change the power curve, but I'm still gonna say that back pressure in general is not a good thing.

toytech76

alot of backpressure is bad yes but most engines require some sort of backpressure to run correctly in the power curve, mileage ect. Yes your cat would quiet it down. You could find a high flow cat to make it better

isaac338

popping in the exhaust on deceleration is a sign of an exhaust leak at the cylinder head. theory is, unburnt gases mix with fresh oxygen and ignite in the pipe somewhere. did you replace manifold gaskets when you had the exhaust torn down?

PCE91V64x4

I do not think back pressure has anything to do with it. Assuming the O2 sensors are operating correctly and feedback data to the engine, you can run an engine with no cats/exhaust just fine. Well, just fine, but very loud. A buddy has a viper and a neon for racing, and both are run no cats/no mufflers, and while the viper is deafening, the neon is rediculously loud as well.

You might be able to add a resonator in between the engine and your new muffler and, depending on the volume increase (from current volume of muffler to new volume of muffler plus resonator) you will see a quieter exhaust note. Otherwise, you may need a bigger muffler to get a quieter ride.

MMA_Alex

glass back= glass pack?

You're gunna want a higher end muffler, and a cat. a cherry bomb will not quiet it down!

you need some backpressure for most of these engines to run right. cut everything off right before the cat, and see how poorly, and how rich it runs, and tell me that its running well...

Kiff

Magnaflow isn't high end? I don't need a cat where I live so I'm not going to run one. I know that since I no longer have the stock x-over, clogged cat and stock muffler that my exhaust is flowing much better and has much less backpressure than before. The new setup is also making for the exhaust to be much louder than stock because it doesn't flow back into the other mani and go through the clogged cat.

I don't mind a louder than stock exhaust sound, but when it screams HEY LOOK AT ME, that's no so good for a place where the cops look for anything to bust a 4x4 on.

Tofer

not true..... yoter motors need some back pressure for the torque. thats why is not recomended to pull the cat and run anything larger then 2.5" exhaust.

MMA_Alex

a lot of "high end" mufflers are designed to create more noise, because a lot of people with custom exhausts want em louder. You need to shop for a quieter one. It will also be quieter with a cat

stormin94

That's what I ended up saying

SC2WD

high flow cat high flow cat high flow cat high flow cat.
Quieter, enough back-pressure to make everyone stop arguing about whether it helps or not and we (and our children) will all breathe better.