NunaNunaNuna

Hi, my '98 needs a muffler and I was wondering what you guys suggest. First off, I want to know if going to a less-restrictive muffler is good or not. I always thought that less restriction was better for power and the engine, but I also heard somewhere that engines are designed so that they need back pressure...which is correct? If I can use a performance muffler, I'd like something like the Moroso spiral flow, and want to know what you think of a muffler like this for the XJ.

OOdynamite

Engines do not, and I repeat, DO NOT need back pressure. People think that engines need back pressure cuz most engines come with an exhaust that creates back pressure from factory. A freer, faster flowing, less restrictive exhaust is always better then stock.

As for that muffler I have never heard of it so I can't give you an opinion. I will say that I have a magnaflow muffler on mine, and I couldn't be happier.

wiggles

No back pressure is great but a little is good for fuel economy. I have ran a complete chop before and besides it being extremely loud I could feel a loss in performance and mph, I now have a new cat and cherry bomb glass pack and love it!

NunaNunaNuna

That's what I heard before, and it didn't (and still doesn't lol) make sense to me because I always thought back pressure wasn't so good for the engine. Why does the power and fuel economy go up with some back pressure?

ASNFMOM

I'd second the magnaflow muffler. The spiral flow muffler are made for high compression v8s and the last time checked only come in 3inch or above.

mr white

It has to do with the powerband.

wiggles

Bp is good for mpg but if you are racing than you want no Bp that's why drags have open headers. The reason they do that though is because they produce so much power and exhaust they they need to dump it fast and they don't care about how much gas they use since its only a 1/4 mile run

NunaNunaNuna

Thanks ASNFMOM for the info on the Moroso, looks like it's out the window for me. One of the reasons I was looking at the Moroso, though, was the fact that it's so compact and wouldn't be too heavy or be hanging low to get caught on anything...what other mufflers should I be looking at that offer the same advantages?

OOdynamite

As I said before, I love my magnaflow.

wiggles

My cherry bomb is a tube so I'd say its pretty compact, I also tucked my exhaust system so its even more out of the way. The bottom of it sits less than an inch below the "frame" rail

ASNFMOM

No prob. The cherry bomb tube mufflers will offer the same thing as the spiral flow in the shape of the muffler. But will be quieter then the spiral flow as the spiral flow is basically like running straight pipe.

UsmclovesXJ

Flomaster 44 on a manga flow high flow cat. Foot set up on the cheap. If u got coin. I don't like this set up imo. But go all Magana flow

DailyDriven

How good does this setup sound? I want something throaty but not obnoxious. Something that gets loud when u gun it but doesn't draw too much attention.

UsmclovesXJ

That would be a flowmaster very nice and aggressive. Not annoying like a glass pack. Very nice. And you can tell its there when u gun it

UsmclovesXJ

Won't set off car alarms or wake neighbors