ericfx1984

on a 4.0 HO should I run a dynomax turbo muffler or a flowmaster 40

I have both sitting around

also I WILL be using the catalytic converter

Free Jeep

I run a Flowmaster 40 with a Magnaflow hi-flo cat. It has a nice deep sound and is not too loud.

N20jeep

its all personal preference.

i prefer the 40 series

crystalion

JEGS is offering a 75.00 rebate on the Dynomax catback system for the XJ


150.00- 75.00 and I think free shipping

Seems like a great deal considering I just paid 145.00 2 months back

BigC9164

i have the flow 40. we actually it is the American Racing version of the Flowmaster super 40. it is the same design but made of aluminum or aluminized steal or something. so it wont rust. on my truck i had to replace my actual flowmaster super 40 every two years. they rust BAD!!

ericfx1984

I took FreemansXJ's advice and tried both mufflers (since I had them both)

I tried the dynomax turbo... it was just TOO quiet... sounded all right, deep tone, just a hair louder than my stock Heap o' Jeep muffler, but way deeper

I went with the Flowmaster 40... the one I had laying around had the inlet on one corner and the outlet on the diagonal corner... this did not work for me SO I cut off the inlet face plate and welded in a new 1/4" plate steel plate with a centered inlet hole...

then I ran only a turn down (and the CAT...)

RESULTS... the flowmaster 40 sounds awesome... it is not too loud (thanks to the turn down and the cat still being in place) BUT it has an awesome tone! VERY deep and throaty!

this is the chambered flowmaster btw...

cab noise is increased but not too much... sounds great around 2000 rpm

00-buck

Cant go wrong with the 40

bluedragon436

I was going to say run the 40 anyways.. I love my 40 series... everyone told me it would be too loud, or the drone would be too much... I drove it from DE to SC and back with absolutely not issues, and didn't mind the little bit of extra interior sound at all...

s14unimog

No experience to add yet but I just bought a Dynomax Super Turbo from Advance today for $29.99. I went this route for two reason, first: I have no interest in making anymore noise in the woods, and that's the cheapest I've seen for a replacement. It's just the muffler but after measuring my stock muffler back pipe section, it looks as though I can just cut it off the stock muffler and it'll slide inside the new muffler. I'll let you know how it goes but that's the best price I could find on them.