Flowmaster Question

[BJoe]

I've been thinking about getting a 2.5" center in/ 2.5" offset out Flowmaster 70 series muffler for my Cherokee to replace the factory 126k muffler and tail pipe, but have seen that Flowmasters don't "flow". Is that true or should going with one that large behind my otherwise stock 4.0l I-6 negate the accused "restriction"? Reason I'm thinking it shouldn't matter much in my case is that the 4.0l is 242ci while the muffler is intended to go under full size trucks, vans, motor homes, ect that use large displacement V-8's and diesels.

[Mnster]

I had on on the Nissan pickup I used to have. V6 3.0 with 40 series Flowmaster through 2.25 tubes. There was a noticeable performance gain over stock. The truck would rumble at lower rpms but was never loud when driving at speed. Was not rice sounding at all. The truck seemed to gain most of the power from the muffler near the top end around 3500-5000 it also seemed to pickup in throttle response in comparison to stock, revs would rise and drop faster. Torque also in increased, when in 4low wheeling I no longer had to worry about stalling as much as before.

Back pressure in the right amount = torque. If your exhaust is to free flowing you gain lose it off the bottom end and put it at the top. That is why I stuck to the 2.24 tube and 40 series for a more overall pickup.

The muffler is tough as nails, super heavy gauge steel with fully welded construction. Fully backed with a warranty to I believe.

[BJoe]

Thanks Ben! I've heard of them being use as lift points with some jacks on XJ when guys needed a solid place to lift the truck and still working well after getting flattened on rocks, which is why I kinda question the "doen't flow" statements. Reason I'm looking at the 70 is that I want to keep it fairly quiet and not attract much unwanted attention but still have something that will be a bit more aggressive sounding and breath better than what's left od the stocker.