just install flowmaster muffler

[lasvegash2]

i just had the local shop install a flowmaster 70 series big block II version muffler. it has a nice rumble at idle and at cruising it has a nice mellow tone but when you full throttle you know you have a flowmaster muffler on. they told me that i could of gone with the 50 series big block version which is a little louder but i would of have had some interior drone at certain rpms.

[gsmith9898]

did you notice and power difference or mpg?

[lasvegash2]

didnt notice any gains in mpg but that is because i cant keep my foot out of the gas pedal. hp i cant really tell but that is probably because i am running 38.5" tires

[gsmith9898]

what is the part numbers for the 70 s?

[tomp]

surely you lost some low end grunt with that muffler

[lasvegash2]

part # is 524703. i drove it normal today and my mpg used to be 8.9 with the stock muffler/normal driving and with the flowmaster it went to 10.0 i did lose some low end torque.

[Htothe2]

y do u lose low end torque?

[HUMMERcustoms.com/TAZ]

I run twin super 40's with true dual exhaust and tailpipes over axel in stock location and sounds great. Gained good low end and at cruise do not notice them much but, usually have music on. It starts with a growl like a mean bear and maintains a good deep sound at idle. When You get on it it is heard for block away. Take off at normal speed and sounds mean but, not blowing any windows out. Mufflers are hooked to Dynatech long neck header catback system to improve low end even more with 2 1/2" dual pipes all the way out the back. If You deal with a good exhaust shop, if they are to much for You they will let You try 40's or 50's. No need for part numbers if the shop You use know what they are doing.

I rolled up to My performance exhaust shop that builds systems from scratch for some of the best track racers in our area as well as the rice rockets and I told him the programmer etc. I had on the rig including the headers and catback system and he said I know what You need to get all the performance You can get out of add-ons. He then said try them for a while if it is to much from what You were used to then I will switch them for something else. You have to keep in mind You are moving from a stock sound that hurts performance of even the stock setup so anything is going to seem loud at first. So get a shop that will let You try them out for 3 or 4 days. My shop said take a week if need be. Anyway Jason hit the nail on the head the first time. I like mean sound but, not to the point of over riding my audio/video and as long as I'm driving normal with foot out of the supercharger, which was not on when the super 40's were installed, it sounded even better. When I want to let someone know that the "Beastly Beauty" can be serious it does that very well.

Everyone that has been in it has thought it had a great sound for whatever occasion was called for. Just look for performance exhaust shop versus a muffler shop and you will normally get someone that will work with you till you get the sound you like. There is a difference in the service as I learned the hard way many years ago of being sold what was not selling well and collecting on the shelf versus being sold what they had on hand because it was what was selling best and making most people happy.
Good luck,

TAZ