Well, after a call to Mufflex and another one to Flowmaster, it became clear the single muffler, two in ,two out cannot handle the volume of exhaust our Lightnings put out.

I have to say, even though I live in Dallas, Denny at Mufflex took the time to help me with his experiences and was very helpful and considerate.

I went back to the muffler shop and he re-fabricated an installation with two 50 series Flowmasters. Some people are using the 40 series with the delta technology (less cabin resonance) and having good results too. Not too loud. Anyway, just a note to be sure and use two cans if you go flowmaster.

It sounds really agressive, like a Lightning should. I'm very glad to be rid of that milk-toast muffler from Ford. I did save it for any purchasers of my veh. The new installation bolt right up to the origional header pipes and he fabricated new tailpipes running up to the stock tips. Very stealth.

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1999 Red Lightning
Bed Rug, Soft Cover, Super Chip, K&N filter coming this week!

 

Hey Radarlove, glad to hear you replaced that big old paper weight of a muffler, I know you like the sound now.....

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99 SVT Lightning
BLK. #1476 5/20/99
2 Chamber Flowmasters
Superchips
A-pillar Phantom Boost Guage
Sportmaster Flip tonneau
Tow package
CD changer

Best run to date 13.52@102.4
N.O.S. (on order)

"Empty Pockets Racing"Drag Race Team NJ-DE

 

I also called Flowmaster tech after reading these posts, since I've been running the same thing. The tech did say he was unsure of whether or not the muffler could handle that much horsepower, especially if additional mods were being done.

The first time I ran my truck at the track, I had the Flowmaster on and I did 13.9, the RPMs don't seem to be lowered either. We also opened the intake on the muffler to 2.5", since it came as 2.25". But still, with all this unsureness, I think I'm gonna go with a setup that I know will be okay, especially after I add the chip and nitrous.

Mike

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99.5 Black Lightning
PowerSurge Cone Filter
JBA Jet-Hot coated headers
Flowmaster muffler

 

Well, I'm back in the muffler shop, swapping the "3 chamber" 50 series for the even more aggressive "2 chamber" 40 series. Heck it sounds good with the 50's, but this is the fastest pickup in the world, so more aggression is warranted. Should have it back out this afternoon. Can't wait!!

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1999 Red Lightning
Bed Rug, Soft Cover, Super Chip, Flowmasters, K&N filter coming this week!