Lexxus99

Yeah it seems the oem exhaust has some bigger sections at 70mm and much smaller section at 50mm. I hope the 63mm will be a better more free flowing system with that piping and removing all the resonator plus the flowmaster 40's series mufflers

Clifton

I would use a X or an H pipe in there and definitely not Flow master (flowdisaster). Do some searching on muffler comparisons and you'll find they are one of the loudest but perform the worst. Magnaflow or Dynomax are straight through mufflers without gimmiky worthless back pressure making chambers. Mandrel bends are best though most shops don't have the benders.

BCP43002

Just a thought for kicks. Before you change it out. Go to the back and see if you can somehow measure the exhaust flow coming out. I don't know, if you are brave use your hand otherwise maybe see if it can knock something over Then with the new exhaust do the same thing. Again, just for laughs.

Lexxus99

Yeah he's going to do an H-pipe for the section that come off the 2 cats. I couldn't anyone in my area with a Mendrel bender either. I had flow masters on my 97 Cobra and they did sound pretty good but never had a dyno done. Do you have a recomendation magnaflow mufflers? The shop only carries Flow master and Magnaflow's for choice of mufflers. I know the flowmasters have more back pressure than the magnaflow's but I thought you'd want some back pressure having a N/A set up compared to a FI set up where you want as much straight through as you can.


I've owned 2 Conra's both with 4.6 32v v8 and alot of people run a catless set up and flow masters because they produce some back pressure compared to other mufflers(straight through design) and with a straight through design they tend to lose some low rpm end tq. I don't know if the GS400 is in that same boat or not but any feed back would be appreciated.

Clifton

A muffler is designed to muffle the noise, not add back pressure to the system. You actually want velocity. I would use smaller header primaries or smaller tube diameter rather than a restrictive, poorly designed muffler. If you are doing this for power get everything you can.

Here's one comparison http://ls1tech.com/forums/archive/in.../t-119518.html The Hooker Maxflo on there is a straight through muffler like the Magnaflow, just painted black and not stainless.

Lexxus99

Yeah, I'm defiantly trying to achieve as much flow as I can out of this. Thanks for the link too