Do Flowmasters hurt performance?

I have checked for exhasut leaks I have none. Now mine do not sound like what is being described above. Maybe we are all thinking something different but describing it the same? I know what an exhaust leak sounds like, and what to look for. I do not have one.

Like I said, I have had many many cars over the past 16 years. Almost all of them have had after market exhaust of some sort. All of them made some sort of popping upon slowing from higher RPM.
 
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I don't know if Flows rob power but they aren't the best flowing muffler. I have seen several cars pick up 5-15 rwhp just by switching out the Flows for a set of Borlas or Spintechs etc...but these were all 400+ rwhp cars.
 
my guess would be if other peoples flows are not popping u might have an exhaust leak somewhere. I know ive got a leak somewhere with my exhaust i think its where my xpipe connects to the manifold. but i have a sort of rattle sound around 2k and under when im hitting the gas. its not a ping type rattle. and it pops on decel but im pretty sure all borlas pop a good bit on decel lol.

i would check everything again something may not be lined up properly and ur just not seeing it.

I know for a fact I don't have any exhaust leaks at all. I don't necessarily think that the sound around 2k is coming from the exhaust, but it could be. Maybe a Cat is coming apart internally:shrug:
 
Hi,

Popping is normally caused by un-burnt fuel being thrown into the exhaust system causing the fuel to explode. I think you'll find it's very common in racing cars, rally cars where full throttle is followed promply by closed throttle and thus the result is popping.

Sounds quite cool really you should try it :D
 
I don't know if Flows rob power but they aren't the best flowing muffler. I have seen several cars pick up 5-15 rwhp just by switching out the Flows for a set of Borlas or Spintechs etc...but these were all 400+ rwhp cars.

I lost 8rwhp after installing flows with dumps on my car. I dyno'd at 187 stock and after I had the flowmaster 40s with dumps I had the car re-dyno'd the same day and made 179rwhp and I gained 5rwtq.