Any comments on using a Flowmaster 40 as the rear muffler?

The Vortex Classic on the back of my race car has finally crapped out and needs to be replaced. Not a whole lot of choice in this corner of the world so any comments on the flowmaster or design to look for would help.

Current setup is stock headers no cat (ROW), resonator middle and the vortex

cheers

 

George, its interesting to know that ROW cars didn't get a cat. What are the power ratings for these cars in NZ? Also, what octane gasoline is recommended?
I am sure your chip maps are different based on increased airflow.
Very interesting.
Raj

 

Use the SUV muffler that they make. It holds enough backpressure to maintain the torque and doesn't affect the higher RPM's.

 

Raj - quoted power/ torque is the same as US cars and recommended octane is 98RON. Certainly with the aftermarket chipsets , there are different chips but have to say there was no difference between the stock chip and the promax ROW chip beyond the increased rev limit.

Workaholic - SUV muffler is not imported here, does the 40 have insufficient back pressure?

 

The SUV mufflers are much bigger and heavier the 40 series.

I have a 40 series 3" in/out with no cat and a perforated resonator and it works fine for a track car. It's built very solidly and I expect they will last a very long time. It flows plenty of volume at high rpm.

 

I have a 40 series on my daily driver toyota, 2.25" in/out and it sees rain, snow, salt, sand and the welds are still holding up after a year and a half with around 15-16k miles put on it.

Just make sure you keep your welds sprayed with high temp silver paint. This helps reduce the progression of rust, which is inevitable on these mufflers since they're not stainless steel. Make sure you do the welds where the exhaust it welded in, as well as the welds on the case of the muffler. I've been doing this and it's still looking good after 16k miles, with no leaks.

 

Could this be the reason CS's aren't allowed in the US?