Well, it's not the same set-up as yours but it will give you an idea. I initially installed the O/R H-Pipe with the Flowmasters and I can tell you it was terribly raspy, trumpeted, and it was pretty darn loud. I did much searching and ended up installing some resonators. You be the judge, but I'm now very happy with the sound/power.
Outside the car
Inside the car
Outside the car
Inside the car
I just removed a BBK off-road H pipe with no cats from an 88 Saleen Mustang. Before removal of the Off-road H pipe for ****s and giggles the car was set up and 2 pulls made on a chassis dyno. Immediately after the re-installation of the stock original H pipe with the factory cats we again ran the car full 2 pulls on the same chassis dyno.
The result of this same day test with the same car with the only change being the H Pipe was an idicated 2 horsepower GAIN and a 15 lb/ft INCREASE in torque with the FACTORY H pipe with cats re-installed back on the car OVER the BBK Off-road H pipe with no cats. The same cat back flowmaster exhaust system was used in both cases.
Why would you want to ditch the factory H pipe for an off-road H pipe?
The result of this same day test with the same car with the only change being the H Pipe was an idicated 2 horsepower GAIN and a 15 lb/ft INCREASE in torque with the FACTORY H pipe with cats re-installed back on the car OVER the BBK Off-road H pipe with no cats. The same cat back flowmaster exhaust system was used in both cases.
Why would you want to ditch the factory H pipe for an off-road H pipe?
That's what I alway had heard also though not necessarily so!
This 88 Saleen had a competely mechanically stock engine with only addition being BBK headers which were installed when the BBK offroad H pipe was installed. The BBK headers remained with the re-installation of the stock H pipe with cats AND with the small increase in HP and torque.
I ran just the M-80s for a while with LTs and an O/R-H. Loud as all hell, I mean seriously loud. Lots of drone on the freeway (from 2200-2800 rpm). I put the stock mufflers back on, so it was M-80s into the stock mufflers, sounds good but too quiet for my tastes. Now I have some flowmaster 40s, sounds really good, but still a little quiet, though insane amounts of rumble and bass.
Dan
Dan