I would like to personally test the X pipe because I would agree that removing a 180 would make more power, but if you think about it, the side mufflers have a 180 in them too and per my dyno test above, removing them completely made no power gains.

 

That’s true, and evidence to show that exhaust improvements are part science and part art. Eliminating a bend in one part of the stream can have completely different effects than eliminating it somewhere else. Just like adding an X or H pipe in one part can help while doing it in another is detrimental.

 

It’s probably placebo, but ditching the third muffler does feel a little more responsive to me. I didn’t notice anything when I put on the fister mufflers.

 

your math is off, i think ? Stock Hp = 385. 327/385 = 85%. 15% power loss.

 

There in lies the problem/issue... This dyno was NOT done with Stock Exhaust...

OP " the previous owner of my car had already installed an FVD cross pipe and didn't have the OEM center muffler, so the first dyno test was bone stock *(BUT)* with the FVD x-pipe only" So, that would mean the x-pipe added 7 hp to equal the 392 I calculated. Again, without 100% oem pipes in place, we will never know for sure the difference the x-pipe truly added.

 

Great post and video Hindsight2010.
As you said - ditched a lot of unnecessary weight and it sounds really great

 

The difference between one dyno and another can be 10%. You hear a lot about Mustang Dynos reading low, and some other dynos reading high, etc. Plus they can be calibrated up or down. Because of this, I don't feel it's a worthwhile effort to try to "back in to results" by using known numbers in an equation (such as factory crank HP or drivetrain loss percent) against a dyno test to find for X (in this case, "X" being a center muffler delete". Take a stock car onto 3 different dynos and you will get 3 different results.

So to me, the only way to determine effect of a part is to test the same car on the same dyno, with before and after.

 

I agree 100%... And, because you were on a dynojet to begin with, I gave you the benefit of the doubt with a 20% calculation since dynojet numbers tend to be on the higher side then Mustang dyno's, which notoriously read lower numbers for the same car. It has more to do with their setup and software calculations compared to Dynojet's. Anyway.. thanks for posting the video and dyno.

 

@Hindsight2010 Any update on how you are liking the exhaust over the years? Is it bearable?

 

I couldn't handle it. I think it was a matter of weeks before I pulled it off. I liked the sound but the harmonic resonance of the droning was just too much for me. Gave me a headache. I ended up putting the FVD cross-pipe back on and swapping the OEM mufflers out with the Fister modified mufflers. From my research here and elsewhere, that was the one setup that had overwhelmingly positive reviews from people, and I understand why. Zero drone, it's louder than stock but not too loud, and it opens up and deepens the sound. Never any raspy/ratty notes. I love it.

 

Dang I was hoping for some positive feedback, I was really interested in this FVD setup you tested.