Still waiting on tweaking my tune. Initial pulls had me actually losing power but they're playing with the cam phasing ATM, power has come back but still not significant. Pics will be up later but I'm happy to report they fit fine with an inch of clearance on both sides of the tranny pan. Sound is much deeper,and doesn't sound louder sitting still, we'll see when we get back on the road what differences I hear.

Stay tuned!!

 

What were you running before? HFC?

 

Stock cats and full cat back MD VQ exhaust.

 

Very weird that it would lose power, especially compared to stock cats. Perhaps a gasket leak?

 

Damn I posted the update with pics while I was at UpRev this afternoon, don't know where it went?

Any hoo, here's the skinny. I'm happy to report that fitment is not an issue with the V2.1s. I had about an inch of clearance between the resonators and the AT pan. And the cat brace Peter mentioned fit like a glove, not sure what the issue was with his car. Here are some pics from beginning to end of install. I'm too tired to edit them so the quality's not great but you'll get the idea.

Stock cats out, driver's side ART going in

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Driver side installed-note it even clears the small clip for the O2 sensor wire

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Closer pic of driver's side

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Passenger side going in

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Passenger side being tightened down

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Passenger side in

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All bolted up to the XYZ

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Cat bracket about to be bolted up to the ARTs

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And now the results, I'm a little disappointed but I had Omar re-tune the car, he's very experienced and I trust him completely. I ended up with only a 5 HP/TQ gain at peak but around 10/10 throughout the 2-5K rpm range. So final peak numbers are 257/237. Omar worked on the tune for over 2 hours and ended up having to play with the cam phasing which is where I finally got over the initial loss. First 3 pulls showed a loss of 5/5 which I was really surprised at. Jared, the lead tuner at UpRev, also tweaked it a little and I called Church's in SoCal to seek their advice. There are no leaks in the system so it is what it is. Overall full bolt on MD from the headers back gave me a 15/12 gain over what it had been with stock cats and my Frankenstein'd stock exhaust so I'm happy with that. The tone of the exhaust got noticeably deeper, it's starting to not sound like a V6 but still has the sweet VQ warble. And the overall volume got significantly louder, car sounds plain mean when I get on it. But, when I'm cruising at 60 with no load on the motor it's completely silent.

So overall I'm really happy with the end result, just surprised that removing the stock cats didn't free up more power. The car is definitely faster from 1500 RPMs up, but I didn't get back the low end grunt I lost with the 3" exhaust piping. The sound is magic when driving with the windows down, I've had a big grin all evening. The exhaust smell isn't any more prevalant than it was with the exhaust installed, and me being an old school muscle car guy, I actually like the smell.

I'm uploading a vid of one pull on the dyno and will add it to this post when it's finished. I need to get one off the dyno, the roller made a lot of noise. So if you're contemplating this mod, it definitely gets the Blue Dream seal of approval, it's well worth the money!!

Video

 

Really surprised you didn't gain more power. Your numbers are pretty much in line with your mods though (around 260ish hp). Maybe they just know how to squeeze the most out of the tune with the OEM cats? I dunno. There was another member on here that went to UpRev and didn't gain much after tune.

 

Yeah me too, however when I look at the 15/12 gain from full bolt on MD set up, I'll take it. And it sounds sooo sexy, even with 2 resonators.

 

interesting... you would think that with a FULL md set up you would get quite a bit more... almost double...

 

it's not uncommon to lose power (especially low end torque) when adding hfc - until a/f is adjusted... when I first got cats the car was a slug (60 to 65mph took over five seconds, literally)... off the line it felt like the car was laboring bad, like when the AC is on but 10 times worse...

Once it's tuned with a/f adjusted, the gains are significant - particularly low end torque... I'm sure the ART pipes are as much so, if not more.
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Congrats on the new tricks Tim

 

Mike that's my issue. Don't get me wrong I'm very happy overall, but to only see a 5/5 gain from removing the horribly restrictive cats, adding the ARTs, and getting a re-flash was not what I expected to see.

 

welcome to the NA game... try spending five times that amount to get only 15/10 (cams & headers)... if it was cheap/easy everyone would do it

Years ago I determined (after low hanging fruit, easy gains) it's an average of $100 per hp to go NA on a VQDE.

Of course the economical route is FI... but where's the challenge in that?

 

Is your exhaust 3"? I wonder if you would have seen a larger gain with a true dual.

 

smaller diameter would definitely help... it was tested years ago = 3" lost power... one example was the first or second Stillen day dyno - there have been other reports as well...

But Tony may have engineered the MD exhaust in a way that is different from previous results

 

yea, i would say ditch the 3" exhaust and give it to me

 

Just saw a post on my350z where the dude gained 15 hp/10 tq. with the new v2.1 ART pipes paired with the TDX2 exhaust, and about 25 hp/20 tq. total over the completely stock setup. The TDX2 is dual 3", so Blue Dream's lower results are definitely not because of larger piping