I've owned my new to me '07dB9 for a year now and have been unimpressed with the exhaust note. I was really wishing to hear the V-12 vs the dual inline-6's from the factory. So as soon as I saw some used de-cat Velocity pipes for sale, I started thinking....hey why not pair that with the Velocity x-pipe modification and then throw in an ECU flash plus air filters?! Stuart guided me to this approach as it's the low hanging fruit for hp/tq to $$ ratio.

I wanted everything done simultaneously, but I ended up getting everything done except the ECU flash first. Either way, the air-filters/de-cat pipes/x-pipe modification was immediately noticeable. The car has a better throttle response and the exhaust note rips like a proper V-12 now! I love how while in neutral I can rev the car up and the revs fall back down quicker without holding on to the revs. It just rips up and falls back down to idle quickly - sounds EPIC. I finally have the sound I've been wishing for and this is with the stock exhaust out back. Tunnel driving is pretty much a giggle fest and I'm sure I get a lot of rolling eyes behind me as I slow a bit, and then pin the throttle .

So fast forward a few days and I get the ECU flash back. I load the flash into the car via the supplied controller and take it out for a test drive. Patiently waiting for the oil temp to come up to the proper levels, I notice a different sound even at idle. Throttle tip-in response is better and I can now leave without any lurches - I cannot stand it when manufacturer's use an aggressive tip-in to make the owner's believe they have more power than reality. Partial throttle response is impressive and at this point I'm wondering if this is a placebo effect? After multiple partial throttle runs I confirm it is NOT. I firmly believe in never revving any engine past 3krpms or going WOT until the oil temp gets up to normal and that usually takes ~10mi of driving IMO.

Oil temp is (finally!) at operating temps and I decide to roll into it in 2nd gear. All I can say is that my butt-o-meter can definitely feel it throughout the rev range. At only 2000 rpms I can really feel a difference. Once it gets up on the cams, the car keeps pulling and I am blurting out some expletives

I can definitely recommend Sturart and Velocity AP for anyone wanting approx 30hp/tq by doing the filters/ECU flash/de-cat pipes/x-pipe for additional performance and that oh so lovely TRUE V-12 soundtrack. In years past I would have done a pre/aft dyno curve, but I have enough experience doing mods that I trust the claims of approximately 30hp/tq. My butt-o-meter is pretty dialed in from my Bimmer days and I feel no need to re-flash to stock, dyno, then flash back and re-dyno. It is pure bliss and I am enjoying it very much! I've still yet to do a WOT 1st-2nd-3rd due to wet pavement

I'll try to post a clip of the exhaust note, but with this oh so lovely Pacific NW weather that may be awhile

 

I've been thinking about doing a tune like this on my DB9. Does the change with the exhaust cause it to drone or be noticeable loud at freeway speeds? I occasionally take long road trips with the car and would like the exhaust to be louder on acceleration but quiet or not noticeable when highway cruising. Did you leave fuse 22 alone or did you pull it?

Also, dumb question of the day, is the plan to swap the cats back in when it's time for the emission test, and if so is that something that is easy to do? Does doing the de-cat throw any check engine light O2 errors?

 

There's 6 catalysts on a DB9, 4 that are monitored and 2 that are not monitored. When you install decat pipes, your just deleting the 2 non monitored downstream catalysts.... So being there not monitored, you will not get a CEL light. Now when you install headers, you delete the 4 upper catalysts that are monitored and have no choice to get a tune..and the power increase

Either approach, I've driven both types of mods on DB9's with a tune...the car's are always night and day!! Especially on the older DB9's, the tune deletes the touchy throttle causing that lurching feeling from factory.

 

The exhaust sounds just like stock at normal throttle positions. I left the fuse alone so that the valves can operate. Once you get on it however, the exhaust comes to life and makes spine tingling noises! Zero drone at highway, and is perfect imo.

I'm telling you that this feels like an entirely different engine!! Way more low-end torque, impressive torque! Feels like it pulls harder on the top end as well indicating higher hp. I would recommend this to anyone in a heartbeat.

 

Exactly, what he said

 

Congrats ;

Looking forward to seeing (hearing) a video.

 

I'm looking forward to the video as well. It was pretty nice around the PNW yesterday. :-)

So if the 5th and 6th cats (the unmonitored ones) are not necessary to pass emissions (since all the State does nowadays is plug a OBD-II into the car and look for a check engine light), then why did AM put them on there?

As a side note, I changed the oil in my DB9 yesterday, what a PITA to get that oil filter out. Does anyone know of a filter relocation kit?

 

Anything I say would be an assumption of theory..With that said:

Being the old Vanquish could not meet the new CARB regulation that was to be released(2006 was the last). DB9 was added with the extra catalysts to meet the new coming regulation of CARB for tailpipe byproducts.. If CARB was to change, AM could just change the downstream catalysts to meet the regulation for tailpipe byproducts versus an entire section of the exhaust and mapping file... Don't forget, DB9 doesn't have a EGR nor SAIR. So the downstream catalysts will help increase pressure between the upstream and downstream catalysts, which will help maintain heat to the upper catalysts and warm them up faster.

A newer V12 might trigger a code from catalyst temp, but the older V12's like yours have much more time to stay in open loop programmed such from factory, this provides enough time to warm up the catalysts. The newer V12's have a tighter time frame to exit open loop..so if a code came up on a newer V12, it would need to be programmed...but I've yet to see any issue with one

 

Irish07 - thanks for the response. I always appreciate reading your take on this forum.

 

Getting rid of that lurch would be great, but I am not a fan of tunes, as some tuners just lean out the car to get the HP. Also, you said the car is night and day after mods, can you expound on that?
Does it just rev faster or what?

OP, does the car run hotter and what does the car sound like?

TIA

 

It was sunny out for once here in the PacNW! First time trying to take and publish a video disclaimer I think the revving portion shows off the exhaust more than what happened afterwards

*Two spotters used, one at the start and the other at the end of the run After hours, private lot, no one there. And yes I realize I forgot to blur license plate out - oh well.

 

Sounds wonderful! If you want to get a little nuts and ramp it up a little bit, pull off the stock muffler and get a pair of Stewart's rear box delete pipes. I've got the Fabspeed Xpipe with an unmodified center section and no muffler at all and the sound is very similar to what have in the video with just a bit more noise.. I've got a couple videos on YouTube if you're interested. One with the muffler delete and another with my RSC Supersport rear box (with Xpipe). I wound up removing the RSC muffler because it was way too quiet with the Xpipe. I think we talked about this stuff a little bit when I was selling you the test pipes but not sure if I mentioned those videos I posted. I could send you the links if you're interested?

At the risk of jinxing the deal, I am in the process of buying a 6 speed DBS.. Had no real plans to do this but I came across a car I just fell in love with. Anyways.. I'm trying to figure out what to do with the exhaust on the DBS and I really like this center section Xpipe you have.. Kinda regretting selling my test pipes now.. Oops. LOL

Congrats! Your car sounds awesome!

 

Thanks! For now I love how it sounds stock unless I get on it. The microphone got tricked due to the tires squealing so it masked a bit of the loudness. I've seen your videos, they sound great!

DBS?! Nice, that will be better than any cat-delete pipes

 

Just swap it all over, will all fit the same

 

But I'm wondering what the difference would be between what you're doing with the modified center section versus just replacing the second cats with the Xpipe is? What was your thinking about doing it this way? Seems "easier" to just replace the secondary cats with an Xpipe right?