Vanquish manifolds on db9

[crispyj]

Thought I would post a pic off my new manifolds, from a 2012 onwards vanquish. A little bit off work to get them to fit but should hopefully free up a bit of top end power.

db9 2020 by chris jones, on Flickr

[Dan1heMan]

Looks ace, I'm thinking of doing the same with mine. Can I ask, was there anything to note when fitting them?

[Kumayama]

thumbs up! any before picture?

[crispyj]

The main issue with fitting these manifolds is the throttle bodies for the vanquish are 6mm larger diameter, hence the fitting holes are wrong, I made up a plate to fit the db9 throttle bodies too.

I gave the car it’s first run tonight, the mod has made a big difference after 5500 rpm, before the car felt as if it was starting to hold back. Now it revs very quickly up to 6800 when I changed gear. It feels if I have lost a little bottom end torque but I was expecting that due to the shorter intakes. I will have to get her on the rolling road at some point.

All In all I’m happy.

[8Tech]

Interesting that the 2012 on manifolds use a larger throttle body. I installed the shorter DBS manifolds and the throttle bodies went straight on.



Increasing the throttle body bores would certainly move the power up in the high rpm range whilst losing some bottom end torque. I improved the stock throttle body flow by porting them.

From this....



To this....

[crispyj]

I have smoothed the throttle bodies and smoothed the ports as you did mate. I got the ideas from your post.

[ragpicker]

Can you not use the larger throttle bodies with the new manifold instead of fitting the old DB9 TB's? Surely this would provide further gains?

[crispyj]

I did think about that but I thought I may need to remap then due to the increase of air flow, also I would need to change the inlet pipes as well.

[ragpicker]

I would've thought that the MAF would register the increased volume of airflow and adjust fuelling accordingly. Thats how it works on other cars I've had at least. Dunno about Astons though.

Interesting mod, makes me consider doing it to mine when I do the plugs/packs. Wonder if BamfordMike has any comment to make on this?

[8Tech]

ragpicker said:

Can you not use the larger throttle bodies with the new manifold instead of fitting the old DB9 TB's? Surely this would provide further gains?

They clearly fit the manifold but as mentioned above, you would need to also replace the rubber intakes which may not fit the air boxes and MAF sensors.There is also no guarantee that the electrical connectors or calibration would suit the DB9 throttle position sensor on the fly-by-wire system.

Worth a look though. Just need an amicable Vanquish owner to lend you his throttle bodies to try out. Hmmmm.

[crispyj]

Yeh I just thought it was too much hassle to sort throttle bodies, Plus I’m more than happy with the performance gains. So going to stick with what I have done.
The only thing I may do is if I remove the manifolds again, cut of the old throttle body mountings and weld the smaller ones in place.