V8 Vantage 420 bhp & 430 bhp

[LTP]

Out of the blue a question struck me. As far as I know the only difference between the "standard" Vantage 420 bhp and the Vantage 'S' 430 bhp is the engine map and the "sports" backbox, but I don't think the exhaust adds much power, just changes the noise.

So has anyone ever investigated or actually had a 420 bhp Vantage remapped to 430 bhp? The advantage I would imagine is that it's a standard Aston map, so well proven. The disadvantage? It's only 10 bhp and a little more torque across the rev range, but a slightly "peakier" torque curve.

edited to fix a typo

Edited by LTP on Tuesday 1st June 19:15

[Jon39]

How would we notice a 2% power increase, other than lap times ?

[LTP]

Jon39 said:

How would we notice a 2% power increase, other than lap times ?

I agree. And on that basis I'm surprised AML persisted with two different tunes for as long as they did, but they obviously thought there was a marketing advantage in having the 'S' and the likes of the N430 with that extra 10 bhp.

[RB99]

I always thought (perhaps mistakenly) that the difference was due to the black airbox and that had been taken from the n400.

[LTP]

RB99 said:

I always thought (perhaps mistakenly) that the difference was due to the black airbox and that had been taken from the n400.

OK, that's interesting - I wasn't aware of an airbox difference. It also implies AML running with two different airboxes lineside as well as the different exhaust back boxes, which is even more odd for just 10 bhp.

A different engine map would be no issue as it would just go in as part of the config file download at the end of the line that tells the car what hand drive it is, what territory it's going to and what options it has, etc.

[bogie]

Yeah i thought the extra 10bhp was coming from the different airboxes (that you can get as upgrade)

On another note I dont think you need to bother with a remap and you can get the 10bhp (or a bit more) from the 420bhp model just buy replacing the secondary cats and the ECU will adjust accordingly, along with improved sound. At least thats what the companies selling cat replacement pipes will tell you

[AdamV12V]

I wonder if they are the same two types of airbox on the V12 then, valved and non-valved? They account for more like 5bhp and 10nm of torque on the V12.

My understanding was the normal airbox was fitted to the V8, so maybe rhe valved airbox what what gave the S the extra power albeit the fact it gives 10bhp to the V8 sounds iffy

[RB99]

Regarding the N400, Grant's book says; 'Development work carried out to liberate more power from the DB9 V12....
...would also bring further benefits. Engineers designed a new induction system that allows the system to breathe better at higher revs liberating more power.' It later alludes to the same system on the S, so perhaps its not actually a feature of the airbox, but the air management upstream.

[telum01]

I have an explanation of the air boxes here:
https://www.redpants.lol/info-intake-systems

The air boxes do differ depending on the car.

[bogie]

great article Rich, well explained, so know we know whats going on with the airboxes

[AdamV12V]

Thanks Rich, thats very helpful and does confirm the normal / valved airbox issue I mentioned is the same on the V8 as on the V12.

It seems it is a somewhat overlooked, well at least far less spoken about feature of the higher engine outputs that evolved as the years went by.

Edited by AdamV12V on Tuesday 1st June 23:36

[JohnG1]

The 4.3 V8 Vantage generated 380bhp.

The N400 had 400.

10 of the delta was due to the airbox

The other ten was from using 100 RON petrol.

That is from two sources:
(A) the Gaydon brochure they produced for the aftermarket to modify a standard 4.3 V8 380bhp to 400bhp
(B) the engineer who designed it

[LTP]

telum01 said:

I have an explanation of the air boxes here:
https://www.redpants.lol/info-intake-systems

The air boxes do differ depending on the car.

Thanks Rich - this really answers my original question. If I have it right it's a different exhaust backbox, different inlet manifold, different airbox (with valves), extra wiring to operate said airbox valves, different engine tune; all for 10 bhp and a little extra torque? They must have been insane.

[telum01]

The different muffler is pretty irrelevant, and isn't part of the "Power Pack" but yeah, retrofitting the air boxes, intake manifold, and adding the fuse is a lot of work for a small power increase... All of which is in the upper half of the RPM band.

The tune is easy to do but you can get those anywhere (best around is Chris at VelocityAP, and you guys can get that from DAE).

Even crazier is that half the claimed additional power is based on high grade fuel that isn't even available everywhere, so realistically is a ton of money for 10-20 go, half as much torque, and only in the top half of the RPM range.

[AdamV12V]

Out of interest Rich, what grade of fuel was needed for the 10bhp output? Presumably thats the same on the 430bhp 4.7 too?

Here in the UK, when the V12V went to the V12VS and jumped from 510bhp to 565bhp (intially) it also required the UK 100 octane fuel, whereas the 510bhp V12 didnt have a knock sensor so was pre-set only for 95 octane, so again the fuel improvement accounted for a chunk of the "gain".

If I recall your octane (RON?) ratings in the USA/Canada are slightly different to what we quote here in the UK?

[Jon39]

The AM V8 (4.3 and 4.7 displacement) is a great engine, but it is remarkable how design and power outputs have moved forward since 2005.

The AM V8V has two overhead camshafts.
Christian Koenigsegg has developed a 3 cylinder 2 litre engine, which with two turbos produces 600 BHP.
No camshafts at all and also only one gear.

It can run on E85 ethanol, or petrol. The Koenigsegg Gemeral using this engine also has electric motors, which combined produce 1,700 BHP.
0 to 62 mph = 1.9 seconds
Top speed .. = 249 mph

That should be more than enough performance for power modifiying enthusiasts, but unfortunately the car is expensive and in limited supply.

Oh and it is a full 4 seater but without a B piller, provides easy access to the rear seats, even though it is a two door car.

.~.~.~.~.~.~.~.~.~.~.

Edit.

How about this design concept shape for a Rapide successor?
Side view with doors closed and it looks like a 2 seater sports car.
Door open then reveals the 4 seater easy access 'trick'.
(If your garage does have a low ceiling, the door will stop opening before hitting the ceiling.)








AML did show a Lagonda concept, which also used the same absent B piller idea.

Edited by Jon39 on Wednesday 2nd June 20:39

[telum01]

AdamV12V said:

Out of interest Rich, what grade of fuel was needed for the 10bhp output? Presumably thats the same on the 430bhp 4.7 too?

Here in the UK, when the V12V went to the V12VS and jumped from 510bhp to 565bhp (intially) it also required the UK 100 octane fuel, whereas the 510bhp V12 didnt have a knock sensor so was pre-set only for 95 octane, so again the fuel improvement accounted for a chunk of the "gain".

If I recall your octane (RON?) ratings in the USA/Canada are slightly different to what we quote here in the UK?

UK 100 is US 95. East coast US pumps have 93 at max (97 in UK), west coast is almost entirely 91 at max (95 in UK).