I think many of us have been waiting for some 'inside' information, and some hard evidence, showing what can be done with the 4.3 and 4.7 AM engines.

A UK company, staffed by some former engineers and technicians from AM, including the former Aston Martin engine performance development and vehicle calibration engineer for the 4.3L and 4.7L V8 Vantage, Vantage S, Virage, DBS, DB9, V12 Vantage, N400 road, N24 race, Vanquish S and DB7 GT, has identified the areas for improvement on these engines. I have no connection to the company, actually, I'd never heard of them a month ago, but its a fascinating read.

I'm not an engineer, but the arguments look really solid, to suggest that for a 4.3 or 4.7:

• Changing silencer can give no more than approx. 3.5BHP
• Sports cats can give 10.5BHP
• New manifold can give further 15 BHP
• Remap for standard fuel isn't going to deliver any reliable power increase, weakening mixture at higher revs can give +10BHP, but the rich mixture is there to cool the catalysts, so weakening it for more power will wreck catalysts and possibly damage exhaust valves
• Remap for 100 octane can give +10BHP
• New airbox can give +10BHP

Potential is therefore +39BHP for 4.3 to take it to 419 BHP
or 429BHP on 100 octane

• They can upgrade a 4.3 to 4.7, and have done a few engines already, adding a further 40BHP and 50NM torque

Potential is then 459BHP 7300 rpm / 470Nm @5000 rpm
or 469BHP on 100 octane

If the information is accurate, this is as close as we'll get to an official AM view on the potential for these engines, full thread is at:

http://www.pistonheads.com/gassing/topic.asp?h=0&f=70&t=978848&mid=17856&nmt=Aston+Ma rtin+repair%2C+servicing+and+advice+from+Bamford+R ose

 

That information is highly inaccurate. There are tons of ways to get a lot more power than that and I will provide the dynos in due time . The 4.3 was sandbagged to the extreme so naturally you can unlock alot more power than that.
________

 

007 the wait is killing me! I hope these are good given the "hype"

 

I would say SOME of that information is FAIRLY accurate, but saying that the car runs rich to cool the catalysts is a bit... well.... rich. Unburnt fuel in the cats will combust there and burn off catalytic material - I'm seeing lots of OE cat failures on totally stock setups so you tell me...

I also find it.... well.... let's say *Interesting* that this company refers to a bunch of exhaust companies claiming larger gains as 'the emporer's clothes' and yet they are partnered up with an exhaust company who at one point claimed +20BHP from their Vantage and DB9 exhausts. Interesting that they no longer make those claims and are now partnered with a company who says 3.5BHP... (we are seeing 5-7 from the RSC exhausts and have always said so.)

So which one is/was right? 3.5 or 20? Seems strange to me....

 

I could see both sides of the fence, but....with pretty much the same mods as RSC (except the filters I believe), Prodrive got 425 hp (or 415 on the quiet setting) out of a 4.3. Prodrive wouldn't lie about numbers....

 

Sorry but I agree with the other posters here...that's largely bogus info...some is correct but it's definitely being spun a certain way to protect their interests. I'd say it's more than a little convenient that the total sum of all upgrades on the 4.3 lands right at 419 hp...one hp shy of the 420 that the 4.7 makes. Sounds like marketing.

I guarantee you that the N24 and the racing-prepped 4.3 Vantages made more than 419 hp but those numbers were never published. I'm still not sure why Prodrive isn't taking a more dominant role here with aftermarket parts including racing upgrades...AM seems like they are trying to limit the potential of this car.

Next thing they will say is that it's impossible to supercharge the Vantage.

 

^^your supercharger has yielded a maximum of 24.8 horsepower. Trust me, I'm an engineer.

 

Ha ha...

 

I think most of what Bamford Rose is accurate or close to. From my previous experience with Prosche 997s, adding headers, CATS and after market exhaust. Most of the supplier claimed HP increased that sounded plausable, 20 HP for the exhaust, almost the same for CATS, and 15 or so with the headers. But with independent DYNO, 1/4 miles times and using a GTech indicated at best 5hp gain. Cheap and easy HP gains for non-turbo cars really do not exist for anything built in the last 10 years or more. If you want to change the exhaust do it for the sound as there is very little HP to be found. I love the pleneum claims for 997s, showing 15-10 hp, don't you think if Porsche could provide another 20hp for anothe $5 that they would have overlooked it?

 

There's a balance between power output and reliability. I think AM really played it safe on the 4.3...not only to minimize wear on the engine, but also not to step on the toes of DB9 owners. For a high-compression, relatively high-revving 4.3L V8, 380 hp (and even 419hp) is pretty low. I would a agree that 450 should be easily achievable.

 

I would not say that....look at the RS4's 4.2 V8 ...420 hp ...and that is with an 8,000 rpm redline and direct injection. Look at the BMW's M3's 8,400 rpm 4.0 liter 414 hp. Look at Maserati's Ferrari developed V8 ...400 hp out of 4.2 liters.

 

All three of those cars you mention make more hp/L than the Vantage...the RS4/R8 engine has 100hp/liter (vs. 88 for the Vantage) and get max hp at 7800 rpm...only 500 more than the 4.3 Vantage. And all compare poorly to the Ferrari 430 and Scud that get 483-503 hp out of a 4.3.

The point was that AM could have gotten a lot more power out of the 4.3 if they had wanted to...the rev limiter could be pushed higher, the compression ratio could be higher, the tuning could have been better, etc etc...and even with the current parts in place there is more power to get out of the engine. This engine is not as highly tuned as a 997s, as was mentioned earlier, where they are trying to get the most out of it.

 

I think we can attribute at least some of that to a lack of variable valve timing....

 

Yes I agree with all of that, my point was considering the lower power peak, redline, lack of VVT, and lack of direct injection 380 hp for 4.3 liters is not bad. All of those factors would allow more compression, more power, and most of all more torque. Still 419 flywheel hp capability is pretty stout considering.

And all of the other factors listed above, considering the AJV8 this was based on was never know for outright power. I consider the 4.3 to not be that bad, I would think however that agressive gearing would definitely fix some of the perceived lack of low end torque.

 

That's fair. I think that AM could easily add direct injection and variable valve timing if they wanted...that's just part of them holding the car back so as not to step on the toes of DB9 drivers.