There is a lot more to the intake dynamics than we could discuss here but I suspect there are much better places to spend mod money. Ford makes a dual blade throttle body for the GT (GT40) that Accufab developed into a larger oval throttle body. If you really wanted to explore that, it might be a good avenue to look at. My guess on the 'wall' is sound reduction but that pictures seem a bit drastic, even for that.

 

still be patient until the end of the year

 

Already addressed this... But based on what I've heard from a few places, as well as AM's own completely-revised intake manifold for the V8's in their race cars, it's safe to say that there is plenty of room for improvement. I've also been told that 430 hp is basically where the factory 4.3L runs out of steam, and that's because of the intake side.

 

Not sure if it's the same TB as the GT/GT40's, but this is the one I mentioned earlier. (I was probably being confusing by saying "dual-TB" rather than "dual-blade TB", sorry about that!)

 

what happens at the end of the year?

 

i actually have the tools needed to port my throttle body... and i'm very tempted to do so. i'd just rather leave it to a professional because i don't want to mess anything up haha!

 

Get a 2nd hand one and try it out on that.

 

Nothing could be further from the truth... 430hp is where the 4.3L is just getting started lol. I was pushing 430hp on my 4.3L with stock headers and cats and bone stock intake (even stock original air filters). "I heard someone say.." Is hardly concrete fact when compared to actual independently verified dyno testing.

In theory to the 4.7L that should run into the intake restriction issue given its larger displacement. Stock intake is one of the freest flowing I have ever seen, heck power doesn't even peak at 7600rpm. If it were a serious restriction you would start to see power taper off, it doesn't at all at 430, in fact the power band gets even steeper (indicating still plenty of room to go). 470+ is where the real limitations are on the 4.3L, 4.7 probably closer to 490hp.

 

How were u getting 430hp with all those stock items???

 

I have dyno'd my car, and will continue to as I make changes to the car. What I've heard is from talking with Aston Martin techs, tuners, and engineers.

I'd love to see your dyno charts, especially if you're getting 430 HP with a mostly-factory setup. 470 HP from a 4.3L is getting close to a Ferrari F430, which makes 483 HP at 8500 RPM. The Ferrari 4.3L makes that power using much more aggressive hardware, and with an extra 1000+ RPMs.

Here's the chart from one of the times I've dyno'd my car. This WHP readout equates to about 410 BHP. This was done with the AM Power Pack, 200-cell cats, and rear exhaust. You can clearly see that from 6k RPM, there is a noticeable decrease in the power gain, it definitely does not get steeper.


With an extra 1k RPM (to match the F430), and following the arc of the HP plot, you'd be at an extra 20-30 BHP, giving a total of 430-440 BHP. But I highly doubt a factory AM 4.3L would make it to 8500 RPM.

The stock intake is free-flowing, yes, but the pathway isn't linear. That's why the racing manifold changes the direction of airflow to bring it from the sides (directly at the runners) rather than from the front (against the sides of the runners, which makes the airflow change direction).

 

PROOF:

I will provide the dyno chart progression from just the two modifications I did. All the dyno charts were performed on the much more conservative Dyno Dynamics dyno (a true loading dyno). These numbers are much closer to real world conditions compared to the Dynojet inertia dyno (which isn't nearly as accurate). The Dyno drivetrain loss conversion rate is closer to ~24% rather than dynojets ~18% because of its loading nature. They don't call it the heart breaker dyno for no reason. The stock power numbers of 291.3HP /.76 (24% conversion) comes out to 383HP stock, this same conversion rate will be used throughout to illustrate my point and convert back to crank numbers...

From this data you will get a better understanding of the vantages bottlenecks.

Stock vs. RPI catback:

The stock catback although decent flowing at lower rpms, lacks the high rpm air flow which is why I opted for the X-pipe RPI exhaust. The reason I opted for the X-pipe is it drastically improves airflow above 6000 RPM (although below that gains were minimal gains due to the rest of the car being bone stock with no tune or anything). None the less, the car made 13.7HP at the wheels at redline with the RPI and started making the HP curve much steeper at higher rpms (more proof its NOT the intake side that's causing the restriction). If the intake side was the bottleneck restriction you would see gains down low through the mid range and then tapering off towards redline to zero gains). This is the exact opposite.





Eurocharged Custom Dyno tune (now their normal plug n play "007" Vantage ECU tune, for which I was the development car):

The Eurocharged tune was crucial in unlocking the majority of the untapped power out of the power band. Whereas most ECU tunes off the market are just rebranded from the same base aftermarket tune (they just slap their brand name on the off the shelf aftermarket tune and act like they developed it themselves, common practice in the aftermarket ECU tuning industry). Jerry at Eurocharged actually writes his own custom tunes in house, which is what makes his tunes so unique & different. I literally watched him do it with my own eyes, and its unbelievable how many thousands of lines of code are in the ECU. He reads it as if it were the green Matrix code lol. (pretty impressive to say the least). He finds power where most tuners never even bother to look and the results are in his ECU tunes.

The ECU dyno tune made 31.4HP AT THE WHEELS utilizing an additional 300rpm. and as you can see, not only did the power not taper off, but it continued to get steeper as the tune took advantage of the super aggressive cams that come in the car stock. Also, keep in mind, we voluntarily stopped that day prematurely not b/c we hit a max power gain, but simply b/c we figure for now that was "good enough" for now. There is still MORE power to be unlocked out of the stock ECU, but to this day, nobody else has ever figured it out. Jerry did show me some of the development progress on the 4.7L project and he has found even more power left on the table. Sadly, those dyno charts have never seen the light of day as they were never completed due to one of the houston Aston owners disappearing and never paying for his base tune (big nono, You know who you are). But the results were shocking, even for me. As soon as I jump back into my Vantage you can believe I am dropping it off there for a full days worth of dyno tuning. I can't wait to see what he can do with the Vantage S platform.




Final Before/After dyno:

These are the dyno gains of the car comparing stock to aftermarket. The gains were a massive 45.1HP AT THE WHEELS on the most conservative loading dyno. Its been a while since I looked at the charts so I was actually conservative in my numbers. If you do the conversion it actually comes out to 442HP @crank or almost 59HP gained given that same conversion rate. Even if you drop it to 23% to be conservative, that's still 436hp above my conservative estimates. Also, because the entire fundamental shape of the curve has changed you know the results are legitimate. You cannot fake a chart like that, where as if the entire power band had been shifted up or town uniformly you could argue foul play by the dyno ... but in this case you cannot (not to mention I was there for every single dyno and watched the progression myself with my own eyes). Even more impressive Telum is that I got within 5HP of your dynojet numbers on a much more conservative Dyno Dynamics loading dyno. The car was a screamer on top end to say the least. So much so that I wish I had more rpms (7800 would have been ideal given the shape of that power band).



As I have stated time and time again, these vantage motors are EXTREMELY detuned (intentionally I believe by Aston themselves). The original V8 Vantage motor was originally supposed to rev to 8000rpm, and I believe these dyno results are 100% proof of that. The cam profile alone shows that the cams in this motor are WAY too aggressive for its stock HP rating 380HP and 7300 RPM redline limit. Even at 7600rpm the power was still building an avg or 2HP/100rpm with no signs of stopping.

Given how these gains were on bone stock cats and headers, and the fact that both mods would only steepen the power curve above 6000rpm where airflow restriction would be greatest at high rpms, I have no doubt in my mind 470HP is piece of cake for the 4.3L motor with those two additional modifications (headers & cats, if necessary with new custom tune to match).

Once you performed all those mods, THEN I believe you would slowly begin to hit the natural breathing limits of the engine at roughly 109.3HP/L (110 is where things start getting really difficult). You have to remember these are basically race motors detuned for the road for extremely unnecessary reliability standards and engine smoothness of operation for the avg aston customer.

I am a firm believer one of the main reasons the Aston 4.3L bottom end is so anemic is because it was originally designed to be a high rpm screamer, and the cam profile is proof of that. On the 4.3L at least, the stock intake manifold is more than enough to flow to 8000rpm given the right exhaust hardware upgrades.

The ONLY point in which you should start thinking about throttle bodies is if you get to the 470HP mark (which not a single one of you is even close to on the 4.3Ls thereby making it a moot point). If you were at that level, yes you would pick up about 10-12HP with the throttle body but only from around 6500-7600rpm, below that there would be no gains. At that point the top end of the power band would continue to get even steeper.

The 4.3L is also at an advantage because of its shorter stroke it is able to sustain much higher rpms (compared to its 4.7L brother). In fact I also think this is another reason why they lowered the rpm rev limiter so much on the 4.3L in order for it to not have a higher rpm limit that the newer 4.7L (which they probably were already working on in development) as well as the V12. It would simply "look bad". The 4.7L is a totally different animal with a different cam profile, more torque, and longer stroke so you cannot compare the two really in this regard although they have similar properties, they are not the same for a number of reasons. The 4.7L cannot rev as high as the 4.3L because of its lower natural rev ceiling (due to the longer stroke) and for that reason the % gains you can achieve on the 4.3L are higher (that and aston left more power on the table to begin with because of its horrendously rich stock ECU tune on the original 4.3Ls).

As I have said time and time before (and proven just now) ... with these Aston v8s ... 90% of the gains are in the software & exhaust side. Don't waste a dime on any intake mods until you have done all or most of the mods mentioned. The stock intake manifolds have all the airflow you will ever need, Fix the exhaust side & upgrade to eurocharged tune and you will have all the power you could ever ask for.

 

Wow what a great write up.

I have sport cell cats, x pipe + H pipe , titanium rear box and new headers going on soon.

So I think I will be ripe for a custom tune.

Some of what I am going to ask for is...

1. Reduce the rpm that the cams open up.
2. Increase redline to 7800 or possibly 8000

I know the owner of a UK ecu tuning company that write their own software so I will ask him if he can do something for my car. When I gave him mine before when it was stock he only got 20bhp out of it which was a bit disappointing. But he only had the car for an hour or so because I had to rush off to a meeting.

 

For anyone interested some pics of the intake.

 

Hello Vergis,

Yes you will definitely need a custom tune. If you buy the remote ECU EuroFlasher from eurocharged they can actually remote dyno tune your car from half way around the world. All you need is a laptop and wifi Internet connection (technology is crazy these days). For the record, if anyone was my exact dyno tune, you can call of up eurocharged and have them upload my exact file to your car, just ask for the "007" 4.3L tune, Jerry will know exactly what you are talking about.

You cannot actually change the cam timing from the ECU (that's purely hardware hence the 4.3Ls weak bottom end), what you can do is change some of the parameters in the ECU to come on stronger at lower rpms. As evident by the before an after dyno, peak torque shifted from 4600rpm stock to roughly 5400rpm after the mods. However, STOCK peak torque was achieved at almost 3500rpm. This created a much broader more usable torque band and made driving around town much more enjoyable from the 3500-5400rpm band range. With cats the midrange would have been even better. Same is true of long tube headers, in addition tithe crazy top end they provide. If you look at 4300rpm on my final dyno chart you can clearly see where the advanced kicked in (and you could definitely feel it, as well as the 6000rpm cam phase change).

For now I would stick to 7600rpm limit just to be on the safe side and drive the car after all those mods are on the car for a while. I wouldn't up it past that until you do throttle body at the very end. Do you have a picture of both the front and back side of the stock throttle body? Trying to see how much room there is to play with. Using a set of digital calipers to measure the intake manifold opening along with the throttle body opening front and rear will help greatly if you could provide that information.

Ya 20 crank HP is a typical off the shelf generic performance tune, and that's what all of them return (even though they claim much more). Unless you do a true custom dyno tune from someone who really knows what they are doing it will be hard to get more than that.

I up suspect with all those mods you should easily get to the 470hp level.

There are 1-2 more mod tricks I have up my sleeve, but I won't reveal those until I finally get my hands on a Vantage S I like (proving to be difficult, last one fell through bc it had undisclosed mods on it I did not like).

 

Lots of great info, thanks for posting it!

Those are some great gains. Did you get AFRs during dyno runs after you got the tune? I only see them for the pre-tune run.