Agree. The 4.3 takes a long time to spool up. It was enough to make me look for solutions. I added 200 cell cats to mine in hopes of improving things. While it made the car very loud (!), I don't feel like it made much difference in power/torque under normal driving conditions. My ultimate solution was to move to the V12V. If you can, hold out for the 4.7.

 

I love my 4.3 AMV8. Honestly, it could use just a little more HP. That said, I don't feel like the car is slow at all. It's a real pleasure to drive and it does give you complete confidence in what it's doing and where it's going, even when you put the spurs to it.

 

Definitely not denigrating the power in a 4.3. IMO it has copious amounts of power; more than ample for any endeavor. And how it puts the power to the road is most pleasurable indeed. It is the experience in it's entirety that is incomparable. The synergy of technology craftsmanship, crazy attention to design detail, and the resulting beauty, yield something rare, we are lucky to live in this era.

 

I agree -- the 4.3 is a fantastic car and really is plenty quick. Sometimes, though, some posts can make it sound like a 4.3 can be made as quick as a 4.7 with just a few fairly simple tweaks, like an exhaust and a computer mod, and that's not the case.

 

I was really impressed with Richard's 4.3 on the philly trip...car had plenty of grunt, a really strong 3rd and 4th gear...and just growled with a great exhaust note while on throttle! ....Honestly, It felt as strong as the 4.7 from my observation I really couldn't feel any differences, I think he has cats or exhaust and tune or something, maybe he can chyme in.

 

I believe he has the Prodrive power upgrade as do I. It makes a big difference provided you have the right gas. In addition I have the high flow cats. These upgrades run around $7.5 to $10k, depending on cat brand and dealer installing the upgrade. There is a difference in torque at low revs for sure. My previous experience with HP engines has taught me to keep the revs where the engine is the happiest AFTER IT IS WARMED UP thoroughly, so my driving style renders low rpm torque moot. But I wonder what the 4.3 upgrades would do for a 4.7? That intrigues me because the balance of the car would remain the same. Hmmmmm....

 

for power mods... AM Power Pack, RSC cats and exhaust
dyno'd at 343 RWHP (about 410 BHP on that dyno). i think i've got the dyno charts somewhere, i'll have to find them.

edit: here you go


edit edit:
i found a couple vids of AM's on dynos. a mod'd 4.3L and a stock 4.7L.

my mod'd 4.3L: 343 whp, 277 wtq (AM power pack, RSC cats and muffler)
modified 4.3L: 359 whp, 295 wtq (AM power pack, RSC cats, Quicksilver muffler - basically same stuff as me)
stock 4.7L: 367 whp, 298 wtq

dynos are different, so the dyno figures are all entirely relative. just providing as food for thought. i posted my dyno to show the torque and horsepower curves. the numbers are arbitrary on their own.

edit edit edit:
i want to go driving now.

 

Then it must have felt as strong as your DB9 too

 

^^^ lol... Hard to say. My DB sounds a lot different and feels different in how it delivers power and torque. The v12 just does things differently and sounds nothing like the v8. Truthfully my car was in the simeone museum in Philly for the best of Britain exhibit so I hadn't driven it in over 3 weeks... Rich's car felt strong, real good pulling in 3rd & 4th, but it's slightly modded. I've driven various astons and I wouldn't be able to tell the difference between the modded 4.3 and the 4.7 ... Both a great options with a little modding the 4.3 can be made quite a screamer!

 

something else to consider with the 4.3L... the slow rev is what really hampers its performance relative to the 4.7L. the 4.3L is fantastic in the top end (look at my dyno chart above, the torque curve is flat and the hp climb is very linear). the crank pully on the 4.3L (maybe the 4.7L, too, but i haven't looked) is MASSIVE and can lose a lot of weight. between that and a lightened flywheel, you can get the engine to rev much more freely, getting the engine where it needs to be much more quickly.

for me, i won't be getting a 4.7L any time soon, if ever. i've already got the right mods started on my 4.3L and i love it too much to justify swapping it out for anything similar or incrementally "better". and, for the cost, i'm perfectly happy with what i'll be investing in it compared to getting a 4.7L.

 

It really is the torque (and the turbine-like smoothness) that makes the V12 in your DB9 feel so different -- and feel quicker -- than the modified 4.3, even if they would run very similar acceleration numbers. The torque makes the V12 engine's performance so easy to access.

About not being able to "tell the difference between the modded 4.3 and the 4.7," if you tried them back to back, I think you would be able to tell them apart. It's the torque that would again distinguish them -- the modded 4.3 makes most of its gains at higher revs, so I would expect to feel a "coming on the cams" effect since it would be comparatively less torquey/powerful at low and mid revs, but then give a good kick as revs increase and power rises toward 4.7 levels. The 4.7 would feel more linear. You'll have to work harder to access the performance of a modded 4.3 than you do a stock 4.7 (which is not necessarily a bad thing, BTW).

 

^^^ this makes a lot of sense. nicely explained buddy

 

Thanks, guys, but I'm bowing out of this search for now. My wife has health issues, and all my energies are now focused there. Hopefully, I can revisit this in a few months.

 

best wishes, i'm sure i speak for everyone when i say we hope she gets well soon.

 

Very true Jumpin' Joe...when your wife is healthy and you are back thinking of jumping into a v8 Vantage we will be here for you, until then god bless!