Question (related to if not exactly on topic): The "first gen" OEM exhaust ('06 - '09 I think) had the primary cats "downstream" from the headers/manifolds, whereas the "second gen" ('10 on if I'm correct) OEM exhaust has the primary cats in the headers/manifolds (I assume so the cats heat up faster). Is there any performance difference between the two? I have to wonder if the early system breathes a little better.

 

I've seen a number of dynos of 4.3l vantages(all dynojets) that have all been in the 300-310 rwhp range. For what its worth.

 

349whp. Air filters, 200cell cats, VelocityAP tune. 2007 V8V.

 

Your description is correct, as is the reason for the change (emissions cycle.) I don't know about performance differences between the two OEM setups. There might be a little bit, it would be interesting to swap the earlier setup onto a later model car and see what happens, but that would be a lot of time & money just to what would only be a couple of HP difference if there was any at all.

 

Hang on, I thought we were calling yours the 'Sonny D' tune?

 

if it helps, I have a 4.3L with the AM factory power pack, K&N air filters, 200 cell cats, QS SS exhaust and am at 375RWHP on a dynojet

 

Stuart,

Thanks for the reply. I was curious because your headers/exhausts are more like the earlier design, and also because the quickest 4.7 cars in magazine tests seem to be '09 models (full disclosure -- mine is an '09 ). Of course, Aston quotes the same hp and torque for all 4.7 cars (non-S, of course), and it seems likely that, even if the earlier design does allow more power, the difference would be very small -- too small to show up in magazine acceleration tests.

 

I have been observing this as well. It seems that there were '09 cars tested as the 4.7L became available that were very fast. The "S" in '12 though was tested 0-60 in 3.9. That is faster than the V12V. Has anyone else seen or experienced this? NOw that there is a 6-speed available in the S, does this time fall off?

http://www.zeroto60times.com/Aston-M...mph-Times.html

Stuart, have you looked at this?

 

^^^ Interesting site. I don't know which magazines it takes data from, but the figures for the V8V are slower than those recorded by C&D, R&T and MT (and, IIRC, Autocar) -- which show V8V 0-60 figures typically of 4.3-4.4. I've seen 4.5 and 4.6 in other mags (the slowest I recall seeing, and recent tests), but I've also seen 4.1 (a manual '09 Coupe in MT). However, I've never seen 3.9 for any Vantage (seems like the V12V should do it, but it's traction-limited off the line). Jay, do you know which magazine test did 3.9 for a V8VS?

I think 1/4 mile speeds are more informative than 0-60 times since the 1/4 mile run is 1) less dependent on the launch and 2) tests acceleration over a longer period of time and over a greater range of speed. For the V8V, most tests I've seen show speeds of 112-113. The fastest ran the 1/4 at 115 mph (that same '09 manual car). The slowest was the most recent -- 111 -- which is partly why I raised the question about exhaust designs. For the V8VS, I've seen 1/4 miles speeds of 113-114. The V12V ran 117 (maybe one test showed 118?), and the only figure I've seen so far for the V12VS is 121 (with 0-60 in 4.1, same as the V12V).

In any event, the '09 cars seem to show the slightly quicker times -- is it just test-to-test/car-to-car variation, or are they (perhaps due to their exhaust?) slightly more potent?

 

Beautiful exhaust system, thank you for posting the detailed install pictures. I always like to see the way a car is put together. I presume the owner was using inconel heat shields, they are remarkably effective. I'm not sure why he needed them but its a first class install.

I looked at changing the exhaust on my car (2012 V8V-S) but opt'd not to because I like the valved system. It's really nice to be able to 'turn off' the big sound when I'm trying to sneak in to the neighborhood. However, I do agree that the catytlitic converters could be a spot for major improvement on the stock system. I think the secondaries could be cut off and replaced pretty easy but I wouldn't touch the car unless I could tinker with the tune. Do you mind if I ask what system you guys use to modify the factory ecu?

 

Here's another source with the V8's from 4.3 to 4.7 and S

http://www.autorooster.com/0-60-time...in-v8-vantage/

C&D V8S:

http://www.caranddriver.com/reviews/...s-drive-review

They tested the S at 4.0 and the standard at 4.3

 

I'd like to know the source of that site's figures too, because the numbers don't make much sense and the figures for the V8V are significantly slower than C&D's, MT's and R&T's. The S couldn't be just short of a full second quicker through the 1/4 mile with just 10 additional hp and a 50 lb weight savings. The 7 spd SS doesn't explain such a huge advantage either, especially when the magazine tests show little or no difference. Also, that site says the 40 hp advantage of a 4.7L over a 4.3L gives just 0.1 sec advantage through the 1/4 mile, yet just the 10 hp gain in the S gives an advantage of 0.9? Further, it says the 4.7L car is 0.4 sec quicker to 60, but the 4.3L car has REGAINED 0.3 of that deficit by the 1/4 mile (at which point it would be traveling 6 to 8 mph slower). Not possible.

The C&D article linked isn't a full test, and the performance figures given are just estimates. FWIW, C&D's Aug. '09 test of a V8V showed 0-60 in 4.3 and the 1/4 in 12.7 @ 112. MT's '09 car did 60 in 4.1, the 1/4 in 12.5 @ 115 (quickest numbers I've seen for any V8V).

 

We use Alientech tools, either the Kess V2 or the Powergate, but write a lot of our own map drivers.

You know we make a valved exhaust system and can do some custom sound levels - pretty quiet with valves shut. You can quite easily rig up an open/close switch for the valves. We might be able to find something that really works for you.

 

Sorry, I missed a point there. Yes, we can reprogram the valves to open & close at pretty much whatever points you want. Still open on cold start though.

 

Yeah the whole thing is confusing. My whole reason for the inquiry is to find out which starting point brings you to the best outcome with the Velocity Power Pack. I know how easy it is to get off topic in a thread. I have been considering a used Vantage V8 roadster. I would like a 6 speed and send it through the process of the full tune. It would be interesting to see if a 4.7S finishes close to 500HP. I wonder if there is something in the tune or the mapping that brings about the extra acceleration. Could similar performance be attained with a manual? I often wonder if there is a huge variation from car to car that leads to the differences in the times. These aren't being assembled in Germany, at least not yet.