So I've been doing some research on performance increases for my soon to have 07 V8.

I see a fair amount of threads on removing the secondary cats, xpipes, headers and or full decats, performance air filters, ECU programming, and then the really big jump to a supercharger. I haven't seen any threads on a camshaft upgrade.
This seems a little strange to me because usually camshafts for any cars that must meet EPA requirements are fairly tame with a mild lift and usually no overlap between exhast and intake openings to help with scavenging the cylinders.

Has anyone looked into a set of performance camshafts for the 4.3 \ 4.7?

Thanks!!

 

webcamshafts refinished my camshafts for the DB9, and re-profiled the ones in a 308 FCar that I rebuilt. They can do whatever you want to your cams... But cam profiles are just part of an integrated package. No sense in doing them if you aren't doing all the other performance upgrades to the motor. I have heard on the track more than once "Stock is King on the Street", which is just another way of saying "don't worry, be happy with what you have..."

 

Some years ago a former Aston engine engineer posted that they had found there wasn't much scope to improve things with new cams on the V8 engines, they were so good already.

I don't think I've ever seen a post from someone that had done anything with the cams, so there probably isn't much choice in the market

 

There's scope to improve, I have spoken with someone who was involved in the engine development process (the real process back in 2003, not the stuff the pretenders talk about later on.) There's a different profile that would make more power, but only about 8-9BHP and it wasn't selected for a few reasons (emissions etc.) We've talked before about making some, if there's enough demand.

 

Love what you have done to the Aston. Great mod list and setup. It is a shame that nothing really exists between exhaust and tune to the supercharger. Some of the other cars like BMW can unlock huge gains from just a DINAN tune. Sadly, ours cannot. Did you do all the installs yourself? How were the exhaust manifolds? I'm about to do them.

 

You can hear how "burbly" the stock idle is right? Notice poor low end torque? The stock cams are huge...

Just my opinion, but on a no-expense-spared build, I would just do slightly higher compression forged pistons, slightly lighter connecting rods for the hell of it, and airbox deletes, maybe sport cats. The motor is already pretty racecar-ey.

 

How much would be involved in fitting the new cams, compared to new headers? It feels like a more difficult job, and just 8-9 BHP in return?

Don't these cams have variable timing, which must mean they can be much more aggressive but still work well across a range of revs. Just wondering if VVT means that cam changes aren't as worthwhile as they would otherwise be?

 

2X the work and some extra. Removing the front subframe to remove the front timing cover, camshaft covers and special tools to set it all up. Follow up with a 4 wheel alignment. Probably in the 30 hours of labor cost. Not by all means worthwhile for "swapping" camshafts. I'd settle for a good tune n exhaust.
-James

 

Variable timing just moves the camshaft timing relative to the crankshaft, and these AM engines only have variable timing on the intake cam. The stock cams are already very high duration, so even on the maximum retarded setting there is still considerable overlap (hence the rough idle). Peak power arrives at 7300rpm, which is abnormally high for a street car with a single cam profile. It's like running a Honda K20 in "VTEC" (on the big cam) all the time already.

The only cars with more aggressive cams than this are exotics, Porsche 911 GT3, BMW S65, Audi R8, etc. that rev past 8000rpm with a fixed cam profile.

 

Getting to the camshafts are a huge job I'm in the middle of changing out the guides, chains and tensioner on my aj34 (we use exactly the timing chain kit as the Aston) in terms of camshafts you've already got a 11mm lift and durations of 256 on exhaust & inlet . I having a feeling Stuart is talking about the same tech when saying they picked up a few more hp (7-9) with a uprated camshaft profile I believe the profile was a 265 duration with same lift .

As I said I'm at the stage now where it wouldnt be very hard for me to get my cams reground and fit them up however its simply not worth the money involved unless you do the entire engine .

If I was in your shoes I go after market headers , 100 cell cats , x pipe , bored throttle and a decent tune you'd get some very decent gains with those mods dare I say it similar if not more power then a stock 4.7 .

 

All very interesting stuff, but what is an aj34? I googled it, and it seems to be a type of shoe - the Air Jordan 34, but I can't see that using a camshaft or timing chain?

 

That does seem to be a fair amount of work for in the car. Wouldn't pulling the engine have simplifed the job you are undertaking?

 

Neither here or there however if pulling heads off i would definitely drop it out