So in my quest to explain why the Vantage is slower than other cars with higher (worse) weight/power ratios, the easy explanation was that the engine was making less than stated horsepower. Dynos show around 300-305 at the wheels, which if using a 20% drivetrain loss, does roughly come out to 380. There might be a bit of a difference, but it's not huge.

Then I looked at the gearing. Compared to many other cars with inferior weight/power ratios that are faster, the gearing of the Vantage is pretty tall.

Here are the multipliers for the gears for the Vantage:

1st: 12.31, 2nd: 7.70, 3rd: 5.63, 4th: 4.50, 5th: 3.67, 6th: 3.05

This is consistently 20% taller than the gearing on the R8, which may explain some of the difference in performance. Other cars I checked on that have shorter gearing included the naturally aspirated cars: 370Z, M3 (6speed and DCT), and 911/911 S (6speed).

Ones that didn't have shorter gearing included the turbos and big V8s: 911 turbo, 135i, Mustang GT, Dodge Challenger SRT-8, Corvette. All cars I looked at had similar or worse power-to-weight ratios but similar or better performance.

The point of this is that Aston Martin didn't just leave horsepower on the table, they left performance from more aggressive gearing. This was probably done to make the car smoother, but at the sake of significant performance losses.

I'm hoping someone will step up and offer a ring and pinion kit for this car...I know some tuners have been talking about it, but where is it? I'd imagine that a 20% shorter gear set would take 1/2 second off the 1/4 mile time.

 

I have heard a few tuners talk about a new ring and pinion too ... but also have not seen the actual "for sale now" ... will be interesting when it is available ... sure worked on P-cars !

 

I kinda like that its gt style gearing...I think Im going to trade my s8 in for one...

 

Good research! Now for guys that are supercharging their Vantages, they would want to leave the gearing as-is, correct?

What happens when people FI cars with shorter gearing? Does it make the experience annoying, as they run through their gears more quickly?

 

Yes...no gear change necessary if going with FI. But if going NA, a package of the AM power kit, intake, cats, and shorter gears should put the 1/4 mile time in the mid 12s. Still not as good as the SC, but much better than stock.

 

I would gladly shift quicker/sooner and reduce my top end speed (170 to 150 or there about) to get a better 0-100 time ...

 

I agree, but you shouldn't lose that much on the top end if it's done right...as long as you've got the revs. The ideal thing would be to have a shorter final drive (around 4.2), with increased redline to 7500 rpm and taller 6th gear to keep your top end if going the NA way.

Realistically an ESX SC'd car should be running the 1/4 in the 11s with stock gearing, so going with a shorter gear set in that situation probably wouldn't make sense. For a centrifugal SC like the ESX kit, I'd say stick with stock gearing. For a roots-type SC (possibly PES kit), it may be better to go with taller gearing because you will have so much torque at the low end that traction would be an issue.

 

So I am thinking just a ring and pinion change would basically keep the overall percentage the same, just reduce it all down again as an overall percentage, thus giving a quicker 0-60 0-100 time and reducing the top end. Also a ring and pinion would be relatively cheaper than actually swapping gears in the transmission ? Swapping the actual gears would certainly be great ... I was just thinking back on the old 944 turbos and as I recall, the ring and pinion change seemed to be a very nice effect ... without to much cost (?).

 

Yes that's true, but top gear in the Vantage is in 6th gear at 6800 rpm, so there is a bit of room there to make up for some of the losses...add in software changes to increase the redline a bit and you negate more of the losses. In other words, the horsepower of the car is sufficient to get to 175 so if the gearing allows it will happen...and while with the shorter gearing it won't get back to 175, it might be somewhere in the 160s with sufficient rpms.


And yes, absolutely true that changing the gears themselves would be a much different situation...it would probably require a whole new gearbox and certainly more cost than the ring and pinion swap...that was more of an "in an ideal world" solution.