Has anyone had their VH Vantage tested by a dynamometer?

[Dewi 2]

I came across this two year old post.

Olivera said:

IIRC Max_Torque on PH (hasn't posted for a while) was involved in the development of the 4.3 engine, and he posted on here a year or so ago stating it only made closer to 360bhp than the claimed 380bhp. Combined with a 1.7 ton kerb weight this results in a very similar power to weight ratio to a chav in a Fiesta ST warm hatch.

Perhaps it might be interesting to compile a list of known dyno figures, taking into account V8 Vantage 4.3; 4.7; V8 Vantage S; V12 Vantage; V12 Vantage S and also whether standard, or any modifications.

I understand different dynamometers give different results and atmospheric pressure at the time of testing can also create variations.
If your Vantage has been dyno tested, please note any appropriate results here.

I think we probably all agree with V8VPete, who has one of the fastest V8 Vantage S cars, but has said, 'Some people will never "get" the Vantage. It is so so much more than a power-to-weight ratio.'

[Simpo Two]

Dewi 2 said:

I think we probably all agree with V8VPete, who has one of the fastest V8 Vantage S cars, but has said, 'Some people will never "get" the Vantage. It is so so much more than a power-to-weight ratio.'

Well quite - what would you rather have, an Aston Martin or a Ford Fiesta?

[Calinours]

My V8S was dyno'd back in t'day when it was newish but fully run in by its then proud and careful owner. The 'before' result, likely the worst of the runs, was a corrected 422hp, or 422hp estimated at the crank based on measurement at the rollers in contact with the rear wheels (unknown but likely 10-15% less or 360-380ish), then corrected for the estimated powertrain losses (mainly gearbox and wheels/tyres).

After some fiddling by a well known tuner, expensive manifolds and race cats etc, the 'after' plot showed a healthy 34hp gain in the corrected peak. The real, repeatable gain as a result of the freer breathing and lightly lifted limiter would probably be in the order of 25-30hp. It's still pretty impressive, and is likely to be the resultant lift when the same mods are applied to any of those V8s.

As far as the standard engines go, I'd expect that when new and nicely run in (which hasn't really been a thing for many years) under ideal conditions most would be within 10hp of the published figures.

90hp/litre is around the limit for a modern n/a relatively low rpm cross plane V8 that is fully emission compliant. It was/is achieved with the benefit of CAE assisted manifold and combustion chamber design, multi valve heads, fully optimised high pressure fuel injection, VVT, tolerances made possible by modern metallurgy, manufacturing process and synthetic oils and the compression ratios, knock control and spark strategies possible with modern HT and engine management systems.

What I'd be more interested in is what those older engines, devoid of all the above, used to actually make. 45-55hp per litre was more the norm for a higher performing engine 50 years ago. The last of the Marek 5.3 V8 with 2 valve heads, the fabled X-pack, was claimed to be putting out 415hp, 80hp/litre, and 20yrs earlier the last of the DB5/6/S 4 litre I6 was claimed to be delivering 320hp, again 80hp/litre. I just can't see how they could have ever genuinely got to that with those engines, lovely as I think they all are...

I dyno'd my old 1979 5.3 after a carb tune. It's on its original carbs and bores, not to Vantage tune, but still a healthy 140psi +/- 5psi compression in all bores. It delivered a measured 230hp at the rear wheels, a corrected estimated 265hp at the crank or 50hp/litre.

Edited by Calinours on Friday 27th December 22:05

[v8vantage]

Calinours said:

What I'd be more interested in is what those older engines, devoid of all the above, used to actually make. 45-55hp per litre was more the norm for a higher performing engine 50 years ago. The last of the Marek 5.3 V8 with 2 valve heads, the fabled X-pack, was claimed to be putting out 415hp, 80hp/litre, and 20yrs earlier the last of the DB5/6/S 4 litre I6 was claimed to be delivering 320hp, again 80hp/litre. I just can't see how they could have ever genuinely got to that with those engines, lovely as I think they all are...

I dyno'd my old 1979 5.3 after a carb tune. It's on its original carbs and bores, not to Vantage tune, but still a healthy 140psi +/- 5psi compression in all bores. It delivered a measured 230hp at the rear wheels, a corrected estimated 265hp at the crank or 50hp/litre.

Edited by Calinours on Friday 27th December 22:05

Maybe you can't see how those old engines were getting as much BHP as claimed, but they were. Most the factory saw in the day for a V580V to South African spec (1984) was 437 bhp. 30 years later and my engine to the same spec, with the same camshafts and pistons was showing the same numbers. It's easy to make wild claims but when you have the actual dyno sheets, the B*&llS&^t stops when the data drops!

[Calinours]

v8vantage said:

Maybe you can't see how those old engines were getting as much BHP as claimed, but they were. Most the factory saw in the day for a V580V to South African spec (1984) was 437 bhp. 30 years later and my engine to the same spec, with the same camshafts and pistons was showing the same numbers. It's easy to make wild claims but when you have the actual dyno sheets, the B*&llS&^t stops when the data drops!

I don't doubt your sincerity or belief, know you are considered a real expert in these engines, having owned and tuned a great many, and of course defer to genuine experience and expertise gained from a great deal of time playing about with them. I just struggled a bit with a factory 437hp from that n/a 5.3 V8. That's a big old jump from the original 370hp Vantage, which was a big jump from the original 310hp V8, itself not exactly a slow car.

From the books by the engineers who developed it, the factory got to a consensus 370-375hp peak at the crank with the original V540V after much experimenting and tuning. It is true that the factory could, with care and fettling, deliver engines with a consistent 370hp peak at the crank from the original 1977 V540V, a very healthy 70hp/litre for the time. Its also verified they slightly bettered that with the 1981 V580V, getting to 380hp though it's odd how many heritage specialists here in the UK seem to favour the earlier V540 spec for some reason.

I understood that the South Africa spec, or V580X, an even more extreme tune optimised for breathing at the top end at high altitudes got the 5.3 to close-on 400hp, though I understood the factory claimed 410-420 (hence I stated 415) and it seems this claim was considered already a tad hyperbolic even at the time. This V580X spec engine, as I understand it, became the default in the Zagato and the last 150 or so 86-89 S3 Vantages and all became called 'X-pack Vantages', even though they were not generally the full 'X-pack'

From all I've understood, given the exclusivity, hand made nature and customer base for those cars it seems that no two engines or cars were ever the same, it's impossible to be specific as the factory often wasn't - but it seems that the 'real' X-pack was a series of sort of post sale upgrades that works offered to the V580X that made the engine non-emissions compliant and thus technically not legal in key markets and was thus only made available to a select few. Bigger airbox and inlet, yet more porting, straight through pipes at the rear, even higher compression and the 48IDF carbs very carefully machined out to 50mm bore. Very, very rare in period, no doubt reproduced a bit more subsequently, the wildest state of tune for the 5.3 and it must have been pretty peaky.

It's this spec where claimed power by the factory went to 437hp, and where I'd not only need to be watching but calibrating the dyno in person to believe it. I'm sure it would have been possible in period with a race-prepared engine that would likely become pretty much undrivable on road.

It seems likely that that spec would have been able to pull a genuine 400-410hp at the crank in period though. Hugely impressive n/a numbers especially given the 1960s origins of the engine. Maybe it is possible with modern fuels, tweaked ignition systems and ideal cold conditions to these days achieve absolute peak numbers close to the numbers mentioned. I'd love to see some dyno plots, before/after, same dyno, for a 5.3 taken to that state of tune. It's wild to think that my old 5.3 might have the potential to deliver more peak power than my 4.7S.

Even that wasn't enough, as it never seems to be, hence Richard Williams and the 450hp 6.3litre option. After that was licenced/bought/adopted and marketed by the factory, Mr Williams then going on to develop a 7litre 500hp version. Most UK specialists these days recommend just big bore options 5.6-6.1 which retain the original crank and don't involve any irreversible block machining - this is what I'd be hoping to do with my old lump when the liner seals eventually fail. I can't wait to see how that works with the Tremec which already utterly transformed the car.

[rovcallum]

Before and after a few bits n bobs on the 4.7 V8

[ds666]

Just get a v12 and then you don’t need to test . 😂

[Dewi 2]

rovcallum said:

Before and after a few bits n bobs on the 4.7 V8

Thank you for replying to my topic, Callum.

Interesting that you have extracted more power.
What modifications have you chosen?

My car now has a few tweaks, none of which are visible and I don't think I need anything else to be done.
Twin plate clutch with lightened flywheel.
The single pair of cats have had the honeycombe mods to enhance the exhaust sound, together with a wired 3-way switch (to provide quiet mode).
Prodrive air box mod.

Pleased to say everything on my Vantage is working well. It is resting now, for the usual winter hibernation.
Amazing to think that I have owned it since 2011.

Best wishes for Happy Grigio driving in 2025.

David.

[rovcallum]

Hi David,
I fitted Top Gear exhaust manifolds, 200 cell cats and a tune up/reprogram. I wanted to get the dyno figures to see what the actual difference was. Pleasantly surprised. Mid-range torque is off the scale!
I’m sure I posted somewhere on here at the time.
Great car to drive, currently hibernating.
Twin Plate is bought, ready to fit but I will not get that done until the weather improves in April/May.
Best regards for the New Year!

[cypriot]

ds666 said:

Just get a v12 and then you don’t need to test . ??

sure, but then you have to put up with inferior steering and a front end that feels as though there is an anvil sat on the bonnet...

[Jon39]

cypriot said:

ds666 said:

Just get a v12 and then you don’t need to test . ??

Sure, but then you have to put up with inferior steering and a front end that feels as though there is an anvil sat on the bonnet...

Perhaps when cornering in excess of 2g, that may be discernable, but what a brilliant car.
V12 and a manual gearchange, an extremely rare combination these days.
Someone once offered their opinion, "Wonderful, wonderful, wonderful".

[V8V Pete]

rovcallum said:

Before and after a few bits n bobs on the 4.7 V8

Impressive results Callum, particularly the torque curve.

I've now done 6500 miles with my significantly modified, rebuilt 4.7 V8 (after my engine catastrophe) and I can confirm that it is wonderful, wonderful, wonderful, despite not being a V12. It still hasn't been on a Dyno though and probably never will because I can't get a "before" figure from what's left of the old engine.

Happy New Year to all!

[geresey]

Best use of an old engine ever? HNY !!

[cypriot]

Jon39 said:

cypriot said:

ds666 said:

Just get a v12 and then you don’t need to test . ??

Sure, but then you have to put up with inferior steering and a front end that feels as though there is an anvil sat on the bonnet...

Perhaps when cornering in excess of 2g, that may be discernable, but what a brilliant car.
V12 and a manual gearchange, an extremely rare combination these days.
Someone once offered their opinion, "Wonderful, wonderful, wonderful".

You do not need to be doing 2g... you can tell almost instantly. However if someone wants to jump on a thread and do the usual "just buy the v12" willy waving trope, then also be prepared to hear about the shortcomings of the v12. simples!

[13Red]

rovcallum said:

Hi David,
I fitted Top Gear exhaust manifolds, 200 cell cats and a tune up/reprogram. I wanted to get the dyno figures to see what the actual difference was. Pleasantly surprised. Mid-range torque is off the scale!
I’m sure I posted somewhere on here at the time.
Great car to drive, currently hibernating.
Twin Plate is bought, ready to fit but I will not get that done until the weather improves in April/May.
Best regards for the New Year!

Mind me asking which brand of 200 cell cat you had installed. Also Top Gear? And how does it perform on the emissions test?
HNY!
David

Edited by 13Red on Wednesday 1st January 09:23

[Dewi 2]

cypriot said:

You do not need to be doing 2g... you can tell almost instantly.

There are some older motorway junctions, that have almost complete circle slip roads, so you would think they would be ideal to test for understeer/oversteer. M5 J11A joining and going north, also M26 exit on to A21 going south are two examples.

My Mercedes-Benz E Class has a G-Force meter optional display.
When going around those slip roads at 2g, that is still not fast enough to induce any understeer/oversteer.
It makes me wonder what G-Force might be needed, to reveal a cars behaviour characteristic?

[skhannes]

V8V Pete said:

Impressive results Callum, particularly the torque curve.

I've now done 6500 miles with my significantly modified, rebuilt 4.7 V8 (after my engine catastrophe) and I can confirm that it is wonderful, wonderful, wonderful, despite not being a V12. It still hasn't been on a Dyno though and probably never will because I can't get a "before" figure from what's left of the old engine.

Happy New Year to all!

Absolutely LOVE the table!!....Cheers!!

[rovcallum]

13Red said:

Mind me asking which brand of 200 cell cat you had installed. Also Top Gear? And how does it perform on the emissions test?
HNY!
David

Edited by 13Red on Wednesday 1st January 09:23

Also Top Gear. Emissions are fine provided that the cats are properly hot.

Edited by rovcallum on Wednesday 1st January 13:02

[Calinours]

I had the 200cell race cats and the expensive big bore tuned length exhaust manifolds on my Vantage S but have now removed it all and returned the exhaust to factory standard. Thankfully I kept all the bits.

I found that in the end, I just preferred the overall noise characteristics of the standard V8S, plus I got bored of the annual faff to get it through an MOT, having to get and keep it hot and/or find a sympathetic tester.

[Dewi 2]

Calinours said:

I had the 200 cell race cats and the expensive big bore tuned length exhaust manifolds on my Vantage S but have now removed it all and returned the exhaust to factory standard. Thankfully I kept all the bits.

I found that in the end, I just preferred the overall noise characteristics of the standard V8S, plus I got bored of the annual faff to get it through an MOT, having to get and keep it hot and/or find a sympathetic tester.

For the 2005 to 2010 V8V simple cat 'adjustment', which creates 400 cell cats, there is no problem with MoT, either cold or hot.
On my car, the emissions readings have been unchanged and in some years, improved upon OEM.
Sound remains very Aston Martin, much louder whilst accelerating and the cold idle is just right (louder).