RESULTS: AM V8 Vantage Power Upgrade + Sports Cats

[providence1]

As promised here are the results. Sorry for the slight delay as I have only just managed to get my car to Surrey Rolling Roads and Charlie (who is brill by the way - highly recommended) this afternoon.

So what work has been done:
1. Aston Martin V8 Power Upgrade kit has been added (new plenham chamber, new airboxes, new front fuse box to control new airboxes), quoted to add 20bhp
2. Replace stock cats with Larini 200 cell Sport Cats
This is in essence HWM's 4.3 'end of line special' V400 spec without the five spoke wheels and bling clear rear light housings.



Before work:
As promised I took my car to SRR before the work was done and the results for my car are as follows:

367bhp
max 290 ft lb torque
98 Ron fuel
air temperature 17 Celsius

Slightly disappointing result as Aston state 380bhp from stock - but its my benchmark - as we know manufacturers figures should always be taken with a pinch of salt (my car is two and a half years old with 28,000 miles on the clock). TurboMiller I know put his car on SRR's road and got 376bhp from stock - 9bhp more. Charlie confirmed that my car does not feel as tight as John's at the top end - this maybe due to the age of cars eg. TurboMillers is newer.

Graph below:


After work:
So all the upgrade work was carried out at HWM and the new results are:

400bhp
max 310 ft lb torque
98 Ron fuel
air temperature 21 Celsius

Graph below:


Plus here is one graph showing both before and after results. The red line is before work, the blue line is after work.

Graph below:


This means a net gain of 33bhp, which to be honest I am very pleased with. I believe TurboMiller's car came in at 404bhp with just the AM Power Upgrade added which in his case was a 28bhp net gain. So I could make one of two assumptions; the first being that the Larini Sports Cats add about 5bhp extra in my case, or secondly the Power Upgrade has delivered 20bhp as stated with the Sports Cats adding another 13bhp.

I can safely say my car is more responsive and eager on the throttle, and the work has provided her with a noticeable increase in mid and top end oomph - all from being able to breath easier.

The sports cats have given the car the most amazing sound track - she has become a musical instrument. I can generate bangs and pops on demand, and under full throttle the sound is awesome - I had it measured at 118 decibels (before she pumped out 106). I was at the Goodwood Supercar Sunday Breakfast Club a couple of weekends back and had throttle blipping competition with a bunch of Ferrari's, they and the crowd watching, all conceded my car was way loader and better sounding. The increase and volume of sound has added a huge amount of pleasure to the driving experience, and I now go around with the radio off and the windows down most of the time.

The total cost of the upgrade work was £4,800 inclusive of labour and VAT. Was it worth it? To me the answer is yes. Would I advise others to do it? Yes. In summary there is noticeably more power - not neck snapping, but you can feel it - plus you get a wonderfully more enhanced sound track to play with. All in all the combination of elements has given me a genuine 400bhp car. Though if she had pumped out an original 380bhp we would now be looking at a 413bhp car.

I agree with other comments on the forum that this is not a replacement for a 4.7 car, but it certainly gives a 4.3 one a new lease of life. For me my V8 has just become a keeper.

[providence1]

I forgot to say that this approach is a properly engineered solution with no ECU cheats and my AM warranty stays intact.

Having done all this work I picked up a stone chip to the front windscreen on Saturday which proceeded to crack straight down the middle from top to bottom. Cost of new heated front screen is £922 + £250 worth of fitting. OUCH. Luckily my insurance covers the cost 100%. Cars going back in Thursday - such is life.

[TurboMiller]

An additional 33bhp sounds like a good result. Sounds like you're also seeing the benefits of the upgrade in the driveability of the car.

Oddly we seem to be living vaguely parallel lives, as my windscreen was smashed two days before going in for the upgrade work! Thankfully AM were able to replace the screen while it was in for the upgrade. And I too was at Goodwood breakfast club. If you're planning on heading down for the one in a couple of weeks let me know - would be good to meet up!

[nickco201]

How about a video ?

[SLINC]

Congrats to Providence1 on a splendid result and many thanks for such a detailed post!! I'm a recent convert to the delights of V8V ownership and have my first dyno run booked for this Saturday in order to establish a "base" before embarking on a similar power upgrade route..Pretty sure I won't have the ability to post up graphs etc - but will flag the top-line numbers once it's all been done..Prior to that I intend a "how life's so much better.." type missive in the style of Lady Topaz, whose posts on pre and post AM purchase made such brilliant reading...

[providence1]

TurboMiller said:

An additional 33bhp sounds like a good result. Sounds like you're also seeing the benefits of the upgrade in the driveability of the car.

Oddly we seem to be living vaguely parallel lives, as my windscreen was smashed two days before going in for the upgrade work! Thankfully AM were able to replace the screen while it was in for the upgrade. And I too was at Goodwood breakfast club. If you're planning on heading down for the one in a couple of weeks let me know - would be good to meet up!

Yes I was planning on going on the 28th. Drop me a line via my email address on my profile and we can get arranging.

[providence1]

nickco201 said:

How about a video ?

funny you should say that I have been thinking of capturing the awesome noises for ever. Leave that one with me for a couple of weeks. She sounds fantastic going through the tunnel under John Lewis in Kingston.

[bogie]

good stuff - nice to see a proper test before/after on the same road - looks like a nice upgrade for the cash and realistic.

I wouldnt worry about the absolute figures at all - a manufacturer is bound by laws to have calibrated, certified engine dynos (I think they are allowed 5% deviation) an aftermarket dyno does not. Im sure you could go to a different rolling road and see 420bhp ..or 410bhp...or 390...depending on where you went.

What matters is you have before/after on the same road, same conditions etc, so you can measure the gains..which is whats been done. At least there are some proven mods out there now so you can bolt 20-40bhp on, and not void your warranty

[Mr Noble]

Cracking read! Thank you very much P1 Sir.



Those are some very good gains indeed. I bet its the freer revving-ness of the engine more than the extra top end punch that is the more noticeable and enjoyable result?

Question, did you say that the ECU map has not been touched at all? Is this purely just a mechanical change to effect these gains? Was there no laptop plugged in during the rolling road sessions?

GN

[Mr Noble]

Oh yes that was the other question I had.......



I assume that you still have the butterfly valves in your exhausts and I assume that the 118 db monster din your car now creates is with these open (fuse 22 out).

Can you still put the fuse back in and have a quiet car or is it crazy loud all the time now? It'll need to be pretty quiet at 4000 rpm to pass an MOT, and most trackdays have a 98db max these days. (not that you may be considering taking it on a track)


I bet it sounds in a tunnel though


GN

[Mr Noble]

That puts your Aston in the "profound - may cause ears to bleed" category then, slightly louder than a 747 on take off!!!

Edited by Mr Noble on Wednesday 17th June 09:19

[sadlerj]

Cheers for the informative update...very interesting

providence1 said:

367bhp
max 290 ft lb torque
98 Ron fuel
air temperature 17 Celsius

Slightly disappointing result

I should say so....mine popped out at 398BHP Stock at an AMOC Rolling Road day at Paramount...(cannot remember the torque). This is why I have been holding out to see what net gains people get...alothough after hearing the god like noise of Mr Dryson's V8 at Le Mans last weekend...so sports cats and a new system may be in order.

[providence1]

Mr Noble said:

Cracking read! Thank you very much P1 Sir.



Those are some very good gains indeed. I bet its the freer revving-ness of the engine more than the extra top end punch that is the more noticeable and enjoyable result?

Question, did you say that the ECU map has not been touched at all? Is this purely just a mechanical change to effect these gains? Was there no laptop plugged in during the rolling road sessions?

GN

I agree that the freer revving-ness is more noticable mid range, but you certainly feel the extra torques at the top end.

Yep the ECU has not been touched. In terms of laptop and rolling road I have no idea.

[providence1]

Mr Noble said:

Oh yes that was the other question I had.......



I assume that you still have the butterfly valves in your exhausts and I assume that the 118 db monster din your car now creates is with these open (fuse 22 out).

Can you still put the fuse back in and have a quiet car or is it crazy loud all the time now? It'll need to be pretty quiet at 4000 rpm to pass an MOT, and most trackdays have a 98db max these days. (not that you may be considering taking it on a track)


I bet it sounds in a tunnel though GN

Yep my car has fuse 22 pulled out permanently. Not tried putting it back in since the work, though if I did it would obviously effect the sound below 4000rpm. If you did put it back in though one would loose some of the lovely rich low down V8 rumbles she now makes.

I agree that fuse 22 will have to go back in for her first MOT next year.

On the issue of track days, mine has been on a number and even passing the 98db was a struggle with fuse 22 in before the work was done - now I 'm sure it would not pass. (On a number of tracks I could not pull out of chicanes using second otherwise I would be black flagged.) Going forward now my only option would be 105db days but again I'm not sure thats a possibility even with fuse 22 in. Roll on my track day Elise project.

Edited by providence1 on Wednesday 17th June 09:54

[providence1]

sadlerj said:

Cheers for the informative update...very interesting

providence1 said:

367bhp
max 290 ft lb torque
98 Ron fuel
air temperature 17 Celsius

Slightly disappointing result

I should say so....mine popped out at 398BHP Stock at an AMOC Rolling Road day at Paramount...(cannot remember the torque). This is why I have been holding out to see what net gains people get...alothough after hearing the god like noise of Mr Dryson's V8 at Le Mans last weekend...so sports cats and a new system may be in order.

Aahh you had you car done at Paramount. Now I'm not saying thats bad but I hear they consistently seem to produce exaggerated figures? You should pop yours on SRRs road and see what it records. As Bogie said every road is different and as TurboMiller's car proves some engines are better or worse than others.

In terms of sounding god like I can highly recommend it. Personally you don't need the back box, just go for the cats.

Edited by providence1 on Wednesday 17th June 09:52

[bogie]

sadlerj said:

Cheers for the informative update...very interesting

providence1 said:

367bhp
max 290 ft lb torque
98 Ron fuel
air temperature 17 Celsius

Slightly disappointing result

I should say so....mine popped out at 398BHP Stock at an AMOC Rolling Road day at Paramount...(cannot remember the torque). This is why I have been holding out to see what net gains people get...alothough after hearing the god like noise of Mr Dryson's V8 at Le Mans last weekend...so sports cats and a new system may be in order.

surely all this tells us is that Surrey RR reads lower than OEM engine dynos, and Paramount reads higher ?

Ive been to about 12 rolling roads I think, and the most "accurate" (as in OEM levels) was in Essex where they did OEM tuning work, and had an engine dyno test cell, so they could take an engine off the bench, and put it in a car and get the same results

..I never trust the absolute readings, before and after at the same place is what counts ...otherwise you can end up happy, or sad, depending on the "correction factor" the RR operator uses !

anyway, be nice to get some Vantage runs up on Dyno-plot so we can compare mods

http://www.dyno-plot.co.uk/dyno/dynoplot/index.htm

[providence1]

Mr Noble said:

I assume that the 118 db monster din your car now creates

GN

Just noticed the word din, there is nothing uncultured about the sound it now makes :-)

[CatalystV8V]

Thanks for the write-up.. I'm considering doing something very similar with my 4.3 very soon. I was going to go for a Quicksilver exhaust... I hadn't considered changes the Cats.. Is this a better option than the quicksilver?

[bogie]

CatalystV8V said:

Thanks for the write-up.. I'm considering doing something very similar with my 4.3 very soon. I was going to go for a Quicksilver exhaust... I hadn't considered changes the Cats.. Is this a better option than the quicksilver?

cats generally give more than a sports exhaust, unless the original is really restrictive, and the replacement very open

I would do cats first personally, at least there are some figures out for them now 10-15bhp

[sadlerj]

providence1 said:

sadlerj said:

Cheers for the informative update...very interesting

providence1 said:

367bhp
max 290 ft lb torque
98 Ron fuel
air temperature 17 Celsius

Slightly disappointing result

I should say so....mine popped out at 398BHP Stock at an AMOC Rolling Road day at Paramount...(cannot remember the torque). This is why I have been holding out to see what net gains people get...alothough after hearing the god like noise of Mr Dryson's V8 at Le Mans last weekend...so sports cats and a new system may be in order.

Aahh you had you car done at Paramount. Now I'm not saying thats bad but I hear they consistently seem to produce exaggerated figures? You should pop yours on SRRs road and see what it records. As Bogie said every road is different and as TurboMiller's car proves some engines are better or worse than others.

In terms of sounding god like I can highly recommend it. Personally you don't need the back box, just go for the cats.

Edited by providence1 on Wednesday 17th June 09:52

Just on the rollers and not any mods. They use the same rollers as Surrey and they are all calibrated independently. There were about 50 other Astons done on the day and there were a wide range of results, most V8's were around 370. I have been back and had our stock M5 done and she came out bang on at 504 bhp and the 335d (before mods) and bang on 284 bhp (they did play with her and now she shows a hilarious 332 bhp and 507 ft lb! So I would say it is pretty reliable reading.

Edited by sadlerj on Wednesday 17th June 15:57