V8 Vantage 4.3 Alternative Performance upgrade thread
Discussion
unfortunately we were not able to do a dyno post each mod, but based on my discussions, the contributions to the power upgrade could be as follows:
1) Manifolds (maybe 15bhp)
2) ECU-remap (maybe 10-15bhp)
3) 200 Cell Cats (maybe 10-15bhp)
4) filters (maybe 4 bhp)
5) sport exhaust (maybe 3 bhp)
Maybe Stuart will chip in later with more detail. He has been the selling the above package (minus the manifolds) for many years.
1) Manifolds (maybe 15bhp)
2) ECU-remap (maybe 10-15bhp)
3) 200 Cell Cats (maybe 10-15bhp)
4) filters (maybe 4 bhp)
5) sport exhaust (maybe 3 bhp)
Maybe Stuart will chip in later with more detail. He has been the selling the above package (minus the manifolds) for many years.
Lunablack said:
AMDBSNick said:
He does say that a pre mods RR session showed 335.5 bhp, and post mods was 378.8.... So I think it's fair to say the improvement is 43.3 BHP....
....
I don't see a problem....
I think the results are valid...
The questions needing answers to check validity would be where is the raw wheel result recorded, where is the driveline coast down curve and where are ambient conditions recorded that all feed a final flywheel power calculation? Because, there is something very odd with the calculated flywheel data here which makes scrutiny of raw data relevant. ....I don't see a problem....
I think the results are valid...
What seems strange is that if flywheel power, is as it is stated in the report by the OP, calculated @ 335BHP, we know the trans loss on the 6 speed graziano is about 60BHP, meaning that power at road wheels must have been around 270BHP, unless I'm missing something here????? which is a VERY odd result indeed, and not seen in any dyno test across the globe I have ever been made aware of.
I don't get comments that any dyno measures incorrectly or low? A dyno is a simple measurement device calibrated to a known reference, if calibrated correctly (and why shouldn't it be??) the only variances can be ambient factors and the coast down curve after power test to achive a final calculated flywheel power result from the raw data, again, unless I'm missing something here??
The question I ask myself here is that if we believe such a low calculated flywheel result, means it is low enough to suggest an issue with something could persist in general. It is then natural to question all data including the delta because if whatever caused the strange result to start with was a variable and not a constant, how do we know if any test is stable or not? Of course, tests could well be stable, but something arouses suspicions which begs questions like these.
The OP seems happy with end result, which is all that matters, but where he says
"Thus, as we know the car's real BHP is around 380, thus the true flywheel BHP increase for my car = 12.9%*380 = 49BHP (meaning the car is now at 429BHP)"
...... to say his car is now 429BHP in the fashion stated, is not a robust statement at all.
Wow, what an exhaust note it must be. Pommehogster was once similar to this spec of exhaust and he generated +120db, I can only imagine what it sounds like..!
seems like a good result and if you can feel the difference then it must be at least 30-40bhp ...I could barely feel 20bhp in some modded Vantages
you can always take it to a dyno that's calibrated well and known to be within a few % of manufacturer flywheel figures, there are a few around
you can always take it to a dyno that's calibrated well and known to be within a few % of manufacturer flywheel figures, there are a few around
BamfordMike said:
I don't get comments that any dyno measures incorrectly or low? A dyno is a simple measurement device calibrated to a known reference, if calibrated correctly (and why shouldn't it be??) the only variances can be ambient factors and the coast down curve after power test to achive a final calculated flywheel power result from the raw data, again, unless I'm missing something here??
Measuring inconsistently is the only thing that really concerns me. As has been discussed here, and I think you agreed (although I could be wrong, I haven't searched back through all the threads) a dyno is a useful tool for measuring change, or delta. As long as it reads consistently, you can get an accurate measure of change in output. We chose to use an independent dyno, and chose to use a Dyno Dynamics because they are widely regarded as being the most consistent in the industry. It is also common knowledge that they usually read much lower output figures than other dynos. Google 'Dyno Dynamics' & 'Heartbreaker' and you will find a plethora of information showing that they are notorious for producing low readings. The important thing that a Dyno will tell you is the change in output from a given set of modifications. You can quote that figure as a discrete figure, or you can look at the percentage change. For example, you could put the same car on 2 different rolling roads (which could be calibrated differently), before & after a suite of modifications. One could read 200BHP before and 220BHP after, the other could read 400BHP before, & 440BHP after. I would argue that both are reflecting the same results. If we had put this car on a rolling road that read 425BHP before, & 480BHP after, it would still be showing a 12.9% increase, but a 55BHP gain. If that were the case and one claimed a 55 BHP net gain, everyone would be quite rightly pointing out the important differences between the % and numerical gains. So if the reverse is true (which it certainly is, otherwise we can just go find a dyno which is calibrated to read much higher & quote higher gains) then it certainly is a robust statement to say that this suite of modifications produced a 12.9% increase in BHP.
I think the important thing here is that this is an unfettered, unmanipulated, independent set of results. We have not applied any correction factors, or doctored the results by doing something like pasting a torque curve from a different run to cover a hole in the torque curve. This is exactly what the car generated, consistently and repeatedly. The fact that a +49BHP gain is extremely similar to what BR's analagous products generated only serves to reinforce to the public that the quoted figures by both companies are demonstrable and legitimate. If anyone doubts the veracity of this information, I invite them to speak directly with the dyno operators for full transparency.
In summary, I don't think it is natural to question the data at all, reading consistently high or consistently low (as in the case of the Dyno Dynamics) is not strange and in fact can be verified with a simple GIS. If the figures varied wildly from one run to the next I would agree with you, but they do not.
Anyway, I don't wish to start a 'forum war' with you guys, I have great respect for you and for your products and service. I love these cars just as much as the next guy, a little competition only ever benefits the customer, so let the chips fall where they may
BamfordMike said:
Wow, what an exhaust note it must be. Pommehogster was once similar to this spec of exhaust and he generated +120db, I can only imagine what it sounds like..!
It is a pretty fantastic sound, I assure you. It is quite loud (this system has 4.5" of perf in each of the transverse pipes, not sure what Pommehogster had, the QS 'Sports' has 6" and Supersports has 2", so I'm guessing somewhere in between?) but this is what the customer requested, he likes 'em loud! It is always possible to leave the stock exhaust in place and reprogram the PCM to amend the valve openings to suit individual preferences, or simply produce an exhaust with even more silencing.That sounds like a good power increase and I am glad that you are please with the results.
The gains are in keeping with the work done.
Enjoy the enhanced performance.
My only observation is that you started the previous threar as "a cheaper alternative" to the main competitor. You then go on to say that the cost was £4100 + VAT. The same tried and tested package from the main competitor is £4200 + VAT. Yes this cheaper, but not the huge saving implied unless I am missing something here
The gains are in keeping with the work done.
Enjoy the enhanced performance.
My only observation is that you started the previous threar as "a cheaper alternative" to the main competitor. You then go on to say that the cost was £4100 + VAT. The same tried and tested package from the main competitor is £4200 + VAT. Yes this cheaper, but not the huge saving implied unless I am missing something here
Jockman said:
Glyn.....is this the same pack you are talking about
Yes, I think the OP is over stating the price of the main competitor. Also their package includes some ECU fettling so the valves open at whatever engine speed you desire plus a switch to open them all the time. Most people choose to raise the valve opening rpm, to stay in stealth mode and enable the sneaking home late at night option 
So possibly this option is all of £100 + VAT cheaper than I paid at the main competitor, or less than one tank of fuel (the commonly used unit of currency in man maths calculations).
GlynV8 said:
That sounds like a good power increase and I am glad that you are please with the results.
The gains are in keeping with the work done.
Enjoy the enhanced performance.
My only observation is that you started the previous threar as "a cheaper alternative" to the main competitor. You then go on to say that the cost was £4100 + VAT. The same tried and tested package from the main competitor is £4200 + VAT. Yes this cheaper, but not the huge saving implied unless I am missing something here
Hi GlynThe gains are in keeping with the work done.
Enjoy the enhanced performance.
My only observation is that you started the previous threar as "a cheaper alternative" to the main competitor. You then go on to say that the cost was £4100 + VAT. The same tried and tested package from the main competitor is £4200 + VAT. Yes this cheaper, but not the huge saving implied unless I am missing something here
Just wanted to point out that my initial thread was motivated by BR increasing their pricing from £4.2k to £5k (not incl. Vat). I was going to go with BR but became a bit frustrated when they increased their price, hence the search for the cheaper alternative began.
Gents, firstly a great result, but I was under the impression this was going to be significantly cheaper when you first started? Obviously I mis-read your first post. However regardless of that, you have given people a choice and as intelligent people they can weigh up all options.
I do have a couple of questions if I may? 1) Was the intake air temperature on both runs the same and if not what were they? 2) What was the air pressure on both runs? 3) Was there any measurement of air flow on both runs and what were they? As I am sure Stuart knows these (and other factors) can have an effect on results, often known as fudge factors
. I have had many, many engines built dyno'ed for many cars and over the years of rolling road 'shoot outs' have seen the same car produce wildly different numbers on the same rolling road at different times of the year.
There is no doubt that you have a good result whether it be 49BHP, 45BHP, 51BHP or 40BHP, the fact is that you can feel a significant improvement and that is all that matters really. As for assuming your car started with 380BHP
you cannot do that I am afraid, so your calculation of 429BHP is definitely flawed here. You can only be sure that if all of the variables (temp etc) were in fact not variables , you have a gain of x% for sure. As I say, regardless of the actual headline number, the gains are significant.
It must sound way too loud with those exhaust mods. At 107dB (tested at Snetterton) mine was too loud and that retained the standard cats. It was un-driveable with the 200 cells in also as that woke people in the next county. Especially as you don't have a switchable back box, I think you may in time regret that if you spend anytime driving on motorways
I am not questioning the mods here, just looking for a little clarification and hope my post comes across as a balanced view and not a fanboy view. I think you have taken a bold step and the graphs show a nice improvement that is borne out of your experience on the road. I am sure the grin is even bigger now
I do have a couple of questions if I may? 1) Was the intake air temperature on both runs the same and if not what were they? 2) What was the air pressure on both runs? 3) Was there any measurement of air flow on both runs and what were they? As I am sure Stuart knows these (and other factors) can have an effect on results, often known as fudge factors
. I have had many, many engines built dyno'ed for many cars and over the years of rolling road 'shoot outs' have seen the same car produce wildly different numbers on the same rolling road at different times of the year.There is no doubt that you have a good result whether it be 49BHP, 45BHP, 51BHP or 40BHP, the fact is that you can feel a significant improvement and that is all that matters really. As for assuming your car started with 380BHP
you cannot do that I am afraid, so your calculation of 429BHP is definitely flawed here. You can only be sure that if all of the variables (temp etc) were in fact not variables , you have a gain of x% for sure. As I say, regardless of the actual headline number, the gains are significant.It must sound way too loud with those exhaust mods. At 107dB (tested at Snetterton) mine was too loud and that retained the standard cats. It was un-driveable with the 200 cells in also as that woke people in the next county. Especially as you don't have a switchable back box, I think you may in time regret that if you spend anytime driving on motorways
I am not questioning the mods here, just looking for a little clarification and hope my post comes across as a balanced view and not a fanboy view. I think you have taken a bold step and the graphs show a nice improvement that is borne out of your experience on the road. I am sure the grin is even bigger now
Lunablack said:
He does say that a pre mods RR session showed 335.5 bhp, and post mods was 378.8.... So I think it's fair to say the improvement is 43.3 BHP........ The outright figures don't mean much at all as long as the runs were done on the same dyno under similar onditions, I don't see a problem....
My old Griff was tested on one dyno at 235bhp..... And on the same day at another dyno it was 298. Making the results totally meaningless...... But if the runs are on the same dynos, I think the results are valid...
I agree with this. Its all about percentage increases from a reliable datum, the results look good to me, not as much of a price difference over the competition than I would have expected though..... The outright figures don't mean much at all as long as the runs were done on the same dyno under similar onditions, I don't see a problem....My old Griff was tested on one dyno at 235bhp..... And on the same day at another dyno it was 298. Making the results totally meaningless...... But if the runs are on the same dynos, I think the results are valid...
gibbon said:
Lunablack said:
He does say that a pre mods RR session showed 335.5 bhp, and post mods was 378.8.... So I think it's fair to say the improvement is 43.3 BHP........ The outright figures don't mean much at all as long as the runs were done on the same dyno under similar onditions, I don't see a problem....
My old Griff was tested on one dyno at 235bhp..... And on the same day at another dyno it was 298. Making the results totally meaningless...... But if the runs are on the same dynos, I think the results are valid...
I agree with this. Its all about percentage increases from a reliable datum, the results look good to me, not as much of a price difference over the competition than I would have expected though..... The outright figures don't mean much at all as long as the runs were done on the same dyno under similar onditions, I don't see a problem....My old Griff was tested on one dyno at 235bhp..... And on the same day at another dyno it was 298. Making the results totally meaningless...... But if the runs are on the same dynos, I think the results are valid...
gibbon said:
I agree with this. Its all about percentage increases from a reliable datum, the results look good to me, not as much of a price difference over the competition than I would have expected though.
If you incl VAT, the figures are £4, 920 vs £6, 000. Thus £1, 080 or 18% cheaper, and this package also incl. an Ecu remap. Not too shabby given the quality of materials used and the power increase achieved?Like some of the others who have already posted similar comments, I was expecting there to be a larger differential in price between the two products. I appreciate that over one thousand pounds and 18 percent is not to be sneezed at, but when you compare it against the value of the car as a whole and not just the price of the work, it's pretty insignificant. If anything, the money saved initially could easily be wiped out by the enhanced re-sale value of the BR fettled car when the time comes, unless the rival brand brand manages to acquire a similar reputation in UK Aston circles.
Edited by slippery on Wednesday 19th June 10:43
slippery said:
Like some of the others who have already posted similar comments, I was expecting there to be a larger differential in price between the two products. I appreciate that over one thousand pounds and 18 percent is not to be sneezed at, but when you compare it against the value of the car as a whole and not just the price of the work, it's pretty insignificant. If anything, the money saved initially could easily be wiped out be the enhanced re-sale value of the BR fettled car when the time comes, unless the rival brand brand manages to acquire a similar reputation in UK Aston circles.
Pretty unlikely that that will happen on any modified car.Gassing Station | Aston Martin | Top of Page | What's New | My Stuff