382.8bhp from a VF35 :)
10 October 2010, 10:50 PM
#216
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Re the 1/4 mile time, Bob'5 ran 11.7 at the pod on a (dyno proven lol) 340bhp UK car running a 16g that I mapped some 7 or 8 years ago so you don't need big bhp to run those numbers.
10 October 2010, 10:56 PM
#217
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Oh for a set of 888s and an RA box
Cheers Iain
11 October 2010, 12:22 AM
#218
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Ok had a good read of this again
Whay can't people just accept what bhp iains car is making? He has had it dyno'd as proof what more do u want? Should he have the car sent to NASA for them to investigate
Get off your high horse's and stop putting people down who are achieveing new things. I don't care about this At and IT stuff. Once mine is reafy for a map and had it rolling roaded I shall post my results up too. If they are 380bhp then u going to say its not possible considering I will have alnost the same setup and mods as iains?
Rant over
well done Iain keep it up mate. Will ring u Tuesday or Monday night once back south
Cheers
Dave
Whay can't people just accept what bhp iains car is making? He has had it dyno'd as proof what more do u want? Should he have the car sent to NASA for them to investigate
Get off your high horse's and stop putting people down who are achieveing new things. I don't care about this At and IT stuff. Once mine is reafy for a map and had it rolling roaded I shall post my results up too. If they are 380bhp then u going to say its not possible considering I will have alnost the same setup and mods as iains?
Rant over
well done Iain keep it up mate. Will ring u Tuesday or Monday night once back south
Cheers
Dave
Last edited by Lewak; 11 October 2010 at 12:26 AM. Reason: using blackberry phone and can't spell with it lol
11 October 2010, 01:25 AM
#219
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Good result both at the track and the dyno ( even if you take off 3% its still a good number)
Porting the wastegate does nothing for power. If you look at the dyno sheet on the first page we can see that the turbo can't hold boost. Its fallen to something like 1.32bar by 6000rpm. The compressor can't keep up with the flow demands of the engine.
You wastegate is going to be on about 90% duty with the avcr to try and make target boost. So the wastegate is shut as much as it can. So high flowing it does nothing for power as it shut as much as it can.
Imo if anything your actually hurting power by wastegate porting. But it does stop creep so its a good idea if thats happening.
The uprated actuator is helping make the extra power. On these VF turbos the exhaust housing is small. The exhaust backpressure between the engine and the turbo becomes so great that it over whelms the std wastegate spring and "blows" the wastegate open.
By moving to a higher spring rate on the wastegate it makes it harder for the wastegate to creep open.
By having the wastegate shut your able to drive more exhaust gas thru the turbine, spinning it faster, thus the compressor can flow abit more air. Its probably not flowing too efficiently at these levels but u can still make abit more power.
There is a danger in overspeeding the turbo with these mods which can lead to a reduced lifespan. As usual in life its hard to get something for nothing !
Use methanol / e85 make more power and run a 11.5 !
Porting the wastegate does nothing for power. If you look at the dyno sheet on the first page we can see that the turbo can't hold boost. Its fallen to something like 1.32bar by 6000rpm. The compressor can't keep up with the flow demands of the engine.
You wastegate is going to be on about 90% duty with the avcr to try and make target boost. So the wastegate is shut as much as it can. So high flowing it does nothing for power as it shut as much as it can.
Imo if anything your actually hurting power by wastegate porting. But it does stop creep so its a good idea if thats happening.
The uprated actuator is helping make the extra power. On these VF turbos the exhaust housing is small. The exhaust backpressure between the engine and the turbo becomes so great that it over whelms the std wastegate spring and "blows" the wastegate open.
By moving to a higher spring rate on the wastegate it makes it harder for the wastegate to creep open.
By having the wastegate shut your able to drive more exhaust gas thru the turbine, spinning it faster, thus the compressor can flow abit more air. Its probably not flowing too efficiently at these levels but u can still make abit more power.
There is a danger in overspeeding the turbo with these mods which can lead to a reduced lifespan. As usual in life its hard to get something for nothing !
Use methanol / e85 make more power and run a 11.5 !
11 October 2010, 07:46 AM
#220
Live in ignorance then. As long as its a pretty graph then what do mere facts matter for 
Big "D" - I'd get a re-run at this RR for free since they've fouled up this run.
Another RR known for being hard would also be interesting.
Its a shame that a dyno operator has yet again has blurred what may be an excellent output.
Big "D" - I'd get a re-run at this RR for free since they've fouled up this run.
Another RR known for being hard would also be interesting.
Its a shame that a dyno operator has yet again has blurred what may be an excellent output.
11 October 2010, 08:08 AM
#221
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Good result both at the track and the dyno ( even if you take off 3% its still a good number)
Porting the wastegate does nothing for power. If you look at the dyno sheet on the first page we can see that the turbo can't hold boost. Its fallen to something like 1.32bar by 6000rpm. The compressor can't keep up with the flow demands of the engine.
You wastegate is going to be on about 90% duty with the avcr to try and make target boost. So the wastegate is shut as much as it can. So high flowing it does nothing for power as it shut as much as it can.
Imo if anything your actually hurting power by wastegate porting. But it does stop creep so its a good idea if thats happening.
The uprated actuator is helping make the extra power. On these VF turbos the exhaust housing is small. The exhaust backpressure between the engine and the turbo becomes so great that it over whelms the std wastegate spring and "blows" the wastegate open.
By moving to a higher spring rate on the wastegate it makes it harder for the wastegate to creep open.
By having the wastegate shut your able to drive more exhaust gas thru the turbine, spinning it faster, thus the compressor can flow abit more air. Its probably not flowing too efficiently at these levels but u can still make abit more power.
There is a danger in overspeeding the turbo with these mods which can lead to a reduced lifespan. As usual in life its hard to get something for nothing !
Use methanol / e85 make more power and run a 11.5 !
Porting the wastegate does nothing for power. If you look at the dyno sheet on the first page we can see that the turbo can't hold boost. Its fallen to something like 1.32bar by 6000rpm. The compressor can't keep up with the flow demands of the engine.
You wastegate is going to be on about 90% duty with the avcr to try and make target boost. So the wastegate is shut as much as it can. So high flowing it does nothing for power as it shut as much as it can.
Imo if anything your actually hurting power by wastegate porting. But it does stop creep so its a good idea if thats happening.
The uprated actuator is helping make the extra power. On these VF turbos the exhaust housing is small. The exhaust backpressure between the engine and the turbo becomes so great that it over whelms the std wastegate spring and "blows" the wastegate open.
By moving to a higher spring rate on the wastegate it makes it harder for the wastegate to creep open.
By having the wastegate shut your able to drive more exhaust gas thru the turbine, spinning it faster, thus the compressor can flow abit more air. Its probably not flowing too efficiently at these levels but u can still make abit more power.
There is a danger in overspeeding the turbo with these mods which can lead to a reduced lifespan. As usual in life its hard to get something for nothing !
Use methanol / e85 make more power and run a 11.5 !
For starters the Duty on my Apexi avcr was a flatline 48% solenoid duty from 1500 to 6500rpm (and happily hit 1.4 Bar), hence the slow spool, since the dyno I have introduced alot more duty lower down in the rev range to help with a faster spool and it has worked a treat, hitting peak boost now @ approx 3500/3600 rpm in 4th should be interesting on the Dyno, more torque?.
If I am overspeeding the turbine then what the hell is Pooeater doing to his. The VF35 is prone to boost creep which regardless of what the wasetgate is doing is uncontrollable which is why I ported the 35 in the first place after doing this then yes I did notice a lazy spool and I put that down to wasetgate creep so I fitted an uprated actuator, with the actuator set at 1.0 Bar and the running boost pressure @ 1.4 bar, the turbine will be working no harder than if the wastegate actuator was set at 0.5 bar at a running pressure of 1.4 Bar but the boost duty cycle will be massively different, at the end of the day 1.4 bar is 1.4 bar the turbo has to spool at a certain speed to produce this pressure dictated by air temp/density (before and after the compressor), exhaust flow, turbine and compressor size and intake size inc intercooler. So I think that I am quite safe thanks.
Oh and I should be getting the next Dyno run on a Dyno Dynamics RR on the 30th and I assure you that the IT and AT temps will be correct this time.
Cheers Iain
Last edited by Big 'D'; 11 October 2010 at 08:18 AM. Reason: correcting text
11 October 2010, 08:29 AM
#223
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Live in ignorance then. As long as its a pretty graph then what do mere facts matter for
Big "D" - I'd get a re-run at this RR for free since they've fouled up this run.
Another RR known for being hard would also be interesting.
Its a shame that a dyno operator has yet again has blurred what may be an excellent output.
Big "D" - I'd get a re-run at this RR for free since they've fouled up this run.
Another RR known for being hard would also be interesting.
Its a shame that a dyno operator has yet again has blurred what may be an excellent output.
I dont want to put down the guys at Subaru4U as they were very helpful on the day, if they were to offer a free re-run I would accept it, but I will not go chasing them for one as I feel it was an honest mistake.
Cheers Iain
11 October 2010, 08:44 AM
#224
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Bloody dyno queens 
All that matters is the car proves itself down the strip.. 11's for a car like this is a good result, albeit on drag radials? To compare, fully loaded 4x4 cossies with ~330bhp run mid 12's with a competent driver on street tyres.. Better tyres and a bit more power should show the results this Subaru is getting..
Who really cares if it's 360 or 380hp.. you'd struggle to make your times down the strip consistent enough to show the difference.
All that matters is the car proves itself down the strip.. 11's for a car like this is a good result, albeit on drag radials? To compare, fully loaded 4x4 cossies with ~330bhp run mid 12's with a competent driver on street tyres.. Better tyres and a bit more power should show the results this Subaru is getting..
Who really cares if it's 360 or 380hp.. you'd struggle to make your times down the strip consistent enough to show the difference.
11 October 2010, 08:47 AM
#225
https://www.scoobynet.com/general-te...ti-bugeye.html
I am not knocking Big D's achievement because even when the results are corrected for the inlet air temperature discrepancy it will be a fantastic result for a VF35 turbo.
The facts are however that the result is very much skewed as Len at Subaru4U will realise himself and as any Dyno Dynamics rolling road operator can work out for themselves. Leading people who don't have much knowledge or understanding of tuning a Subaru to believe that a genuine 382 bhp is possible from a VF35 will only lead to upset.
From what has been printed here Big D you do need to understand more on how a turbo works because some of what you have written is rubbish. The advice to read several named books was made in your best interests if you are genuinely interested in continuing to improve your results and understanding.
I have no doubt your VF35, supporting modifications and mapping put your achievements at the top of the tree but to claim this is 382 bhp when you have published the evidence that it clearly cannot be is rather silly and to all those that come out with this sort of crap
Get real. You obvioiusly lack a modicum of knowledge regards tuning and rolling roads.
Big D has a great result even when temperature corrected but some of the rubbish posted on this thread is unhelpful to those with a genuine wish to learn or a desire to improve their car.
I am not knocking Big D's achievement because even when the results are corrected for the inlet air temperature discrepancy it will be a fantastic result for a VF35 turbo.
The facts are however that the result is very much skewed as Len at Subaru4U will realise himself and as any Dyno Dynamics rolling road operator can work out for themselves. Leading people who don't have much knowledge or understanding of tuning a Subaru to believe that a genuine 382 bhp is possible from a VF35 will only lead to upset.
From what has been printed here Big D you do need to understand more on how a turbo works because some of what you have written is rubbish. The advice to read several named books was made in your best interests if you are genuinely interested in continuing to improve your results and understanding.
I have no doubt your VF35, supporting modifications and mapping put your achievements at the top of the tree but to claim this is 382 bhp when you have published the evidence that it clearly cannot be is rather silly and to all those that come out with this sort of crap
Get off your high horse's and stop putting people down who are achieveing new things. I don't care about this At and IT stuff. Once mine is reafy for a map and had it rolling roaded I shall post my results up too. If they are 380bhp then u going to say its not possible considering I will have alnost the same setup and mods as iains?
Big D has a great result even when temperature corrected but some of the rubbish posted on this thread is unhelpful to those with a genuine wish to learn or a desire to improve their car.
Last edited by harvey; 11 October 2010 at 09:15 AM.
11 October 2010, 09:10 AM
#226
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Well I have had enough now really, I must have some sort of idea about what is going on to get the results I have been getting. Let's just see what the Dyno says next time and let that be end to it, if it runs the same power again it is down to the work I have done to the turbo.
The only bit that is rubbish is having my word rubbished on here when the results are quite clear to see and have been repeated on other cars too.
Roll on the next Dyno run as I can't wait to put this to rest lol
Cheers Iain.
The only bit that is rubbish is having my word rubbished on here when the results are quite clear to see and have been repeated on other cars too.
Roll on the next Dyno run as I can't wait to put this to rest lol
Cheers Iain.
11 October 2010, 09:56 AM
#227
Why not have a word with Len @ S4U. Get the correction factor and put this straight today or do another run if you want to bottom this out. Are you big enough for that or do you want to burry your head in the sand and dig deeper?
If it is not obvious to you why an AT of 14 and IT of 43 has greatly skewed the result after the well intended input by several on here, ask Len to explain to you. I have no doubt other DynoDynamis operators can work it out if they have not done so already. The AT/IT difference is usually 2-6 C max on an efficient system. I seem to recall that an increase in IT of 10C is 3% power and I already know that every 4 deg C accounts for 1% power on ACTs. These are not figures I have come up with but from specialists and world renoun tuners. This is something I am dealing with all the time and these figures are close approximations from my hands on practical experience.
You have some knowlege of how a turbo works but from the posts you have already made in some detail it is clearly a limitted knowlege with some misconceptions and the suggestion you improve your knowledge by reading on the subject was a genuine attempt to assist you.
As suggested by Shaun and accepted by you earlier in this thread, if you want your figures to be credible, run your car on another DD RR in the next day or two. Log temperatures, which is already done by the RR. Get the ACT if you can along with boost and AFR. All this will assist you.
When you want to set spectacular results you can add a percentage methanol but need the car mapped for that otherwise you are at risk of engine damage and the gains will only be partial without mapping.
Don't go defensive. You clearly have a good result whatever that may be and it will be a combination of not only the turbo but the supporting mods and hard work you have already done plus the mapping. Whatever the figure,it is not a genuine 382 as explained by several people because of the skew but you clearly have a fast car and you have backed that up on the track/quarter mile.
Do not be disheartened 382 is only a figure as Bob has already told you. Everyone recognises whatever the actual figure you are already at the top for a VF35. Stand back, take stock of the situation and go forward. I sincerely wish you good luck increasing your knowledge and the further achievements you will attain.
If it is not obvious to you why an AT of 14 and IT of 43 has greatly skewed the result after the well intended input by several on here, ask Len to explain to you. I have no doubt other DynoDynamis operators can work it out if they have not done so already. The AT/IT difference is usually 2-6 C max on an efficient system. I seem to recall that an increase in IT of 10C is 3% power and I already know that every 4 deg C accounts for 1% power on ACTs. These are not figures I have come up with but from specialists and world renoun tuners. This is something I am dealing with all the time and these figures are close approximations from my hands on practical experience.
You have some knowlege of how a turbo works but from the posts you have already made in some detail it is clearly a limitted knowlege with some misconceptions and the suggestion you improve your knowledge by reading on the subject was a genuine attempt to assist you.
As suggested by Shaun and accepted by you earlier in this thread, if you want your figures to be credible, run your car on another DD RR in the next day or two. Log temperatures, which is already done by the RR. Get the ACT if you can along with boost and AFR. All this will assist you.
When you want to set spectacular results you can add a percentage methanol but need the car mapped for that otherwise you are at risk of engine damage and the gains will only be partial without mapping.
Don't go defensive. You clearly have a good result whatever that may be and it will be a combination of not only the turbo but the supporting mods and hard work you have already done plus the mapping. Whatever the figure,it is not a genuine 382 as explained by several people because of the skew but you clearly have a fast car and you have backed that up on the track/quarter mile.
Do not be disheartened 382 is only a figure as Bob has already told you. Everyone recognises whatever the actual figure you are already at the top for a VF35. Stand back, take stock of the situation and go forward. I sincerely wish you good luck increasing your knowledge and the further achievements you will attain.
Last edited by harvey; 11 October 2010 at 10:04 AM.
11 October 2010, 10:28 AM
#228
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Can you blame me for being defensive.
RR Booked for Wed, we will see then what the deal is.
What I want to know is if I run 380+bhp again with correct AT + IT will you believe me then or is it all still not possible?
380 is only just a figure, correct, but it is a figure that is for now in dispute, I would just like to know exactly how much power I am getting out of my little 35 and when I get the next results I will post them up too.
Cheers Iain
RR Booked for Wed, we will see then what the deal is.
What I want to know is if I run 380+bhp again with correct AT + IT will you believe me then or is it all still not possible?
380 is only just a figure, correct, but it is a figure that is for now in dispute, I would just like to know exactly how much power I am getting out of my little 35 and when I get the next results I will post them up too.
Cheers Iain
11 October 2010, 10:52 AM
#229
I wouldn't get too hung up on the dyno figures personally, they will vary from one place to another and can be fudged.
The blackstuff doesn't lie though, great result running 11.8s on the strip.
How many runs did you do in the 11s and what were the terminals?
The blackstuff doesn't lie though, great result running 11.8s on the strip.
How many runs did you do in the 11s and what were the terminals?
11 October 2010, 12:38 PM
#230
I cant believe this thread has gone on for 7 pages lol,the guys posted up the graphs and the results are there for all to see,who's looking at I.T/A.T temps
. He has said he may well use another rolling road ,and if he produces the same results will people doubt that as well
.
Seddomyster,we both bought our cars within 2 weeks of each other (2 years a go),and continued to mod them .
I think you chose the vf23 & FMIC option,while i opted for the vf28 & TMIC,mines running really well, so whats made you opt for the vf34 -was the front mount making it to laggy
. He has said he may well use another rolling road ,and if he produces the same results will people doubt that as well.Seddomyster,we both bought our cars within 2 weeks of each other (2 years a go),and continued to mod them .
I think you chose the vf23 & FMIC option,while i opted for the vf28 & TMIC,mines running really well, so whats made you opt for the vf34 -was the front mount making it to laggy
11 October 2010, 12:45 PM
#231
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60ft between 1.68 and 1.72
1/8th in 7.5 @ 93
It will be nice to know roughly what I have in power and torque without people who have not even seen the car passing judgement and telling me that its not possible, granted dynos are going to be different but I can't see them being 20-30bhp out.
Cheers Iain
11 October 2010, 12:53 PM
#232
Scooby Regular
dyno's are extreamly easy to get what ever reading you want, i've seen a 1.6 gl run 350bhp before now at a RR day as a joke. Thats why big figures that are abnormal get questioned. you can only go on what you;ve been told, how accurate that is is whats beoing questioned as far as i can see.
dynos also vary greatly according to atmospheric conditions, 20-30bhp is easy difference to achieve if you make a run on a hot day or a cold day, humid or dry day depending on spec, Even high or low airpressue and also how high above sea level you are affect it. Thats why a difference in air temps is very easy to spot and makes folks ask questions about the results.
11 October 2010, 01:03 PM
#233
um, for those of us not in the know, can someone explain how AT and IT affect the results and, how these are set up wrong on the dyno, as I don't really understand!
11 October 2010, 01:19 PM
#234
Presuming that UK dynos report their figures according to DIN 70020, the as run output will be converted to an equivalent output for std atmospheric pressure and temperature (750 mm Hg and 20 deg C).
If the IT input is used as the temperature variable, then the dyno will adjust the power figure for the change in air density.
If as Harvey says, that a 4 Deg change in IT equals a 1% power change then the power from an IT of 42 deg C will be converted to read for an IT of 20 deg C, an increase of IRO 6%.
But since the true IT was more likely to be the AT 17 Deg C on this run, the conversion is simply adding extra power that wasn't there.
For some reason, the IT probe was placed somewhere hotter than expected.
If the IT input is used as the temperature variable, then the dyno will adjust the power figure for the change in air density.
If as Harvey says, that a 4 Deg change in IT equals a 1% power change then the power from an IT of 42 deg C will be converted to read for an IT of 20 deg C, an increase of IRO 6%.
But since the true IT was more likely to be the AT 17 Deg C on this run, the conversion is simply adding extra power that wasn't there.
For some reason, the IT probe was placed somewhere hotter than expected.
11 October 2010, 01:29 PM
#235
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I am sure the next Dyno graph will be as correct as it can be, I just hope that if it runs the same again and all the temps and corrections are infact correct that the next figue I come back with will be accepted for what it is.
A second dyno run wil be taken as a comparison at yet another dyno dynamics RR just to compare results on the 30th October.
Cheers Iain
A second dyno run wil be taken as a comparison at yet another dyno dynamics RR just to compare results on the 30th October.
Cheers Iain
11 October 2010, 01:30 PM
#236
Sabas : I think it would be best for a DynoDynamics rolling road operator to explain this fully and who better than Len @ Subaru for you on whose RR Big D ran his car.
Len can then set straight the anomoly of 14 deg C ambient and 43 deg C inlet temperature.
Len can then set straight the anomoly of 14 deg C ambient and 43 deg C inlet temperature.
11 October 2010, 02:18 PM
#237
Thanks to Butty for his helpful input.
The power output of an engine will vary with atmosheric conditions. In the same way altitude influences power output with more power at sea level than in the thinner air several thousand feet up.
The rolling road will measure the power produced (at the wheels) on the day. This figure on the DD RR is then multiplied by a predetermined factor to calculate a flywheel figure which is what is quoted for most cars in the UK. For the DD rolling road this is purely a calculated figure.
Some rolling roads, Maha for instance, actually work out the drag power on coast down so the transmission loss recorded takes into account that car's specific transmission losses which are efected by tyre width, tyre pressure, gearing, transmission type, lubricant etc.
Now in order to compare cars from all over the world in varying climatic conditions, many rolling roads apply correction tables to calculate a power figure in accordance with standard operating conditions.
Correction acc to DIN 70020
The overall effect of this is to apply a correction figure to represent the results at the standard settings. The data includes :
Ambient temperature
Intake air temperature
Relative humidityAir pressure.
Air pressure.
With standardised results, in theory, it should be possible to compare results from one DD RR with that of another and indeed DynoDynamics sales literature makes a big thing of comparing results from Australia with those from the USA or anywhere else in the world.
Normally, on a Subaru with good air intake system and a rolling road with good air facilities the difference between AT and IT is usually around 1 or 2 deg C and 5 deg C is a big gap and should be investigated. To apply a temperature difference of 29 C IT over AT will result in the application of an unusually high percentage correction factor and will give a greatly exaggerated power figure. I do not know what percentage relates to such a difference but I guess I can find that out if necessary. The rolling road operator will already know that figure from his retained log and I pointed out to Big D in a very gentle way on this thread or the other one several days ago, that he should get that percentage correction factor. Subsequent advice, several times, to obtain that figure has been ignored.
Again, if you want to deal in facts get the figure or ask Subaru4You to comment but leading people to believe you can achieve 380 bhp from a VF35 that only has an uprated actuator and ported waste gate, running road fuel and 1.4 bar is not helpful to those that may attempt to emulate your result and will result in serious disappointment. I have already had two people wanting to buy uprated actuators on the strength of this.
You clearly are keen and already have great results on the quarter mile and whatever they may be on the dyno but now is the time to stand back, get some genuine knowledge and go forward from there.
The power output of an engine will vary with atmosheric conditions. In the same way altitude influences power output with more power at sea level than in the thinner air several thousand feet up.
The rolling road will measure the power produced (at the wheels) on the day. This figure on the DD RR is then multiplied by a predetermined factor to calculate a flywheel figure which is what is quoted for most cars in the UK. For the DD rolling road this is purely a calculated figure.
Some rolling roads, Maha for instance, actually work out the drag power on coast down so the transmission loss recorded takes into account that car's specific transmission losses which are efected by tyre width, tyre pressure, gearing, transmission type, lubricant etc.
Now in order to compare cars from all over the world in varying climatic conditions, many rolling roads apply correction tables to calculate a power figure in accordance with standard operating conditions.
Correction acc to DIN 70020
The overall effect of this is to apply a correction figure to represent the results at the standard settings. The data includes :
Ambient temperature
Intake air temperature
Relative humidityAir pressure.
Air pressure.
With standardised results, in theory, it should be possible to compare results from one DD RR with that of another and indeed DynoDynamics sales literature makes a big thing of comparing results from Australia with those from the USA or anywhere else in the world.
Normally, on a Subaru with good air intake system and a rolling road with good air facilities the difference between AT and IT is usually around 1 or 2 deg C and 5 deg C is a big gap and should be investigated. To apply a temperature difference of 29 C IT over AT will result in the application of an unusually high percentage correction factor and will give a greatly exaggerated power figure. I do not know what percentage relates to such a difference but I guess I can find that out if necessary. The rolling road operator will already know that figure from his retained log and I pointed out to Big D in a very gentle way on this thread or the other one several days ago, that he should get that percentage correction factor. Subsequent advice, several times, to obtain that figure has been ignored.
Again, if you want to deal in facts get the figure or ask Subaru4You to comment but leading people to believe you can achieve 380 bhp from a VF35 that only has an uprated actuator and ported waste gate, running road fuel and 1.4 bar is not helpful to those that may attempt to emulate your result and will result in serious disappointment. I have already had two people wanting to buy uprated actuators on the strength of this.
You clearly are keen and already have great results on the quarter mile and whatever they may be on the dyno but now is the time to stand back, get some genuine knowledge and go forward from there.
Last edited by harvey; 11 October 2010 at 02:27 PM.
11 October 2010, 02:32 PM
#238
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Thanks to butty for his helpful input.
The power output of an engine will vary with atmosheric conditions. In the same way altitude influences power output with more power at sea level than in the thinner air several thousand feet up.
The rolling road will measure the power produced (at the wheels) on the day. This figure on the DD RR is then multiplied by a predetermined factor to calculate a flywheel figure which is what is quoted for most cars in the UK. For the DD rolling road this is purely a calculated figure.
Some rolling roads, Maha for instance, actually work out the drag power on coast down so the transmission loss recorded takes into account that car's specific transmission losses which are efected by tyre width, tyre pressure, gearing, transmission type, lubricant etc.
Now in order to compare cars from all over the world in varying climatic conditions, many rolling road operators apply correction tables to calculate a power figure in accordance with standard atmospheric conditions.
Correction acc to DIN 70020
The overall effect of this is to apply a correction figure to represent the results at a standard setting. The ambient data includes :
Ambient temperature
Intake air temperature
Relative humidityAir pressure.
Air pressure.
With standardised results, in theory, it should be possible to compare results from one DD RR with that of another and indeed DynoDynamics sales litriture makes a big thing of comparing results from Australia with those from the USA or anywhere else in the world.
Normally, on a Subaru with good air intake system and a rolling road with good air facilities the difference between AT and IT is usually around 1 or 2 deg C and 5 deg C is a big gap and should be investigated. To apply a temperature difference of 29 C IT over AT will result in the application of an unusually high percentage correction and will give a greatly exaggerated power figure. I do not know what percentage relates to such a difference but I guess I can find that out if necessary. The rolling road operator will already know that figure from his retained log and I pointed out to Big D in a very gentle way on this thread or the other one several days ago, that he should get that percentage correction factor. Subsequent advice, several times, to obtain that figure has been ignored.
Again, if you want to deal in facts get the figure or ask Subaru4You to comment but leading people to believe you can achieve 380 bhp from a VF35 that only has an uprated actuator and ported waste gate, running road fuel and 1.4 bar is not helpful to those that may attempt to emulate your result and will result in serious disappointment. I have already had two people wanting to buy uprated actuators on the strength of this.
You clearly are keen and already have great results on the quarter mile and whatever they may be on the dyno but now is the time to stand back, get some genuine knowledge and go forward from there.
The power output of an engine will vary with atmosheric conditions. In the same way altitude influences power output with more power at sea level than in the thinner air several thousand feet up.
The rolling road will measure the power produced (at the wheels) on the day. This figure on the DD RR is then multiplied by a predetermined factor to calculate a flywheel figure which is what is quoted for most cars in the UK. For the DD rolling road this is purely a calculated figure.
Some rolling roads, Maha for instance, actually work out the drag power on coast down so the transmission loss recorded takes into account that car's specific transmission losses which are efected by tyre width, tyre pressure, gearing, transmission type, lubricant etc.
Now in order to compare cars from all over the world in varying climatic conditions, many rolling road operators apply correction tables to calculate a power figure in accordance with standard atmospheric conditions.
Correction acc to DIN 70020
The overall effect of this is to apply a correction figure to represent the results at a standard setting. The ambient data includes :
Ambient temperature
Intake air temperature
Relative humidityAir pressure.
Air pressure.
With standardised results, in theory, it should be possible to compare results from one DD RR with that of another and indeed DynoDynamics sales litriture makes a big thing of comparing results from Australia with those from the USA or anywhere else in the world.
Normally, on a Subaru with good air intake system and a rolling road with good air facilities the difference between AT and IT is usually around 1 or 2 deg C and 5 deg C is a big gap and should be investigated. To apply a temperature difference of 29 C IT over AT will result in the application of an unusually high percentage correction and will give a greatly exaggerated power figure. I do not know what percentage relates to such a difference but I guess I can find that out if necessary. The rolling road operator will already know that figure from his retained log and I pointed out to Big D in a very gentle way on this thread or the other one several days ago, that he should get that percentage correction factor. Subsequent advice, several times, to obtain that figure has been ignored.
Again, if you want to deal in facts get the figure or ask Subaru4You to comment but leading people to believe you can achieve 380 bhp from a VF35 that only has an uprated actuator and ported waste gate, running road fuel and 1.4 bar is not helpful to those that may attempt to emulate your result and will result in serious disappointment. I have already had two people wanting to buy uprated actuators on the strength of this.
You clearly are keen and already have great results on the quarter mile and whatever they may be on the dyno but now is the time to stand back, get some genuine knowledge and go forward from there.
Cheers Iain
11 October 2010, 03:18 PM
#239
Again, if you want to deal in facts get the figure or ask Subaru4You to comment but leading people to believe you can achieve 380 bhp from a VF35 that only has an uprated actuator and ported waste gate, running road fuel and 1.4 bar is not helpful to those that may attempt to emulate your result and will result in serious disappointment. I have already had two people wanting to buy uprated actuators on the strength of this.
11 October 2010, 03:29 PM
#240
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Again, if you want to deal in facts get the figure or ask Subaru4You to comment but leading people to believe you can achieve 380 bhp from a VF35 that only has an uprated actuator and ported waste gate, running road fuel and 1.4 bar is not helpful to those that may attempt to emulate your result and will result in serious disappointment. I have already had two people wanting to buy uprated actuators on the strength of this.
Cheers Iain