9m Motec M84 upgrade on non-Varioram
10-06-2011, 04:41 PM
#91
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......
Taking the above hypothesis into perspective and running it against the 9M Singer engine we see the following:
9M dyno shows 340 lb.ft. peak torque. From the limited amount of samples we've seen this should be corrected with 13% to match Porsche TQ in that rev area. This makes for 301 lb.ft. Porsche TQ, or a BMEP of 195....
....this falls well within the limits of my conservative 5% - BMEP of 200 hypothesis threshold.
To me this sounds very realistic as a CR increase from 11.3 to 12.5 can already be accounted for 80% of this 5% increase. But then again this still is just my educated opinion....not solid fact.
In summary what the above shows is that the 9M Singer engine's torque readings converted to Porsche TQ show a 7% BMEP increase compared to the 3.8 RSR, and according to my personal hypothesis on the subject is more than realistic. When converting max HP it shows a healthy 13.5% increase over the RSR's 350 Porsche-HP with a number of 397.
Rgds,
Harald
Taking the above hypothesis into perspective and running it against the 9M Singer engine we see the following:
9M dyno shows 340 lb.ft. peak torque. From the limited amount of samples we've seen this should be corrected with 13% to match Porsche TQ in that rev area. This makes for 301 lb.ft. Porsche TQ, or a BMEP of 195....
....this falls well within the limits of my conservative 5% - BMEP of 200 hypothesis threshold.
To me this sounds very realistic as a CR increase from 11.3 to 12.5 can already be accounted for 80% of this 5% increase. But then again this still is just my educated opinion....not solid fact.
In summary what the above shows is that the 9M Singer engine's torque readings converted to Porsche TQ show a 7% BMEP increase compared to the 3.8 RSR, and according to my personal hypothesis on the subject is more than realistic. When converting max HP it shows a healthy 13.5% increase over the RSR's 350 Porsche-HP with a number of 397.
Rgds,
Harald
Harald,
You're spot-on mate, well done.
The first 3.8 engine we built for Singer was assembled in NY and was trucked to Conneticut by me and Geoffrey to run on a known conservative DTA engine dyno. In view that we had a small issue that required the impromptu resetting of the cam timing we were delighted with the result at 392hp, a number which the shop owner owner himself expressed surprise at. It was the most powerful aircooled 911 engine he had tested, and that was on 94 octane pump fuel in a dyno cell which peaked at 35C.
The second engine was assembled at 9m and with the benefit if using my digital electronic camshaft setting rig my feeling is that it was a slightly more responsive & powerful motor than the first.
10-07-2011, 10:17 AM
#92
Harald,
You make me sound like an evil person. Reality is I am not filtering any information whatsoever, this cr@p takes so much time that this is not fun at all and I have better things to do.
The GTO debate honestly does not interest me and it is not because it proves me wrong at all. Please
To answer the question straight forward, and despite being a hardcore fanatic of aircooled engines for 20 years, NO I do not think that even in 50 years, the techonological advances will make the aircooled 2V engines any more efficient than the currently available Porsche watercooled engines... dream on
You make me sound like an evil person. Reality is I am not filtering any information whatsoever, this cr@p takes so much time that this is not fun at all and I have better things to do.
The GTO debate honestly does not interest me and it is not because it proves me wrong at all. Please
To answer the question straight forward, and despite being a hardcore fanatic of aircooled engines for 20 years, NO I do not think that even in 50 years, the techonological advances will make the aircooled 2V engines any more efficient than the currently available Porsche watercooled engines... dream on
It has not been my intention to portray you as an evil person since I respect you as both an intelligent person and a good debater....you brought the concept of BMEP and accompanying data to this discussion which I feel has proved a very meaningful way to analyse and discuss engine performance.
I am also not aiming to waste time. The GTO example was meant as a means to transparently project 2Valve BMEP potential on to a 3.8 liter Porsche engine.
Not aimed at proving you wrong but inviting you to look at things from a different perspective (and perhaps change your standpoint)...a perspective that I feel is a very valid one.
Since you seem to feel this perspective is irrelevant to consider I think we agree to disagree on this matter.
As for the 9M calculated BMEP of 195 being higher than the 206 of the current GT3, I don't know how we can not be in agreement that the GT3 has 6% higher BMEP.
Rgds,
Harald
10-07-2011, 11:02 AM
#93
Harald,
Larger injectors DO NOT bump BMEP and do NOT impact torque, only if the engine has fuel starvation and not enough fuel, but that is already factored in the combustion process!! Exhaust hardly gets you a fraction of a percentage gain on BMEP!! CUP and RSR cars have free flow with a hoooost of other improvement to breathing, cams, valves and breathing, and cannot get much better BMEP than street GT3 engines. Compression does not yield linear increase in BMEP but only a fraction again, there are several examples here on the graph to show it.
You said it yourself, Colin's dyno is optimisitic vs the factory numbers, by about 12-13%, that IMO is totally unacceptable. So that absolute number error has been established, and when Colin shows a dyno of 350lbs of torque, in reality it is more like 320lbs Porsche factory numbers... This needs to be understood by customers and forum readers. Then remains the comparability with other engines on the same dyno..... let's see..
You try to rationalize a BMEP improvement of 12-13% on the engine posted on this thread....However if you check my previous post for the changes between the 3.2 and the 3.6 engine that were needed for an increase of 14% or so in BMEP, radical changes going TWIN PLUG, in cooling, components, engine electronics, heads and displacement increase of 12.5%, compression, and so much more, and you seriously want to compare those changes done by the factory to what the STOCK engine (meaning unopened) 993 9M discussed here had done to it to achieve almost similar results?
Larger injectors DO NOT bump BMEP and do NOT impact torque, only if the engine has fuel starvation and not enough fuel, but that is already factored in the combustion process!! Exhaust hardly gets you a fraction of a percentage gain on BMEP!! CUP and RSR cars have free flow with a hoooost of other improvement to breathing, cams, valves and breathing, and cannot get much better BMEP than street GT3 engines. Compression does not yield linear increase in BMEP but only a fraction again, there are several examples here on the graph to show it.
You said it yourself, Colin's dyno is optimisitic vs the factory numbers, by about 12-13%, that IMO is totally unacceptable. So that absolute number error has been established, and when Colin shows a dyno of 350lbs of torque, in reality it is more like 320lbs Porsche factory numbers... This needs to be understood by customers and forum readers. Then remains the comparability with other engines on the same dyno..... let's see..
You try to rationalize a BMEP improvement of 12-13% on the engine posted on this thread....However if you check my previous post for the changes between the 3.2 and the 3.6 engine that were needed for an increase of 14% or so in BMEP, radical changes going TWIN PLUG, in cooling, components, engine electronics, heads and displacement increase of 12.5%, compression, and so much more, and you seriously want to compare those changes done by the factory to what the STOCK engine (meaning unopened) 993 9M discussed here had done to it to achieve almost similar results?
Jean,
The larger injectors do not impact torque through higher volume but through their shorter pulsewidth and more modern design leading to greater efficiency, as also argumented by Colin in much greater detail.
I calculate the effect of compression on torque with an equation to the 0.4 power which stems from this book: . If you have a better way please let me know....
Exhausts do not impact BMEP? Can we agree that exhausts (especially catless) can have a very measurable effect on top end power? Since power = torque X revs ----> torque is increased. The question is how much of this torque can be found in the lower than max power rev range where max torque is found to calculate BMEP. I've used Akrapovic exhaust GT3 dyno sheets to derive at my estimate of 2%.....
....BTW 964 cup cars ran cats as far as I'm aware, they even ran HJS Metalkat sponsoring on the sills.
"You try to rationalize a BMEP improvement of 12-13% on the engine posted on this thread....However if you check my previous post for the changes between the 3.2 and the 3.6 engine that were needed for an increase of 14% or so in BMEP, radical changes and you seriously want to compare those changes done by the factory to what the STOCK engine (meaning unopened) 993 9M discussed here had done to it to achieve almost similar results?"
Yes I want to indeed since this is what the 9M dyno shows in comparison whether measuring HP/NM or Banana's / Curley Wurley's. As for radical changes being necessary:
*going TWIN PLUG ---- Colin has posted 993 dyno comparisons with one plug bank disconnected. Twin plug is shown to be worth 2.25% max torque
*in cooling --- I honestly don't know the effect on 964 head temps and/or HP/TQ
*components --- see comments on following points
*engine electronics --- if this includes actual mapping then yes.
*heads --- also a function of displacement increase, the heads at least need to flow 12.5% more to match HP/liter level and not strangulate the engine. I have no flow bench data so can not comment other than the 964 is at a slightly lower (69) HP/liter level than the 3.2 (72). Breathing seems to be unimproved upon in relative terms. Higher port velocity and tumble/swirl might benefit BMEP in the max torque rev range.
*displacement increase of 12.5% --- zero influence since displacement is integral part of BMEP calculation.
*compression --- 11.3 vs. 10.3 is worth 3.75% BMEP
*and so much more --- can’t comment;-)
This brings us the following:
*3.2 ---> 3.6 = +14% BMEP
* adjusted for compression = 10,25%
* adjusted for twin plugs = 8%
* adjusted for cooling = unknown to me, assume 7%
*adjusted for inlet/heads/cams/exhaust = unknown to me
* adjusted for Ecu and mapping = 0%
Since the 964's evolved breathing doesn't yield higher HP/liter levels , a different Ecu and mapping seems to yield 7% torque in Porsches hands. Or a further 5% when using RS mapping = 12% in total.
Hmmm, now where have I heard this number before ?
Anyway, let's just agree to disagree on this matter as well.
Rgds,
Harald
10-07-2011, 12:32 PM
#94
Harald,
You're spot-on mate, well done.
The first 3.8 engine we built for Singer was assembled in NY and was trucked to Conneticut by me and Geoffrey to run on a known conservative DTA engine dyno. In view that we had a small issue that required the impromptu resetting of the cam timing we were delighted with the result at 392hp, a number which the shop owner owner himself expressed surprise at. It was the most powerful aircooled 911 engine he had tested, and that was on 94 octane pump fuel in a dyno cell which peaked at 35C.
The second engine was assembled at 9m and with the benefit if using my digital electronic camshaft setting rig my feeling is that it was a slightly more responsive & powerful motor than the first.
You're spot-on mate, well done.
The first 3.8 engine we built for Singer was assembled in NY and was trucked to Conneticut by me and Geoffrey to run on a known conservative DTA engine dyno. In view that we had a small issue that required the impromptu resetting of the cam timing we were delighted with the result at 392hp, a number which the shop owner owner himself expressed surprise at. It was the most powerful aircooled 911 engine he had tested, and that was on 94 octane pump fuel in a dyno cell which peaked at 35C.
The second engine was assembled at 9m and with the benefit if using my digital electronic camshaft setting rig my feeling is that it was a slightly more responsive & powerful motor than the first.
If necessary I can help get more info....
Rgds,
Harald
10-08-2011, 06:57 PM
#95
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Colin, thanks for sharing your knowledge on the theory of combustion and efficiency, you are a good writer for sure.
I am sure Geoffrey must have shared with you the excellent essay about BMEP that was also published sometime back in Race Technology. Good reading and one that, if I recall correctly highlights the difficulty of improving BMEP even marginally.
From these last posts, I believe it has been acknowledged that your dyno is optimistic in the order of 12-13% (guesstimate) in absolute terms, i.e. when your dyno reads 340lbs. of torque, the Porsche equivalent would be around 300lbs.ft of torque.
This explains why your dyno numbers on a “relatively” simple setup like the one we are discussing here, exceed any other aircooled racing or street N/A the factory has ever built or that I know of at least. Your Dyno reading translates to a 199 BMEP. I do realize now that this number out of the dyno is not accurate.
I was comparing your 993NVR to Factory numbers for the 996 GT3, 997 Carrera and 996 Cup, as it should be in my opinion given that it is the best benchmark.
I believe my initial question that opened this debate has been therefore answered, dyno numbers posted are inaccurate, at least on an absolute basis.
Then you mentioned that the dyno can be used as an accurate tool to measure the delta between a base run and a run post-mods. It might be, none of us knows for sure, however, I still maintain that gaining 12-13% BMEP from the changes that you performed cannot be supported, and I base my point on the fact that radical engine changes had to be done by the factory to produce similar results when they moved from the 3.2 Carrera to the 3.6 964, and then from aircooled 2V to watercooled 4V, but at this stage let each one have their own informed opinion as it has become too repetitive.
Let’s not forget that it has been seen on this forum, that on the same dyno and following the same methodology, a reknown UK tuner showed a base stock engine values that measured similar to the factory on his dyno, yet once the engine had the MAF, exhaust and ECU mapping modified, the TQ numbers become totally unrealistic and inaccurate by a huge margin. Since the UK tuner in question had used the same methodology for both runs, h defended his numbers tooth and nail, however evidence ended up taking over and he finally acknowledged that his readings must have been wrong.. I am not saying it is the case here, but ther eis a chance it could be
I am sure Geoffrey must have shared with you the excellent essay about BMEP that was also published sometime back in Race Technology. Good reading and one that, if I recall correctly highlights the difficulty of improving BMEP even marginally.
From these last posts, I believe it has been acknowledged that your dyno is optimistic in the order of 12-13% (guesstimate) in absolute terms, i.e. when your dyno reads 340lbs. of torque, the Porsche equivalent would be around 300lbs.ft of torque.
This explains why your dyno numbers on a “relatively” simple setup like the one we are discussing here, exceed any other aircooled racing or street N/A the factory has ever built or that I know of at least. Your Dyno reading translates to a 199 BMEP. I do realize now that this number out of the dyno is not accurate.
I believe my initial question that opened this debate has been therefore answered, dyno numbers posted are inaccurate, at least on an absolute basis.
Then you mentioned that the dyno can be used as an accurate tool to measure the delta between a base run and a run post-mods. It might be, none of us knows for sure, however, I still maintain that gaining 12-13% BMEP from the changes that you performed cannot be supported, and I base my point on the fact that radical engine changes had to be done by the factory to produce similar results when they moved from the 3.2 Carrera to the 3.6 964, and then from aircooled 2V to watercooled 4V, but at this stage let each one have their own informed opinion as it has become too repetitive.
Let’s not forget that it has been seen on this forum, that on the same dyno and following the same methodology, a reknown UK tuner showed a base stock engine values that measured similar to the factory on his dyno, yet once the engine had the MAF, exhaust and ECU mapping modified, the TQ numbers become totally unrealistic and inaccurate by a huge margin. Since the UK tuner in question had used the same methodology for both runs, h defended his numbers tooth and nail, however evidence ended up taking over and he finally acknowledged that his readings must have been wrong.. I am not saying it is the case here, but ther eis a chance it could be
10-08-2011, 07:11 PM
#96
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Two distinct questions here, let’s separate them..
1- Can optimized timing impact torque?..definitely YES. Does it impact BMEP..YES as well, but to a lesser extent probably, given that timing optimization can give you a broader torque band, but not necessarily better peak torque, which is where BMEP is being calculated.
2- Do injectors impact torque? Yes they “ might” under a set of circumstances.. However, in this case, and this engine, larger injectors will NOT impact max. BMEP..Here is why..
Let me disregard the “better atomization” adjective, I consider all new Bosch high performance injectors to be optimized at least for any street usage and 99.99% of modified engines.. At least grant me this one.
Your Max BMEP is not impacted by larger injectors since your injector duty cycle is nowhere near its peak. Even if, for argument sakes, we take the numbers that the 9M dyno gives us, what is the amount of fuel required by the engine at peak torque?
Fuel consumed at peak torque: HP@ peak TQ x BSFC ( for readers, this is the amount of fuel required by this engine to produce 1 HP/hr.)
Fuel required by the engine: 275 x 0.45 = 124 lbs of fuel/6 (cylinders)~21lbs/hr. Since the Stock 993 injectors = 44lbs/hr => You are using around 45% of the injector’s potential only.
So no, larger injectors won’t do anything to peak torque on this particular engine, you simply do not need them. Sure we can start the debate of flow optimization etc.. but while it all sounds very sexy, that is 1- not measurable hence subjective, and 2- no matter what, the best injectors in the world would have an irrelevant impact on max BMEP on an engine like this one being discussed.. Notice I am not saying torque
In fact, worse yet, larger injectors can be detrimental to an optimum combustion and erratic idle.
What is amazing is that if instead of looking at this from a BMEP angle, if you calculate the Volumetric efficiency for this 993NVR engine, you will see that according to your dyno, you are reaching VE’s of above 100% from 4k RPMs onwards… reaching almost 115%...
And that’s for an engine without any sort of breathing improvements except a MAF conversion to MAP.If I recall correctly, F1 engines have a VE of around 120+...
10-10-2011, 09:29 PM
#97
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Hi Jean,
It has not been my intention to portray you as an evil person since I respect you as both an intelligent person and a good debater....you brought the concept of BMEP and accompanying data to this discussion which I feel has proved a very meaningful way to analyse and discuss engine performance.
I am also not aiming to waste time. The GTO example was meant as a means to transparently project 2Valve BMEP potential on to a 3.8 liter Porsche engine.
Not aimed at proving you wrong but inviting you to look at things from a different perspective (and perhaps change your standpoint)...a perspective that I feel is a very valid one.
Since you seem to feel this perspective is irrelevant to consider I think we agree to disagree on this matter.
As for the 9M calculated BMEP of 195 being higher than the 206 of the current GT3, I don't know how we can not be in agreement that the GT3 has 6% higher BMEP.
Rgds,
Harald
It has not been my intention to portray you as an evil person since I respect you as both an intelligent person and a good debater....you brought the concept of BMEP and accompanying data to this discussion which I feel has proved a very meaningful way to analyse and discuss engine performance.
I am also not aiming to waste time. The GTO example was meant as a means to transparently project 2Valve BMEP potential on to a 3.8 liter Porsche engine.
Not aimed at proving you wrong but inviting you to look at things from a different perspective (and perhaps change your standpoint)...a perspective that I feel is a very valid one.
Since you seem to feel this perspective is irrelevant to consider I think we agree to disagree on this matter.
As for the 9M calculated BMEP of 195 being higher than the 206 of the current GT3, I don't know how we can not be in agreement that the GT3 has 6% higher BMEP.
Rgds,
Harald
Harald,
This evening I managed to locate the measurement data from the certified DTA engine dyno run of the first Singer engine that me and Geoffrey assembled and tested. Measured to SAE J607 standards at BAP 29.38", 83F intake & 36% RH and running on 93 octane US pump fuel the engine produces a peak of 310.56lbft at 5500rpm. Since the SAE to DIN conversion is approximately x1.014 the measured DIN torque of this 3.82 litre engine is approximately 315lbft.
Since BMEP = 150.8xTq/ci displacement, the actual BMEP of this engine is 203.8psi, i.e. a difference of just 1% to the quoted specification of the current GT3. Given that we usually run these engines on Shell V-Power and in more optimal conditions than a heat soaked dyno cell, I think that is a very credible result for the aircooled 9m 3.82 Race engine. Well, I'm proud of it anyway!
Now, to save you looking it up, here is the comparison that I quoted earlier from the results of tests on the 9m chassis dyno:
9m engine records 431hp @ 7300, GT3 408hp at the same rpm.
9m engine records 466Nm (343.7lbft) at 5425rpm peak, GT3 records 440Nm (324.5lbft) at 4809rpm peak.
Specific torque of GT3 engine is 324.5/3.6 = 90.14lbft/litre
Specific torque of 9m engine is 343.7/3.82 = 89.97lbft/litre
The difference between the Singer engine and the GT3 is less than 1%.
This result tells me that nomatter whether you measure the 9m engine on an engine dyno & compare to Porsche measured GT3 data or measure it on the 9m chassis dyno & compare it to identically tested GT3 data, the comparative results correlate within 1%.
10-11-2011, 06:18 AM
#98
Colin,
I think you're rightly proud!!!
The reason for pointing you towards the engine dyno is the fact that it runs familiar to you Dynostar Software, and might save time in engine developments / testing and gives added flexibility not having to 'test mount' engines in your own car to be able to run it up the rollers. That is of course if you have the space available....
I agree with you that the 9M rolling dyno is a great development tool in itself, furthermore I'm convinced that the comparative readings it provides are very accurate and allow valid assessments of % increases in performance......
.....just like you have always stated, I might add.
Furthermore I believe this thread contains more scientific formula's, raw data and hypotheses reviewed from differing angles than anyone might care for to make up their own mind on the subject....
I've made up my mind for sure, to end on a spiritual level in my mind the following two quotes to me sum it all up:
"Progress is impossible without change, and those who cannot change their minds cannot change anything." George Bernard Shaw
"The world of engine tuning is littered with opinion of what works and what not, I don't have an opinion....just my dyno and flow bench" David Vizard
Rgds,
Harald
I think you're rightly proud!!!
The reason for pointing you towards the engine dyno is the fact that it runs familiar to you Dynostar Software, and might save time in engine developments / testing and gives added flexibility not having to 'test mount' engines in your own car to be able to run it up the rollers. That is of course if you have the space available....
I agree with you that the 9M rolling dyno is a great development tool in itself, furthermore I'm convinced that the comparative readings it provides are very accurate and allow valid assessments of % increases in performance......
.....just like you have always stated, I might add.
Furthermore I believe this thread contains more scientific formula's, raw data and hypotheses reviewed from differing angles than anyone might care for to make up their own mind on the subject....
I've made up my mind for sure, to end on a spiritual level in my mind the following two quotes to me sum it all up:
"Progress is impossible without change, and those who cannot change their minds cannot change anything." George Bernard Shaw
"The world of engine tuning is littered with opinion of what works and what not, I don't have an opinion....just my dyno and flow bench" David Vizard
Rgds,
Harald
10-11-2011, 07:37 AM
#99
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Thanks Harald.
We have plenty of space and I'm quite interested in acquiring an engine dyno, and you are right that it would save a lot of time in development. However I am also aware that if I do get one it will tempt me back to being a engineer/geek and the business will definitely suffer as a result. Anyway, you best send a PM to let me know how much the guy wants for it....
We have plenty of space and I'm quite interested in acquiring an engine dyno, and you are right that it would save a lot of time in development. However I am also aware that if I do get one it will tempt me back to being a engineer/geek and the business will definitely suffer as a result. Anyway, you best send a PM to let me know how much the guy wants for it....
10-11-2011, 10:07 AM
#100
Nordschleife Master
Let’s not forget that it has been seen on this forum, that on the same dyno and following the same methodology, a reknown UK tuner showed a base stock engine values that measured similar to the factory on his dyno, yet once the engine had the MAF, exhaust and ECU mapping modified, the TQ numbers become totally unrealistic and inaccurate by a huge margin. Since the UK tuner in question had used the same methodology for both runs, h defended his numbers tooth and nail, however evidence ended up taking over and he finally acknowledged that his readings must have been wrong.. I am not saying it is the case here, but ther eis a chance it could be
Those asking about conversion boxes for the 993, I just built 2 of them (One race car and one street car) and due to the changes between the 964 Motronic and 993 Motronic, it makes the box much more complicated to build. The nice thing about the 993 though, is that we can use the MAF to meter fuel with the MoTeC, but it requires the 993 MAF to be sent out to have a calibration table built for it.
10-11-2011, 08:45 PM
#101
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Are the readings between MAF sensors that different? How far out-of-spec are we talking? (just curious)
10-12-2011, 10:05 AM
#102
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MAF sensors each have their own calibration. There is a different calibration between the 993 and 993TT. MAFs within each series have the same basic calibration subject to minor electrical differences. Once a calibration is determined for a particular part number, it can be used for any of the MAFs with that part number.
11-13-2011, 03:41 PM
#103
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Hi Colin. Hope you are well.
I have now resolved the idle issue by getting the car idle tuned closed loop (PID) as you described. It settles now to 950 rpm rock steady unloaded warm and never hunts or undershoots/stalls etc. Very happy with that. Even with a/c load or lights it hardly moves. The fuel maps needed some attention, some extra resolution added to those and the ignition maps. I replaced the ISV with new as a precaution (although it wasn't necessary).
Theres a small amount of "bunny hopping" in 2nd and 3rd gear on light throttle applications like in traffic but I think we can tune that out but adjusting rpm and tps% lockouts for idle and maybe some other tables...maybe you have some ideas for that?
Anyway Big Thanks for your help.....
Onto my actual question. Im just checking the resonnance flap settings on my ECU. I wondered if you could confirm the setting you use? It seems I have it set to do something between 3000 and 5500 rpm and 60% TPS for flap closed. I want my tuner to make sure its set up properly so would value your input. Car is 1994 NVR manifold. Is it open full stop from a certain rpm or does it open between a range and does it need to be reliant on TPS% or just any throttle setting?
Last question (promise). Do you dyno in 5th gear on your roller type dyno?
Thanks in advance. Almost there, we even managed to get a little more power and torque out of the latest tune, but most importantly of all the idle is now better than motronic was with these cams and LWFC - its very good!
Cheers
I have now resolved the idle issue by getting the car idle tuned closed loop (PID) as you described. It settles now to 950 rpm rock steady unloaded warm and never hunts or undershoots/stalls etc. Very happy with that. Even with a/c load or lights it hardly moves. The fuel maps needed some attention, some extra resolution added to those and the ignition maps. I replaced the ISV with new as a precaution (although it wasn't necessary).
Theres a small amount of "bunny hopping" in 2nd and 3rd gear on light throttle applications like in traffic but I think we can tune that out but adjusting rpm and tps% lockouts for idle and maybe some other tables...maybe you have some ideas for that?
Anyway Big Thanks for your help.....
Onto my actual question. Im just checking the resonnance flap settings on my ECU. I wondered if you could confirm the setting you use? It seems I have it set to do something between 3000 and 5500 rpm and 60% TPS for flap closed. I want my tuner to make sure its set up properly so would value your input. Car is 1994 NVR manifold. Is it open full stop from a certain rpm or does it open between a range and does it need to be reliant on TPS% or just any throttle setting?
Last question (promise). Do you dyno in 5th gear on your roller type dyno?
Thanks in advance. Almost there, we even managed to get a little more power and torque out of the latest tune, but most importantly of all the idle is now better than motronic was with these cams and LWFC - its very good!
Cheers
11-14-2011, 05:58 AM
#104
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I'm still taking all that life can throw at me and coming back for more, so I guess that means I'm good! Thanks for asking.
It's really tricky setting these things up from first principles, so glad my numbers came in useful. One aspect seldom factored in to the cost of an ecu is the time taken to programme it, so whilst the Motec M48 & M84 conversions are not inexpensive you will get the benefit of our experience with the start file that we use having idle control & the like pretty much nailed - which will more than compensate paying another tuner for the time required for them to work it all out for you from scratch.
Hunting (or bunny hopping as you call it) is caused by having too large an ignition advance difference between rpm sites or similar sudden changes in fuel numbers between sites. Typically this occurs from 1500 to 2500rpm & from 5% to 20% throttle. The easy solution is to smooth out the transitions in these areas of the main fuel & ignition tables.
It's a pleasure, I'm always glad to pay it forward.
It's just a shame that too many other so called "experts" cannot do the same.....
The resonance flap settings vary according to the tune of the engine, but on a standard 964 or nVr 993 the flap is tuned to open around 5500rpm at full throttle. What you need to do is dyno the engine with the flap closed, then do it again with it open. The open setting will make more top end power and lose midrange, so the actuation point is simply the cross-over point of the two power curves. On a stock engine the gain is around 25hp at 6000rpm with the flap open.
On some engines that have a higher rpm limit than stock you may actually see a slight advantage to closing the valve again somewhere after 7000rpm, but since the difference is minimal this is not something I would overly be concerned about.
Once set don't forget to re-check the fuel and ignition timing requirements because they will be different with the flap working correctly.
I usually test in 5th but with additional load on the rollers to limit the acceleration rate of the wheels.
As mentioned previously, some customers have bought a 9m Motec upgrade for their 964's purely on the ability of the system to idle the engine correctly. The proof of the pudding for us is to drive the car on the idle map up through the gears - my 993 engined 911 will pull 4th up a slight incline at zero throttle. Now that's a strong idle....
I have now resolved the idle issue by getting the car idle tuned closed loop (PID) as you described. It settles now to 950 rpm rock steady unloaded warm and never hunts or undershoots/stalls etc. Very happy with that. Even with a/c load or lights it hardly moves. The fuel maps needed some attention, some extra resolution added to those and the ignition maps. I replaced the ISV with new as a precaution (although it wasn't necessary).
It's a pleasure, I'm always glad to pay it forward.
It's just a shame that too many other so called "experts" cannot do the same.....
Onto my actual question. Im just checking the resonnance flap settings on my ECU. I wondered if you could confirm the setting you use? It seems I have it set to do something between 3000 and 5500 rpm and 60% TPS for flap closed. I want my tuner to make sure its set up properly so would value your input. Car is 1994 NVR manifold. Is it open full stop from a certain rpm or does it open between a range and does it need to be reliant on TPS% or just any throttle setting?
On some engines that have a higher rpm limit than stock you may actually see a slight advantage to closing the valve again somewhere after 7000rpm, but since the difference is minimal this is not something I would overly be concerned about.
Once set don't forget to re-check the fuel and ignition timing requirements because they will be different with the flap working correctly.
Last question (promise). Do you dyno in 5th gear on your roller type dyno?
Thanks in advance. Almost there, we even managed to get a little more power and torque out of the latest tune, but most importantly of all the idle is now better than motronic was with these cams and LWFC - its very good!
Cheers
Thanks in advance. Almost there, we even managed to get a little more power and torque out of the latest tune, but most importantly of all the idle is now better than motronic was with these cams and LWFC - its very good!
Cheers
As mentioned previously, some customers have bought a 9m Motec upgrade for their 964's purely on the ability of the system to idle the engine correctly. The proof of the pudding for us is to drive the car on the idle map up through the gears - my 993 engined 911 will pull 4th up a slight incline at zero throttle. Now that's a strong idle....
11-14-2011, 06:16 AM
#105
Rennlist Member
Colin,
I would like to thank you for helping me as well. Last week we were finally able to start my 993 with the Motec. The problem we had was that in the configuration file I got from you, there was a MAP correction of -100 in the last row of the file. I don't know why it was there but once we corrected that, the engine fired up right away and idled perfectly!!
Tomorrow we will redo the fuel and ignition maps on a dyno but it is so much easier to fine tune the existing maps I got from you vs. starting from a scratch.
I also ordered the TPC superhcarger kit (without the additional injectors and electronics) last week and will do the install this winter. Can't wait to see the results! This I consider stage I.
Stage II will be a crate 3.8vr3++ engine from you but I first need to figure out how to deal with the yearly smog testing...
I would like to thank you for helping me as well. Last week we were finally able to start my 993 with the Motec. The problem we had was that in the configuration file I got from you, there was a MAP correction of -100 in the last row of the file. I don't know why it was there but once we corrected that, the engine fired up right away and idled perfectly!!
Tomorrow we will redo the fuel and ignition maps on a dyno but it is so much easier to fine tune the existing maps I got from you vs. starting from a scratch.
I also ordered the TPC superhcarger kit (without the additional injectors and electronics) last week and will do the install this winter. Can't wait to see the results! This I consider stage I.
Stage II will be a crate 3.8vr3++ engine from you but I first need to figure out how to deal with the yearly smog testing...