Omex 710 controlling VVT on ST 170 engine
Discussion
We have been testing a Westfield fitted with an Omex 710 controlling VVT on an ST 170 engine for Karl and Oli at Norris Motorsport, which I understand is a first for controlling the VVT by a programmable map. It is also a first for us seeing the effects of split cam timing. Previously we have just altered cams a little each way on a few twin cams and on many more Pinto engines to achieve best torque, best power or a best of both worlds setting.
We were impressed how fast we could do testing of cam timing variations, one and a half hours start to finish, including tea, coffee and hot chocolate breaks.
I know Karl worked hand in hand with Omex to sort it including an NMS sensor for the loop control. I have asked Karl to jot down the relevant details so I can post them on PH as ‘new fangled’ stuff is beyond me
The graph is rather busy but I will ascribe each line from lowest reading on right hand of scale to cam timing setting.
Line 1, blue, Ford original cam timing, 145 at wheels, 30 recorded coastdown losses, 175 guesstimate at flywheel; very conservative timing for emissions?
Line 2, yellow, 100 degrees timing flat, max wheel power 157.
Line 3, brown, 105 flat timing, 159 max wheel power.
Line 4, pink, 115 flat timing, 160 max wheel power.
Line 5, tourquoise, 110 flat timing, max wheel power 162.
Line 6, red, Karl’s mapped cam timing, 163 max wheel power and best power at all rpms.
Looks like the Karl map would make a good generic base for VVT control on the ST170 engine. I am sure NMS will produce a kit in due course.
We were impressed how fast we could do testing of cam timing variations, one and a half hours start to finish, including tea, coffee and hot chocolate breaks.
I know Karl worked hand in hand with Omex to sort it including an NMS sensor for the loop control. I have asked Karl to jot down the relevant details so I can post them on PH as ‘new fangled’ stuff is beyond me
The graph is rather busy but I will ascribe each line from lowest reading on right hand of scale to cam timing setting.
Line 1, blue, Ford original cam timing, 145 at wheels, 30 recorded coastdown losses, 175 guesstimate at flywheel; very conservative timing for emissions?
Line 2, yellow, 100 degrees timing flat, max wheel power 157.
Line 3, brown, 105 flat timing, 159 max wheel power.
Line 4, pink, 115 flat timing, 160 max wheel power.
Line 5, tourquoise, 110 flat timing, max wheel power 162.
Line 6, red, Karl’s mapped cam timing, 163 max wheel power and best power at all rpms.
Looks like the Karl map would make a good generic base for VVT control on the ST170 engine. I am sure NMS will produce a kit in due course.
Sounds like your record is stuck Dave. The figures are taken direct from software with no massaging except a level of smoothing. The figures are for comparison and that they do that very well on a like for like basis.
It is obvious to everyone that if you put your money where your ego is and had a rolling road or an engine dyno it would be the best in the world and super accurate, sadly you don't or you could do some research and put up some PH original posts rather than just attacking mine or harking back to your good old days with rose tinted spectacles or being a legend in your own mind.
It is obvious to everyone that if you put your money where your ego is and had a rolling road or an engine dyno it would be the best in the world and super accurate, sadly you don't or you could do some research and put up some PH original posts rather than just attacking mine or harking back to your good old days with rose tinted spectacles or being a legend in your own mind.
I don't need to buy a cow to know what a glass of milk should taste like. I don't need to buy a rolling road to see what you keep doing wrong with yours. You never input the mph/1000 rpm correctly which is why your power figures peak too low and your torque ones are too high. But you're clearly not educatable anymore.
2 solutions....
Do as the yanks do, and post power vs speed graphs, instead of rpm.
Or just use an rpm pickup ?
But to a degree it does detract from the point of Peter's post which regardless of numbers shows improvements from cam timing adjustments, which can easily be made with variable valve timing
Do as the yanks do, and post power vs speed graphs, instead of rpm.
Or just use an rpm pickup ?
But to a degree it does detract from the point of Peter's post which regardless of numbers shows improvements from cam timing adjustments, which can easily be made with variable valve timing
stevieturbo said:
2 solutions....
It's hardly rocket science to get the rpm right. Run the car at X000 rpm, press a button and the dyno knows the speed / rpm calibration. The only way I can see to get it as badly wrong as this all the time is to set the calibration in one gear and then run it in another. If you set it in say 4th at 20 mph/ 1000 rpm and then run it in 3rd at say 15 mph / 1000 rpm the dyno thinks the rpm is only 3/4 of what it really is and calculates the torque 33% high. But that should become blindingly obvious even to a newbie operator when a 7000 rpm engine peaks at 5250 and has 90 ft lbs at the wheels.Stevie, if folk prefer I will happily save graphs for PH as bhp/torque vs speed.
Dave, if you didn't fall out with the world including myself you would always be welcome to play on the rollers, see how we set rpm vs speed for yourself. The dyno and software have not been messed with since installation. The inertia calibration does not change unless the rollers get significantly lighter or heavier or the bearings seize up; that is an inherent beauty with inertia testing. On the minus side to you, lighten the rotating mass and we record higher bhp, thus improvement is reflected in acceleration improvement on the road or track. It is not the same type of measurement as pau roller testing but you do not seem to be willing to embrace it, just pooh pooh it. As for max rpm power, we have always seen about 500 rpm less at wheels than quoted max rpm power from factory, I put this down to the fact increasing tyre losses hide the engine peak at the wheels.
Dave, if you didn't fall out with the world including myself you would always be welcome to play on the rollers, see how we set rpm vs speed for yourself. The dyno and software have not been messed with since installation. The inertia calibration does not change unless the rollers get significantly lighter or heavier or the bearings seize up; that is an inherent beauty with inertia testing. On the minus side to you, lighten the rotating mass and we record higher bhp, thus improvement is reflected in acceleration improvement on the road or track. It is not the same type of measurement as pau roller testing but you do not seem to be willing to embrace it, just pooh pooh it. As for max rpm power, we have always seen about 500 rpm less at wheels than quoted max rpm power from factory, I put this down to the fact increasing tyre losses hide the engine peak at the wheels.
PeterBurgess said:
Stevie, if folk prefer I will happily save graphs for PH as bhp/torque vs speed.
Dave, if you didn't fall out with the world including myself you would always be welcome to play on the rollers, see how we set rpm vs speed for yourself. The dyno and software have not been messed with since installation. The inertia calibration does not change unless the rollers get significantly lighter or heavier or the bearings seize up; that is an inherent beauty with inertia testing. On the minus side to you, lighten the rotating mass and we record higher bhp, thus improvement is reflected in acceleration improvement on the road or track. It is not the same type of measurement as pau roller testing but you do not seem to be willing to embrace it, just pooh pooh it. As for max rpm power, we have always seen about 500 rpm less at wheels than quoted max rpm power from factory, I put this down to the fact increasing tyre losses hide the engine peak at the wheels.
I don't prefer...but then he couldnt complain about rpm being wrong lol.Dave, if you didn't fall out with the world including myself you would always be welcome to play on the rollers, see how we set rpm vs speed for yourself. The dyno and software have not been messed with since installation. The inertia calibration does not change unless the rollers get significantly lighter or heavier or the bearings seize up; that is an inherent beauty with inertia testing. On the minus side to you, lighten the rotating mass and we record higher bhp, thus improvement is reflected in acceleration improvement on the road or track. It is not the same type of measurement as pau roller testing but you do not seem to be willing to embrace it, just pooh pooh it. As for max rpm power, we have always seen about 500 rpm less at wheels than quoted max rpm power from factory, I put this down to the fact increasing tyre losses hide the engine peak at the wheels.
I wonder if showing speed vs power is a throwback to the old Clayton rollers Stateside when the gauges gave power and speed with no data captured for printing unless written down mandraulically.
It would be nice to be able to chat about rolling roads, warts and all so we can all understand how the different ones 'work'. For instance, Dave rates the Dastek rolling road as it gives what he believes are the best flywheel figures, he also goes on to say the dyno was moved and never read the same again, it doesn't add up but it is a fact of life of running rolling roads. We have become converts of the simplest measurements we can get with minimal pau interference.
Back on topic, Oli will give Karl a reminder to spill the beans about controlling the vvt. As I have written before, I can feel the claws of evolution closing around my throat
It would be nice to be able to chat about rolling roads, warts and all so we can all understand how the different ones 'work'. For instance, Dave rates the Dastek rolling road as it gives what he believes are the best flywheel figures, he also goes on to say the dyno was moved and never read the same again, it doesn't add up but it is a fact of life of running rolling roads. We have become converts of the simplest measurements we can get with minimal pau interference.
Back on topic, Oli will give Karl a reminder to spill the beans about controlling the vvt. As I have written before, I can feel the claws of evolution closing around my throat
PeterBurgess said:
Dave, if you didn't fall out with the world including myself
I wasn't aware you now thought you spoke for the entire planet Peter but that's another psychological issue of yours you can look into in your own time and perhaps with professional help. However confining things to yourself, you are, and always have been, unable to take any constructive comment without flying into a paranoid defensive rage and launching ad hominem attacks. You and Donald Trump would get on well I think.Here's an interesting article on ecu control of the ST170 VVT system with graphs showing where these engines do actually produce peak power, and how much of it, on a proper Dyno Dynamics set of rollers.
https://motorsport-electronics.co.uk/tech-st170vvt...
Note how he says the standard ones only show about 150 bhp flywheel which ties in with my own findings (maybe mid 150s) and also Rototest hub dyno figures. Depending on cam timing peak power is anywhere between 6250 and 7000 rpm. Peak flywheel torque is about 135 to 137 ft lbs. It should be apparent to anyone that 180 ft lbs at the f'ing wheels, and peak power at 5250 is ludicrous.
The Rototest site seems to be down atm but they obtained 145 bhp at the hubs (156 flywheel with the 0.93 correction factor) and 128 hub ft lbs (138 flywheel ft lbs) so very much in line. Peak power at the hubs was at 6,500 and peak torque at 3,000.
stevieturbo said:
I don't prefer...but then he couldnt complain about rpm being wrong lol.
The rpm is a symptom but the actual problem is ridiculously inflated torque per litre. Graphs of power vs speed only are meaningless because in that case torque can't even be calculated. No one would want printouts like that. Rpm, and correct rpm of course, is essential.Yea, not really sure why the yanks do it. Whether they cant be bothered with an rpm pickup, or it's to do with them silly automatic transmissions, or whatever. But it is quite common in the US.
Occasionally in Oz too, but not so much. And it is bloody annoying as the graphs dont make a lot of sense.
Occasionally in Oz too, but not so much. And it is bloody annoying as the graphs dont make a lot of sense.
With US in mind it got me thinking about V8 stuff, it is ironical that a lot of people have come in for rolling road tuning with tuned V8s who reckon my rolling roads have always been low! The most memorable one to me was an Rover V8 engined car which had been assembled with all the std parts which, according to the owner were selected to give the best bhp, it showed (manual box) around 130 at the wheels on my old Clayton, he claimed this was well over 200 at the flyhweel. I put my SD1 Vitesse on which had a mild cam and a nice pair of heads, this gave 180 at the wheels over the std Vitesse 150 at the wheels, I reckoned that was around 210 at the engine, which he swore blind must have been 250 +!!!!
What we do find with tuned V8 US stuff is the power holds on a lot longer than a standard one but the NA ones don't often sizzle the rollers unless seriously modified which makes sense.
What we do find with tuned V8 US stuff is the power holds on a lot longer than a standard one but the NA ones don't often sizzle the rollers unless seriously modified which makes sense.
What amazes me about the motorsport electronics graphs is that with the cam locked at 50 degrees it very closely resembles the factory power and only loses out 4hp at the top end. I know every little helps, but this surprisingly low gain from the VVT really makes me wonder why the bothered, unless the gains in economy / emissions are what they were really interested in ?
It also begs the question that if swinging the inlet cam makes such small gains, what does any exhaust cam timing changes do?
It's going to lead me on to another new topic ..
It also begs the question that if swinging the inlet cam makes such small gains, what does any exhaust cam timing changes do?
It's going to lead me on to another new topic ..
Just a quick update about the development of the Omex unit. The important part of what Guy and Karl have worked on is the fact they have made it closed loop so the inlet cam stays where it has been told to be.
Guy at Omex had been working on the closed loop system for a year or so. Karl provided the hardware in the form of a Hall effect sensor picking up the five pegs in the cam to control the PWM regardless of oil pressure variations or cam belt vibrations/pulses etc.
I understand the controlling of the fuelling, timing and vvt tends to be very poor in the standard set up making many of the 170s show poor power compared to what they should show. The ST170 we ran for Karl was on throttle bodies and a special ex manifold and system.
Guy at Omex had been working on the closed loop system for a year or so. Karl provided the hardware in the form of a Hall effect sensor picking up the five pegs in the cam to control the PWM regardless of oil pressure variations or cam belt vibrations/pulses etc.
I understand the controlling of the fuelling, timing and vvt tends to be very poor in the standard set up making many of the 170s show poor power compared to what they should show. The ST170 we ran for Karl was on throttle bodies and a special ex manifold and system.
Edited by PeterBurgess on Monday 10th December 14:48
spitfire4v8 said:
What amazes me about the motorsport electronics graphs is that with the cam locked at 50 degrees it very closely resembles the factory power and only loses out 4hp at the top end
4 bhp out of 150 is 2.7% not to be sniffed at on an N/A engine.Also, do any of these curves have a standard engine intake and exhaust fitted? ie std inlet manifold and manifold / catalyst etc? If not then the intake ram and EBP will likely render the OE settings null and void.
PeterBurgess said:
We have been testing a Westfield fitted with an Omex 710 controlling VVT on an ST 170 engine for Karl and Oli at Norris Motorsport, which I understand is a first for controlling the VVT by a programmable map. It is also a first for us seeing the effects of split cam timing. Previously we have just altered cams a little each way on a few twin cams and on many more Pinto engines to achieve best torque, best power or a best of both worlds setting.
We were impressed how fast we could do testing of cam timing variations, one and a half hours start to finish, including tea, coffee and hot chocolate breaks.
I know Karl worked hand in hand with Omex to sort it including an NMS sensor for the loop control. I have asked Karl to jot down the relevant details so I can post them on PH as ‘new fangled’ stuff is beyond me
The graph is rather busy but I will ascribe each line from lowest reading on right hand of scale to cam timing setting.
Line 1, blue, Ford original cam timing, 145 at wheels, 30 recorded coastdown losses, 175 guesstimate at flywheel; very conservative timing for emissions?
Line 2, yellow, 100 degrees timing flat, max wheel power 157.
Line 3, brown, 105 flat timing, 159 max wheel power.
Line 4, pink, 115 flat timing, 160 max wheel power.
Line 5, turquoise, 110 flat timing, max wheel power 162.
Line 6, red, Karl’s mapped cam timing, 163 max wheel power and best power at all rpms.
Looks like the Karl map would make a good generic base for VVT control on the ST170 engine. I am sure NMS will produce a kit in due course.
Can you explain what is going on here or is it (by your own admission) too difficult for you to understand and therefore explain? We were impressed how fast we could do testing of cam timing variations, one and a half hours start to finish, including tea, coffee and hot chocolate breaks.
I know Karl worked hand in hand with Omex to sort it including an NMS sensor for the loop control. I have asked Karl to jot down the relevant details so I can post them on PH as ‘new fangled’ stuff is beyond me
The graph is rather busy but I will ascribe each line from lowest reading on right hand of scale to cam timing setting.
Line 1, blue, Ford original cam timing, 145 at wheels, 30 recorded coastdown losses, 175 guesstimate at flywheel; very conservative timing for emissions?
Line 2, yellow, 100 degrees timing flat, max wheel power 157.
Line 3, brown, 105 flat timing, 159 max wheel power.
Line 4, pink, 115 flat timing, 160 max wheel power.
Line 5, turquoise, 110 flat timing, max wheel power 162.
Line 6, red, Karl’s mapped cam timing, 163 max wheel power and best power at all rpms.
Looks like the Karl map would make a good generic base for VVT control on the ST170 engine. I am sure NMS will produce a kit in due course.
Are these runs with VVT enabled? If so there should be a maximum low speed timing figure and a maximum high speed figure. (It will vary to anything in between the two if it's intelligent enough, but let's not go there for now).
What is the actual timing figure you've supplied? What is "115 flat timing" ? It could be either ICA or LCA, it could be either (or something else?) but if it is then It reads the wrong way around to me, the power figures should increase as the cam angle decreases (and the intake cam opens earlier), but it's the opposite way round for some reason?
I could well be wrong, but that's the way I read it with half the information missing....
The VVT was enabled on all runs.
On the lowest power run, that was Fords map. On the best power run it was Karl's map derived from the best torque at each rpm tested with the VVT holding at commanded fixed timing. The actual numbers, like 105/110/115 do not relate to anyone but Karl, but, to give you an idea Karl's final map varied the timing from 100 to 120 degrees max inlet lift ATDC in relation to crank. The important thing is the closed loop maintains the timing to whatever it has been 'told' to do.
On the lowest power run, that was Fords map. On the best power run it was Karl's map derived from the best torque at each rpm tested with the VVT holding at commanded fixed timing. The actual numbers, like 105/110/115 do not relate to anyone but Karl, but, to give you an idea Karl's final map varied the timing from 100 to 120 degrees max inlet lift ATDC in relation to crank. The important thing is the closed loop maintains the timing to whatever it has been 'told' to do.
Not an advert as far as I am concerned. Interesting to see effects of cam variation tested, it should be obvious which runs are with advance and retard even though at some point too much advance or too much retard will upset the applecart. The final figures varied from 100 to 120 degrees but not divulged specific info at each rpm. From my own viewpoint I couldn't believe how easy it was to see effects of variation of cam timing in such a short period of time it was enjoyable working on modern stuff that NMS specilaises in. I get the same buzz working on pre war stuff.....they both make a change to the norm.
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