The Vvt when fully activated will advance 60 degrees. The exhaust was retarded 5degree. I've not put my graph on, will start another post, and will try and get the graph up. But it is nice to drive, loads of low down grunt.
The Vvt when fully activated will advance 60 degrees. The exhaust was retarded 5degree. I've not put my graph on, will start another post, and will try and get the graph up. But it is nice to drive, loads of low down grunt.
"Horsepower sells cars, torque wins races" - Enzo Ferrari
It's the inlet cam that advances 60degrees, that's what the Vvt advances it to when fully on.
So why didn't ford make them produce 193hp from the factory then? They could have called it the ST190 then. That's 23hp over std on std bits. Can't see it myself.....
Also, I thought Dave walker @ emerald said he'd never seen a std ST170 actually make 170hp?
Last edited by boXXer; 12-11-2011 at 14:37.
There is some speculation that the engine was designed with more power in mind to go for the rs model that was on the go, and was de tuned for the st. Am sure ford had worked it all out. The guy who did mine also says that he not seen a focus give out the claimed 170, but then, a better flowing manifold, aftermarket ecu, cam vernier, lighter flywheel, all go towards increasing power, plenty of stock engines out there that respond well to aftermarket ecu and remapping. The st motor is a quite developed engine by ford. Bigger valves, better porting, longer duration cams, stronger bottom end. Gives better scope. It's getting more popular for a power unit every day due to the potential it has.
About the power figures they might be a little optimistic but I don't think they are miles out, the throttle bodies have got to be adding 6 to 8 bhp over a single throttle body and optimising the cam inlet + exhaust timing and proper fuel and spark tuning has to be worth a nice bit of extra hp, std engines are down tuned a little to lower emissions, where as this was tuned for best power and torque, on top of that rolling road figures can easily be off by 10bhp
Anyway peak figures don't matter, he is obviously happy with the engines performance and that's all that really matters
"Horsepower sells cars, torque wins races" - Enzo Ferrari
You're right, 60 was too much, hence only getting to near 170bhp. It now advances mid 40ish degrees max, and have gained a steady 20+ bhp all round. Guess it had to be capable of going beyond what was required. When using the shift light to power the Vvt solenoid, it switched it fully on, right up to it's maximum, hence the 60degrees. Dynoman,who did the mapping, showed the figures as he was getting it all working on the laptop,
I thought it was on standard induction though?
IT is, think rwd is getting some of the replies mixed. Shame dynoman not around, he'd verify, and give more substance than I.
The cam does not move 60 or 40 or even 30 degrees, those numbers are not realistic at all.............
"Horsepower sells cars, torque wins races" - Enzo Ferrari
You would bend the valves to death with that sort of a timing swing
"Horsepower sells cars, torque wins races" - Enzo Ferrari
Well, it's funny you should say that, as they were the figures that newman cams quoted me as well when I discussed the camshaft upgrade with then. Not wanting to question your knowledge on this engine, but you Did think the Vvt was on the exhaust cam!
In fairness, I cannot recall if the degrees quoted are crank or cam, but even if crank, it would be still 30 deg at cam
We will agree to disagree then......
"Horsepower sells cars, torque wins races" - Enzo Ferrari
Pardon? Bs figures?
ok, it got the better of me. i searched this from a previous post (mine)
Re: ST170 engine any advantage
and from here http://forum.rs-ford.co.uk/viewtopic...c959053b4365c2
Duratec st's intake camshaft is equipped with an electro-mechanical control mechanism that allows the cam's maximum opening point, relative to crankshaft degrees, to be varied between 85 and 145 degrees after top dead centre. Variability is calibrated according to engine speed, load and operating temperature. It is accomplished by changing oil pressure on either side of a piston in a helix between the cam and its drive pulley.
I feel i need to step in here . As i have said in the past , on previous threads, the ST170 requires a seperate map for the VVT. I have been developing ( in conjunction with MBE and SBD) the 9A4 ecu to accommodate the mapped VVt which was only available on MBE's Pro ecu @ £2.5K! As i am also a dealer for DTA, which accommodates this facility, in their S60 i felt that MBE needed to match this in their entry level system.
Dyn-car-gwyn ( aka Alan ) kindly leant me his car as a donor for the development of this system ( no mean feat considering he is based in Manchester and i am in South Wales).
Now you have seen his progress with switched VVt in other threads but the best figure i had achieved with his car was 160 ish bhp with the vvt switched similarly to the Honda system.
The best i had seen (on DTA mapped VVT) had been 188bhp and his attained 193bhp. The inlet cam has a 62.5 deg variation within the map and reaches a maximum of 51 deg's . To attain these figures the exhaust cam requires some adjustment. Considering this is a std engine the figures are impressive , for cheap power/torque. ( not uncommon with modern day engines).
I hope this clarifies things, but feel free to ask.
Ah look lads, sorry if I was being a bit of an ass arguing about the the vvt adjustment figures as they sound very big to me, but hey I will leave it at that, who cares, it looks like dynoman has done a very good job on the engine tuning and dyn-car-gwyn you have a good engine there
Life is too short, peace, J
"Horsepower sells cars, torque wins races" - Enzo Ferrari
i dunno anything about the st170 system, but some of the new stuff does have simply massive adjustments all mainly in the name of emissions, something that some of them are now doing is egr without needed an egr valve, for those that dont know egr stands for its, exhaust gas recirculation, its normally done using an external valve, but these do give problems, what some manufactures are now doing is playing with the valve timing to such extent that they can feed the exhaust gasses back in through the still open inlet valves
i did a lot of reading and researching into this engine before committing for the plunge! theres a lot of info out there, probably a lot more than i needed to know tbh, so i got directed towards dynoman, who had already had dealings with engine, a wealth of information! i did myther him for a long while whilst getting myself sorted, so credits where its due! i quickly established that this is essentially a blacktop zetec, although labelled duratec! it has however been breathed upon by ford, or some other firm on their behalf. the bottom end is strengthened, and the head is worked on, including flow, bigger valves, bigger ports, the vvt, and am also pretty certain it has higher compression ratio over the standard blacktop. so all in all, a good little motor to set off with, and a very underestimated one at that. as graham stated, there are massive adjustments available within modern engines, mainly to do with emissions, but then, they have their other uses as well! once mapped correctly, it will deliver a very low down delivery of power, and carry on doing so until near 7k. the down side, as everything, is the cost of getting set up initially. it is a little pricey, but still cheaper then the equivalent pinto, probably by half! and the big plus is if the engine goes pop, off you go to the scrappers for another, and you'r back on the same power. maybe there is a slight discrepancies with the final bhp, but its a benchmark, and have increased the overall bhp/torque quite significantly with the correct set up. i do know of people that have left dynomans workshop with a bhp figure, and when attending another tuning session at a different location, they have walked away with the same result, so it cant be far off the mark if at all. ultimately, the end figure is just that, a figure, a benchmark maybe for the next time, although i do feel i'm at the end of the road with power/torque with out interfering with the internals. im certainly impressed with the outcome, much more friendly to drive over the honda method vvt, ie on or off. it will never be a pinto, but pound for pound, i'll be definately staying put with what i have!
i was quoting someone elses article (see the link),its an interesing subject really (for us saddos)
the way i read it was that the inlet valve full open point can be between 85 and 145 after tdc. as has been said, it seems it has more adjustment available than is actually required for best results.
Honestly the inlet opening point would never be 85 to 145* before top dead centre in any engine, if it was anywhere near 60* it would bend all of the inlet valves around TDC, for example valve timing figures with lest say a 280* cam with a 108* LSA are more like:
Inlet opens 32* BTDC closes 68* ABDC, Exhaust opens 68* BBDC - closes 32* ATDC
With almost every engine advancing the inlet more than 10* would be excessive and at serious risk of bending inlet valves, more lift @TDC and a lot less piston to valve clearance the more you advance the inlet cam, you can retard the inlet cam as much as you like, but they are no gains to be had by retarding the inlet cam more than around 5 to 10 camshaft degrees, if you go any mroe than that power will drop like a stone everywhere in the rev range due to a very late intake closing point and very low cylinder pressures
And when advancing the cam there would be a lot of mid range gains, but again there is a limit to how far you could safely advance the cam in terms of cylinder pressures/detonation and also the inlet valve to piston clearance issue, you would benefit from advancing the cam 10* that would be a practical limit, so 10* advanced + 10* retarded = 20 camshaft degrees or 40* crankshaft degrees, that is a very big swing each way, in reality I believe it would be more like a 25 to 30* difference between the best dyno tuned low to mid range power and best top end power
Have a look at real world valve timing specs and dyno tuning results from cam timing adjustments and you will see what I mean
Last edited by RWD fords rule; 13-11-2011 at 17:21.
"Horsepower sells cars, torque wins races" - Enzo Ferrari
Maybe with a modern day engines these tolerances are there, but then maybe ford have got their figures wrong.......
The ST170 system advances the inlet camshaft and as i have said reaches a maximum of 51 degrees on Alans engine. but also has 0 degrees in other places. I honestly don't think you can compare conventional tuning /cam timing to this engine. Certainly, if you replace the VVT and fit uprated cams then normality is resumed . It would appear that there is a lot of clearance available on this engine as Alans first engine arrived and ran with the cam timing some 4 teeth out!
I do think that with modern engines you have to open your mind to what settings they run on. When was the last time you saw a standard road car engine running on 12.1 compression ratio? yet the VW 1.6 Lupo GT does.
the quote was actually atdc so it would be between 215 and 275 btdc
these figs are indeed a long way from your expected figs and would suggest a possible error somewhere ? maybe a google search would turn up more tech info on the std engine but im all googled out.
Your right in one way. At low revs if the vvt is set to switch to the max setting it will hit the valves. There are a few post up from people who have the ST engine running a shift light to switch the vvt. They have found poor or low engine compression. Guess what that is from.
As Graham put the VVT is for emmissions on current modern cars. The timing will move way beyond what is required for power tuning.
Back to the ST. What exhaust wheel was used? the zetec adjustable one?
I ran mine on the shift light, and ran wit plenty of power tbh, it was just a little rough on or around 30mph in 4th or 5th. But that was due to the Vvt being activated then, and never reached what I Have now. The cam wheel Is for a normal zetec, both the exhaust and inlet are the same on non Vvt engines. That on it own can give around the 10bhp mark.
Dyno-man, you still haven't said how much the ECU is The top spec mbe is half the cost of my car! Can old MBE systems be upgraded as I've one sat in the garage out of a factory westfield.
To answer one question about my plots,
The first is a bog standard engine with no VVC.
The second is a 1/2" increase in exhaust bore and -5Deg on the exhaust cam.
Finally, the last is the VVC switched by an old Omex 500 ECU coming on at 2400rpm.
I'd love to see how much a proper ECU would develop, but as my ECU and engine were under £600 I'm a happy bunny.
We'll find out how much quicker it is @ Combe in March, as they say Lap times are the true measure of power.
Cheers Dan.
Last edited by scutter; 13-11-2011 at 19:37.
I found a supplier in America for the wheels, only came as a pack of 2, But was as cheap as 1 over here! Food for thought!
Mines a CFM pulley that came with the engine.
http://focus.c-f-m.com/cfmadjustable...tecpair-1.aspx
I could sell both of my ecu's and stump up the rest, NO must resist and sort out my chassis
Dan.
Last edited by scutter; 13-11-2011 at 20:08.
Could be after an ecu for mine. when its together
I wonder if anyone has retrofitted vvt to older engines, looks fairly simple apart from proper ecu control
http://youtu.be/9A6S1NUjg_A
"Horsepower sells cars, torque wins races" - Enzo Ferrari
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