PSpirine
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| posted on 17/1/12 at 06:44 PM |
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Some ST170/Zetec engine questions
Found an ST170 for a decent-ish price (400 quid?). From what I understand these "Duratecs" are actually a Zetec engine with VVTI so will
fit my MT75 rwd box. The engine is missing an inlet and some ancilliaries so:
1) What is the main difference between a ST170 and a standard black-top?
2) Is the inlet interchangeable?
3) Does the ST170 need a different wiring loom/ECU? (May be a moot point as I've got a megasquirt lying around)
4) Has anyone run the ST170 in a kit with the VVTi or have people somehow locked it out/got rid of it? If so, how?
Thanks,
Pavel
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big_wasa
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| posted on 17/1/12 at 07:10 PM |
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manifolds will swap over but the ports are a little higher so not a perfect match with out porting.
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stevebubs
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| posted on 17/1/12 at 08:17 PM |
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quote:
Originally posted by PSpirine
Found an ST170 for a decent-ish price (400 quid?). From what I understand these "Duratecs" are actually a Zetec engine with VVTI so will
fit my MT75 rwd box. The engine is missing an inlet and some ancilliaries so:
1) What is the main difference between a ST170 and a standard black-top?
2) Is the inlet interchangeable?
3) Does the ST170 need a different wiring loom/ECU? (May be a moot point as I've got a megasquirt lying around)
4) Has anyone run the ST170 in a kit with the VVTi or have people somehow locked it out/got rid of it? If so, how?
Thanks,
Pavel
1) VVTi
2) See above
3) Yes unless you find a way to lock the VVTo
4) As far as I know, people have successfully controlled it using an Emerald; not so sure about Megasquirt.
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stevebubs
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| posted on 17/1/12 at 08:18 PM |
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http://passionford.com/forum/technical-help-q-and-a/383466-aftermarket-ecu-for-st170.html
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rhinopower
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| posted on 17/1/12 at 09:44 PM |
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I run an st170 engine on megasquirt.
The vct is a waste of time, time up the inlet cam for full lift at 110 degrees for peak power.
All the wiring is the same as a normal zetec, and there is loads of power to be had from it
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PSpirine
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| posted on 17/1/12 at 09:53 PM |
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Thanks both.
Reading the other forum it seems possible to get the MS to activate the VVTI as on/off (much like a VTEC).
Perhaps with a switch on the dash it could be made to have a "cruising" mode when VVTI activation would work.
Are the standard Ford ECU's untunable then?
Thanks,
P
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rhinopower
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| posted on 17/1/12 at 10:00 PM |
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Having run the vvt take my advise and ditch it.
You can run it with a standard ford deep/desk/dewy ecu with matching maf sensor will with good results. A friends st170 engine made 155bhp with that
setup.
If your running an aftermarket setup with a switch for it, you will find the car running dangerously lean when you activate it. Fixed cam timing and a
proper map will give you a good powerful engine!
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coozer
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| posted on 17/1/12 at 11:11 PM |
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I have a St170 in mine, when I put it in I used the inlet and exhaust sraight off my silvertop, all worked well and the only other ting was the VVT,
triggered it off the megajolt with a relay
Straigth swap for a silvertop or blacktop.
1972 V8 Jago
1980 Z750
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scutter
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| posted on 17/1/12 at 11:21 PM |
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I run a ST170 in my locost,
The VVC is well worth trying to get mapped, I used the ST inlet with GSXR bodies and a old Omex 500 ECU, this is controls the VVC the same as a
megasquirt by using the shift light output.
Power is roughly the same, but with a 15 FtLbs increase in torque, check out the difference in Torque curves below.
 
rolling road 05/08/10
 
VVc
ATB Dan.
The less I worked, the more i liked it.
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rhinopower
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| posted on 17/1/12 at 11:39 PM |
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Running vvt leaves the cam at 90degrees at rest, and 130 degrees at advance, neither of these are the cams peak power figure. I understand the reasons
for running it, and I did previously, however there is a better way of doing it.
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Rob Allison
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| posted on 16/2/12 at 01:05 AM |
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The ST's VVT need to be correctly controlled or it may as well be just locked off in one position.
The VVT is full variable and i have seen some good results on a standard ST170 engine/inlet with the correct mapped vvt putting out 193bhp. When it
would only do 163bhp with the vvt not correctly working.
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coozer
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| posted on 16/2/12 at 02:39 AM |
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quote:
Originally posted by Rob Allison
The ST's VVT need to be correctly controlled or it may as well be just locked off in one position.
The VVT is full variable and i have seen some good results on a standard ST170 engine/inlet with the correct mapped vvt putting out 193bhp. When it
would only do 163bhp with the vvt not correctly working.
Can u explain that a better? How does it create an extra 30bhp?
1972 V8 Jago
1980 Z750
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Rob Allison
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| posted on 16/2/12 at 04:24 PM |
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The VVT is not just on or off. It is a variable system. I dont have the full information on the timing at the moment but its something like this.
The inlet timing varies by 60deg from 85deg btdc to 145deg btdc. Its not just on or off. So if you use it just switched the timing will go from 85deg
btdc to the full maximum of 145deg btdc. The maximum power is not developed at either of these settings.
So far it looks like 142deg btdc is giving the best power figures on a standard manifold set on the long inlet runners. its not been dynoed with
throttle bodies yet.
The VVT is a PMW system so it a 1 to 5 volt pulse that increases in frequency. This opens and closes the vvt solenoid to variy the oil pressure to the
cam vvt. Just putting a 5 volt signal on to the solenoid will force the cam timing to the max setting of 145deg btdc.
The problem is finding an ecu that will control the VVT with PMW control. If your just going to use a switched 5 volt to the vvt then you may as well
just fix the vvt in one position using a vvt delete kit, as you will get better power setting the timing to a better position i.e, 140deg btdc area.
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Dave Bailey
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| posted on 16/2/12 at 06:02 PM |
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Rob are you sure it is 5V that triggers the solenoid. I have been told by DTA that the solenoid is 12V operated.... but this is not the first time I
have heard it is 5V... Mine is wired to 12V but not sure if it is working correctly....
Dave B.
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Rob Allison
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| posted on 16/2/12 at 10:08 PM |
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Thats one of the things i'm unsure about. Still trying to get the information on the driver signal and timing info.
The idea of the vvt is to advance and retard from the normal timing position.
Under high load, high rpm the timing is retarded.
Under Low to medium rpm, high load the timing is advanced.
Under light engine load the timing is retarded.
And its not just a case of on or off. Its variable amounts of degrees. Thats why in most cases the engines are only showing 150 to 170 bhp. If the VVT
cant be used right then it should be just locked off, as it will make far better power.
I know someone with one on carbs, fixed cams and a little head work thats about 220bhp. It needs to rev though 8500rpm
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johnH20
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| posted on 18/2/12 at 05:52 PM |
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I have been trying to get good info on the Ford VCT for some time. I think Rob's summary is basicaly correct as far as power and torque are
concerned but we must remember that VCT ( not to be confused with Honda V-tec which is completely different in both intent and function ) is as much
an emissions and fuel economy optimisation device as any thing else and this is why the required map is so complex in the standard Ford ECU. If we
only require best power and torque I believe things can be made easier.
A couple of years ago one of the kit car mags , I forget which, built a Riot with 1.7 Puma engine. This was fitted with an Omex 600 and mapped by
Omex. As I recall they took basically 2 power curves 1) at full advance and 2) at full retard. Max power ( equal to standard catalogue spec ) was
achieved at full retard but torque was improved by up to 20% between 1500 and 6000 rpm with full advance. Hence I believe simple switching at
appropriate speeds, while perhaps not quite optimum, is a pretty good aproximation for our purposes.
As another check on this is if you look at the Piper cam catalogue you will see that static timing for eqivalent 1.6 ( non VCT ) and 1.7 ( VCT ) cams
( for the Ford Sigma engine ) is basically the same, indicating that full retard of the VCT is best for power.
When I get the chance I intend to put a volt meter on the VCT selonoid and get a WOT curve done. This should show what the Ford standard ECU does
under these simplified conditions. Could be done with a standard Puma if I had one!
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coozer
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| posted on 18/2/12 at 08:17 PM |
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Load of bollocks, mine would not trigger at 9v never mnd 5v. Check the Focus wiring diagram, it sits on a 20 amp fuse with 1mm wiring. It takes 12v to
trigger and its not worth PWM it on our cars.
AND, if I'm wrong tell me what the best position is to lock the cam at. However I am more than happy with the sudden 100hp increase in power
when it kicks in....
Also no good comparing with the Puma, its totally different system. Puma is electronically controlled whereas the ST170 is mechanical....
Mine is setup as advised by Northamton Motorsport and it comes on at 1500rpm and above 30% TPS. This means its variable in that at WOT its at maximun
and off on the overun.. oil pressure deals with the rest.
Theres no advantage in trying make it more complicated!
[Edited on 18/2/12 by coozer]
1972 V8 Jago
1980 Z750
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johnH20
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| posted on 19/2/12 at 09:01 AM |
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Very interesting, I did not know the ST 170 system was different to the Puma, but since a Puma is what I have got it is what I need to understand in
more detail. Sadly I have not found any published information that is any use. Sorry if my post caused any confusion, obviously the wrong thread.
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Rob Allison
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| posted on 19/2/12 at 08:15 PM |
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I know someone that is doing his Motorsport degree on an ST170 supercharged engine. So I should have the info on the vvt/timing/power soon
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silky16v
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| posted on 3/8/12 at 01:23 PM |
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Hi was any further information found on the above, i've very keen to know as i have bought Coozer old MNR and i'm planning to taking it
for mapping and need to know if i should just invest in a cam locking kit or carry on using the omex 600 ecu to control the vvt to fully advanced over
2000rpm/20% throttle
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baz-R
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| posted on 28/5/13 at 10:31 AM |
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quote:
Originally posted by coozer
Load of bollocks, mine would not trigger at 9v never mnd 5v. Check the Focus wiring diagram, it sits on a 20 amp fuse with 1mm wiring. It takes 12v to
trigger and its not worth PWM it on our cars.
AND, if I'm wrong tell me what the best position is to lock the cam at. However I am more than happy with the sudden 100hp increase in power
when it kicks in....
Also no good comparing with the Puma, its totally different system. Puma is electronically controlled whereas the ST170 is mechanical....
Mine is setup as advised by Northamton Motorsport and it comes on at 1500rpm and above 30% TPS. This means its variable in that at WOT its at maximun
and off on the overun.. oil pressure deals with the rest.
Theres no advantage in trying make it more complicated!
[Edited on 18/2/12 by coozer]
on my hunt for info this above is pritty much true a st170 timing is on/off and to iron a few extra things out the inlets on a st170 head are taller
and aprox 10mm higher up so manifolds need work to match.
the st170 also has a real odd cam trigger pattern that moves with cam advance!
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scutter
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| posted on 28/5/13 at 01:19 PM |
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The ST VVC isn't just on/off, otherwise why would Ford give the car a seperate ECU to control the VVC and Inlet lengths. the engine oil
pressure is set by the relief valve in the pump and the solenoid lets varying abouts of that pressure to advance the pulley around, a fella on
Turbosport got his max power on the rollers at something in the region of 45-50 degs rather than 60degs that came from just switching it on.
Apart from that, yes the ports are taller as when I put the ST inlet on a blacktop it kept sucking the O ring seals into the inlet tract until I
refitted the old seals.
Regards Dan.
The less I worked, the more i liked it.
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silky16v
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| posted on 28/5/13 at 01:40 PM |
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quote:
Originally posted by scutter
The ST VVC isn't just on/off, otherwise why would Ford give the car a seperate ECU to control the VVC and Inlet lengths. the engine oil
pressure is set by the relief valve in the pump and the solenoid lets varying abouts of that pressure to advance the pulley around, a fella on
Turbosport got his max power on the rollers at something in the region of 45-50 degs rather than 60degs that came from just switching it on.
Apart from that, yes the ports are taller as when I put the ST inlet on a blacktop it kept sucking the O ring seals into the inlet tract until I
refitted the old seals.
Regards Dan.
correct the VCT is controlled by the cam phase sensor, rpm, tps and other sensors it is a continually altering the position of the camshaft
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baz-R
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| posted on 28/5/13 at 03:22 PM |
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quote:
Originally posted by silky16v
quote:
Originally posted by scutter
The ST VVC isn't just on/off, otherwise why would Ford give the car a seperate ECU to control the VVC and Inlet lengths. the engine oil
pressure is set by the relief valve in the pump and the solenoid lets varying abouts of that pressure to advance the pulley around, a fella on
Turbosport got his max power on the rollers at something in the region of 45-50 degs rather than 60degs that came from just switching it on.
Apart from that, yes the ports are taller as when I put the ST inlet on a blacktop it kept sucking the O ring seals into the inlet tract until I
refitted the old seals.
Regards Dan.
correct the VCT is controlled by the cam phase sensor, rpm, tps and other sensors it is a continually altering the position of the camshaft
so all of thoes reputable tuneing co.'s and meny experts in the aftermarket field are all wrong then?
i wanted to use a st170 with full vvc control with aftermarket ecu but everyone said it cannot be done as ford do it on and off!
inlet lengths are of no interst as i wanted to run throttle bodies
now if anyone can give me info on how to actualy do it and how it realy works im all ears as it is an engine upgrade im intersted in
[Edited on 28/5/13 by baz-R]
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big_wasa
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| posted on 28/5/13 at 03:24 PM |
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But its not a separate ecu. The main purpose of the vvt is for emission's.
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