davetheboat
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| posted on 18/6/13 at 10:53 AM |
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Ford Puma vct control?
Hi All
Just hoping someone will know how the vct is controlled on Puma 1.7 Zetec se. I know that it is activated by oil pressure but that is controlled by a
solenoid. What I don't know is if it is variable or a fixed stage activation.
Trying to find out as I want to build a megasquirt ecu for it & ms2 will manage fixed stage & ms3 variable.
The other option is to disable it. I can find deletion kits for the zetec e but not the se if anyone knows how to disable it i would appreciate any
information that is available.
Thanks David
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theprisioner
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| posted on 18/6/13 at 11:39 AM |
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I investigated this at one point in my build and my conclusion was that there was (at that time) no aftermarket ECU's that progressively
adjusted the vvct. It is my belief the Ford ECU does do this progressively. The aftermarket ecu's can be set to energise the solenoid on a
bang-on bang-off at a certain rev limit (so I was told by an engine tuner). I guess you could have several rev point controls from the ecu and develop
your own piece wise progressive system.
I elected to stay with the ford ECU for now and have the cam upgraded and hopefully a better ECU mapping to match the cam.
http://sylvabuild.blogspot.com/
http://austin7special.blogspot.co.uk/
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davetheboat
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| posted on 18/6/13 at 12:18 PM |
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Thanks for that I am also building a J15 as it happens.
Apparently the megasquirt MS3 can cope with continuously variable cam timing. I am intending to install bike throttle bodies and upgraded cams at some
point hence the intention to use an aftermarket ecu & I quite fancy building it & learning how things work.
Another thing you may be able to help me with is how does the tickover react when started from cold? Does it drop back in one go or does it reduce
gradually as the engine temperature increases. I think it drops back gradually but having just been out & started the donor I cannot tell as its
been sitting in the sun all morning & is allready quite warm!
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Jenko
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| posted on 18/6/13 at 12:55 PM |
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I'm also going through this at the moment.........
So, the VVT on the puma is continously variable and is controled via sensor on the inlet camshaft, thet feeds back to the ecu and sends a PWM signal
to the soliniod. This then controls oil pressure to the clever mechanisum on the cam pully that changes the timing.
There are ECU's out there that will do this OMEX 710, DTA S80 etc......BUT....you can also operate the solinoid as on / off and most ECU's
can do this if they have an aux ouput. This is simply programmed in to kick in at a certain rev range and throttle load.
Having now read a fair bit about this, it seems that actually, you can kick in the cam full on at relatively low revs (2.5k) and get performance gains
throughout the rev range. It basically coms off for a could tick over.
Due to the cam profile I would certainly not say disabling is an option if you want a good tick over....you might as well use it if it's there.
It might be worth do the on / off via a relay if you want to limit the switching current required from the ECU.
P.S. I did the megasquirt thing on my last Westfield, and it was a fantastic learning experience. I mapped it on the road and got almost there, but
could not match the skill of the rolling road operator at Northampton who managed to extract a further 8bhp and a load of torque.
This time around I've installed GSXR 750 TB's via a customer made manidfold, and for an easy life I'm going to go with an OMEX 600
ECU that I can hand over to NMS to map.
You may want to take a look at the first few months of my blog for some info on the puma engine and the hassles associated with the inlet manfold!.
MY BLOG - http://westfieldv8.blogspot.co.uk/
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puma931
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| posted on 18/6/13 at 05:39 PM |
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contact Alan @ www.pumabuild.co.uk as he knows loads about this and the modified FRP engine.
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davetheboat
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| posted on 18/6/13 at 07:24 PM |
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Hi Jenko thats great just the info I needed.
I guess that having the cam switched on & off at only one point in the rev range should make mapping it easier?
Did it the other way round with my westfield used Dta
Its the learning curve & the flexibility that is attracting me to the megasquirt. Bailey motorsport are only 10 miles away I gather they are good
with megasquirt. So have sombody to do the final set up.
I have been keeping an eye on your blog for a while & very helpfull it is too. Having seen the fun you had with the inlet manifold I spoke to
Danst at the weekend he can make a manifold either with alternator in original position or in an ideal world with it moved! Not sure how feasable that
is but it would shorten the manifold which has got to help given the lack of clearance. Looks like I have some fun ahead!
I know Jeremy made up your engine mounts he recons I will only need to modify the drivers side. One question does the engine sit level across the car?
Puma931 will try Alan @pumabuild
Thanks both
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Jenko
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| posted on 18/6/13 at 07:45 PM |
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Megasquirt if installed correctly is as good as the next Ecu.......I learnt so much when I converted my Westie to bike tbs. so good luck with it.
Re the inlet manifold..I couldn't really work out a way to move the alternator, so had to adjust the manifold to suit....now it's all done
I'm happy but dropping the engine by 18mm made all the difference. The engine does sit level across the car, so no issues there, and jp is
correct the ib5 gearbox is the same, so hat mount remains un-changed, the top mount needs to accommodate the cam pulley used for the vvt system.
MY BLOG - http://westfieldv8.blogspot.co.uk/
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davetheboat
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| posted on 18/6/13 at 08:14 PM |
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Thanks puts my mind at rest megasquirt it is then.
Engines still in the puma at the moment so will have proper look at alternator position when its out.
At least I now what engine position I need to end up with!
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davetheboat
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| posted on 23/6/13 at 01:32 PM |
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Just a quick update for information.
Having emailed diyautotune the only megasquirt that can cope with fully variable cam timing is the ms3 pro which is not available as a build it
yourself option & is more expensive. So looks like being ms3 with simple on off cam timing function as suggested by Jenko.
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monkeyarms
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| posted on 23/6/13 at 03:47 PM |
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Adam Wilkins from Complete Kit Car magazine built a riot with a puma engine and if i remember correctly he used an Emerald ECU with an on/off control
of the VCT. He had two rolling road sessions done, one with cam on and one with cam off. Then the RR guy looked at were to activate the VCT.
It is a while ago since i read it but i seem to recall that the VCT was activated at the low rev range and then deactivated in the upper rev range.
I wish i could find my copy, but think i got rid in a big clear out. But you can still buy a back copy i think.
http://www.completekitcar.co.uk/adrenalinemurtay.html
[Edited on 23/6/13 by monkeyarms]
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fishywick
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| posted on 23/6/13 at 04:55 PM |
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quote:
Originally posted by monkeyarms
Adam Wilkins from Complete Kit Car magazine built a riot with a puma engine and if i remember correctly he used an Emerald ECU with an on/off control
of the VCT. He had two rolling road sessions done, one with cam on and one with cam off. Then the RR guy looked at were to activate the VCT.
It is a while ago since i read it but i seem to recall that the VCT was activated at the low rev range and then deactivated in the upper rev range.
Yes you are right. I have a copy of this somewhere, I'm pretty sure he used Omex and it switched on at 1500rpm and cut out at 5000ish rpm.
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davetheboat
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| posted on 23/6/13 at 06:20 PM |
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Very interesting I shall order a copy.
Thanks guys
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nickm
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| posted on 24/6/13 at 07:51 PM |
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Hi
The Riot build article was an omex (i clocked it cos JP always uses Emerald) but i believe the engine was left as virtually standard.
Ive gone the whole hog expensive route with jenveys and clearance with the inlet manifold is an issue and that is with DTH but im on the no vibration
proof mounting.
Part of me wishes id gone megasquirt and bike t/b as i have done carbs and megajolt before to good effect but ive sworn to keep this car forever and
never build another so i splashed out.
Nick M
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