Jenko
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| posted on 7/6/14 at 02:46 PM |
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VCT on the 1.7 Puma engine - The real facts!
There has been so many discussions on this. On Friday I took the J15 to Northampton motorsports to map a standard engine on TB's with the VCT
working as an on / off function. The reality of the system, is if mapped in correctly, it works remarkably well. The results are in my latest blog
post. But 155bhp on a standard engine with a decent power and torque curve is admitedly more than I expected.
Check out the blog for the full story.
MY BLOG - http://westfieldv8.blogspot.co.uk/
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ceebmoj
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| posted on 7/6/14 at 03:11 PM |
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great blog, interesting read.
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Ugg10
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| posted on 7/6/14 at 07:41 PM |
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Excellent news, great car and confirmation that my engine should do what I want. Are those figures at the flywheel or at the wheel?
For info what size are your tbs (jenvey?) an also what diametre exhaust and length of headers. My exhaust will have shorter headers and 42mm tbs so
interested to see the differences. Also glad the vtec way of controlling the vct works well which opens up my ecu choice a bit.
Thanks for sharing.
[Edited on 7/6/14 by Ugg10]
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Jenko
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| posted on 7/6/14 at 08:17 PM |
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Figures are at the flywheel....I think it was somewhere around 130bhp at the wheels........
The tbs are good old gsxr750's, k1's I think....not sure on diameter, but 42mm rings a bell, tapering down to 40mm. Exhaust, 2 1/4
inch.....
Just make sure the ecu has a feature to turn the VCT signal off at higher revs.
MY BLOG - http://westfieldv8.blogspot.co.uk/
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Ugg10
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| posted on 7/6/14 at 08:35 PM |
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Thanks, sounds similar to my set up. I'm starting to get hopful of what mine may do, anything around 150 would be great. Looking at emerald at
the moment but omex 600 is a possibility. My tbs are 42 inlet and oval 43x34 exit which closely matches the head ports.
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Ugg10
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| posted on 8/6/14 at 09:23 AM |
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Had another read of your blog, and a look at the power graph, you say that you turn the vct off at 5850rpm, would you care to share when you turn it
on at the lower end as it looks like it is before the graph starts. Looking at other comments on the Web they are all around 5500 to 6000rpm to turn
off (consistent with yours) but not found out what the turn on point is, info ranges from 1500 to 2500 rpm.
Also for info what injectors were you using, the puma ones in the head or ones in the TBs?
Sorry for all the questions but best to ask twice and do once.
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Jenko
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| posted on 8/6/14 at 10:35 AM |
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It turns on at around 2000 rpm...can't remember exactly, but alas graph does not show it....
Injectors are standard puma ones in the head not the Tb's
MY BLOG - http://westfieldv8.blogspot.co.uk/
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Ugg10
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| posted on 8/6/14 at 02:31 PM |
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Many thanks again for the info, very useful for my build as it seems we will have very similar engine setups, I am planning to use the puma injectors
as well. I think 150hp in a ford anglia should be plenty (to start with).
I'm going to be really cheeky and ask whether I can have a copy of your omex map as a starting point, I should be able to translate it to
whatever ecu I go with. If that is ok then pm me and I will send you an email address.
The more I look at the j15/vectis the more it looks like a baby lola t70, your colours scheme really suits it.
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beaver34
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| posted on 8/6/14 at 03:54 PM |
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nice results
are you running standard cams currently?
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Ugg10
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| posted on 8/6/14 at 04:24 PM |
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From the post and his blog looks like engine internals are all standard, be interesting to see what it would do with a set of SS4's (there is a
mention of future upgrades, looking froward to seeing this evolve) ?
---------------------------------------------------------------
1968 Ford Anglia 105e, 1.7 Zetec SE, Mk2 Escort Workd Cup front end, 5 link rear
Build Blog - http://Anglia1968.weebly.com
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beaver34
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| posted on 8/6/14 at 06:39 PM |
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Very surprised to see that power on stock cams
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Jenko
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| posted on 8/6/14 at 07:08 PM |
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[Edited on 8/6/14 by Jenko]
MY BLOG - http://westfieldv8.blogspot.co.uk/
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Jenko
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| posted on 8/6/14 at 07:09 PM |
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Standard engine apart from Tb's and of course the exhaust system and omex 600... Can't wait to get it through iva and chuck in a set of
frp cams.
MY BLOG - http://westfieldv8.blogspot.co.uk/
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beaver34
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| posted on 8/6/14 at 07:30 PM |
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Ss4 shawspeed cams are better than the frp and work well with itbs
Some stronger valve springs and rod bolts will see it rev to 8k to make the most of the cams
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Jenko
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| posted on 9/6/14 at 11:55 AM |
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Must admit, I was unsure about what to rev it to. We figured 7.2k would be safe, but it was still making power at the point. I think the puma engine
uses some strange powdered metal construction for the con rods....Can't work out if thats a good thing or not, but there does not seem to be too
many horror stories out there......
MY BLOG - http://westfieldv8.blogspot.co.uk/
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beaver34
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| posted on 9/6/14 at 12:49 PM |
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quote:
Originally posted by Jenko
Must admit, I was unsure about what to rev it to. We figured 7.2k would be safe, but it was still making power at the point. I think the puma engine
uses some strange powdered metal construction for the con rods....Can't work out if thats a good thing or not, but there does not seem to be too
many horror stories out there......
they are powered cast and broken to separate.
with hd rod bolts you can rev to 8k, you will need uprated valve springs to do 8k really though, piper make them, shawspeed make the rod bolts
anything above 8k you will have cambelt tensioner issues when lifting off the gas at high rpm
you could go a for a ss3 cam and have the pistons pocketed to run these, would do over 170 then no worries
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johnH20
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| posted on 9/6/14 at 04:04 PM |
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Hi Jenko, very interested in your approach. Do you have two complete fuel/spark maps that you switch between? It is difficult to imagine that one map
would be optimum for both cam positions.
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Jenko
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| posted on 9/6/14 at 05:27 PM |
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As I understand it, it was fairly straight forward to figure out a base setting for both the on off position. I know he spent some time getting this
right. To be honest, Troy from nms is so familiar with the omex software he could really rocket the settings.
I'm exactly sure where it does turn the VCT on as the rpm on the plot does not go down that far, but I will try and find out.
Paul.
MY BLOG - http://westfieldv8.blogspot.co.uk/
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nickm
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| posted on 9/6/14 at 07:27 PM |
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Hi Jenko
Your making me wish id kept my old Puma and not bought a brand new 1.6 !!
Good figures but the pull with the VVC will make it feel even more
Nick M
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Jenko
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| posted on 12/6/14 at 08:33 AM |
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If interested, I've added some more plots to the blog, that shows the comparisson between the full on, full off, and on/off of the vct system.
MY BLOG - http://westfieldv8.blogspot.co.uk/
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Ugg10
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| posted on 12/6/14 at 11:01 AM |
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quote:
Originally posted by johnH20
Hi Jenko, very interested in your approach. Do you have two complete fuel/spark maps that you switch between? It is difficult to imagine that one map
would be optimum for both cam positions.
Sorry to butt in but my understanding of the process is -
Keep the VCT in the Off position - map the engine as normal maximising power/torque/efficiency etc. - save the map (map being tables of load vs rpm
for injection duration and ignition advance)
Switch the VCT to the On position - map the engine as normal maximising power/torque/efficiency etc. - save the map
Print out the two power/torque runs for the on/off positions, one will give better performance at low and high rpm (off position), one will be better
at mid (on position), find the cross over points - approx 2k and 6k for the Puma 1.7.
The in a new map copy the low and high (below and above the identified cross over points) rpm bits out of the Off position map and the middle (between
the identified cross over points) rpm bit out of the On position map. You now have a composite map that cover all loads and rpm sites but takes the
best bits of the two positions of the VCT. The last thing to do is to set the rmp switch aux output to come on and go off at the chosen rpm to conrol
the VCT (you also need to plug in the cold start, cranking parametres etc. as usual).
So, one map but made up of two separate mapping sessions at on and off VCT positions and then controlled by the rpm triggered Aux out.
Hope that helps.
---------------------------------------------------------------
1968 Ford Anglia 105e, 1.7 Zetec SE, Mk2 Escort Workd Cup front end, 5 link rear
Build Blog - http://Anglia1968.weebly.com
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Ugg10
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| posted on 12/6/14 at 11:05 AM |
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quote:
Originally posted by Jenko
If interested, I've added some more plots to the blog, that shows the comparisson between the full on, full off, and on/off of the vct system.
Many thanks for posting the on/off/total plot, very useful and graphically shows the benefit of the VCT and also the point at which to switch. I am
starting to get a little excited at the thought of getting my engine up and running later in the year (to many mechanical jobs to sort out first !).
[Edited on 12/6/14 by Ugg10]
---------------------------------------------------------------
1968 Ford Anglia 105e, 1.7 Zetec SE, Mk2 Escort Workd Cup front end, 5 link rear
Build Blog - http://Anglia1968.weebly.com
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Jenko
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| posted on 12/6/14 at 11:28 AM |
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quote:
Originally posted by Ugg10
quote:
Originally posted by johnH20
Hi Jenko, very interested in your approach. Do you have two complete fuel/spark maps that you switch between? It is difficult to imagine that one map
would be optimum for both cam positions.
Sorry to butt in but my understanding of the process is -
Keep the VCT in the Off position - map the engine as normal maximising power/torque/efficiency etc. - save the map (map being tables of load vs rpm
for injection duration and ignition advance)
Switch the VCT to the On position - map the engine as normal maximising power/torque/efficiency etc. - save the map
Print out the two power/torque runs for the on/off positions, one will give better performance at low and high rpm (off position), one will be better
at mid (on position), find the cross over points - approx 2k and 6k for the Puma 1.7.
The in a new map copy the low and high (below and above the identified cross over points) rpm bits out of the Off position map and the middle (between
the identified cross over points) rpm bit out of the On position map. You now have a composite map that cover all loads and rpm sites but takes the
best bits of the two positions of the VCT. The last thing to do is to set the rmp switch aux output to come on and go off at the chosen rpm to conrol
the VCT (you also need to plug in the cold start, cranking parametres etc. as usual).
So, one map but made up of two separate mapping sessions at on and off VCT positions and then controlled by the rpm triggered Aux out.
Hope that helps.
First off, it wasn't my approach, it was the knowledgable chaps at NMS...whereas I do understand how the system works, the real clever bit is in
the mapping.
But what Ugg10 has said here is correct. One map is used after the two points of on/off are found. The only thing to add was there wasn't really
two mapping sessions, just from a quick optimisation it was clear where to turn on and off from there on in it was just like mapping a normal car. The
only other thing to build in was the throttle load. Under light throttle load (i.e. <30%) there was efficiency savings to be had, so they figured
out that there was no need for the vct to be on at gentle motorway cruising speeds. This is nice because you can hear a notable change in the
induction noise between on and off, so it's fairly quiet when you want it to be.
P.
MY BLOG - http://westfieldv8.blogspot.co.uk/
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Paul AS
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| posted on 12/6/14 at 12:21 PM |
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code:
Your making me wish id kept my old Puma and not bought a brand new 1.6 !!
Dear oh dear Nick - you need to get your car finished mate!! 1.4, 1.6, 1.7 , VVC ? You're gonna wish you had em all!!
Any danger of IVA yet??
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johnH20
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| posted on 12/6/14 at 02:26 PM |
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Thanks for the above. I would only add that ,in theory at least, you could be anywhere in the speed range at less than 30% ( or what ever your chosen
value ) of throttle opening hence you would need a full VCT 'off' map to cover this. Only likely to be a transient condition outside of
cruise though.
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