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-   -   VVEL if you can't tune it why not modify it (http://www.the370z.com/engine-drivetrain/91153-vvel-if-you-cant-tune-why-not-modify.html)

colin55 06-12-2014 05:19 PM

VVEL if you can't tune it why not modify it
 
Hey all,

As the title suggests, if we cant tune vvel for more lift, why can't we alter the amount of lift that the control shaft 'thinks' its going to get.
I have read about the screw adjustment, but I imagine that will alter the lift at idle which we don't want.

So I wonder if someone with a bit of machining know how, can re-engineer the 'output cam'.

As you can see in the pic below, it seems that two 'output cams' are driven by one ' link b'.

So if we could make a replacement output cam / shoe piece (see pics) you could adjust the lift at any point.

If you left the profile of the shoe the same for the first half, lift up till that point would be unaltered.

But if you then changed the profile for the final part of the shoe, you could give more lift just at 'peak lift.

eg:

standard lift altered lift
1 1
2 2
3 3
4 4
5 5
6 6.5
7 7.5
8 9
9 10
10 11
11 12.5
??


http://i1177.photobucket.com/albums/...ol_87/vvel.jpg

http://i1177.photobucket.com/albums/...disasemble.jpg

http://i1177.photobucket.com/albums/...7/vvelboot.jpg

excuse my crap explanation, hopefully these equally crap pics will help.

Cheers.

1slow370 06-12-2014 08:44 PM

because that shaft is 10 mother bitches to take apart and get back together to get the output cam pieces off. then you need to find a shop that will design a fixture to grind the things, and then you need shops that are willing to do this work for people because no one is going to want to take that shaft apart themselves, and then because you would have reground a different profile on it you would need longer valves/thicker lifters to make up the clearances, and at the end of the day its going to cost 2-3x more than an hr head swap and big cams.

colin55 06-13-2014 07:27 AM

I suppose that is a pretty good sum of reasons not to go down that road.

Did anyone ever experiment with the adjustment screws? (and actually start the engine)

jwick 06-13-2014 08:49 AM

What are you referring to as 'tuning the VVEL'? My tune has some VVEL adjustment in it.

takjak2 06-13-2014 09:09 AM

Quote:

Originally Posted by colin55 (Post 2857380)
Did anyone ever experiment with the adjustment screws? (and actually start the engine)

One of Megan's engines?

Megan370z 06-13-2014 11:21 AM

Quote:

Originally Posted by takjak2 (Post 2857514)
One of Megan's engines?

nop I didn't

takjak2 06-13-2014 12:59 PM

Quote:

Originally Posted by Megan370z (Post 2857707)
nop I didn't

Found the post I was thinking about: http://www.the370z.com/engine-drivet...ml#post2321256

JWT has looked at the VVEL adjustment screw:
https://www.youtube.com/watch?v=LyubJV4siss

1slow370 06-13-2014 09:04 PM

I may have some info on this in a couple months, ill post up when i know more

Sent from my HTCONE using Tapatalk

Cell 06-14-2014 01:52 AM

Quote:

Originally Posted by 1slow370 (Post 2856880)
because that shaft is 10 mother bitches to take apart and get back together to get the output cam pieces off. then you need to find a shop that will design a fixture to grind the things, and then you need shops that are willing to do this work for people because no one is going to want to take that shaft apart themselves, and then because you would have reground a different profile on it you would need longer valves/thicker lifters to make up the clearances, and at the end of the day its going to cost 2-3x more than an hr head swap and big cams.



Has anyone done a HR head swap yet and gotten some good dyno results?

Megan370z 06-14-2014 07:20 AM

Quote:

Originally Posted by Cell (Post 2858811)
Has anyone done a HR head swap yet and gotten some good dyno results?

Me and Shamu are the only 2 known guys on thisforum to have done the HR head swap.
but
in the pro racing , it is quite popular if rules allow.

depending of the intake setup with an very aggressive cams the result as far as I saw was about 380 with the stock plastic intake manifold up to 414whp with ITB & Motec and then 405+ with an air boxed ITB setup ... this is a friend of mine ( Onpointdyno.com )

With some more intake/exhaust tuning, there is still quite a bit under the table and . Im talking about the stock 370z stroke which is a 3.7L

Shamu is 4.0L or 4.2L, I cant rememeber but this should be a nice gain over the 3.7L.

colin55 06-15-2014 12:44 AM

It'll be good to find out a way to make a bit more power utilising VVEL, seems such a shame if it doesn't get cracked.
It would be interesting to tinker with the screw a little bit, 1/4, 1/2 a turn of adjustment on all screws. Then Dyno.
As long as you kept track of exactly how much each screw was turned it would be easy to return to standard.
That way you can keep turning them incrementally till peak power is made.
Once someone does that and shares their findings, the rest of us could wind the screws that amount.

It's good to hear some people are still trying 1slow370

jwick 06-15-2014 12:50 AM

:facepalm: UpRev has this capability

colin55 06-15-2014 01:49 AM

It does? Some seem to say so but where is any proof.

jwick 06-15-2014 01:51 AM

My tuner has been tuning UpRev for a couple years now. My turbo tune definitely has VVEL adjustment to it

colin55 06-15-2014 02:07 AM

you do mean VVEL and not C-VTC yeah?

If it is VVEL where is any info, how much is the lift & duration being adjusted?
What's working for N/A? how bout boosted?

It seems bloody hard to find any info about


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