Uprev/Ecutek VVEL and VVT and other cam tuning basics

cwrenny

After spending some time going through the threads on this forum I have been unable to come across the information I am looking for. I have also noticed the lack of information regarding DIY cam tuning in general. If am at all wrong in making this statement, and you can point me in the right direction, then I will remove this post.... but for now let us continue.

Before anything please note that everything here is related to NA tuning... Tuning cams for FI will be a little different, however we can also discuss that later if we get a discussion going or if anyone has some questions about it.

Uprev and Ecutek have had the G and Z VVEL and CVTC unlocked for some time now, with some changes to the tables here and there over the past little while. As we all know the VVEL portion lets you customize the cam lift and duration as you please creating a completely custom profile ant any RPM/Load. The CVTC portion lets you change the cam's timing throughout the RPM/Load range. Now with the VQ37VHR motor the EGR functionality was moved to the cams themselves, something that, if I remember correctly, was done on a previous version of the VQ motor but then was taken away but then brought back again... Ether way this means that the EGR functionality is tuned right into the cam timing and possibly even the VVEL itself. Since I am working with Uprev (lucky me...) I will be using Uprev tables, however I encourage anyone with a tuner version of Ecutek to post pictures of their tables as well.

Cam Phasing / Timing (CVTC)
CVTC.JPG
Here is a picture of the current CVTC mapping used on my 11 g37 IPL, this is the same ECU used in the Nismo 370Z. I have modified this slightly but haven't done anything aggressive yet as I am looking for some feedback from you guys before I go ahead and work off of my assumptions. My assumptions are this: The area with the most cam advance (originally as high as 65deg) is in the general "cruise" area of the mapping. I believe this large amount of advance is acting as a way to reduce emissions and fuel consumption. The area further to the right on the main driveability maps (A and B) are closely related to the WOT map and what I would think of as a more normal CVTC map for performance. Now I have reduced the "cruise" part of the map to the low 50s to see if I can gain any additional torque/throttle response under lighter load.

My questions are:
1. Will reducing this area in the mapping give me any real benefit seeing as this is the low load portion of the map and wouldn't be used where performance would be required, and if not would at least reducing the size of this "cruise" area give better throttle response when transitioning into the heavier load part of the map?
2. what is the difference between Main Driveability A and Main Driveability B? Both maps look very similar just with different scaling and resolution.
3. For those of you who have had a chance to mess with the WOT cam timing, what numbers did you find worked best for good low end torque and peak HP?

In addition to all of this... lets just state the basics for intake cam timing... A more advanced intake cam will yield more torque where as a more retarded intake cam will give better top end/ peak HP. Over advancing the intake cam under low load will cause some exhaust gasses to get into your intake side of the head during the exhaust stroke, this reduces O2 levels in the cyl and therefor reduces NOX emissions similar to what an EGR does. Less oxygen also requires less Fuel to get a proper A/F ratio so mileage is also gained.

VVEL
VVEL.JPG
Probably the more confusing part, by far... is the VVEL system. Some of it is straight forward however Uprev hasn't really given a good explanation as to what each map is used for.. some I think I understand. The VVEL Decel map is as it states.. for deceleration. This is used when the motor is coasting to a stop and is used to help slow the motor. The duration is greatly reduced to help put more restriction on the intake air, similar to closing the flap on the throttle body. The main driveability maps A and B don't seem to show any emissions related tuning and follow a similar RPM scaling to that of the WOT MAP at the full load end of the scale. However they are different from one another and have different max values... These I believe are all relative to the valve duration as well. The three boxes to the bottom right (VVEL Max, Min A and Min B) are used for determining the angle of the cam, or how quickly the valve opens to full lift.

questions I have here are:
1. Where frack does the veritable lift come into play? there is a locked "valve limit map" is it just too risky to modify so Uprev kept it locked? if that's the case, to me it looks like lift is reduced the longer you keep the valve open probably to reduce the chance of kissing the piston at high RPM while still taking advantage of the scavenging effect gained with longer duration and less cam advance at higher RPMs.
2. We can assume more duration is better as long as it doesn't over extend the intake stroke at low RPMs .. however, for those of you who have messed with this stuff, what numbers yield the best torque and power, what max duration did you use?
3. Again What are the differences between the A and B maps?
and what is the angle min and max? the valve angle maps are all very different...

If you guys have access to your maps or have done any tuning yourselves please post your numbers and lets get some discussion going! In reality a dyno is required to properly tune you power/torque curves however proper knowledge can get you close and greatly reduce your time on a dyno, not to mention learning to tune is part of the fun!

cwrenny

There is some good information here on the effects on power in relation to a cam's profile:

Secrets Of Camshaft Power - Hot Rod Network

Bobbeh

Interested to see how far you chased this down and where you ended up. I'm building a 4.5L VHR stroker n/a to be a high compression animal.

husam2012

I wouldn't mess with partial throttle VTC timing as you can lose a considerable amount of MPGs and not gain much. The factory map is pretty well dialed in for that region. As for WOT, it will depend on your exhaust modifications. For most cars you'll want 0 degrees as it gets near redline and then about 3-5 degrees added in the low and mid range. Every car is different from my experience tuning these VQs but most respond well to +3 degrees VTC everywhere but redline.

As for VVEL, it's different on Ecutek so I can't comment on the exact map but increasing lift at the mid range will pick up some power.

__________________
Creator of the GTR TT Conversion Kit, NA Record Holder (401WHP)
Ecutek Master Tuner (VQ37, VR30, VR38, B58, S55, S58)
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