How to: Tune VVT

[DYI01]

After lots of requests and PM's I have decided to wrie up a guide on how to Dyno tune the VVT on a APEX'i Power FC via the FC-Datalogit for max power. I have no experience with the FC-Commander, and from what I have read about it, trying to tune a car using the Commander is very tedious. The FC-Datalogit will make tuning on the dyno extremly easy.

Tuning the a/f and the ignition on the street will cut down your dyno time a lot. You will need a wideband a/f meter to street tune your a/f. Bring your knock index to acceptable levels.

Start by tuning the low cam first by setting VTLI high to 7000 and VTLI low setting to 6800. Set all the values in the VVT table to 0 and make a pull on the dyno, and dont hit lift. Keep going up in steps of 10 until 50, dynoing each VVT change. Now overlay all the plots and you will see clearly which VVT setting made the most power. Make a composite map mixing and matching the VVT numbers. Then make a pull using the composite map and see if it makes good power, if you did it correctly it should look just like the best line traced when all the dyno plots were overlayed. Save the map, label it as 'tuned low cam'.

Now on to tuning the high cam. Set VTLI high to 5000 and VTLI low to 4800. Set all VVT values back to 0 and make a pull on the dyno, again step the VVT values in increments of 10 until 50, dynoing every VVT change. Remember to make the dyno pull all the way to your desired fuel cut. Overlay all the pulls and again make another composite high cam map of all the VVT numbers that make the best power. Make a pull on the dyno of the composite map, again if you did this correctly it should look just like the best line traced when all the dyno plots were overlayed. Save the map, label it as 'tuned high cam'.

Now take the tuned 'low cam map' dyno plot and 'tuned high cam' map dyno plot and overlay them. you will see a point at which the the HP and TQ lines intersect, this is where the lift transition should be set for optimal power. You may have to rescale the N and P settings to make the most of the tuning.

Regarding the VVT #: I have tested the extent of which MY car reacts to the values that are inputed into the FC-Edit. Inputing any value over 50 yields the same numbers and trace the exact same line as 50 on the dyno. This tells me that 50 would be the limit of the adjustability of the VVT.

[danGTS]

can I say Hondata!? (without the interactive video)

My idea would be to start with MWR's base map, and then move all the values by +/- 5 or 10?? to avoid starting from scratch. AF and ign should have needed to be retuned after each vvti variation, was it the case?? Then fine tuned would be needed. Dont forget we still (as far as I know) dont know what the vvti represents .. Not that I am an experienced tuner but ..

It is a nice thing to know that vvti stops to increase after 50 tho ..

[Jesse IL]

I'm stickying this, but I gotta say...I thought it was pretty clear what you did from your first post about it

[lost27]

Interesting related thread on VVTI tuning on spyderchat:

http://www.spyderchat.com/phpBB/viewtopic.php?t=25111

[Jesse IL]

Bah! IThe Spyderchat email so I can log in and post in that thread won't come through

?? for lost27: Why do you say your timing in load rows P01-P02 is throwing off your timing under load? That simply doesn't make any sense.

Also, there is criticism in that thread about using the same VVT number for an entire column. Do you have a better method for tuning VVT number at part-throttle?

[lost27]

well the reason I thought it was the root cause was because looking at the logs from a run it would jump from the p1-p02 rows down to p08 or so... the timming in p1 -p2 was around 40-45 degrees and the timming in the p08 row in the same area was around 30 or so but the log showed the timming to be around 39-40 at the point i was making the knock and you can see the map trace was in the p1 row then the next step it jumped to the p08. This is when i was in 3rd gear and then shifting to 4th and getting back on it right in that area.

Let me say I am not knocking DIY01s map in anyway... it had a considerably smooth transition into lift and the over all knock values were a lot lower than my other map. It would definatly be a good starting point for some dyno time and when i get some spare money I'll test my current map vs the DIY01 map and post the results.

Its not super important anymore as I've returned to tweaking the map that was previously on the car as it was making quite a bit more power and torque across the power band than the DIY01 map.

The interesting part about the spyderchat disscussion was the vvt numbers and how it relates to an increase/decrease in cam overlap on our cars... just something to think about.

As long as we're in this disscussion mode I'm sure its been asked a couple times that DIY01 post the torque curves for the various runs he did while tuning the vvt...it would just be helpful to see the whole picture when looking at the maps instead of just the HP curves.

[Jesse IL]

Originally Posted by lost27

The interesting part about the spyderchat disscussion was the vvt numbers and how it relates to an increase/decrease in cam overlap on our cars... just something to think about.

I wasn't aware that this is new info There are Toyota technical papers about this.

The odd thing I've noticed on my car is that decreasing the VVT number towards zero actually will cause the car to idle worse. This would see be be counter to the idea that VVT=0 is the lowest overlap point and should make the car idle the best. The VVT system is operated by duty-cycle controlled oil control valves. The one guy on Spyderchat is definitely wrong in his assumption that the VVT system can only hold two positions. The duty-cycle control allows the cam to be held in variable positions.

[Torqued]

Originally Posted by Jesse IL

I wasn't aware that this is new info There are Toyota technical papers about this.

The odd thing I've noticed on my car is that decreasing the VVT number towards zero actually will cause the car to idle worse. This would see be be counter to the idea that VVT=0 is the lowest overlap point and should make the car idle the best. The VVT system is operated by duty-cycle controlled oil control valves. The one guy on Spyderchat is definitely wrong in his assumption that the VVT system can only hold two positions. The duty-cycle control allows the cam to be held in variable positions.

Actually not so odd. With the VVT=0 (highest overlap), there is more overlap. The overlap causes a certain amount of blowback into the intake. This is explained on the Hondata site, and the Toyota VVT technical article does a pretty good job at explaining it too. I have the article in PDF format somewhere, PM me if you want it.

[Jesse IL]

Originally Posted by Torqued

Actually not so odd. With the VVT=0 (highest overlap), there is more overlap. The overlap causes a certain amount of blowback into the intake. This is explained on the Hondata site, and the Toyota VVT technical article does a pretty good job at explaining it too. I have the article in PDF format somewhere, PM me if you want it.

No kidding...that is quite odd. That being the case, you would expect VVT number to decrease as rpm increases. Also, in the technical articles I've read, a failure of the VVT system would cause them to go to their rest position, which is minimum overlap. That seems like it should be VVT=0...

[AndySimmons]

Keep in mind that the 2zz-ge has 11.5:1 compression. Its likely that Toyota is miller cycling the engine using the intake cam. If this is the case then its likely they would have the default cam position in the most drivable position (ie. not in a position that would cause detonation due to high compression). This would also allow for easier startup, especially in cold weather (high compression = harder to start)

I've been experimenting with valve timing under different loads since I received my PFC in the summer of 04 and would welcome some insight from those who have had success with vvti maps that differ from MWR. (I would certainly be willing to share my findings as to make the trade more 'fair') -Andy

[white flash]

This thread also has some interesting info, for those of you who want to know more about the VVT settings in Datalogit. http://www.spyderchat.com/phpBB/viewtopic.php?t=28407 Hopefully this will shed some new light on the subject.

[InSw1tchedFlame]

what about tuning vvt with camcon? i have searched and searched and searched.....all i found was stupid people "whats better camcon or emanage" who cares, im looking for tuning of camcon haha, anyone know how to tune??

[Jesse IL]

Originally Posted by InSw1tchedFlame

what about tuning vvt with camcon? i have searched and searched and searched.....all i found was stupid people "whats better camcon or emanage" who cares, im looking for tuning of camcon haha, anyone know how to tune??

The method would be exactly the same as described in this thread.

[InSw1tchedFlame]

but i didnt happen to read anything i could use, it talks about changing low cam high cam and lift and everything, camcon can't change lift, i thought it just did changed degrees by the 500 RPMs. but only to a max of +-20 degrees..i saw numbers such as 50 and things.

[Jesse IL]

Originally Posted by InSw1tchedFlame

but i didnt happen to read anything i could use, it talks about changing low cam high cam and lift and everything, camcon can't change lift, i thought it just did changed degrees by the 500 RPMs. but only to a max of +-20 degrees..i saw numbers such as 50 and things.

No offense, but if you can't relate the general technique to your own situation, I don't think you're really qualified to do this.

[2KGTS]

Originally Posted by InSw1tchedFlame

what about tuning vvt with camcon? i have searched and searched and searched.....all i found was stupid people "whats better camcon or emanage" who cares, im looking for tuning of camcon haha, anyone know how to tune??

Here's some info which links to a tc dyno exercise and more specific input on the Camcon. Use Google - it's your friend!

http://my.is/forums/archive/index.php/t-273407.html

From that thread:

=========================================
CAMON setting:
2: 0
2.: -2
3: 3
3.: 4
4: 5
4.: 4
5: 3
5.: 2
6: 3
6.: 2
7: 2
7.: 2
8: 2
8.: 2
9: 1

thats from a 2ZZ application, so it seems to be mostly advanced on those engines, not sure how the 2JZ will react.
===============================================

As always in ECU tuning, travel at your own risk...

[InSw1tchedFlame]

Originally Posted by Jesse IL

No offense, but if you can't relate the general technique to your own situation, I don't think you're really qualified to do this.

how do you figure? the post that was just made by 2kgts was the most useful thing i have read about camcon. the top post didnt have anything to do with 2kgts' post, which was swift and exactly what i needed to know, thanks a lot 2kgts, appreciate it, do you know what the gains were on that set up you just told me??? maybe a dyno sheet

[Jesse IL]

The scientific method escapes you.

DYI01 tuned VVT using the PFC by setting the map at a fixed VVT number and doing a dyno pull. Then he changed them and did another. He overlayed all the plots and then was able to see which settings were best.

You can do EXACTLY the same thing with a CAMCON. Do you want a tuning method or do you just want someone to tell you what settings to use?

[InSw1tchedFlame]

i was just looking for a base diagram of what someone used so i don't blow my car up testing what works best haha, i understood what he did, and you're correct the same concept can be applied to using Camcon, but i was looking for exactly what 2kgts gave me, a basic set up for me to run off of so i didnt start to strong or anything

[kortik]

you can go to camcon official site and they have a .pdf file of US and JP base maps.

[2KGTS]

The issue with re-using others' maps is that each engine is really different - even if modded exactly the same or dead stock. It pays to use that "Scientific method" - guaranteed to get the best results.

No matter what you do, good luck and post results!

[InSw1tchedFlame]

not sure how ill know results, i dont plan on dynoing really.....im just going to go to the track and see which map runs fastest......good point on every engine is different tho, but they still gota have some area of basis

[enjoi4586]

Thats a lot of pulls at the track man. But anywho, on a different note I think I'm just going to tune my VVT based on feel. The only bad thing to this is - in my own head/theory - the VVT won't be dead accurate in the lower gears because its a mechanical mechanism the actually adjusts throughout RPM, taking an extra second to get that added 1 degree.Example: Jesse, In your map where you go from 5500 to 5700, do you think you'll ever see the most advanced overlap (being the drop from 45 to 1) unless your in a high gear? So comment/correct, do whatever it is you guys do best. Still in the learning process

[Jesse IL]

Not really sure what you're after. The only answer I can think of for you is do whatever works.

[enjoi4586]

Alright, let me make it more clear; 2nd gear pull, in your map from the drop from the VVT being 45 straight to 1, and then back up. Do you think you'll ever see the 58 or whatever degree's of advance (given that 1 is the most advance)? Since you're only going to be in the 5,700 RPM range for a split second (since your in 2nd gear), do you think the VVT can change degree's that quickly?

[Jesse IL]

I have no idea. The idea is to determine optimum VVL change point, and determine optimum VVT number for that point on both the high and low cam. Once you actually implement the change, you might be forced to make some compromises in VVT tuning to achieve a smooth swicth. Compromise is the nature of tuning. Assuming you're optimizing the power below the transition, your value above the transition might end up artificially low in order to command the fastest change possible.

[enjoi4586]

And again... I have a GT

[Jesse IL]

Originally Posted by enjoi4586

And again... I have a GT

Well then you don't have to worry about large jumps in the VVT map like on a GT-S.

[enjoi4586]

I know, but VVT doesn't directly affect knock, does it?

[Jesse IL]

Please take your general discussion type questions outside this thread. It is a sticky intended as a how-to. Questions within the thread should be related to the topic.

But yes, VVT can affect knock.

[deltaB]

The spyderchat links work, but not as written. Try these:

Originally Posted by lost27

Interesting related thread on VVTI tuning on spyderchat:

http://www.spyderchat.com/phpBB2/viewtopic.php?t=25111

Originally Posted by white flash

This thread also has some interesting info, for those of you who want to know more about the VVT settings in Datalogit. http://www.spyderchat.com/phpBB2/viewtopic.php?t=28407 Hopefully this will shed some new light on the subject.

dB

[Jesse IL]

I just realized today that Dan's original thread where he did all this testing is not linked here:

http://www.newcelica.org/forums/showthread.php?t=186132

[Exotic II]

I see alotof information applied to the PFC and CAMCON. Does the E-Manage Ultimate have the same flexability?

[Jesse IL]

Originally Posted by Exotic II

I see alotof information applied to the PFC and CAMCON. Does the E-Manage Ultimate have the same flexability?

No. The PFC and CAMCON are the only two units capable of doing this. Don't waste your money on an E-Manage Ultimate. Get a Power FC.

[Exotic II]

Great ! Too bad the Greddy s/c is packaged with a emanage ultimate. I only paid $2,530 shipped for mine, so no big loss.

[zzt231 gr]

http://www.hondata.com/help/flashpro...vtec_point.htm

Has anyone tried that type of RPM breakpoints,regarding the VVT?sounds very logical and I think it can help a lot!What do you guys think??

[many]

This totally makes sense and has some great logic,
but....It can't be applied to the Power FC.
The only way we could do that is if the Power FC had a Low cam map and a High cam map. But then it would only make sense if the switchover point was variable, meaning =>depending on load and throttle response(which again doesn't exist in Power FC).
The Lotus Exige has that.
You can follow the logic behind it for tuning though....thats how we did set up some VVT numbers.
You log(or at the dyno) multiple runs on the low cam up to 7000rpm.
and then you do the big cam from 5000rpm till redline.
Comparing the MV(millivolts from the MAF) or the dyno runs will give an idea what performs the best.

As breaking points go, you can debate it all day long....with most experienced tuners out there. ...but basically they all work just fine.
The thing is.....you want to have as much as possible breaking points in your map to cover the entire tune....and the more the better IMO.
Ex: if you can only rev to a safe 8400rpm theres no point in having the scale all the way up to 10000rpm. Same goes with the load...if your only seeing a 11 500 load and your scale goes to 13 500 then your falling short .
So again it all comes to preferences and common sense.

[zzt231 gr]

many,I am mostly talking about the 50 rpm breakpoint just before VTEC,to equalize the stumble our cars have when hitting lift!Something like my map,but w/o the dip right before lift!

[zzt231 gr]

Wow,I'm really sorry!I rushed and made a mistake and I want to add something.

Go in the end of the page and click on the link "VTEC crossover tuning".

I don't know why it doesn't links directly...