Nissan 370Z Forum - Smooth Throttle for UpRev

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- - Smooth Throttle for UpRev (http://www.the370z.com/tuning/43384-smooth-throttle-uprev.html)

I am almost ready to pull the trigger on the UpRev Tune and am most likely going to use wstar's 2300 map... anyone else have thoughts on this setup?

Quote:

Originally Posted by richc2jeter (Post 2910275)

I am almost ready to pull the trigger on the UpRev Tune and am most likely going to use wstar's 2300 map... anyone else have thoughts on this setup?

Are you going to get dyno'd or pick up the cable and reflash it yourself?

Quote:

Originally Posted by seymore4 (Post 2910324)

Are you going to get dyno'd or pick up the cable and reflash it yourself?

I'm going to get a custom dyno tune with the UpRev software license at Innovative Tuning in Upstate NY.

Subd so I don't forget about this thread. Love all the effort and research on this.

Quote:

Originally Posted by jrb55gh (Post 2819083)

Here is a data log from my Ecutek software of throttle pedal sensor and throttle opening sensor for several easy starts. It appears that the throttle roughly follows the throttle pedal and does not remain wide open. The pedal sensor voltage is in blue and the throttle opening sensor is in yellow. The second screenshot overlays the VVEL (magenta) and VVT (red). There is truly a lot going on with every movement of the throttle pedal.

http://i1372.photobucket.com/albums/...psc550a2af.png

http://i1372.photobucket.com/albums/...pscb49df30.png

http://i1372.photobucket.com/albums/...ps61a148a9.png

from what i've read about VVT, the VVT advance should be zero (ie. not advanced nor retarded) when the gas pedal is at rest. Unless Nissan's CVTC system is different to that of other makes. Or i may have just misunderstood the materials i've read.

Your screenshot is of interest to me because i am trying to figure out an intermittent throttle response loss, which occurs mainly when the engine is fully warmed up.

Your VVT cam angle appears to be advanced at approx 35* when you are coasting which is pretty much the same conclusion i formed after graphing my Uprev logs. The only time cam angle is at zero is at a standstill idling.

Quote:

Originally Posted by wstar (Post 1338754)

Update - the old top post was wiped out in favor of new, better data and a better map. If you saw/used the map that was originally here, that map is what's called "Linear" below.

This post is all about the Throttle map in UpRev. You'll need the Tuner license (or take this data to a tuner) to use this. Keep in mind this is all from an NA vehicle with a fairly maximal set of bolt-ons and a dyno tune. YMMV on a bone stock car, and I especially wouldn't blindly follow this on FI.

After a bunch of testing (and posting, and thinking, and testing more, etc) I've finally settled on a throttle map I really like. I've done some drivability testing on this map, and more importantly I've done datalogging of several reasonable candidate maps with Cipher to add some numeric credibility to my subjective opinions.

Background:

The stock throttle map uses lower values at the upper end of the pedal range when at lower RPMs. This doesn't let you get on full power in the lower part of the range, instead opening up a bit gradually as the RPMs rise. This is sometimes perceived as throttle "lag" at low RPM. UpRev tuners have figured out that you can "fix" this by putting a solid line of slightly-over-maximum values (3800) in the uppermost column of the data, and then trying to smooth that into the existing factory data a bit for drivability. The idea is to give you a similar-looking throttle curve in the useful parts at all RPMs, which reaches the maximum.

However, "simple" or "naive" attempts to just set a few top columns fixed at 3800 and step off of that in linear amounts (which is what my tuner did. I don't fault him for that, it took hours of mathing around with curve fitting algorithms, plotting software, and testing to do better), you get a jerky throttle response map, and you can feel it places when driving.

My first attempt to smooth this out (while retaining the benefits) was a linear map from low-end stock values out to a couple columns of 3800, which was better, but still not ideal. I found that a simple 2nd order polynomial curve going through 3 target data points (stock 0% values, a fixed value at 50%, and 3800 at 100%) seemed to give better results, given some tuning on the middle fixed value. A reasonably magic value for the 50% mark seems to be 2300. The polynomials were derived using the perl module Algorithm::CurveFit from CPAN.

The Data:

In all of the charts below, the maps in use are:

Linear: This was my first smoothing attempt, the one that was posted here at the top originally. It's a straight shot from around 18.8% up to a couple columns of 3800's at the end.
Curve 2700: This is the good polynomial curve, but with the middle value set to 2700, as an example of what happens when it's a bit out of range.
Curve 2300: This is the good curve, with the middle value at 2300. You'll notice it tends to approximate the stock curves in Cipher data graphs, which is a really good sign.
Stock: This is the bone stock throttle map
Tuner: This is the simplistic "jam some 3800s into the top of the chart and roughly smooth down from there" approach that came from my tuner. I didn't datalog this for the data charts since I threw it out of the running long ago, but it's in the first chart just for comparison sake.

These charts were generated from the raw data using Plot.

This first graph is of the raw table data itself, just the line of values for the 4800 RPM row, to give you an idea of the shape and smoothness of each of the candidate maps. Note that axis labels are what they're called in the UpRev Rom Editor, but even UpRev acknowledges that we don't really know what these numbers really mean. "Flow Potential" seems to roughly correspond with the accelerator pedal position, and "Driving Force" has something to do with engine throttling via the butterflies and/or VVEL.

Note that "Curve 2300" makes a good smooth curve approximation of the Tuner values, and the "Curve 2700" is the same shape but roughly bumped up to enclose the Tuner values.

http://www.the370z.com/members/wstar...0-rpm-line.png

The next two charts are based on Cipher data logging of the first 4 candidate maps above. The log snapshot was taken with me rolling through the accelerator pedal from a low position to full throttle at a reasonable approximation of "linearly" in 3rd gear from around 3000 RPM to redline. Since I knew I wouldn't be able to reliably reproduce the same pedal curve for each run, the time-axis was thrown out and the data has been re-mapped strictly versus the accelerator position itself, to provide clean comparisons.

The first datalogging chart is Accel Pedal vs Throttle Position Sensor. The important takeaways here are that (1) the Linear map actually has a big non-linear bump in the real world versus the stock curve, (2) the 2700 curve does crazy things up top and doesn't even sustain full throttle, and (3) the 2300 curve does a good job approximating the stock response curve.

http://www.the370z.com/members/wstar...rottle-pos.png

The other is Accel Pedal vs "VVEL Position Sensor". Don't ask me what that means, but it's still interesting to observe diffs in the shapes. Note again the 2300 curve is the closest to stock, the 2700 curve is kinda screwy at the bottom, and the linear curve is a bit off at the top in the opposite direction. I take the stronger divergences away from the stock shape to mean the engine is telling me "you're doing it wrong" :)

http://www.the370z.com/members/wstar...s-vvel-pos.png

So I've settled on the 2300 Curve above. It seems to provide the best blend of (a) getting those 3800 values across all RPMs at the top of the pedal, so you're not limited by "throttle lag" at lower RPMs, (b) having a smooth graph shape with no sharp, unpredictable transitions, and (c) having smooth results that closely mirror stock in the important related Cipher datalogs during a smooth pull through 3rd gear.

The 2300 Curve Data:

You can copy this straight from here and paste it into a throttle table in UpRev:

Code:

8064 8101 81A0 82CC 83F1 8507 8718 88FC 8AB5 8C41 8D4F 8DA3 8DF3 8E44 8E8F 8ED8 

803E 80DE 8181 82B3 83DE 84F9 8712 88FC 8AB8 8C46 8D53 8DA6 8DF6 8E46 8E90 8ED8 

8018 80BC 8162 829A 83CB 84EB 870C 88FC 8ABC 8C4B 8D57 8DAA 8DF9 8E48 8E92 8ED8 

7FF2 8099 8142 8281 83B8 84DD 8706 88FC 8ABF 8C50 8D5B 8DAD 8DFC 8E4A 8E93 8ED8 

7FCB 8076 8122 8267 83A4 84CE 8700 88FC 8AC3 8C55 8D60 8DB1 8DFF 8E4C 8E94 8ED8 

7FA5 8053 8103 824E 8391 84C0 86FA 88FC 8AC7 8C59 8D64 8DB5 8E02 8E4E 8E95 8ED8 

7F7F 8031 80E4 8235 837D 84B2 86F4 88FC 8ACA 8C5E 8D68 8DB8 8E05 8E50 8E96 8ED8 

7F59 800E 80C5 821C 836A 84A3 86EE 88FC 8ACE 8C63 8D6C 8DBC 8E08 8E53 8E97 8ED8 

7F33 7FEC 80A6 8203 8357 8495 86E8 88FC 8AD1 8C68 8D70 8DBF 8E0B 8E55 8E98 8ED8 

7F0D 7FC9 8087 81EB 8344 8487 86E2 88FC 8AD5 8C6C 8D74 8DC3 8E0E 8E57 8E99 8ED8 

7EE6 7FA6 8067 81D1 8330 8478 86DC 88FC 8AD8 8C71 8D78 8DC6 8E11 8E59 8E9A 8ED8 

7EC0 7F83 8048 81B8 831D 846A 86D6 88FC 8ADC 8C76 8D7C 8DCA 8E13 8E5B 8E9C 8ED8 

7E9A 7F60 8029 819F 8309 845C 86D0 88FC 8AE0 8C7B 8D80 8DCE 8E16 8E5D 8E9D 8ED8 

7E64 7F2F 7FFC 817C 82EE 8448 86C8 88FC 8AE5 8C82 8D86 8DD3 8E1B 8E60 8E9E 8ED8 

7D47 7E2C 7F13 80C1 825D 83DD 869B 88FC 8AFF 8CA5 8DA5 8DED 8E30 8E6F 8EA7 8ED8

The results should look like this in the editor when displaying decimal values:

http://www.the370z.com/members/wstar...-data-view.jpg

And this is the UpRev view of the whole map surface for it:

http://www.the370z.com/members/wstar...rface-plot.jpg

If you're concerned about compatibility between my stock ECU setup in general and yours, this is what my stock throttle map looks like for comparison:

http://www.the370z.com/members/wstar...rottle-map.png

Hello , any other more text about throuttle tuning ?
thanks for shareing

I really wish I could try these, I do not have editor on my cable :(

When I first tried your tables this spring it caused a dead pedal situation in my car. I will try again with these values and hopefully it works better, now sure if the boost is throwing it off or what.

Quote:

Originally Posted by Mitco39 (Post 2950378)

Are you talking about wstar map or my modified wstar (awgd8)?

My Modified Wstar Map was not designed for boosted engine. Just an FYI.
I have not posted my new Map yet. I made the midrange to top end a little more aggressive than original wstar and modified awgd8 map. PM me if you want to try it out on NA engine.

BTW, post # 286 is the original Wstar throttle MAP
My modified one is at post # 287
And I also have a newer more aggressive modified #2 wstar (awgd8 modified 2) - I just posted below.

The reason why I made changes to my AWGD8 (modified wstar map) was the lowend to midrange is best now, but mid to top end starts to get flat, bec. we tend to get used to the sudden lowend responsiveness and the midrange to top end has less aggressive setting which appears or feel less responsive. I made the throttle a bit more aggressive from mid to top end.

Quote:

Originally Posted by jrb55gh (Post 2811445)

Jordo,

I do not have access to the hex files in my Dynotronics tune for the throttle response. However, I can post the data logging graphs of the actual throttle, VVT, VVEL responses to throttle pedal input. Apparently these responses are accomplished by bypassing the Uprev throttle table and directly specifying each parameter in the Ecutek software.

The first plot is the throttle opening in degrees (green), VVEL (yellow), VVT (blue) vs. throttle pedal sensor voltage in a 2000 rpm roll on. Idle is about .7 volts and full throttle is about 4.66 volts.

The second plot is the standing start data with the VVT (blue) incorporated into the same graph.

The third plot is the throttle opening in degrees (green) and VVEL (yellow) vs. throttle pedal sensor voltage in a normal standing start.

http://i1372.photobucket.com/albums/...ps68f2cc66.png

http://i1372.photobucket.com/albums/...ps15e5999c.png

http://i1372.photobucket.com/albums/...ps6b730932.png

Very interesting and insightful datalog, m8!
If I interpret your data correctly, the VVT and VVL reach their final values at around 25% throttle plate position, which means that beyond this point the engine load is indeed controlled by further opening the throttle plate only, not valve lift.

I did try the map above and it seems like my low end gets a bit smoother than the modified #2, and the mid to top end are a lot better with this map 3.

If I could blend the lowend of map 2 and mid/top end response of map 3, it should have been perfect. Map 2 seems like the best blend of low end street us and highway mid to top end. Map 3 is best for G37 low end gearing, not aggressive enough for my non close gearing 5 speed A/T, but smooth low end with more oomph at the mid to top...

anyone ever experience weird throttle issues with this map like the following:

start engine, shift into 1st, give it gas and the car putters along hardly moving even if i floor it. takes no joke, 5 sec to get upto 20mph. looking at throttle % in torque (android app) it says ~20% until it catches up a few sec later. if i shut the car off and immediately restart it, lag goes away.

if i switch to my stock map i never run into this issue?

Quote:

Originally Posted by chops (Post 2955712)

Which MAP are you using? Original Wstar ?

Quote:

Originally Posted by Awgd8 (Post 2955745)

Which MAP are you using? Original Wstar ?

i had wstar's map included in my uprev

Quote:

Originally Posted by chops (Post 2955748)

i had wstar's map included in my uprev

Would you be able to email me your MAP (e.g. Uprev.OsirisROM) ? I am just curious?
Pls. PM me so I can give you my email. Sometimes when I am tweaking my MAPS using the ROM Editor, when I select or highlight a section of the map, sometimes it highlight a different area (for some weird reason) and accidentally change the wrong parameter. That`s when I started checking my .osirisrom file 3x before flashing my car.

Ok maybe my post was missed I have a tune and the cable that allows me to flash the car an data log ECT. I'm currently doing and ETune can I use your throttle map or at atleast try it ? How ? Any help would be appreciated . Thank you

Quote:

Originally Posted by ANMVQ (Post 2956100)

Yes, you can use these Throttle MAP. It will be safer to Try wstar smooth throttle first then once you get comfortable, you can try my wstar modified (awgd8) throttle MaP.
BTW, as mentioned before, copy and paste at your own risk, wstar and me are not responsible to any legal isssue it may cause yo or the others to play with our maps.

Instruction below:

It is pretty simple. All you have to do is open up the .OsirisROm file that your tuner gave you using the ROM editor. Click which MaP you want to change. (1,2,3,4 or 5). Open that Electronic Throttle section, on that specific MAP you picked , and it will load the throttle tables.

Next, find the hexcodes I posted here (which includes wstar original hexcode) and pick which Elec. Throttle map you want to use. So highlight the enitire Map hexcodes found here and right click mouse -copy.

Go back to the Map Table you want to change on the ROM editor. Highlight the whole Map table you want to change, from top left corner of the throttle tables down to the lower right corner of the table. Once highlighted, there are 7 i think, icons on the upper right corner of the throttle MAP tables, click on the second icon (paste) from left, while you still have the table map highlited. This will paste the hexcode you copied here in the forum and using that icon on the Rom editor, it replaces the current map table that you wanted to change. Verify if the numbers are change compare to old ones. Save the ROM file using the main rom editor window. (The main windows that open first when you open the Rom editor) . When saving, it is a good idea to save the new one as a new .OsirisRAM file and save it to a differenct folder in your computer. This way you still have a backup of your original MAP.

After flashing the car's ECU, don't forget to select(toggle pick) the specific map you just change, if you change it at MAP 2- 5 you need to switch MAP on the steering, since flashing default it to MAP 1.

Post# 297 are all the Throttle MAPs I created which came from wstar original throttle MAP. I also posted wstar orignal throttle MAP hexcodes #1 to credit his WORK here. BTW, I modIfied wstar original throttle MAP to make more aggressive all throught the powerband. Pls. I need some feed bCk if you use the awgd8 modifiied ones.

http://www.the370z.com/tuning/43384-...-uprev-20.html

Quote:

Originally Posted by ANMVQ (Post 2956100)

I think if you have an Etune from Uprev you can't modify it. They lock the tune.

Quote:

Originally Posted by Kabestro (Post 2956215)

I think if you have an Etune from Uprev you can't modify it. They lock the tune.

True! That is why it is worth checking out Seymore4 here. He Etunes unlimited for $100 and does not lock the file.

Quote:

Originally Posted by Awgd8 (Post 2956268)

True! That is why it is worth checking out Seymore4 here. He Etunes unlimited for $100 and does not lock the file.

Nice, didn't know that. One question, for etuning, do you simulate something, is there a program for that? Or just by looking at data logs?

I gave up I cant open my ROM file, ( Tune) says its corrupt :/

Quote:

Originally Posted by ANMVQ (Post 2956791)

I gave up I cant open my ROM file, ( Tune) says its corrupt :/

Can I take a look? PM me for email...

Quote:

Originally Posted by Kabestro (Post 2956609)

Nice, didn't know that. One question, for etuning, do you simulate something, is there a program for that? Or just by looking at data logs?

Just by looking at your data log. Basically, concentrating on A/F mixture on WOT... That alone is a good insurance for $100.

Quote:

Originally Posted by wstar (Post 1338754)

[snip]
Background:

The stock throttle map uses lower values at the upper end of the pedal range when at lower RPMs. This doesn't let you get on full power in the lower part of the range, instead opening up a bit gradually as the RPMs rise. This is sometimes perceived as throttle "lag" at low RPM. UpRev tuners have figured out that you can "fix" this by putting a solid line of slightly-over-maximum values (3800) in the uppermost column of the data, and then trying to smooth that into the existing factory data a bit for drivability. The idea is to give you a similar-looking throttle curve in the useful parts at all RPMs, which reaches the maximum.
[snip]

Hi Wstar, hi all,
I was trying to reproduce your throttle map plots in order to also get a graphic representation of AWGD8's curves, and stumbled upon the following:
Can you explain why the "3800" is actually referred to as 3800 when in fact its corresponding hex value x8ED8 equates to decimal 36568? By calling it a "3800" we ignore an offset of 32768, or, exactly x8000. I find this value curious; it seems more deliberate than random. You got any insight or is that UpRev magics?
Also, in light of the ignored offset negative throttle map values are not really negative values anyway, and thus, their sign of no special meaning. If one had chosen another (arbitrary?) offset there might well be no negatives at all.
Cheers
http://www.prelude.myzen.co.uk/370Z/...rottleMaps.jpg

V1H,

Thanks for taking the time to analyze those Map curves.
My Awgd8 modified #3 seems to reach the maximum allowed number to feel the gain in the low end power at 1/4 to 1/2 pedal push. I basically felt that the number I put on the 40% - 60% flow potential is at the max/passed the limit to feel the gain from low end up to mid range RPM. Although, the mid to top end power can be felt.

So far my favorite MAP is the AWGD8 # Blend 2&3. You can see I tried to have variation of line angle to feel the change in power. The lowend has steep climb starting at 25% low potential. (About 1/4 pedal push) In my 5 speed AT tranny ( using manual mode) the power start at 2k RPM at 1/4 gas pedal. If you noticed I bumped up the curved to feel another power in the midrange and tapers of a bit at 3/4 of the curve graph. Then steep it up again on the top end to feel a continous power all throught the power band. Wstar map is too smooth were I could feel a better lowend initially and tapers off towards the top. I understand his point about touchy throttle input and I am actually doing the opposite, since I dont have a close gearing ratio tranny and I try to compensate an early throttle response that can be felt all through out the power band. A lot of trial and error changing those numbers, it is hard to explain, but I could feel where the power start and how far the pedal is push and the sound of the engine (less strain or smooth) by playing the throttle table. Still all my modified MAPs were tested at 7.6K RPM and I honestly feel smoother. (No jerky feeling or bogging issues)

My problem is I do not know how my map behaves on the G37 since I designed it for a 5 speed A/T. 3.5 liters VQ35HR engine....??? I only have one member here commented that my MAP #1 is more aggressive on the midrange vs wstar but still smooth..

BTW, i wish wstar can enlighten us with your question. I could be wrong, but my feeling about those negative numbers might be the a buffer when you let off the throttle.... I have no clue, but you know how the power behaves when you suddenly downshift and left off the throttle... It smooth things up... ????

Hi Awgd8,

I have another question. I believe I read the 3800 value was considered to give a 100% WOT. Now that you topmost values are significantly beyond 3800, do you feel the throttle still keeps opening further past 3800 in your case? It'd consequently meant the 3800 supposedly chosen by UpRev Tuners couldn't be 100% WOT, or might you not truly be able to tell any change in Throttle position for your 3800+ values? I wonder at what mx value the ECU might "crash".

Quote:

Originally Posted by V1H (Post 2957596)

POST#8 by wstar on the 1st page of this thread.

Originally Posted by Jordo! View Post
Awesome, thanks -- I will pass this on

"Driving Force" appears to = Load and "Flow Potential" is either VE or MAF counts (or a calculated perecentage based on both).

Load is based on RPM, VE, and g/sec of metered air, so that's probably about right.

WSTAR : " Yeah the table still doesn't make intuitive sense to me though. The tuner I used (as in, the dyno-tuning professional) seemed to know what he was doing and set all "3800" values in the last few columns though, and that seems to correspond to WOT at full pedal. "

It's clear from experimenting that this table does affect how the throttle reacts to pedal input, but both of the non-obvious labels seem like secondary effects. The position of the throttle butterfly will determine airflow, and that combined with RPM is pretty much going to define load or driving force or whatever. It just seems like one of these axes must be mislabeled for this to be a throttle table.

I wish wstar can chime in here... My AWGD8 # 3 MAP is at 4300 MAX. It might fully open pass the 3800, but not sure. All I know is there is a certain max at a certain flow potential %. As I mentioned on my MAP #3 . I lost a little bit of seat of pants pull when I reached the 50% flow potential as you can see on your MAP curve. ( the highest point @50% ) Those number weren't even close to 3800, but I did feel a strong pull from the middle of midrange to top end and those are around 3600-4300....

BTW, I just happened to noticed while looking at the curve Graph you posted, that my AWGD# blend 2/3 MAP looks a bit the same curve with the stock G37 MAP. It just happened that the Blend MAP power comes in earlier with a less throttle/pedal push....No wonder why I like it BEST!

Quote:

Originally Posted by wstar (Post 1348126)

Random notes from testing: the Throttle Position (as in butterfly) data in OBD-II may be faked, but it does track something roughly equivalent in VVEL if so. I did some logging on the curves while trying to roll through the throttle smoothly and consistently using different test maps. One was my standard smooth map to 3800, and the others were modified to smoothly reach 3200 and 4200. The funny thing is that in spite of the large change in the wide-open numbers, it was hard to detect any real difference in the graphs or the driving feel.

The 4200 map did tend to ramp out a bit quicker at the end (which just makes fine-grained control with the pedal more difficult), and the 3200 map did seem a little smoother at the top, but the differences were pretty trivial. It seems like the numeric maximums are largely irrelevant within reason. What causes throttle behavior changes is the shape of the curves (since they all started at the same low-end values, the 4200 map had a sharper slope than the 3200 map).

Also, based on testing, and based on reading some google search results of UpRev guys posting on other forums, reaching WOT at any RPM was never an issue on this car. Even on my stock throttle map, I can get the TPS output to peg when I stab the throttle from a stop in first gear. Apparently running a map like mine does remove some throttle latency in lower speeds/gears though.

What's left to test really is playing with the curvature. Right now I'm running linear (by percentage) from 18.8% to 96.9% on the table, and the TPS outputs still look fairly non-linear when rolling through the pedal smoothly. By that I mean, it goes relatively smooth for a while, but in the upper region it tends to just skyrocket relative to pedal position (i.e. more in the shape of an asymptotic graph), which I guess means I need to run the numbers up a little quicker near the bottom and flatten out the deltas in the upper-mid part. Going to try some other curves on the data and see what makes it smoother.

My AGWD8 Blend 2/3 happens to have 4200 max on the throttle table, so wstar originally experiment those 2 values (3200 and 4200) and did not feel a difference. I think this proves that in order to feel a significant increase in throttle response is to give more pronounce curvature on the graph and the right location where you needed it to kick in. Too smooth of a curve feels less torque all through out the powerband.

Now I wonder why the tuner (wstar post#1) graph has significant steep curvature from low end, mid and top... (see the graph he posted LIGHT BLUE LINES)

Quote:

Originally Posted by Awgd8 (Post 2957641)

BTW, I just happened to noticed while looking at the curve Graph you posted, that my AWGD# blend 2/3 MAP looks a bit the same curve with the stock G37 MAP. It just happened that the Blend MAP power comes in earlier with a less throttle/pedal push....No wonder why I like it BEST!

I see what u mean :rolleyes:

And on Wstar's comment that a linear curve wouldn't result in a steady throttle valve opening towards the upper end.. I think I know why that may be. It's a simple trigonometric relation. Opening an almost open butterfly a little further has much less an effect on additional air flow than doing so at a half opened butterfly. Therefore the ECU may have a built-in non-linear interpretation of throttle curve to actual throttle position. If that makes sense.
If all was purely geometric and idealistic this non-linear relation would simply be sinosoidal in shape. Some call this the "S" shape in a throttle map, which is a part of a sine square function. But I wouldn't be surprised Nissan also accounted for other physical parameters (partial pressure, turbulence, etc) which will probably make this non-linear relationship more complex than a simple trig. function.
In order to "reverse engineer" this non-linearity one would really have to play with throttle curves, point by point, until the datalog of the TPS becomes linear with accelerator pedal. That would of course be a huge PITA to do :icon17:
And on top of that you'd have to repeat everything for all other rpms, coz flow characteristics change with rpm. (No motor has a perfectly flat volumetric efficiency across the rpm range)

i might be able to offer some insight as to why they did this. i just got my vhr car a month ago and have yet to mess with tuning it, but i have extensive r&d/tuning experience with a radical revup combination that i developed outside the light of the public forums. i tune this car myself using an aem infinity standalone ecu. the car uses a large single ported 87mm gm throttle body (along with a custom intake manifold that i also built) which brings its inlet airflow cross-sectional area on par with that of the hr and vhr. prior to this i attempted to make this work on the stock ecu and found the limits of the system, as well as experienced a lot of the frustrations you guys have been going through with this, minus the vvel connection. it becomes apparent after messing with it for a while that what uprev supplies you as a throttle map doesnt exactly directly control the throttle like you wish it would. in fact that map literally does nothing anytime the ecu sees that the engine is operating within the idle range. that said, what everyone always wants with regards to throttle control is what the standalones provide... a throttle position vs pedal position/rpm map. now, given that i have been able to experiment with a comparable amount of inlet airflow (potential) as the hr/vhr cars, but with the ability to control the throttle in this fashion, i can see why the power delivery is designed to be s-shaped. i was able to set the throttle table up, relative to pedal position, in a completely linear fashion with the aem. what might not be readily apparent is that the engine doesnt necessarily increase its airflow potential relative to throttle position. so, what you find with a big 87, or a pair of 60's, with a truly linear throttle curve is that it is way, way, way too responsive at low throttle angles to the point that it makes low speed maneuvering jerky and awkward, while shifting becomes annoying, uncontrollable and unpredictable. i have a triple carbon disc clutch that without the rjm bracket is more or less an on/off switch. the bracket allows you to slip the clutch effectively enough for the car to drive and shift closer to that of a stockish car. well, that all goes out the window if the engine response is ultra sensitive at low throttle angles. what i did to fix this was dampen the throttle response, relative to sub-50% pedal position below 4k. the map is setup such that the x-axis is rpm and the y-axis is pedal percentage... while the map content is throttle position. with my gearing/tire combination all cruising and general commuting is done under 4k, so this works out very well. i rev to 8k, with the real meat of powerband beginning a little after 5k. throttle response is practically instantaneous on my setup. its very easy to get into the powerband when you want to. this way, any time you are more than 50% into the pedal, regardless of rpm, the car acts as if it has a cable throttle control... yet it is predictable at low throttle angles and rpms and easy to move slowly and shift. i sold my uprev cable prior to buying my aem, not knowing i would have a vhr car in another few months. i plan on buying uprev again and experimenting with this very sort of thing (although im "supposed to be leaving the car alone"). hopefully, once i can tune this new car/engine and gain some experience with this new cam timing/throttle control arrangement i can be more helpful. great job so far guys, this thread made a very interesting read!

new table...for pro license

left : 09 g37 sedan
right : 09 g37 coupe

All of the tables is the same

but
Throttle enhancement table are different.

http://i.imgur.com/b6B78ZZ.jpg?1

Hi juicinjake :hello:
Interesting story. You seem to have the right expertise with throttle map tuning to get us all a step forward with how to best program the UpRev throttle map.
Looking fwd to hearing more:driving:

Juicinjake,

Thanks for the info. We hope you get that Uprev cable/license soon. =). Check with Seymore4 here if you are ready to buy an Uprev. He is an Uprev pro tuner /Etuner and also sells Uprev. He could give you a better pricing.

Just so you know, I do not have throttle lag using one of my Modified wstar MAPs(AWGD).
As long as the RPM is at 2K and up, the power is instant. It does feel like a throttle cable, which shows on that initial very steep curve I made that start at 25% flow potential. (Pls. See V1H posted Line Graph) . The throttle is responsive once you hit 1/4 pedal push.
Also, I made less aggressive throttle opening on RPM's that is less than 2K. I realized why would I make the throttle open early when the car is cruising or idling? (Such a waste of gas.... More air more gas to mix)

My car does not have a close gearing ratio like the G37 , so I needed an aggressive throttle at lower RPM band, but if my MAP is too aggressive for the G37 at lower RPM, all you need to do is put that steep curve at around 50% flow potential. This way, the pedal gets heavier and responsive at close to 1/2 pedal push. This is good for tracking/racing, but not my preference for DD. My ideal setup for street use is a good throttle response start at 2K for off the line roll. My VQ35HR is a slug from stoplight until it reach 3k RPM. This is just a normal roll from the stoplight. I noticed a corolla seems to have a better pickup on initial roll with less effort than my HR engine... =) I have driven some loaner G37 sedan before and I know how close the gearing ratio on the first 3 or 4 gears. I hated it at first since it took a nano second to shift from 1st to 2nd. LOL! But I love the 3rd gear on that car.

I hope you can go back using Uprev and chime in here with your expertise...

awgd8, I love my 3rd also, :) I wish my tune wasn't locked and I could help contribute to this I have been following this since day one. great thread and GREAT work ! To have our cars act like a cable throttle car would be awesome, I so hate the FLOOR it from a dig and the car says "OH WAIT a second you have the pedal all the way down" Tho if I go 1/4 throttle and slowly mash it the car seems to accelerate faster. That's just hard to do LOL wanna smash it !