VE table generator ?

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VE table generator ?

Postby Motoren » Thu Dec 28, 2017 8:02 pm

I was messing around with the Ve table generator, why doesn't it take into account what size injectors you are running?

It just come up with some weird high numbers for the most part, and there is a lot of difference between turbo and turbo w/intercooler too.
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Re: VE table generator ?

Postby billr » Thu Dec 28, 2017 9:44 pm

The VE of a particular engine has nothing to do with the number of injectors or how much they flow. If you find changing injectors requires much change in the VE table, then either the req_fuel was incorrectly calculated or the injector dead-time is incorrect.

I can't really help with the turbo question, but would expect the VE to be quite different with inter-cooling. That's one of the main benefits of inter-cooling isn't it, to increase the amount of air on each cycle? I understand that some of the "increased air" is handled by VE, and some by having MAP "multiply" on, but can't explain much more than that. If you don't have multiply on, then the VE table will end up with some especially high values but they won't really represent VE any more.
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Re: VE table generator ?

Postby Motoren » Fri Dec 29, 2017 1:50 pm

I mean, if I use the "fuel VE table 1-> Tools-> VE table generator" to give me a fuelmap to start with. that just come up with something that seems very wrong.

my ms3pro is not up and running yet so I downloaded the pnp 2jz file to have something to play with.

this is how the VE table looks like from the pnp file.

Skærmbillede 2017-12-29 kl. 21.41.56.png
Skærmbillede 2017-12-29 kl. 21.41.56.png (156.25 KiB) Viewed 597 times


and this is when I hit the generate button.

Skærmbillede 2017-12-29 kl. 21.42.30.png
Skærmbillede 2017-12-29 kl. 21.42.30.png (142.21 KiB) Viewed 597 times
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Re: VE table generator ?

Postby Motoren » Fri Dec 29, 2017 2:07 pm

this is how its generating the VE table if I put in data from my friend 2jz engine.
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Re: VE table generator ?

Postby jsmcortina » Fri Dec 29, 2017 2:08 pm

Hmm... both look wrong to me?!
EDIT: and the third is clearly garbage, how accurate is the input data?

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Re: VE table generator ?

Postby Motoren » Fri Dec 29, 2017 2:26 pm

last VE generator is plotted in with this dyne sheet, its with 280kpa absolut pressure and its crank hp. WHP will be around 100hp less. but the table generator doesn't say anything about it its who or not,
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Re: VE table generator ?

Postby Motoren » Sat Jan 06, 2018 5:47 am

No one knows why the table generator is making tables with such large values?
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Re: VE table generator ?

Postby LT401Vette » Sun Jan 07, 2018 11:52 am

Not really, that will take some digging. But it clearly doesn't like your inputs..
It looks like you converted nm to lbft, but not Hk to HP. I did though and things don't look much better.

I would guess it is with how close together your HP & TQ are RPM wise.
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Re: VE table generator ?

Postby Motoren » Tue Jan 30, 2018 5:04 am

The odd thing is that it make the VE number so large. They shouldn’t go much over 100 at peak torque right ?
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Re: VE table generator ?

Postby VLC-05L » Wed Jan 31, 2018 5:09 pm

Motoren wrote:The odd thing is that it make the VE number so large. They shouldn’t go much over 100 at peak torque right ?


On a forced induction motor it is usual, expected even that the VE numbers will be greater than 100 at peak torque.
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Re: VE table generator ?

Postby Motoren » Thu Feb 01, 2018 4:37 pm

But when you use speed density and use "multiply map" you VE table shouldnt go much over 100VE as far as i understand it? even thought you are running 50psi boost
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Re: VE table generator ?

Postby BlackBird_SR71 » Sat Feb 03, 2018 7:02 pm

Motoren wrote:But when you use speed density and use "multiply map" you VE table shouldnt go much over 100VE as far as i understand it? even thought you are running 50psi boost


Simple answer is Nope. You can have Cell numbers all the way to 255 at the high end, if you want more resolution at idle for example.

Boosted VE numbers can be well over 100 . A normally aspirated VE calculation should come out to close to 100 on the 100 KPA row. But boosted figures can be well over 100. And these are not true percentage values from my understanding. Just hexidecimal numbers based on a fuel calculation. . A basic Fuel calculation is much easier to program than a true engine VE Table. I think that's where your confusion lays.

From my understanding, the TS VE Table is based on an ideal gas law. It is NOT n actual VE engine " Mechanical " or " Air Pump " calculation. If it did, the inputs in VE Table generator would require many more Parameters. Such as Bore and Stroke, CR, number of valves, size of valves, type of Cylinder head, Port Volumes, Camshaft specifications, exhaust manifold type and size, Intake manifold type, exhaust system sizing and muffled or un-muffled , Carb or TB CFM , Ambient air temperature and density and more...

There are a LOT of calculations to make to get a true VE mechanical calculation. I have some basic engine Dyno simulators that do calculate the true VE of engines . They have a TON of parameters to enter. And that's with just NA engines. Forced induction has a second page of parameters to enter....
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Re: VE table generator ?

Postby prof315 » Tue Feb 06, 2018 5:49 am

So we had this same issue at a class I was attending this past weekend. It only seems to be an issue with forced induction. if you create a table for an N/A engine it works fine.
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Re: VE table generator ?

Postby Motoren » Wed Feb 07, 2018 4:26 am

I will grap the ve table from the pnp 2jz ms3pro ecu. I was just wondering why it made such large numbers.

I’m the regards to blackbirds post, I don’t agree with the numbers, if you get a VE table with very high or very low numbers, then your required fuel is not set correct. Fuel injectors, engine ccm etc.
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Re: VE table generator ?

Postby BlackBird_SR71 » Wed Feb 07, 2018 10:30 am

Motoren wrote:I will grap the ve table from the pnp 2jz ms3pro ecu. I was just wondering why it made such large numbers.

I’m the regards to blackbirds post, I don’t agree with the numbers, if you get a VE table with very high or very low numbers, then your required fuel is not set correct. Fuel injectors, engine ccm etc.


With respect. Tune a few more engines with big injectors and you'll find out why you may have to re-scale the VE tables. It is an advanced method of fine tuning the fuel table. .

Bear in mind that the TS way of generating VE tables can be out as much as 20% on the high and low scales. If you read the MSExtra Manuals thoroughly you will find that the MS Developers warn you repeatedly IN BIG RED letters that the VE table generator is ONLY and approximation... and can be wildly inaccurate. Happens especially when you start running larger injectors than normal . NA or Turbo. It' all to do with getting the necessary Cell resolution at idle and low RPM. You really don't want idle Cell resolutions any lower than 30 at the minimum. Any lower and you just can't tune the AFR fine enough. The Fuel percentage change between, 15 >14 Cell value compared to 30 > 29 is much larger . It is a " Coarse adjustment. )

Also, and this is very important that you understand. The VE Table generated by Tuner Studio is NOT a true engine VE table. I mentioned that before. It's just a Mathematical equation to generate a " Rough " fuel curve. In some cases VERY rough. They are just hexadecimal numbers.... nothing more.

Simplified Req-Fuel X VE value = Pulse Width . So 50 x 10 = 500. So does 10 x 50 + 500. Get it. It's just a way of manipulating the Fueling eqaution if the idle and low RPM Cell values are too low and don't offer good resolution. As long as you don't go over 255 in the Upper Cell areas you are fine.

But here is a very good explanation by one of the MS regulars.
I think you have a misunderstanding of how REQ_FUEL and the size of the VE values work.

First off, the VE values in your table are not real VE. It's possible (and desireable) to use the full 8 bit resolution of the VE table on an n/a engine, and have values of 200% and higher. this is not related in any way to your duty cycle, although the actual PW calculation gets part of it's value from there.

the req_fuel is basically the base pulsewidth that all of your enrichments, corrections, VE values, load, etc. get calculated into a final pulsewidth that you see on a running engine. The manual probably needs to be updated - I believe the idea of keeping values in the range of 8-16 was because of an old firmware that could cause damage if you went too far outside these ranges. also, I believe warmup enrichments are a % of your req_fuel, so keep that in mind if you do any changes there.

Now - if you are saying that the highest VE you have in your table is 100% (or close to it), and your req_fuel is 22%, this just means that your req_fuel is too high. What you want to do is minimize req_fuel as much as possible, in order to gain as much resolution as you can in your VE table. If you are only seeing values of 100 in your VE table then I bet at low load/RPM areas you are in the single digits, and it's even worse if you turn off multiply map.

this is bad for tuning - it's impossible to accurately tune when the smallest possible change is 1, and your VE values are less than 10 (that's a minimum 10% change in fueling for moving the VE up or down by 1). I wouldn't worry about using small req_fuels too much either - lots of people have successfully tuned with a smaller req_fuel to gain more resolution. I'm currently using a req_fuel of 2.4, with multiply map enabled my VE values range from ~60 to 240. That's lots of resolution.

Here is what I reccomend you do - save a backup of your MSQ since you just got it running decently. Open your VE table, go to Tools - VE Specific - Table Transform. You can safely cut your req_fuel in half and double your VE resolution, so I would enter 11 as your new req_fuel. save it and it will automatically rescale your VE table - your max VE value should be around 200. if you're comfortable, you can make your req_fuel even smaller - I like to leave a little margin at the edges, so try not to go much over 240-250 as your max VE.

Keep in mind you may need to do some tuning on your warmup enrichments after doing this - I haven't experienced any ill effects after dropping my req_fuel however.
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Re: VE table generator ?

Postby Motoren » Wed Feb 07, 2018 12:08 pm

Yes I get what you are saying :)

I just thought that even with big enjectors and the required fuel set corrrect yours VE% would be over 30% and you would be fine with tuning idle due to the 0.1 steps. (I’m gonna run 2000cc injectors btw)

I’m gonna run flex fuel. Most of the time on pumpgas and some times on E50+. Won’t I run into trouble if I scale the VE table to 200ve on pumpgas ?

On a side note, I have never used the separate idle tune, where can I read about how that works ?
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Re: VE table generator ?

Postby BlackBird_SR71 » Sun Feb 11, 2018 5:39 am

Motoren wrote:Yes I get what you are saying :)

I just thought that even with big enjectors and the required fuel set corrrect yours VE% would be over 30% and you would be fine with tuning idle due to the 0.1 steps. (I’m gonna run 2000cc injectors btw)

I’m gonna run flex fuel. Most of the time on pumpgas and some times on E50+. Won’t I run into trouble if I scale the VE table to 200ve on pumpgas ?

On a side note, I have never used the separate idle tune, where can I read about how that works ?


Actually, since you are running a MS3 you'll probably be fine. MS3 a much better Fuel algorithm than MS1 and MS2. Those adjust to only 1% not 0.1% as the MS3. Ms3 has much finer resolution than MS1 and MS2 .( My replies about adjusting Req_Fuel to a lower value to gain resolution were meant for MS1 and MS2 mainly )

And the VE Table generated by MS3 is usually much more accurate. You'll likely be fine with MS3 at it's default calculations.
Last edited by BlackBird_SR71 on Sun Feb 11, 2018 6:38 am, edited 2 times in total.
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Re: VE table generator ?

Postby BlackBird_SR71 » Sun Feb 11, 2018 6:09 am

For a Baseline Tune on a Turbo engine, I usually like to start off with the factory HP and Torque figures at factory Boost. This will give you the best baseline VE Table generation. You can add higher values in the KPA Table and those should automatically re-scale. I just had to look up some stock specs for a 2JZ GET ( surprisingly hard to find info ) and got the following.

280 HP @5,600 RPM
333 Torque @4,000 RPM
Boost = 9 psi ( 162 KPA )

Running Flex fuel is going to require two separate tables. Make sure that you set the E50 fuel Stoich Value to 11.85

So I plugged these figures into Tuner Studio along with 2000 cc injectors and here is the VE Table that was generated for an MS3 Pro Ultimate.

Pump Fuel:

Pump Fuel 2000cc.jpg
Pump Fuel 2000cc.jpg (255.91 KiB) Viewed 127 times


Pump Fuel VE 2000cc.jpg
Pump Fuel VE 2000cc.jpg (791.4 KiB) Viewed 127 times
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Re: VE table generator ?

Postby BlackBird_SR71 » Sun Feb 11, 2018 6:17 am

And here is E50 Tables based on same Parameters. Generated VE Table for E50 will be the same for pump Fuel. So with the idle Cell values around 24ish... you will probably just get away with it.

E50 Req-Fuel. Stoich = 11.85

E50 Req-Fuel.jpg
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Re: VE table generator ?

Postby Motoren » Wed Feb 14, 2018 3:25 pm

it seems like when you are generating the VE table it doesn't take into account that you use speed density with multiply MAP on.

don't know how it generates this table. it doesn't matter if you choose NA or turbo or whatever from the dropdown menu, it dosnt matter if you change your injectors either, so I don't know how it calculates a new VE table.

i don't know if someone can confirm that.
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