Asphalt Assault

Edit: If you have a good tune then keep it. If you want to learn how to tune then just so you know your starting from scratch here. you cant take info I have here and make one change to your current tune and expect that it will run better. It is souly up to you to get it right. the steps I providing are how to go about building your own tune. not fix or make a tune you have better that someone else provided you. the tune your running took countless hours to perfect. they minipulated numbers to obtain the same goal I have. good drivealbility with performance. the end result is the same but how we get there can be different and that is ok.

Please dont change one factor in your tune and expect it to run better. it will affect the VE and PE and MAF, Etc. You have to do every step I am providing to build your tune. More segments will be provided. As well this is just based on my research so if you have a different way that works for you that is great. This is just how I approach tuning. hopefully it will help you. This may seem obvious but always have your WB on the car and monitor it. Bottom line I am not responsible for your tune.


1st SETUP injectors (flowrate, rate modifier, Min pulse width, PW adder)

Flow rate

I have calculated the G/Sec I wanted in the injector flow rate table. problem encountered was the the PCM table has a max value of 8 that you can put in so I recalculate the table of what I wanted and put in values based on 8 being the max. this is what I came up with.

New values for flowrate rate table for 60lbs/rated with 43.5 fuel PSI

7.303 7.381 7.458 7.548 7.622 7.697 7.771 7.856 7.929 8.000 8.071 8.154 8.224 8.293 8.362 8.441 8.508
8.575 8.642 8.719 8.784 8.849 8.924 8.988 9.051 9.114 9.187 9.249 9.310 9.372 9.443 9.503 9.563

New values that can be put into table with 8 being max value. (PCM limted)
Injector Flow Rate vs. KPA VAC
6.110 6.175 6.239 6.314 6.377 6.439 6.501 6.572 6.6330 6.693 6.752 6.821 6.880 6.938 6.995 7.061 7.118
7.174 7.229 7.294 7.348 7.403 7.465 7.519 7.572 7.624 7.685 7.737 7.789 7.840 7.899 7.949 8.000

just kept it linear.


Rate modifier
put at 1.19. in the Flowrate modifier VS. Voltage for all values. this will increase the Injector flow rate beyond the the 8 PCM limit in the IFR VS KPA vac table.

It will look like this in HPT




Minimum Pulse width and PW Adder

Pulse width is all that needs to be changed from GMS2 #'s. I researched to what is needed for Siemens injectors. Any injector can be done similarly you just need the specs.

According to HPT the Adder table is associated to the Short Pulse Limit.

here are specs for Siemens
- Turn on time @ 14volts = 1.14ms
- Turn off time at 600kpa = 0.85ms
- gain = 0.11 ms/mg
- offset = 0.055ms

Pulsewidth - the time it takes the injector to complete one complete cycle to turn on and turn off.
so, 1.14ms + 0.85ms = 1.99ms

EDIT for Insert of additional tip
I found setting it worked well with adder values at 0 and min. pulse width at 0.094. You experiment with this and you may find that 0.9 or 0.8 is a good value for the Minimum pulse width as that is all I had seen. Higher minimum pulse width will make it difficult to get AFR at low air flow to be leaner than 11 to 12 afr (aiming for 14.7)



Adder the injector pulse = minimum wdith allowed
I found if set up to provide a minimum of half of full pulse width then your idle ran rich and at any RPM at 28MAP you ran to rich. the pulse width to provide 14.7 was 0.9. I just set it to 0.094 like GM did for GMS2. worked out very well.


Specification Confirmation with source

Specifications:
Coil Resistance: 12.5 Ohms / High Impedance / High-Z (No ECM driver modifications required)
Static Flow Rate @ 43.5PSI ( 300kPa ) w/Gas: 60 lb/hr = 630 cc/min = 453 g/min
Static Flow Rate @ 87PSI ( 600kPa ) w/Gas: 85.7 lb/hr = 900 cc/min = 648 g/min
Gain: 0.11ms/mg
Offset: 0.055ms
Turn on time @ 14VDC: 1.14ms
Turn off time: 0.85ms @ 600KPa
Connector: Bosch EV1
Orifice Type: Multi-orifice
Spray Pattern: 30 Degree Spray Cone
Factory fitted with Viton upper and lower o-rings

From: http://www.bmotorsports.com/shop/pro...sk8h24bkdr09m6


Now your ready to VE TUNE. I will collect info I obtained from various threads to get on to here. I cant take credit for the knowledge. just that I asked people and they had helped and it works. thanks Wiitt.

other consideration. your WB. if you dont have one your going to need it. get a good one and purchase one that works with HPTuners. I didnt but I got it to work with my Autometer. then you need to get it error corrected. another thread to do in this series. oh well. its going to help someone.

Kennyspec

shoould be done tonight

Ok here we go with Kennyspecs VE table tuning how to.

The VE table and the MAF are both used to calculate fueling and they both have a “error” in them. We need to eliminate the error and get the car to shoot for a 14.7:1 AFR during light throttle and cruzing. We do now know how much error the VE table or the MAF has so we will first start out by eliminating the error out of the VE table. And by error I am meaning lean or rich.

Step 1 Fail the MAF.

Open up Hptuners and set the “Maf fail High” to 0
Then set the P0103 code to “MIL on first error”
If done correctly you should now have a check engine light on when you start your car.








Step 2 Set up the car for open loop.

Under fuel control OL &CL TAB there are 3 tables that need to be changed. They are adders/multipliers for fuel. We want to change them all to 1 cause the less multipliers and adders you have the easier tuning will be.
The three tabs are

Gas (Gear)
Gas (P/N)
IVT Gain

The entire table does not need to be changed. Just change them where I have highlighted.





Turn off DFCO



Step 3 PE table.

The PE table is a multiplier for fuel when the car is under high load/WOT. It determines the AFR that you get during WOT. You set the PE table to the right multiplier to give you the desiered AFR that you want at WOT and then LEAVE THE TABLE ALONE!!! You then adjust the VE table or MAF table to obtain the correct AFR. The equation for it is
14.7/”EQ Ratio vs. RPM” = AFR at WOT

So lets say that I want a 11.9 AFR at WOT so the value in the “EQ Ratio vs. RPM should be 14.7/ x = 11.9 x = 1.235

So I then set the EQ ratio vs. Rpm to 1.235 across the entire range.

(disclaimer: I am not saying that a 11.9 AFR is safe and should be used but it is what I use with my meth injection)


I did not like how in the gmstg2 tune the car didn’t go into PE mode until above 4800 rpm so I changed some things.

PE Enable MAP to 115kpa ~ 3 psi
PE delay RPM 0
PE table TPS (see table below)
Enrichment rate 1
Piston Protection 8000rpm

Now the car will go into PE mode regardless of rpm. Anytime you are over 3psi the car will richen up and go into PE mode.




Step 4 Turn off COT



Finally its time to go drive around and tune the car!!!!

So I assume that you have a WB 02 set up to log into HPtuners. Also you have to have a AFR% error histogram set up in HPtuners. It should log error based on your wideband. NOT based on LTFT or STFT.

Start up car and wait till it has reached operating temp 180* F

Start logging with hp tuners. hit the reset fuel trim button.

Drive around nicely on a open highway hitting as many cells as much as possible. Vary the rpm and map as slowly as possible. Try to stay out of PE mode. (stay below 4psi) and I don’t bother tuning anything above 4000rpm as I don’t do any “nice” driving above 4000 rpm. These are the cells that you want to “hit”



Once you have all the cells hit at least 20 times copy and paste by % error into the VE table. Start the car up again and restart the process. Drive around on the open highway again for about 5 mins before starting to log again. The reason for this is when you shut the car off to flash the new tune the car heatsoaks. This will throw off the tune. Driving around for the 5 mins just gets rid of the heatsoak. Now when you copy and paste by % error into the VE table you should have less error than last time. Now as you get closer to 0% error you should see that the WB gauge is closer and closer to 14.7 at part throttle driving. When you now paste the error in the VE table paste by % error half option. This just prevents you from going to far and overshooting the error. you will never get to 0% error so dont bother wasting your time. you should be able to get +-4 though.

There ya go. Your car should be now tuned in open loop. once done this its time to tune
the PE mode in open loop. To tune the PE mode is the same as tuning part throttle but now you are tuning at WOT. HAve fun with this. just watch out for knock and keep a eye on your AFR.next comes the maf. that will be in part 3 of the series.

zinner

Stuck and cleaned out the unneeded posts. UNLESS you are posting more to this how to, don't otherwise I will just delete your post.

SJSchafer

I have actually heard a bit of conflicting info on these injectors as to lbs/hr, but the 630 cc/min were all the same, so I did some math based on those. Seimen calls their injectors 60#, but if you take:

cc/min x .103 = lbs/hr then
630 x .103 = 64.89

That gives us a base table of:


7.898434727 7.982645255 8.065976655 8.162121408 8.243638761 8.324357882 8.404301772 8.496619019 8.574957078 8.652585915 8.729524451 8.818437709 8.893941632 8.968809948 9.043058444 9.128918474 9.201875169 9.274257963 9.346080189 9.429181374 9.499832394 9.569961841 9.651135484 9.720173365 9.788724349 9.856798593 9.935629069 10.00270359 10.06933132 10.13552107 10.21220025 10.27746992 10.34232769

or

62.68709539 63.3554447 64.01681668 64.77988374 65.42685826 66.0674975 66.70198401 67.4346735 68.05641509 68.67252783 69.28316191 69.98883513 70.58808318 71.18228664 71.77157081 72.45301164 73.03204324 73.60651999 74.1765477 74.83609255 75.39682482 75.95341755 76.59766417 77.14559353 77.68965855 78.22993986 78.85558958 79.38793645 79.91673728 80.44206202 81.05063764 81.56866007 82.08341337

Which actually gives us a multiplier of 1.29 (roughly). Not sure how big a difference that .10 would make, but I thought I would point it out.

Now if only I can figure out that pesky offset table...

Update - As it turns out, 1.29 still puts us just a touch above the cap, so here are the values to be used with a 1.3 multiplier (assuming, of course that the injectors are truly rated at 64.89 @ 43.5 psi and that your fuel rail pressure is 58 psi):

48.22084261 48.73495746 49.24370514 49.8306798 50.32835251 50.82115192 51.30921847 51.87282577 52.35108853 52.82502141 53.29473993 53.83756548 54.29852552 54.75560511 55.20890062 55.73308588 56.1784948 56.62039999 57.05888285 57.56622504 57.99755755 58.42570581 58.92128013 59.34276425 59.76127581 60.17687682 60.65814583 61.06764342 61.47441329 61.87850925 62.34664434 62.74512313 63.14108721

Asphalt Assault

What I have learned out of tuning is numbers are just numbers. what matters most is stability and a 14.7 AFR. so if you can achieve that with whatever number then do it. your calculations are what I believe whould be correct. your still adjusting a VE table to achievet that 14.7 tune. I only way anyone would start over is if there was something seriously wrong with there table. I have seen someone take WANTED injector flow rate #'s and inputed half the value and then in the Volatage multiply inputed 2 for all values. it doubled everything to acieve the final injector rate they were looking for. lots of different ways to accomplish the goal.

Good discussion! plus rep to you.

SJSchafer

I absolutely agree that the VEs and MAF will both need to be retuned, even if the numbers in the IFR table were sent down by God.

Jmc007

So what's wrong with the stock MAF ? Is that the HZ vs g per sec table that's not set properly ?

SJSchafer

Keep in mind that GM made thousands of LSJs. They opperate in all kinds of different climates, altitudes, etc. Also keep in mind that no 2 internal combustion engines run exactly the same in every curcumstance. Right there you have hundreds of variables. So what would you do if you built a car for mass production? You obviousely don't have the time to dyno tune every one of them, right? So you would set up the cars with a tune that will be safe for everybody. That usually means rich at higher RPMs, etc. When I first logged my car with a stock tune, I had long fuel trims all the way to +/- 15%. That would cause me to enter PE and get 10.4 or even lower AFRs when commanding a rich 10.8. Throttle response sucked as well. Just dialing in the MAF gets you better throttle response (IFRs help there too), more torque and more HP. They are still safe for my car because it is tuned to my car. Of course the same values that work great for my car, could blow yours up (okay, slight exaggeration, but you get the point).

Answer to second question = correct.

Asphalt Assault

FYI - I editted the above again based on my results last night.

I found that just idling and reving motor up to 3200 rpm and taking those results (% error) to correct my AFR (this is a good and easy test to get a good start in ensuring your able to tune your car without driving). Problem was it was not changing. My pulse width did not change from 1.1. just would not go lower than that. and as I did the VE table changes my AFR did not improve.

Too fix it I had to put the min. pulse width to 0.094 (like GMS2) and the pulse width adder to 0 for all values. It worked. Editted the how to to reflect the same. I believe I may have misinterpreted Witt's info. this is real world experience. my car drives very nice. I have VE table completed and PE done in one evening with the help of Kennyspec (so much easier if you have someone else tuning in passenger preparing a file ready to flash). Kenny's experience made sure we were on track with the setup of the file in order to get good info. Open Loop VE and PE tuning to come very shortly.
Stay tuned!

SJSchafer

Sweet. Althought Wit said min pw, I think he actually meant the short pulse limit, since that is what the adder effects. Anyone heard from him lately to get verification of this?

Also, as to my math in the post above. Those numbers may be off a touch. My injectors should be in this week and I am going to take them to be fully flow tested and try and get the numbers for the offset table.

SJSchafer

Update - injectors are here! I had them flow matched and they came in between 62.19 - 62.66 lb/hr. Now, i just have to find an injector guru who can let me know what the numbers should be for the tables we are all struggling with. Wish me luck!

an0malous

this has been invaluable to me!

need the next parts!!!!

SJSchafer

I know ssnipes is working on a MAF tuning how to, to add to this. I also have some additional info on the above posts that I have posted to other threads, that may help as well.

Asphalt Assault

put in links and post #'s if you can. it would help others the best.

jgarciarivera

iTrader: (1)

very nice guys!

SJSchafer

You're right. My bad.

https://www.cobaltss.net/forums/tuning-131/question-about-siemens-60lbers-74498/

#1 was the question. I added an update as well. Keep in mind, this is work in progress stuff and I am learning more every day.

Z Speed

subscribe

RJW

HPT Corvette tuner here..trying to help out some local Cobalt owners

In looking at their current tunes, IFR table shows numbers around 40

So what is the deal with a max of 8...as per the other posts in this thread?

The cars in question are 2006 cobalts with Eaton sc

Also, is the MAP sensor on these cars 1 bar? and to go sd, I could change them out to 2 bar (like the Cobalt baro sensor) and fake a 2 or 3 bar tune?

Yes...No....out to lunch?

Thanks

SJSchafer

The max in lbs/hr on the IFR is 63.5. We are 2 bar.

RJW

Ok thanks

What are the options if I need 3 bar?

And what is max boost before head gasket problems?

thanks

One car has a turbo feeding the sc???? we saw over 25 psi on a mechanical boost gauge

this car was making 20 to 22 psi before, so we wil change back to the oem sc puley and take it from there

Question is...can we tune it and what are the options?

Also, will we be out of fuel and what are the options there?

Witt

Yeah, this is exactly what I meant. Allows the use of lower than 1.0 ms pulse without the abrupt changes that cause a hunting idle.

Asphalt Assault

Witt I found that when set at 1.0 and with the adder at 0 across the board that the idle indeed was not hunting but I found at the same time the idle was very rich.

what should be done from there? reduce short pulse limit. thankyou.

SJSchafer

Yea, idle is rich as is decel. Right now I have Short pulse limit to 2 and min PW set at .906. My adder is setup to equal PWs of .9ish up to .875 where it starts going up from there. The problem I am finding is that it can be really tough to distiguish between MAF errors and short PW errors.

Witt

That number is too high to run at idle. The amount of fuel needed to sustain 15-1 a/f at idle on our mouse motors is less than 1.0ms which is why you are showing a rich condition.

Set the min. pulse wdith to about half that and use the short pulse adder table to add pulse width to values below 1.0ms in a progressive fashion. (something like .1ms at 1.0, then 12.5% less at every value below that until you hit 0 which your adder would also be 0.....the interpolate function is good for this).<----Just an example, don't quote me on those numbers. Basically you have to play around with the short pulse adder table and find the rates that allow a smooth idle and smooth sweeping air-fuel gauge. Jacking up the idle a little is another easy fix and will become almost necessary as you increase the pipe diameter the o2 is housed in as o2 switching speed becomes an issue at idle.

I think the advertised min. pulse width for 650cc injectors is like 1.1ms at 100kpa (atmospheric) so at lower pressure it will obviously also be a lower possible pulse width.

jimbos'ss

iTrader: (2)

subscribing for later reading