How To: HP Tuners and GM Eco S/C, Fake 2.5 Bar - Page 4 - Tuning Forum

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Re: How To: HP Tuners and GM Eco S/C, Fake 2.5 Bar
Sunday, May 17, 2009 6:11 PM
i changed everything.



12.33 @ 111.67 mph [Oct 2009]
Dyno'd on 08/02/09 - Mustang Dyno:
327.6 WHP 333.6 WTQ [10.1 AFR]

Re: How To: HP Tuners and GM Eco S/C, Fake 2.5 Bar
Sunday, May 17, 2009 8:10 PM
Admiral Jedi wrote:Are you guys changing all your map value tables, or just the timing ones?


Changing the map sensor will effect ALL MAP referenced tables since they are all referenced to the original 1 bar setup.


___________________________________________________________________

Hahn Stage II - Mitsu TD06-20g |3" Turbo-back Exhaust | 61mm Bored TB |
HP Tuners | Innovate WB02 | Spec Stage 3 | Team Green LSD | TurboTech Upper | Full Addco Sways | Sportlines & Yellows |
Re: How To: HP Tuners and GM Eco S/C, Fake 2.5 Bar
Tuesday, May 19, 2009 8:14 AM
That what I thought, I've been playing around with a 2 bar map sensor and wanted to be sure.
Re: How To: HP Tuners and GM Eco S/C, Fake 2.5 Bar
Tuesday, June 02, 2009 1:43 PM
evilmonkitar wrote:More info for this:

I actually got the car to run with the "correct" injector constant [(old constant * (old size/new size))]

What I had to do was increase my VE offset to get more fuel in there. Since it wouldnt start i just assumed it was too lean so thats why i thought of playing with the VE offset

First i started off by increase the VE offset from 20% to 60%, after i flashed that and tried to start it and it didnt run, i just added 40% to the idle table only. that actually let the car idle. i still couldnt drive it though.

To get it to drive, i boosted the constant to 75% and subtracted 15% from the idle table after (tried to keep the numbers the same since it idled fine with them). i was able to barely drive it and i just kept increasing values from there.

I ended up with a 99% VE offset in the end, and that still wasnt enough fuel at the top, so what I did was use the IPW vs VAC table and increased the multiplier over 1.0 to around 1.25 for now and it seems to get enough fuel at the top end. still working out some minor fueling issues, but its drivable and stable. Only issue right now is KR because my AFRs are slightly lean in some spots, but that is what im fixing with the multipliers.

So, to use the correct injector constant (which i think is probably important to get the correct injector duty cycle (which i was told would not be correct with a constant that high)), put the calculated constant in, increase your VE offset if your car wont start after, and once you can get it to start and drive, use the histograms after that to get proper fueling. once you feel like your VE tables and offset are as high as they will go or in the correct spot, play with the IPW vs VAC multiplier to get more fuel if needed.

Hope this helps some people who are trying to do the fake 2.5 bar. this is pretty much what i did today after class,before work,after work, hopefully the tune im flashing on in the morning (minor fuel tweaks with closed loop re-enabled) works well.

Also a TIP for fuel tuning, the low rpm and high rpm VE tables overlap. they both have a 3800 RPM column, but the high rpm table doesnt have as many TPS percentages as the low one. just make sure they match at each TPS %. i guess they dont HAVE to, but i had a lean spike when i was driving and it was annoying and i realized this was the culprit, so i matched them. havent extensively tested that tweak yet, that will happen maybe tomorrow and probably friday, but from the 2 runs i did with that change, i didnt notice that lean spike anymore.

thats it for now, time to get some sleep..


Same thing here. Are you still at 100% offset? How did you fix it if you're not?
Re: How To: HP Tuners and GM Eco S/C, Fake 2.5 Bar
Tuesday, June 02, 2009 3:53 PM
Nevermind, I figured it out.
Re: How To: HP Tuners and GM Eco S/C, Fake 2.5 Bar
Tuesday, June 02, 2009 8:49 PM
sorry didnt get a chance to check it until now. play with IPW multiplier vs VAC. mine is currently 1.120 which yields me a 11.9-12.1 afr



12.33 @ 111.67 mph [Oct 2009]
Dyno'd on 08/02/09 - Mustang Dyno:
327.6 WHP 333.6 WTQ [10.1 AFR]
Re: How To: HP Tuners and GM Eco S/C, Fake 2.5 Bar
Monday, July 06, 2009 11:53 AM
evilmonkitar wrote:will also add something else. the constant im using for 440cc injectors with the fake 2.5 bar. just did it and it seems like it works, did some logging going to fuel tune in a minute on the way to work and see how it goes. heres the math:

0.270000 * (380/440) = 0.2331818181818182

0.270000 * (36/42) = 0.23142857142857

0.2331818181818182 - 0.23142857142857 = 0.00175324675325

0.00175324675325 / 2 = 0.0008776623376625

0.2331818181818182 - 0.0008776623376625 = 0.2323051948052

so i used that and am using currently for 42# (440cc) injectors with a fake 2.5 bar tune: 0.23230


seems to work decent right now, will know more this weekend.


Is anybody using this constant for 42lb injectors?
Re: How To: HP Tuners and GM Eco S/C, Fake 2.5 Bar
Monday, July 06, 2009 12:43 PM
no, that was before i tried changing the VE offset. i tried both and have better results with adjusting the VE offset. my injector constant is .11xxx



12.33 @ 111.67 mph [Oct 2009]
Dyno'd on 08/02/09 - Mustang Dyno:
327.6 WHP 333.6 WTQ [10.1 AFR]
Re: How To: HP Tuners and GM Eco S/C, Fake 2.5 Bar
Monday, July 06, 2009 1:55 PM
That's odd. I'm using an MSD map sensor - 2 bar with the 36lb injectors now using the .27000 constant and the car runs very well.
Re: How To: HP Tuners and GM Eco S/C, Fake 2.5 Bar
Monday, July 06, 2009 9:06 PM
how does it idle? mine idled like crap with the .27000 constant with 36# injectors



12.33 @ 111.67 mph [Oct 2009]
Dyno'd on 08/02/09 - Mustang Dyno:
327.6 WHP 333.6 WTQ [10.1 AFR]
Re: How To: HP Tuners and GM Eco S/C, Fake 2.5 Bar
Tuesday, July 07, 2009 8:05 AM
It idles fine. I wonder why there's all the difference.

Re: How To: HP Tuners and GM Eco S/C, Fake 2.5 Bar
Thursday, January 04, 2018 2:20 PM
Hi,

Just writing to second the original post and tell people that it worked "flawlessly" for me. Yet it seems it is not an "out of the box solution for boosting l61". One does need to fine tune things and couple parameters, but only by applying this info on a stock tune with a GTP 2bar map (this is the difference with the OP in my case) the car started and idled really fine.

So i want to add that if your tune does not run (idle) well after following that post, it really might be because you missed something and you screw up, or your injector constant is not well defined (will talk about that right now!).

While reading this post and analysing at the same time the LD9 reflash, I kept asking myself WHY does the injector constant has to be fudged up?! Well after a few calculation with the constant on this post comparing to constant on LD9 reflash I ended up with this formula : (stock inj size / new inj size) * stock inj const * MAP BAR

So if you check deeper I only find my new inj constant using the good old formula and multiply by the number of bar my MAP sensor is. Try it with LD9 tune values :
240cc / 310cc * 0,20250 * 2 = 0,31354 which is damn near the LD9 reflash const (0,32359). Now if I try it with the info in this post (assuming it uses ss injectors) it seems to work again : 240cc / 380cc * 0,178 * 2,5 = 0,28105 Damn near again.

Now I know maybe the information above is not quite spot on, but I must say that this formula applied with all data changes of the original post made my car start first try and it was idling pretty well. So try it.

Now this is cool and it is a running solution but tuning is required no matter what. And here is a step by step how I made it work :
- I fine tuned the injector const to be as close as possible to +10/-10 total fuel trim at idle
- Since we fudged up the injector const and there might be some adjusting table we don't have access to in the original binary that are used for fueling calculation VE will be off and it needs to be retuned. (normal driving will work because of fuel trims but you might have random stall problems pushing clutch at a stop)
- What I dont is setup an histogram for both total fuel trim (LTFT + STFT) and AFR (requires wideband and HPT pro) for RPM VS TPS
- After logging a run and hitting as much cell as I can I go and change VE little by little flash the tune, rinse and repeat
- What I done before was create an histogram that was logging the AFR err with wideband input VS commanded AFR, and it should tell you the factor you should substract of add in each cells to get a perfect VE, but it can be dangerous, for exemple, if you don't turn off deceleration enleanment, you may have off values and substract or add too much to your cell so I prefer to go little by little until I am happy with the result.
- Same than above with the LTFT + STFT histogram when tuning non PE cells. Theoricaly you could use the exact % to add or remove from VE cells because it determines how much to add or substract to stay stoich but it can be screwed up by accel enrichment and or DFCO ( decel enleanment)

Other than for fueling fine tunes I am very happy with what the OP made me learn and I hope that my post just help you out a little more, so a great thanks to John02 and if I got some info wrong just tell me or please discuss politely, I am only trying to help and learn also.

Cheers
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