LSA G8 Tune Review-Injector Scaling?

[Burntendzz]

Hello All,

Last month I had my car re-tuned for bigger injectors, flex fuel and bigger fuel pumps. I'm not super familiar with HP Tuners, but I have been going through YouTube, and other resources, so when mine arrives I will at least know my way around a little. Here is where my question comes in. Looking over my "recent tune" the injectors do not seem to be scaled any differently than when i had my 850 cc injectors in, at least not according to all of the tutorials I've viewed so far. I asked the tuner about why all of the fueling looks the same as my last tune, mostly because I was curious and wanted to learn, and he got offended, so I left it at that. I'm hoping my wideband and HPTuners show up soon, in the mean time I was hoping someone would be able to look over the tune to see if its "scaled" correctly for 1300s? If i do a compare, very little looks like it was changed from the last tune.. The car cruises decent, but I'm hesitant to give it too much throttle until i can get a wideband hooked up. I know I'm a beginner, but I was hoping to get some veterans opinions on the current tune. Please keep in mind this is a "well known" remote tuner, so it could be spot on. Unfortunately, after I had the car tuned I've had people tell me I made a mistake going with the tuner. I'm just curious for others opinions. Thanks!

[PGA2B]

Make sure under Edit>View you have it set to Advanced.

[Burntendzz]

Make sure under Edit>View you have it set to Advanced.

Good advice! I have been making sure that is checked.

[blindsquirrel]

MAF-only tune on a speed density custom OS. Brilliant!

Don't worry, it looks like he used the MAF curve to compensate for the new injectors instead of going through the tedious process of inputting all that fiddly injector data. No worries (this is sarcasm).

[Burntendzz]

MAF-only tune on a speed density custom OS. Brilliant!

Don't worry, it looks like he used the MAF curve to compensate for the new injectors instead of going through the tedious process of inputting all that fiddly injector data. No worries (this is sarcasm).

What issues could this cause? I did notice he did basically disabled ve tables, as it is set to always use the MAF. I'm assuming i was right in asking about the fuel tables not being changed?

[GHuggins]

It's still going to use ve for transients, startup, big rpm swings such as a cammed motor for instance and other things regardless of being set to run maf only or not. I haven't personally looked at the tune, but if he just scaled the maf for the overly big injectors, then get ready for idle problems, possibly running way too much timing because of miss airmass calcs and putting in a new trans due to load miss calcs.

In other words. Get it fixed as quick as possible and stay out of wot.

[GHuggins]

OK, just glanced at it - his MAF is much higher than stock and looks like he doubled stoic to make them fit. You should be fine. All other internal module calcs will be within reason, so shouldn't need to worry... There are things in the tune like alcohol timing that I don't like among other things, but I should have looked at the tune before making my last post.

[Burntendzz]

OK, just glanced at it - his MAF is much higher than stock and looks like he doubled stoic to make them fit. You should be fine. All other internal module calcs will be within reason, so shouldn't need to worry... I should have looked at the tune before making my last post.

Such a bummer to hear, coming from a "popular" tuner. I guess this is another reason that I need to learn how to tune myself.

[GHuggins]

Such a bummer to hear, coming from a "popular" tuner. I guess this is another reason that I need to learn how to tune myself.

MAF being higher is what you should have. If he had cut the MAF to make the injectors work then you would have been in big trouble. He even scaled the timing tables although it does look like low timing and then he's running way too much for alcohol in the regular no load areas - should pull timing with alcohol. Other areas in the tune aren't necessarily how I would do it, but not wrong either. He doubled knock, but still not horribly high. It should be fine to drive as long as fueling is correct trim wise.

[blindsquirrel]

But the 850cc tune file and the 1300cc tune file have exactly the same injector data. Either it was wrong before or it's wrong now, can't both be right.

[GHuggins]

But the 850cc tune file and the 1300cc tune file have exactly the same injector data. Either it was wrong before or it's wrong now, can't both be right.

Well that's interesting All he did was double stoic, which would be the same as 1700cc injectors, which is why he had to add a bunch to MAF - still needs terms halved and yes injector data itself is wrong. At least he added to MAF and didn't reduce it. Surprised with him doing the engine side halfway that he bothered at all with the trans stuff.

[Burntendzz]

Well that's interesting All he did was double stoic, which would be the same as 1700cc injectors, which is why he had to add a bunch to MAF - still needs terms halved and yes injector data itself is wrong. At least he added to MAF and didn't reduce it. Surprised with him doing the engine side halfway that he bothered at all with the trans stuff.

Would you mind explaining, or pointing me in the right direction, how to MAF can take care of fueling if the injector data is the same?

[GHuggins]

MAF is a measurement of airflow for your vehicles computer. If you have more air coming into the engine beyond it's original calibration then you have to increase the MAF g/s values to represent this increase in air. This is how you tune for your typical fueling changes ie - different diameter intake tubes, cams, different flowing heads and so on - basically anything that changes "airflow" into the engine. Where the problem began in your tune is when your tuner doubled stoic without inputting the correct injector data. In other words your cars computer thinks it's running 1700ish cc injectors (x2 of the original 850's data that's still there) instead of 1300cc injectors. In turn it removed or trimmed fuel because of the injector settings, soooo your tuner added fuel back in to compensate for this via the MAF curve. Problems can arise with this though as everything in the cars calibration is based off of airflow. Cylinder airmass for spark calcs. Idle controls. Trans shifting torque tables and on and on. You got lucky with the tuner screwing it up the way he did, because if he had done it the opposite way - well I'm not sure it would still be moving... I've seen many a person have to replace transmissions due to improper tunes - slipping while cruising with constant throttle for example - even fixed quite a few of these... It's in my honest opinion that when a tuner is trying to hide or not disclose why he/she is doing something that typically he/she doesn't know what they are doing, can't explain what they are doing or they're knowingly doing something wrong and don't want to explain why...

Hope that helps better explain the airflow adjusting for fuel and other things...

[Burntendzz]

Thanks!

[Kittyboy]

A quick way to compare injector data tables is to visit the injector OEM web site, the tables are available for many of the more popular injectors, injector pulse width and other info too. Need to get the fuel dialed in with good data.