Tune for LS1 with FAST 102 and 100 MAF

[thehemi]

I just installed a FAST 102 and 100 MAF on my nearly stock LS1 (only other mod is LTs).

Even updating the MAF table, it's too unstable to be able to drive to a shop for a tune. Something in the tune isn't happy. It seems to almost be okay and then suddenly it goes super rich, like something in the tune is hitting some kind of fail safe configuration.

Does anyone have a tune with a stock-ish LS1 w/ FAST 102 and 100 MAF they can share? I would be curious to compare and see what else might need to be adjusted beyond just the MAF table. If nothing else, close enough that I can actually drive it to the tuner.

Thanks,
Scott

[Josue Galban]

I just installed a FAST 102 and 100 MAF on my nearly stock LS1 (only other mod is LTs).

Even updating the MAF table, it's too unstable to be able to drive to a shop for a tune. Something in the tune isn't happy. It seems to almost be okay and then suddenly it goes super rich, like something in the tune is hitting some kind of fail safe configuration.

Does anyone have a tune with a stock-ish LS1 w/ FAST 102 and 100 MAF they can share? I would be curious to compare and see what else might need to be adjusted beyond just the MAF table. If nothing else, close enough that I can actually drive it to the tuner.

Thanks,
Scott

well, first your file would be needed to see what happens, but one of the most common things is that it could be your VE table

[blindsquirrel]

No one can see things in your file you might be overlooking or getting wrong if you do not post it here.

(also, ignore anything the person above me says)

[Josue Galban]

No one can see things in your file you might be overlooking or getting wrong if you do not post it here.

(also, ignore anything the person above me says)

[Josue Galban]

No one can see things in your file you might be overlooking or getting wrong if you do not post it here.

(also, ignore anything the person above me says)

To start (stop hating me) I'm trying to help, and you're right we can't help him if he doesn't send the file.

[blindsquirrel]

To start (stop hating me) I'm trying to help, and you're right we can't help him if he doesn't send the file.

I'm not hating you, I don't doubt that you genuinely think you are trying to help, you just give consistently bad advice on every single topic you reply to. I don't know if you're just not very good at this or if something is getting lost in an auto-translation app or something but please stop.

[gtstorey]

What is a 100 MAF?

[SiriusC1024]

100mm diameter.

[thehemi]

No one can see things in your file you might be overlooking or getting wrong if you do not post it here.

Are we talking about the tune or a data log?

I will get a data log collected today and post both.

Thanks,
Scott

[Josue Galban]

No one can see things in your file you might be overlooking or getting wrong if you do not post it here.

(also, ignore anything the person above me says)

I'm not hating you, I don't doubt that you genuinely think you are trying to help, you just give consistently bad advice on every single topic you reply to. I don't know if you're just not very good at this or if something is getting lost in an auto-translation app or something but please stop.

I really do try to help, the least I want is to have enemies in a forum as big as this, I don't even want you and me to be enemies, I'm interested in making friends who have good knowledge in tuning and high performance, but I don't know if that's the case. Maybe something is lost in my translations but believe me, the least I think about is giving bad opinions, I would never give advice to someone about something that hasn't worked for me, I just want to have a pact of friendship and for our differences to end

[thehemi]

No one can see things in your file you might be overlooking or getting wrong if you do not post it here.

I'm attaching my pre LSXR tune (baseline), post LSXR tune (MAFx1.33) and recent cold start data log.

I can get a longer data capture if I can find out why it's running so rich. It's pegging my AFR gauge at 10.

Modifications between pre/post tunes:

• FAST LSXR Intake Manifold
• FAST Big Mouth 102mm TB
• Hawks 100mm MAF (LS3 Sensor)

The only change I made was a 1.33 multiplier (75mm to 100mm) on the MAF table, hoping it'd at least be drivable.

What else might you guys suggest I check/change to compensate for these mods?

Thanks,
Scott

[blindsquirrel]

Are you not able to fail the MAF? I mean, if it ran before, and all you changed is the MAF, and all you need it to do is drive to the dyno...

[thehemi]

Are you not able to fail the MAF? I mean, if it ran before, and all you changed is the MAF, and all you need it to do is drive to the dyno...

I changed more than just the MAF -- FAST LSXR 102 intake, 102 TB and 100 MAF.

Thanks,
Scott

[blindsquirrel]

Can... you not try it with the MAF failed? It doesn't cost anything extra as far as I know, which is good since you just spent probably near $2000 on those bling parts...

[bk2life]

I changed the MAF -- intake, TB

Scott, did you change injectors?
Anything else get changed?
Becuase what blidn squirrel is saying is turn the maf off, the vheicle should technically run the same as before--no tuning or changing needed, this way you can get it to the tuner to do their magic.

[thehemi]

Can... you not try it with the MAF failed? It doesn't cost anything extra as far as I know, which is good since you just spent probably near $2000 on those bling parts...

I assume I can just unplug the MAF to run in MAF failed mode?

Thanks,
Scott

[thehemi]

Scott, did you change injectors?
Anything else get changed?

No, just the intake manifold, TB and MAF.

Thanks,
Scott

[thehemi]

OK, I attempted a few more things.

- I disabled the MAF
- It throws P0103 and runs super rich
- I reenabled the MAF
- I disabled Closed Loop (I believe)
- It idles reasonable for ~10 seconds, throws P0101, and then runs super rich

From what I understand, it's throwing P0101 since the MAF and PCM effectively disagree too much, so it ignores the MAF.

I read the PCM uses MAP, IAT, ECT and RPM to compare to the MAF. IAT, ECT and RPM should not have changed, but I notice the MAP results with the FAST LSXR are much different.

I believe this tells me the MAF scaling is close, but my VE table needs to be scaled... does this sound about right?

Thanks,
Scott

[thehemi]

For what it's worth, I think I may have discovered what is the problem.

Someone reviewing one of my logs noticed the MAP was reading 75 kPa all the time. Even when it wasn't running.

I pulled the MAP sensor out -- 75 kPa. I applied vacuum to the sensor -- 75 kPa.

I bypassed the MAP extension cable -- 103 kPa, and it would respond to vacuum.

Looks like I'm ordering a new MAP extension cable...

Thanks,
Scott