RWTD - I took your suggestion on MAF only CL

[bcar]

I am going to try this

[1genls2]

402 ls2 forged internals, 11.0 to 1, 90mm FAST intake with Nick Willams tb, Patriot heads, SLP under drive pulley, Areomotive fuel rail / A1000 pump and regulator,Comp 248/254 114 lsa .622 .612, Stainless Works Long tube headers with 3 inch all the way out with x-pipe, Miezere water pump, 6 speed, 9 inch rear end.

Oh yeah, stock injectors. 1999 vcm

Take a look at this log I ran tonight, I put the Hi/Lo thresh a 0 like you said and ran it. I did run better. It is getting closer, thanks again for your time I DO APPERICATE IT.

[69lt1bird]

That looks like a great combo, it should haul

Post your tune up and the config file for the log file.

What injectors are you using?
Do you have a wideband hooked up?

[[email protected]]

I have a question on the MAF only tuning. The last 3 cars I tuned w/HPT were Gen4 with the VVE. By far the MAF only tune was easier than trying to tune both the VVE and the MAF. In fact you have to almost be a mathematician to properly tune the VVE and have many hours to waste/bill the customer. The MAF only tunes (both OL and CL) ran great and were done in several hours.

My Question: The last car to be tuned was an LS2 in a 2009 GTM. I left the PE disabled on this particular tune since the time spent on the MAF calibration seemed to yield excellent results on the loaded dyno including cruising and WOT from various speeds (including idle) and various gears. The car ran out of fuel (no fuel gauge yet) after numerous pulls with great fueling and I decided to leave it this way. I had intended to reenable the PE and make a few additional pulls but why?

Thoughts?

[69lt1bird]

Because you did not tune it correctly. Set the PE table to your desired Commanded AFR for WOT and then tune the MAF. DO NOT DISABLE THE PE TABLE.

[[email protected]]

Because you did not tune it correctly. Set the PE table to your desired Commanded AFR for WOT and then tune the MAF. DO NOT DISABLE THE PE TABLE.

Thanks for the input. I am new to HPT and trying to learn this process and test the affect of different modifications. The first two cars were tuned the way you suggested (i set the PE to 1.157) and tuned the MAF from there. However, I am not sure that it actually made much of a difference in the tune by disabling the PE and then tuning off the MAF alone. I can tell you for certain that the fuel curves are spot on regardless of starting speed to WOT and regardless of gear. Unless of course if setting PE Enable MAP to 256kpa doesn't actually disable the PE? Can you be more specific as to why I didn't tune it correctly?

Also, I was thinking (and may be mistaken) that I should try tune the MAF without any modifiers and then set the PE to my desired A/F at WOT and the ECU would use this information to correct the fueling if necessary.

Thanks,
Mike

[1genls2]

Stock injectors for now, I pulled out the FAST 36 lb's thinking they are to much. Now I understand that they werent the problem! no wideband.

I am new to HPT and this is my first tune.... Take a look.

[69lt1bird]

First things first. You put thousands into that engine and you are trying to tune it without a wideband, STOP until you get one. $250 is cheap compared to what you already spent. Tuning without one on a bolt on car is one thing, a big cammed car, hell no.

Once you get the wideband, your tune file needs a lot of attention, nothing too major, but just a lot of small stuff.

[1genls2]

Done. What is your preference? It will be on the way. I always wanted to get one, but didn't know what to buy.

[Frost]

Because you did not tune it correctly. Set the PE table to your desired Commanded AFR for WOT and then tune the MAF. DO NOT DISABLE THE PE TABLE.

If you run OL, you just command high load fueling appropriately in the OLFA. If I tune FOR OL, this is the table I use to command fueling everywhere and leave PE disabled.

[69lt1bird]

Frost, that is good to know but it doesn't sound like he is leaving it in open loop.

[69lt1bird]

Done. What is your preference? It will be on the way. I always wanted to get one, but didn't know what to buy.

NGK AFX
http://www.ngksparkplugs.com/product...rmance/afx.asp

[[email protected]]

Because you did not tune it correctly. Set the PE table to your desired Commanded AFR for WOT and then tune the MAF. DO NOT DISABLE THE PE TABLE.

Just an FYI, I disabled CL and enabled PE and it made no difference in the A/F, horsepower, torque, timing etc. It did however allow me to easily manipulate the A/F by changing the EQ Ratio rather than the MAF airflow.

So for reference, I'm not sure that disabling the PE table when the remainder of the tune accounts for acceleration enrichment makes much difference.

[blownbluez06]

Just an FYI, I disabled CL and enabled PE and it made no difference in the A/F, horsepower, torque, timing etc. It did however allow me to easily manipulate the A/F by changing the EQ Ratio rather than the MAF airflow.

So for reference, I'm not sure that disabling the PE table when the remainder of the tune accounts for acceleration enrichment makes much difference.

If you enabled what you thought was disabling PE and it made no difference, then I don't see how it could have been disabled in the first place.
Frost, why would you manipulate the EQ ratio table to get your fueling straight unless the reason your fueling was off was temperature based?

[[email protected]]

If you enabled what you thought was disabling PE and it made no difference, then I don't see how it could have been disabled in the first place.
Frost, why would you manipulate the EQ ratio table to get your fueling straight unless the reason your fueling was off was temperature based?

I did have the Enable KPA set to 256 so I am assuming that it was disabled but you know what happens when you assume. With the PE Disabled I tuned the fueling based on the MAF.
On a side note: I did have the EQ ratio set to deliver the same A/F as the MAF only tune.

When I enabled the PE (set the enable KPA to 15) I actually expected the A/F to go rich. When it did not I "richened" the EQ Ratio in the PE table to see if it had any affect. The A/F did go richer as expected.

I won't be changing anything on this car since it runs so well but would like to understand the nuances of HPT so blast away

[5_Liter_Eater]

You simply need to tune the upper part of the MAF table. Either put the car in open loop or use the histogram filters to filter out closed loop data and do a few WOT runs. Then use a histogram that plots the AFR error against the MAF table and copy and paste the % error directly into the MAF table (multiply by %). Attached is a histo I used on your log.

You will need more data though as your upper MAF area you only had 1-3 hits per cell. So you need to do pulls in 3rd or 4th gear (4th is probably not feasible unless on a dyno) and you need to remove some PIDs from your config to stay under 24 bytes. Right now you're at 27. Anything over 24 bytes on your PCM cuts your framerate in half. Removing the STFT and LTFT PIDs should do it. Use different configs for different things that only contain the PIDs necessary for what you're tuning at the time.

I would recommend that you disable the VE while tuning the MAF but since you're only concerned with >4000 RPM's here there is no need.

And you should probably start a new thread.

[Z06SUPERCHARGED]

Hey thanks very much!