.Tun file check?

Hey folks, so I've completed an inital .tun file to flash to my 411 PCM that I'll be swapping into my truck, but I was wondering if someone with some tuning experience wouldn't mind looking it over to see if I made any stupid mistakes, or have any suggestions for it.

the tune is a '02 express van base file, COS3, that will be used on a 411 pcm in a 1996 ECSB C1500, L31, 4L60E, 3.73 rear, 28.88" tires. mod's I've done so far are headers, CAI, Shift kit, corvette + 4th servos, and truetrac.

I'll be doing true MPFI and a cam in a couple months but for now I'm just looking to get a starting point for my tuning, so any help would be appreciated (especially in the trans tuning dept. i.e. shift times, pressures, TM/abuse mode, I've edited some on the TM and shift times in this tune, but would still like someone to look over it for potential problems).

Thanks!

Forgot to mention, I'm swapping out the '96 EVAP system for a '99 tahoe EVAP system to be controlled by the PCM, so the fuel tank pressure and EVAP stuff is enabled on it.

I looked at it very briefly...

I suggest the following:
- B3647: make the last 3 columns rich (rather than just the last column), and start ramping the AFR from say 70kPa... this gives better throttle response as you start to roll the thottle open.
- if you're going to use PE B3618, then set the PE RPM enable B3616 to enable at something like 50-60% TPS at lower RPM and 30-40% at higher RPM (you want PE to kick in as you open the throttle further (90% TPS is too high, you want PE to also kick in at high load low RPM when throttle is medium); also check that the PE delay is zeroed and that the MAP threshold are suitable (I forgot to look at these two).

Cheers,
Joe
:cheers:

Quote:

---

Originally Posted by joecar

I looked at it very briefly...

I suggest the following:
- B3647: make the last 3 columns rich (rather than just the last column), and start ramping the AFR from say 70kPa... this gives better throttle response as you start to roll the thottle open.
- if you're going to use PE B3618, then set the PE RPM enable B3616 to enable at something like 50-60% TPS at lower RPM and 30-40% at higher RPM (you want PE to kick in as you open the throttle further (90% TPS is too high, you want PE to also kick in at high load low RPM when throttle is medium); also check that the PE delay is zeroed and that the MAP threshold are suitable (I forgot to look at these two).

Cheers,
Joe
:cheers:

---

righteous...Thanks Joe! thats the kind of stuff I was looking for, any other suggestions from anyone will help out a ton...

Okay, I did a lot more research and investigated some other tunes more in depth, and made a bunch of changes, including the ones that you recommended Joe, so here's an updated tune if anyone could review it for any stupid mistakes, or possible problems :master: . Thanks!

Al,

Make your PE table AFR 12.8 or similar.

Are you boosted...? If not, you can bring AFR in last 3 columns in B3647 to 12.6-12.8 sraight up-and-down... (below 12.6 is a little too rich if you're not boosted).

Can make high octane spark table level out at 23-24 degrees past peak torque (4000+ RPM)... there's no need for it to dip down like that (if you're getting knock, then something else may be wrong (AFR too lean)).

Cheers,
Joe
:cheers:

Quote:

---

Originally Posted by joecar

Al,

Make your PE table AFR 12.8 or similar.

Are you boosted...? If not, you can bring AFR in last 3 columns in B3647 to 12.6-12.8 sraight up-and-down... (below 12.6 is a little too rich if you're not boosted).

Can make high octane spark table level out at 23-24 degrees past peak torque (4000+ RPM)... there's no need for it to dip down like that (if you're getting knock, then something else may be wrong (AFR too lean)).

Cheers,
Joe
:cheers:

---

nope, not boosted (unfortunately:bawl: ). I'll go and adjust the end of the AFR table to around 12.75 or so. I have been looking at a few boosted tunes though (their's was like +-11.8 or so at the richest point) I guess I just didn't bring it up enough. I actually havent changed the spark tables at all, those are the stock ones from the '02 express van L31 tune. I'll take a look at it though.

as far as the PE table goes, I adjusted is as per the auto VE tutorial, but I'm wondering if I should just totally take it out of the picture and just control the AFR completely with B3647...bad Idea? if not, how would I go about disabling PE? or perhaps setting it to 12.75 (same as the richest part of my B3647) and letting it do it's thing when needed...

I'll go change the AFR table and play with the spark a little and repost.

thanks for all your help Joecar, I really appreciate it. keep it comin'! :D

alright, adjusted spark leveling around 23* @ +4000rpm or so, upped rich AFR to around 12.78, and adjusted PE a little bit.

Al,

I took the liberty of adjusting a few things in the tune of post #8, see attached.

If you detect knock, reduce the advance in the hi octane table in and around the cells where knock occurs.

Do you have a wideband...?
What are you LTFT's...?
Post some logs.

Cheers,
Joe
:cheers:

Quote:

---

Originally Posted by joecar

Al,

I took the liberty of adjusting a few things in the tune of post #8, see attached.

If you detect knock, reduce the advance in the hi octane table in and around the cells where knock occurs.

Do you have a wideband...?
What are you LTFT's...?
Post some logs.

Cheers,
Joe
:cheers:

---

Thanks Joe! I do have a wideband, however I cannot do any logs yet, I'm currently still running a stock '96 blackbox pcm which is not EFILive friendly, so this weekend I am switching over to the 411 pcm (weather permitting), I'm going to start it with a stock tune just to get 'er going, then I'll be able to do some logs, and will put all this in. so give me a week or so and I'll get some logs up.

Thanks again for your help here.