ULTM8Z

First of all I want to say what an invaluable source of information this site has been through the years of tuning my Miniram engine. It's not an understatement to say that there's no #@$%-ing way I'd have this engine running this well without this site. RBob, Grimm Reaper, JP86SS, and a host of other folks (sorry for not mentioning by name). So in the spirit of "giving back to the community", I'm offering up my bin as a "start-bin" free of charge for folks with Minirams who may be struggling with it (as I was for a long time).

Keep in mind now, the hp and torque are probably not optimized yet (though I'm planning on hitting the next local Thirdgen.org dyno day). But the driveability is phenomnal with tire shredding torque off the line, smooth idle, and ZERO throttle tip in problems.

My engine combination is the following (for a reference point of comparison to other people's setups): ZZ4 350, with AFR 180cc heads @9.8:1 compression, Comp Cams roller 212/218 @.050, 1 5/8 exhaust headers, 52mm throttle body. If yours is different, you may need to play around with some of the tables/values to get yours optimized, but my guess is it'll be FAR better than starting with a stock TPI LTR-based bin.

The bin is a 7730 $8D starting with ANHT (Corvette, automatic trans) and it assumes 24 lb/hr injectors and 10° initial timing at the distributor. Why 10° you ask? Because when my large HEI distributor cap hits the fuel rail and won' turn any further, it's exactly 10° BTDC! So it's a very convenient feature when removing and replacing the distributor (don't need to bust out the timing light to reset the timing).

I'm also posting here what is modified, line by line. If you have a different mask, you can simply translate the changes into your specific mask. For example, someone with $8D, but AUJP will have the small cap distirbutor spark latency settings.

The main thrust of the modifications is attempting to mirror the early MAP, batch fire LT1's using the $DA3 mask (BDLD broadcast code in particular which is the Trans Am automatic); given that the Miniram is almost a carbon copy of the LT1 manifold. The timing and AE are of particular importance, and it seems that using them almost verbatim from $DA3 gives the best results. For timing, I actually went with the LT4 map ($EE mask) as the Miniram seems to like a lot of timing (except I added timing at low throttle and high map). All of these bins are available on my website DIY tuning page along with other helpful items

http://ultm8z.com/DIY%20Tuning.htm


As you can see though in the description of changes, there are many other little tweaks here and there that also improve the driveability, the sum of which is giving me the results I'm getting.

If you're interested in this, please drop me an e-mail at ultm8z@yahoo.com. The AE tables, spark tables, etc are in Excel form and on my website for download.

http://ultm8z.com/DIY%20Tuning.htm

Last thing to note, I made a special modification to my Miniram which is probably helping the idle and low speed manners a little more, as it better resemble the LT1 manifold with the internal idle air passages and improves air/fuel distribution at idle. I haven't tried to disconnect it and see how these mods run without it since it's a PITA to disconnect.

https://www.thirdgen.org/forums/diy-...ram-split.html

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Description of changes:

-changed Initial Spark Advance to 10deg in constants

-changed min map for power enrich to 50 kpa

-change min temp for highway mode fuel to 70c

-changed min map for highway mode fuel to 55 kpa

-changed min vehicle speed for highway mode fuel to 55 mph

-changed add to idle in park/neut to 25 rpm

-changed EGR %TPS enable threshold to 99.6% (my EGR is disabled since I'm non-emissions)

-changed EGR %TPS disable threshold to 3.1% (my EGR is disabled since I'm non-emissions)

-changed Fan2 disable speed to 35 mph

-changed fan2 disable speed w/ high press A/C switch to 35 mph

-changed Road speed constant to 4702 pulses/mi (goes with 3.42's and 285/40-17 rear tires)

-unchecked EGR Diagnostic error flag (my EGR is disabled since I'm non-emissions)

-changed to modified LT4 timing map except modifications to low RPM and high map.

-changed closed TPS spark advance to match updated spark map

-zeroed out spark correction vs idle speed error (prevents idle speed "hunting")

-changed O2 closed loop delay timer => cold=80, warm=30, hot=10 (in SoCal, there's no reason for long delays in getting into closed loop)

-changed to BDLD AE tables except ANHT delta TPS vs coolant (for whatever reason, the car likes the original ANHT table on this).

-changed idle speed to 650 rpm (engine idles almost glass smooth in gear at 650 rpm)

-changed fan on/off setting=> Fan1 on 82.25, fan1 off 85.25, fan2 on 88.25, fan2 off 86 (I have a two speed Taurus fan hooked up with both speeds running off the ECM).

-modified upper and lower VE tables to get to 128 (this will be particular to your set up and my values may or may not get you to 128).

-changed base coolant advance correction table bias to 1 deg everywhere (I don't see a reason to have the ECM messing with the timing here and the engine runs really well with this table almost zeroed out... it wouldn't let me put 0 in it).

-enbabled switch "reset Integrator when AE in progress" (this was a major driveability improvement when I found this. It keeps the ECM from pulling out fuel during an AE event and essentially chasing its tail on fuel trim).

-disabeled AIR Divert - set enable temp to 150C (I'm non-emissions and don't have AIR hooked up)

-Zeroed out AIR Divert O2 mV Rich/Lean threshold (I'm non-emissions and don't have AIR hooked up)

-Changed Force BLM Idle Cell CCP %DC Threshold to 0% per Traxxion's recommendation (found this while researching some stuff)

-changed PE values (this is subject to change based on dyno day results, but I'm basically in the 12.5:1 AFR range at the moment)

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So there it is...

Requisite disclaimer here.... I take ZERO responsibility for how this gets used. It's up to the user to ensure it's right for his/her vehicle and the vehicle is proper working order. I accept NO responsibility for damage or anything negative that happens as a result of using this information. This information is for reference only.

Hopefully folks find this useful as I've heard all the Miniram horror stories while researching through the archives trying to solve my own!!

cal30_sniper

iTrader: (16)

I'll be doing some heavy duty reading on this over the weekend. I ran some pieces of the miniram tune that you sent me, and it really cleaned up the tip-in of my HSR/Vortec combo.

I've still got a big flat spot at <2400rpm and >50kpa. I'm going to try and start working that out now using some of your data. Thanks for posting.

cal30_sniper

iTrader: (16)

I'm not able to download your spark advance table comparison though. Any chance on fixing the link on that one?

ULTM8Z

Glad it worked out for you.

You may try a little more spark timing in the flat spot. These minirams seem to like spark timing.

I fixed the link. My web hosting provider crashed and I had to port everything over to a new host... more than a few links broke in that process. I think I got everything corrected though.

cal30_sniper

iTrader: (16)

Cool, I'll check it out Tuesday when I'm off.

I was thinking the same thing about spark timing. I've been using the L31 truck timing down low, as it's a bit hotter than the LT1 tables (at low RPM/high load especially). I advanced that about 20% over factory below 1600rpm, and I plan to keep bumping it up from there, datalogging and adjusting the tune as necessary. I zeroed out PE spark, but I think I'm going to add some of that back in also to help deal with the extra fuel under those conditions. I'm still trying master this whole speed density tuning thing, but I think I'm starting to really get the hang of it.

ULTM8Z

Mind sending me the L31 truck timing tables? I'm always curious to see what the factory is doing.

Fast355

iTrader: (2)

I will dig them out and send them to you if you want. There are alot of multipliers used in them and they are not great tables, even for a stock L31. I was able to add 2-8* of timing almost across the board.

ULTM8Z

That would be great, thanks! ultm8z@yahoo.com

cal30_sniper

iTrader: (16)

Here's what I ended up with for L31 spark advance tables (the L31 computer doesn't use the same layout as the our spark tables, and as Fast355 said, there are multipliers and other things involved, but this should be a fairly close approximation of what is going on in the format the 730 ECM uses.



I also tend to agree with Fast355. These are not great tables. I only used the low-rpm/high load section, because it was a few degrees higher than the 9C1 (iron head LT1) spark advance tables. I've increased quite a bit from there.

ULTM8Z

Yeah, the L31 spark map seems pretty lazy. Unless there's PE spark being added for WOT...

Interesting though, thanks for posting it.

cal30_sniper

iTrader: (16)

Not a lot of advance up high. Then again, the L31 was a fairly high compression motor (for its time), running iron heads and a very small cam. Lots of static and dynamic compression means not a lot of timing is needed, especially in the heavy vehicles most of these engines came in.

I prefer the timing below 1000rpm from the L31 tables as a starting point, especially for a stick car. It helps to keep things moving as you push it off the line. The SA tables in your miniram tune are very aggressive. For anyone else, I would be extremely careful working up anywhere near that level using iron heads of any design.

ULTM8Z

Yeah, I sneaked up on those values over a period of time, keeping close eyes on the knock counts and driving with windows closed to listen for any signs of knocking. So far so good...

BWilcox

Hi Mike,

What about the IAT/MAT Tables?

Did you go with the $DA3 GM parameters?

Best Regards,

Bruce

ULTM8Z

I enabled the INV MAT tables in the switches, but it still has the ANHT IAT tables. I plan to change over at some point and see what happens though.

But when you do, you end up having to alter the VE tables (which is what happened when I did that before). But with my VE tuner now, it'll be much easier to do that (which gives me more of an incentive to try it).

But you gave me an idea... I have a Excel sheet that compares some various IAT tables, including Grimm Reaper's. Grimm Reaper had posted his tables that he created with a lot of testing (which I found during a search on MAT). My matrix doesn't really do anything except put the tables side by side for comparison. It's item 7 here.... http://ultm8z.com/DIY%20Tuning.htm

A little history.... So what happened was I rebooted and started from scratch with ANHT a little while ago. I had made some changes to the car (including correcting a couple of minor malfunctions)... I had been tuning around those issues earlier and the tune had gotten so far off track, I decided to reboot. The changes altered the calibration and I couldn't get the tune right. Notice the current "baseline01" file name.... I had gotten up to "baseline51" before. Changing things, then changing them back, then changing them to something else... I do keep a record of changes, but it got too convoluted to keep track of.

So with the car in tip-top shape mechanically and electrically, I took the things that I KNEW worked from the previous tunings and applied them to ANHT, and the result is what I posted up about. The result is minimal changes and mostly running LT1/LT4 values (which is an indicator that my setup is right since the factory calibrations are very close to perfect).

So I want to make any future changes very methodically so I know where I've been.