twfvette

I would like to thank everybody for the wisdom and knowledge contained on this board, as I know that I am not the only one who has lurked around and learned volumes. I have been working on my tune for a while now, and have several issues that seem to be whipping my butt. This setup has always had a slight hesitation after it warms up, it is extremely snappy during the warm up, but develops a lag after warm up. I now have an occasional lean pop during mild acceleration. I have attatched my bin and latest datalog. I have thought of converting to an s/d setup (I have seen my maf almost maxed out a few times) Is there anybody that has converted the vette over to s/d and knows if the dash maintains full functionality? What has your experience been with throttle body size with this type of combination, I currently have the stocker 48mm. Being from the industrial world, my experience ends at 3000rpm. Thanks in advance, and happy holidays.

Grim Reaper

I cannot answer your questions specific to a Corvette, but I have tuned a Minirams both on SD & MAF cars. Personally, I find the MAF setup easiest to tune to get a good overall running car. But, I find the SD setup permits me to do more "fine tuning" to resolve driveability issues.

I would suggest trying to resolve your problems with the MAF setup first; and convert to the SD setup only if you are unable to resolve them. Minirams do have a seem to have a number of "tuning issues" involving backfiring/popping in the manifold under acceleration. Especially with manual trannies.

Usually playing with the Accleration Enrichment (aka pump shot) helps over come that problem while playing with your spark advance. Do some "searches" on that problem and you should find some good answers.

As for the "maxing the MAF", just give a little extra fuel via the P/E tables in the appropriate rpm range can fix that problem. But you really need a WB O2 to fine tune that. If you don't have a WB, find a dyno that has a WB and tune it there.

HTH

Hope t

twfvette

Was shopping for a new throttle body and contacted Arizona TPI for my purchase. Those people were extremely helpful and knowledgeable. I ordered the new BBK throttle body,(no doubt from them) and in talking to their people I learned a lot about what the Miniram likes. The one thing that I have done so far that has made the biggest difference, is to change the timing map over to the ANHT timing map (as per their suggestion) They explained that the ANHT and ANHU timing maps were wrote for a manifold that is very similar to the miniram. The drivability difference is nothing short of amazing. I have yet to datalog the car since making these changes, and will probably make some changes based upon the datalog. I have not done any work on WOT fueling with this timing map as of yet. The other topic of conversation with them was about the delay on snap acceleration. The '165 ecm is a good ecm, but has several limiting factors. the S/D conversion to my understanding would be a night and day difference if the '7730 ecm was used. The '7730 ecm is a much faster ecm, and as such it will calculate the engine's needs much faster, thus not exhibiting "processor delay". The S/D system is not limited to the flow capabilities of the MAF, which would enable this setup to breathe to it's capabilities. The downside to the S/D setup in the Corvette would be the loss of the MPG and Range displays in the dash. I guess I have a decision to make. I am open to suggestions as to what has worked for other members. I thought I would post a progress report. I hope that others tuning the Miniram will find this helpful. Happy Holidays, and may God Bless all of you with a wonderful new year.

RBob

iTrader: (1)

The MAF Corvettes and SD Corvettes use the same intake manifold system: TPI

The '7165 and '7730 ECMs run at the same processor speed, with the same CPU.

There may be differences in timing between the '89 calibration and the ANHT SD calibration, but it isn't because of what AZ-tpi said. For that matter I know of a slower ECM that runs just as good, and even maybe better then the '165 and '730 ECMs.

Max'ing the MAF isn't the end of the world. You may even being seeing the upper airflow limit kicking in, which is nothing more then a calibration change.

The delays on snap accel and the lean pops are from both the mini-ram and the de-screened MAF. The MAF tables/scalars need to be adjusted. See the sticky Tuning Guide Book. Under the '165 ECM is several articles about how the MAF tables work.

RBob.

ULTM8Z

I couldn't disagree more!

ACtually, the ANHT is for a TPI Vette, the manifold of which looks nothing like the Miniram.

What you want to do is get the timing map out of an LT1 Camaro or Corvette. The LT1 manifolds are mechanically almost identical to the miniram. Depending on how far away your cam is from stock, they're almost good to run as-is. I'm actually running the LT4 Vette timing map, practically verbatim (with a minor alteration at idle).

Grim Reaper

If someone has a copy of the LT1 or LT4's VE & Spark Tables, maybe they could post a copy of it. Then Miniram users could use it as a starting point for tuning the Spark Table of either the MAF or SD setup and the VE Table for the SD setup.

85MikeTPI

iTrader: (2)

The Dash pcm in the '165 equipped vettes relies on communicating with the '165 much like the ALDL scanners do. The simplest way to upgrade to S/D and retain the dash pcm, would be to wire the '165 into the harness in parallel with the S/D ECM, but only to the sensor inputs. All the outputs would still be done by the S/D system.

So you'd wire things like the O2, TPS, CTS, etc. into both ECMs, but only the S/D system would connect to the injectors, timing bypass, etc. (There may be additional wiring around the ALDL port if you want to retain scanning of the S/D system through it, but detaching the Dash pcm from those lines.)

mike

ULTM8Z

Have someone in mind, Glenn?

Actually, yeah I have all that stuff, and more!


Here, see if this works...

It has the tables you're looking for in Excel format, but also a comparison of various tables... i.e. LT4 vette vs ANHT, 94 A4 Trans AM vs LT4 Vette, 93M6 Z28 vs AUJP, etc. You can see how they vary considerably from vehicle to vehicle. The LT4 and DA3 tables were converted into $8D format to make the comparisons though.

ULTM8Z

For VE, here ar some screenshots of a 93 M6 Z28, 94 A4 Trans AM, and an LT4 Corvette.

twfvette

The wisdom in the answers posted here are amazing. I am unable to view the zip file posted. It comes back as an invalid archive. Today I have moved the timing tables from the '94 auto vette over to my current bin. Weather permitting (I don't want to do the ski and track mod.) I'll give it a whirl, and update with the results. Hopefully this thread is also helping many others to tune their miniram. May god bless all of the thirdgen members and families with a happy holiday season.

ULTM8Z

Try this...

I converted it to Word 97-2003 format.

THough I wonder why Thirdgen doesn't let us post excel files directly??




And Merry Christmas to you as well!!

Grim Reaper

I think it is has something to do with limiting the number of "allowable" file types to preserve file space or that it is possibly to "slip" in a virus much easier in an .xls file type. I'm not certain of the EXACT reason but it was something that was decided by old management a long time ago and there is no desire by new managment to allow .xls file types.

I do beleive that if you change the "xls" extension to with an "allowable" file extension and then change it back to "xls", that it will work.

JT

iTrader: (1)

Actually, it was not due to limiting allowable file types for file space purposes. Excel spreadsheets won't be any worse than image usage. The main issue was with the greater possibility of a virus.

Grim Reaper

So I was half right. I figured it was probably one or the other.

396V8

sorry for going a bit off topic, but..

why do e.g. ANHT, AXCN have so low timing numbers in the 85-100 kpa range?
bad heads, bad fuel qualitiy, a mix of it, intake related?

DA3, LT4 runs much more timing..??

thank you

ULTM8Z

As I understand it....

Depending on what RPM you're talking about, when the TPI's hit their "tuned" rpm range they end up with incredible cylinder pressures. With high cylinder pressure, you don't need (or want) a lot of spark advance, particularly at WOT, because the burn rate is already so fast.

Grim Reaper

Also, the TPIs had different heads with smaller L98 cams. Which, as ULTM8Z said, results in more cylinder pressure. Basically they are the opposite of "self-EGR'ing" Long Duration/Narrow LSA cams (which tend to like more timing). Not that the LT1 was a radical cam; but it and even more so, the LT4 cam had more duration than the L98 cam. Thus they (LT series) would want more timing, especially in the upper KPA range (which tends to be your WOT range also).

devilfish

With my lt1 intake converted and hotcamed 355. I tried to use both the LT4 tabel and the stock LT1 manual spark tabel on my 8D code. Just as a start..

It whas horrible from a drivability point of view. Jerky below 2000rpm. To sensetive on the throttel. Alot of popps ( bangs ? ) on de-accel.
I enden up rework the entire tabel to get the best drivability..

just my input on the matter..


/devil...

89gta383

iTrader: (5)

I had no gains in back to back testing of the maf vs sd system on my 89 T/A at the dragstrip. Both systems ran within a tenth of each other at the same mph. I only tuned for driveability at first then made small changes at the track.

The only difference between the two was that with sd I can run a 4" intake which supposedly lets more fresh air in the throttle body vs the 3" maf meter.

Both systems have the pros and cons.

twfvette

I got some time and clear roads to try some timing changes. I morphed the pieces of the anht and '94 vette together. I tryed the '94 vette and felt that it seemed a little lazy and choppy at lower cruise rpms. I used the anht map up to 1400 then from there on up I used the '94 conservativly. The results are feeling much better. I am getting a few knock counts around 3200 though, I'm not sure if I need to add a little more pump shot. (trying to decide if it's lean or there is an area that needs a little timing pulled. Thanks for the help so far.
Steve

devilfish

Its vital that you dont get to "lost" copy and pasting stock tabels back and forth. Stick with a tabel then work from there.
Use your scaning tool and your senses. Feel how the car reacts to your changes. Take notes, adjust, test drive.
Then repeat. over and over again..


Happy tuning

Regards

Devilfish...