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In making tuning changes and hundreds of WOT tests, it was time to see if what has been learned is repeatable.

For this test I first flipped the switches on the MAFT translator to determine that after the PCM has adjusted for a certain level of ATF ratio that I could simply then set the MAFT with certain switch setting and get perfect performance values for :

  • Long term fuel trim
  • O2 voltage
  • limited knock
  • Timing
Keep in mind the Rebel has long tubed headers, custom heads, cam, and larger injectors.
As the results from this test shows, all knock could be deleted, great timing, and O2s reporting exhaust gases showing about perfect ratio for WOT.
This result was during use of cell 22 of fuel table which is under WOT.

Keep in mind the engine compression is higher then stock at 11.3:1

PCM data was collected via the Ease enhanced powertrain scanner.

No Knockers but Great T

John
 

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WOW!! Waaaaay above my head!! /phpBB/images/smiles/icon_frown.gif I'm stupid on this stuff!! Congrats, I guess!! /phpBB/images/smiles/icon_smile.gif I need to go back to school!! /phpBB/images/smiles/icon_eek.gif
 
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Frank,
if you look to the right of the spreadsheet,

It shows that while doing WOT,
there was not one knock, knock reduces timing.

Timing was about as good as it gets for 11.3:1 compression under WOT

Long term fuel trim was also perfect.

That all adds up to outputting the best H.R and torque the engine has.

If I had not tuned, there would be a bunch of knock, retarding timing, which reduces torgue, H.P and fuel trims would be too far from perfect values causes PCM to continually adjust fuel trims.

End result is she really hauls ass when a bit of fine tuning and lying to PCM is done.

John
 

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John,
I'm looking to maximize my performance based on my modifications. I have had several forum members tell me I need to have ECM programming done to get the results I want from my mods. (See "Back From The Dyno" on "Pit Road") I was wondering, in order to do the ECM work, do you need to have the car? It sounds like you did very specific work on the car you referenced. Can the programming be done with just the ECM in hand. (San Jose is a long way from Columbus, Ohio) Any advise would be helpful. (Please speak english) /phpBB/images/smiles/icon_biggrin.gif /phpBB/images/smiles/icon_biggrin.gif /phpBB/images/smiles/icon_biggrin.gif
Thanks!
 
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On 2001-08-14 11:21, Z06 Tom spewed forth this drivel:
John,
I'm looking to maximize my performance based on my modifications. I have had several forum members tell me I need to have ECM programming done to get the results I want from my mods. (See "Back From The Dyno" on "Pit Road") I was wondering, in order to do the ECM work, do you need to have the car? It sounds like you did very specific work on the car you referenced. Can the programming be done with just the ECM in hand. (San Jose is a long way from Columbus, Ohio) Any advise would be helpful. (Please speak english) /phpBB/images/smiles/icon_biggrin.gif /phpBB/images/smiles/icon_biggrin.gif /phpBB/images/smiles/icon_biggrin.gif
Thanks!
Z06 TOM,

You mention an ECM which is for C4 Corvettes. I assume you mean the PCM which is used for C5s.

You have three paths you can take.

1. Send your PCM to some vendor who uploads into the flash memory changes to certain tables ( like fuel trims), change value on certain functions ( like timing, when fans come on, etc). The problem with this is of course every time you need some type of PCm change you have to yank the PCM out and wait for the unit to be shipped back to you.

2. Buy a product that gives you a little hardware unit that you plug into the PCM and upload the modified code into the flash memory. The problem with this is you still do not have full control to change what you want and what values you want. Most products like this allow minor changes like at what temp fans turn on but do not allow you to change the important functons like timing, fuel tables, etc.

3. The PCM monitors functions like the MAF, IAT, knock sensors, cam sensor, etc and decides on what they tell the PCM for it to dicate how the car will perform.
Knowing that this path instead of being dependent on some vendors product working within the PCM, is to control the PCM from the outside by changing the values the external functions are reporting to the PCM.

In looking at your mods, I would say if anything that your fuel trims may be running in a lean state ( because of the increased incoming airflow and with headers allowing better end to end flow allowing more air to be consumed. I also would not be surprised that your timing is a bit low and and WOT not being tuned for best performance.

Now you can go to those vendors that sell you so called custom code, but you have zero ideas what they really did, or even if what they sell you is a good overall tuning or could in fact give you very little performance and from then on you are dependent to that vendor and his costs.

In choosing the path I took, I found that so called custom PCM coding ( in this case is powerloader brand) that was in my '99 C5 was not giving the engine the best tuning configuration and in fact fuel trims were way too lean and and WOT too rich.
Wanting full control of functions like air, fuel, timing, knock, and WOT I choose to use a MAF translator which is a simple electronic circuit that takes 5 minutes to install.
I connects inbetween the MAF and the PCM and has to rotary switches which anyone can understand how to use.
It allows me to dictate/control ( by fooling the PCM ) what those functions are set to being the translator (MAFT) is adding or subtracting to what the MAF is reporting to the PCM.

In simple terms, by monitoring the PCM with decent PCM scanner tools ( I find the Ease enhanced powertain to be the best scanner) you can know exactly how your engine is performing, what functions need to be tuned and you simply twist a rotary switch to dial in the correction you need to better then overall performance.

Some people who have bought PCM custom code found no real performance at all, some find a bit better performance, and some think good performance, but without monitoring the PCM, they are really in the blind as to what really is going on and jsut becaise they are not getting and error codes they think everything is just find when in fact as an example the PCM does not even report a fuel trim problem untill the fiel trim is 25 percent off of being perfect.
Thus your engine could be running 24% too lean and you would not know it.

I myself do not do custom PCM re-programing, I found it much easier, quicker and in the long run far cheaper to re-tune for best performance with just the MAFT and the Ease PCM scanner.

I've worked on about 12 C5s ( most via the internet) and in using the MAFT and scanner have corrected issues such as knock, low timing, too rich/lean fuel trims, high intake air temps and O2s also not seeing the best A/F ratio for performance.

My 1st chassie dyno before tuning was like 380 RWHP with only about 360 ft/lbs.

With proper changes to intake airflow, its temp, and fuel ratio the latest dyno after tuning with a MAFT is 407 HP at 400 ft/lbs of torque. All was adjusted out, timing went from 22 to 28 degrees while in WOT and fuel trims are close to zero which is perfect.

Costs for a MAFT is only $175 and I also can obtain for you the Ease PCM scanner for about $300 which can be used for all you monitoring of engine needs.

If you decide to go with custom PCM code, be sure the vendor allows you to save your stock code and you having a way to reload it back into your PCM esp if your C5 is in warranty and go have to go to a dealer for warranty work.

Also question what functions they are tuning and demand to know the values they are changing those functions too.

My suggestion if you go with that route is go to Ron Zimmer of Z-Industries, he has been doing custom code for Corvettes since 1994 and I have used him in the past for my C4s and know he does quality work and is not guessing on how to properly re-calibrate your PCM for top performance.

John
 

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John,
Wow, thanks so much for all the great info! /phpBB/images/smiles/icon_eek.gif Can a novice operate the scanner you describe? I'm sure I could get the MAFT installed, but my concern is if I would know what I was looking at with the readings from the scanner. Is there a set series of tests you run and how can a idiot /phpBB/images/smiles/icon_rolleyes.gif like me decipher it? This may be over my head! If you could, would you send me a private message telling me how I can get in touch with Z industries. Thanks again for all the help. I never cease to be amazed at the GREAT people on our site! /phpBB/images/smiles/icon_biggrin.gif /phpBB/images/smiles/icon_biggrin.gif
 
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Z06 TOM,

Your welcome, that is what being a Corvetter is all about.

As I mentioned I have helped several do the same thing and they also had never done this before. You'll learn quickly and from that point will always be in control of tuning rather then being stuck with some PCM flasher who will not tell you what his code is doing.

I can talk you through on using a PCM scanner, you can then do some runs and record them and then e-mail me the trace files and I will talk you through what I see and show you to see the same things.
With a template in Excel I've done we can import the traces into the spreadshhet and all the math will be done via the template and you get answers real quick.

It's a simple process and really the main functions we will look at is

timing, long term fuel trims, O2s, and knock.

In tuning those up you'll then have the engine and PCM tuned best for the mods you have ( or will add) for the best overall performance.

The scanner even has several gauges you can set alarms for up to 8 functions being monitored at the same time and is easy to see as your driving so you know exactly what the heck is going on like this :



I can get you the MAFT and the Ease enhanced powertrain scanner ( which works in windows of your laptop) as a packaged deal and save you some money to boot.

John
 
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Ooh, ron's website is:
http://www.z-industries.com/

Ron does PCM coding for vendors like Mallett, LPE and Callaway.

This is his bread and butter and does not have to guess or backward engineer as others have to do.
you tell him excatly what you want, what mods and he can dial the code in.

Keep in mind, as I mentioned, if changes are made to the car afterwards and the PCM code is not matched to it you still need to use a MAFT to fine tune or give the vendor the PCM again to re-cal the code.

John
 

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Sure wished you lived in St. Louis!! Like I said, it's WAAAAAY above my head. I wouldn't know where to begin or even know what I was looking at. I'm an idiot too!! /phpBB/images/smiles/icon_lol.gif

Thanks for sharing your skills and knowledge with the forum. /phpBB/images/smiles/icon_cool.gif
 

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John,

Nice write up. I was considering the AutoTap scanner. What do you like better about the Ease scanner?

What octane gas are you running?

With 11.3:1, I am curious if/what you did to lower your fan turn on temperature without the PCM reprogram (new temp sensor?).

What temp does the fan turn on at? What temp thermostat are you running? At what coolant temp do you see knock/spark retard return?

Thanks much

_________________
Pat

1985 Coupe/Red
2002 Z06 Order# DKFFMZ - TPW 8/6 - DOA /phpBB/images/smiles/icon_frown.gif
2002 Z06/Millennium Yellow/Black/All but PSMs
Try #2 - TPW 8/20!!!
 
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On 2001-08-14 22:00, fcalmes spewed forth this drivel:
Sure wished you lived in St. Louis!! Like I said, it's WAAAAAY above my head. I wouldn't know where to begin or even know what I was looking at. I'm an idiot too!! /phpBB/images/smiles/icon_lol.gif

Thanks for sharing your skills and knowledge with the forum. /phpBB/images/smiles/icon_cool.gif

Frank,
listen, if I can do this I assure you anyone can.
You can get a decent scanner for about $300, heck you fire it up, pick the functions you want it to monitor and bingo, the rest is just going over the data and learning what the values should be.
You could even sit on the pot with your laptop and look at the graphs and meters and sooner then you think you have it down pat.

That's easy too for you have many of us in cyberspace that will pitch in and bring you up to speed.
We all learn from each other and in the end we all know more then we did.

John
 
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On 2001-08-14 22:21, pmontelo spewed forth this drivel:
John,

Nice write up. I was considering the AutoTap scanner. What do you like better about the Ease scanner?

What octane gas are you running?

With 11.3:1, I am curious if/what you did to lower your fan turn on temperature without the PCM reprogram (new temp sensor?).

What temp does the fan turn on at? What temp thermostat are you running? At what coolant temp do you see knock/spark retard return?

Thanks much

_________________
Pat

1985 Coupe/Red
2002 Z06 Order# DKFFMZ - TPW 8/6 - DOA /phpBB/images/smiles/icon_frown.gif
2002 Z06/Millennium Yellow/Black/All but PSMs
Try #2 - TPW 8/20!!!


Hi Pat,
the difference is like night and day.
Ease scanner has more features/functions, works within windows ( where atap Fs up in windows) allows far more control on what you want to monitor (allows you to group up functions and then select the group and all those functions are setup. It does a much better time testing the O2s and the fed's test (I/M)
Graphs and meters have a lot more features and does not loose data frames as I see with atap.
Being Ease does test tools for G.M, the scanner is better designed then atap's that seems to be a kludge of fixes and bugs.

I'm screwed, here in Flako CA, gas has gotten even worse so I have been testing different octane boosters and have mixed 100 octane I get at race track with this stock crap.

Do not understand the quesyion to the engines compression to radiator fan ?
The fans are still at stock relay settings, but I use a radiator that carries 40 percent more volume then stock is and use a heat exchanger to help reduce oil temps which also helps maintain good water temps ( no higher then 210 degrees)
Still using a stock thermostat, engine is so well tuned that even at idle water does not go over 210 degrees.

I have tuned out ALL knock in both WOT and non WOT conditions and still ave 28 degrees at WOT.
Being I got rid of the lean fuel trims and using a fatter spray with larger injectors also helps keep the engine temps down.

With the heat exchanger and a 2 quart AccuSump I installed, oil volume is increased to 11 quarts so that also helps keep temps down.

It's been real cool (pun) to crank up the performance and tune this all in to have a solid engine that runs cool but carries a big stick /phpBB/images/smiles/icon_smile.gif

John
 

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On 2001-08-14 23:02, teamzr1 spewed forth this drivel:
Hi Pat,
the difference is like night and day.
Ease scanner has more features/functions, works within windows ( where atap Fs up in windows) allows far more control on what you want to monitor (allows you to group up functions and then select the group and all those functions are setup. It does a much better time testing the O2s and the fed's test (I/M)
Graphs and meters have a lot more features and does not loose data frames as I see with atap.
Being Ease does test tools for G.M, the scanner is better designed then atap's that seems to be a kludge of fixes and bugs.

I'm screwed, here in Flako CA, gas has gotten even worse so I have been testing different octane boosters and have mixed 100 octane I get at race track with this stock crap.

Do not understand the quesyion to the engines compression to radiator fan ?
The fans are still at stock relay settings, but I use a radiator that carries 40 percent more volume then stock is and use a heat exchanger to help reduce oil temps which also helps maintain good water temps ( no higher then 210 degrees)
Still using a stock thermostat, engine is so well tuned that even at idle water does not go over 210 degrees.

I have tuned out ALL knock in both WOT and non WOT conditions and still ave 28 degrees at WOT.
Being I got rid of the lean fuel trims and using a fatter spray with larger injectors also helps keep the engine temps down.

With the heat exchanger and a 2 quart AccuSump I installed, oil volume is increased to 11 quarts so that also helps keep temps down.

It's been real cool (pun) to crank up the performance and tune this all in to have a solid engine that runs cool but carries a big stick /phpBB/images/smiles/icon_smile.gif

John
Thanks for the all the info. Sounds like Ease is the way to go; it's not all that much more money than the AutoTap anyway.

As far as the fan turn on temp and the relationship to your compression ratio, I was just wondering how you avoided pre-ignition at that high ratio with the normally high Corvette engine temperatures.

Sounds like you addressed the temperature issues fairly well with the richer mixture, and larger radiator and increased oil capacity.

If you could get your temp down another 15 degrees to 195, how much more spark advance do you think you could get away with?

Anyway, cool stuff. I can't wait to get into this stuff on my new Z06.

I used to have a 70' Impala w/454 LS-6 crate motor, 10.2:1. Running a 160 degree thermostat and a four core radiator, I could keep my temps in the 190s, run on 93 octane at the pump, 12 deg BTDC, w/34 degs total advance. Keeping my engine temps low was the key to avoiding knock for me.
 

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Great info. Who sells the eas scanner? and who has the package deal? thanks again /phpBB/images/smiles/icon_biggrin.gif
 
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On 2001-08-15 10:57, pmontelo spewed forth this drivel:


Thanks for the all the info. Sounds like Ease is the way to go; it's not all that much more money than the AutoTap anyway.

As far as the fan turn on temp and the relationship to your compression ratio, I was just wondering how you avoided pre-ignition at that high ratio with the normally high Corvette engine temperatures.

Sounds like you addressed the temperature issues fairly well with the richer mixture, and larger radiator and increased oil capacity.

If you could get your temp down another 15 degrees to 195, how much more spark advance do you think you could get away with?

Anyway, cool stuff. I can't wait to get into this stuff on my new Z06.

I used to have a 70' Impala w/454 LS-6 crate motor, 10.2:1. Running a 160 degree thermostat and a four core radiator, I could keep my temps in the 190s, run on 93 octane at the pump, 12 deg BTDC, w/34 degs total advance. Keeping my engine temps low was the key to avoiding knock for me.

Your welcome,

I would have to test to see if anymore timing can be had running a bit cooler.
Not sure with this compression how much more timing can be had but I'll test that out.

As for Ease, it also has some modules that can be added as you go along.

1. Not only monitor PCM but also body/chassie functions, like abs, traction control, etc.

2. Bi-directional, allows talking to PCM and turn functions on/off ( not adjust) like turn off knocks ( to test to see if a sensor is bad) or turn fan relay on or off.

4. Remote - you install a hardware module and can monitor the car remote, like on a track, scan is done in your pit ( or garage)

5. Instead of a laptop in the car while driving you install a hardware logger, it stores your runs, you then plug logger into your P/C and download traces into the ease program to analyze.

6. the Pro version allows you to monitor all major brands of car nameplates, whereas the personal version allows only one nameplate ( i.e G.M version will not monitor ford nameplate.

John
 

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John,
I would like to try this "Ease" and MAFT. Where do you recomend I look for one? From you? Is there a specific model# for my 01 Z?
I can see how I could have a blast with this!
Thanks, Bob, Sacramento (not far from you)
 

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From what I read on the ease system Im not sure if you can create your on functions to montior for ex Knock.? Can you /phpBB/images/smiles/icon_confused.gif An with the bidirectional you can turn these functions on and off? Is the bidirectional just a software upgrade and/or more hardware. TeamZR1 do you have a section on your site that explains a lot of the data/parameters etc.. about this tool?
great info /phpBB/images/smiles/icon_biggrin.gif
 
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On 2001-08-15 13:30, BADASSZ06 spewed forth this drivel:
Great info. Who sells the eas scanner? and who has the package deal? thanks again /phpBB/images/smiles/icon_biggrin.gif
I can get this scanner for you for $50 less then Ease sells it.
I also can get you the MAFT (I just ordered 10 of them, they are being built by the vendor now)

Let me know and I hold what you want.

John
 
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