93 LT1 computer tuning.....

[biohzrd]

there is know way i would trust a mail order program to work in my car correctly on the first try. i've seen guys lose ecu's, harnesses, and complete engines that way. best thing to do is to find a good tuner in your area. i'm one of the people who happen to have that. here is a good site to go to.

 

http://moates.net/

or

http://www.moates.net/gmecm/hworder.html

 

i can tell you the quality of his hardware is second to none. the engine pictured i helped put in. he does all my and my friends tuning. it is just not a plug and play setup so to speak. at most you could only be close with a mail order program.

[Guest Your Car is Slow]

I had an Ed Wright burn along time ago in my Impala SS...i was QUITE pleased.

 

However back then it wasnt that expensive...sheesh!

[Guest Anonymous]

I had no idea is was 350 for a chip. That is way to much. Is that a new chip or reprogramming yours. They charged me about $100 but I have done a good bit of business with them. Mark

[Mudge]

You dont reprogram a PROM, only EEPROM.

 

Couple notes about this high RPM limit, ALDL wont ever see more than 6475 RPM, 6475/8= 259, so I assume we have probably 253-254 data points, remember this is an 8 bit computer and logging RPM is in increments of 25 RPM.

 

Stock tachs are notoriously crappy, 800 RPM looks like 950-1050 and so on, each car is different in how incorrect it looks.

 

Depending who you talk to, you will hear different RPM limits. I remember for awhile that the rumor spread that the Vette computer was supposed to have a little more headroom, I dont know if thats true, I wouldn't be supprised if it wouldn't - who knows. Lastly I already mentioned that past 100 MAP, past 7k RPM, and past values the computer doesn't expect to see the last known value will be used. Just like on the old L98 PCM that supposedly had no fuel maps above 3400 RPM, it would use the old values (I never owned an L98 so I dont know for sure thier story).

[Tim240z]

According to their site they charge $350 for a chip! That is just rediculous! I could buy a used 94/95 computer$100) and have some one flash it for me with new programming($100) for wayless. I think I will just go with Street & Performance for my chip. I know they will do a good job.

 

 

Guy

 

Guy,

To be honest, if I were you, I would switch to a later computer that is flashable. Invest the <$200 in the TunerCat software and a cable from AKM, and get a laptop (can be found vwery cheap on ebay/classifieds etc). Once you do that you have endless tuning options for free, and will never have to worry about burning chips again. You'll be much happier in the long run. Heck, once you've had one chip burned, you could have paid for the TunerCat setup!!! Setting the later PCM to run SD is merely a switch (radio button) in the software.

 

Tim

[Mudge]

Agreed, you can find a PCM for around $80, you can use the B-Body stuff as well. If you need someone to get a first flash going for you, I'll do it for the cost of shipping.

[80LS1T]

I think I will take you up on that offer Mudge. I am going to start looking for a computer today!

 

 

Thanks for all the help.

 

Guy

[Guest Anonymous]

I would be interested in the tuner cat soft ware if I had some one to help me once I screwed the tuning up so bad the car would not run. Any takers out there to help? Mark

[Mudge]

Mark, I used to be on the Tunercat mailing list - but its slow, and so many various cars on there, that there is not alot of LT1 specific help. I was on the LT1 Edit list for awhile, the terms are sometimes different but once you understand the whole setup, its a good list to be on. http://www.lt1edit.com

 

If you have any questions though I could try to help, shoot me an email.

 

With Tunercat you need the base software package $69 I believe, and the $20 $EE definition file, if your cylinder size is not 717 then you need to use $EEb which should be included with $EE, I believe this effects early 1994s but dont recall for certain.

[Tim240z]

I would be interested in the tuner cat soft ware if I had some one to help me once I screwed the tuning up so bad the car would not run. Any takers out there to help? Mark

 

Mark,

The first thing to do is save your base file (unaltered OEM file) in at least 10 different places so you will always have a copy yo go back to. Then play with it, make changes and save under a different file name, dump to the PCM and try it. If it's completely unuseable, reload the OEM file, and try again.

Tim

[Guest Anonymous]

Thanks Guys, this just may be my next project.

[Mudge]

Yep, sometimes its easier to start from scratch - and you learn fast this way I think because you have to go through each table every time (although you can import with Tunercat).

 

I have a stock 95 M6 file around, and for a 94 also I *think*, not much was changed but off idle injector stuff and maybe a couple MAP cells, anything else would be hidden code stuff, as best I can recall.

[Tim240z]

I have the factory file from my 94 Z28 PCM (unmolested).

 

Tim

[80LS1T]

So which softwar package is better? Tunercat or LT1 Edit? Which one is the easiest to use? Also where can I buy all of the stuff that I need for either one?

 

 

Also what do you mean by...

 

if your cylinder size is not 717 then you need to use $EEb which should be included with $EE, I believe this effects early 1994s but dont recall for certain

 

 

Thanks,

 

Guy

[Mudge]

Tunercat has a Windows flash utility now, for those afraid of DOS and its stability I only use the DOS version myself, but I will try the Winders version again sometime just due to speed on the dyno (no reboots).

 

They both achieve the same end results, I prefer Tunercat, I think it looks better - LT1 Edit last I saw looked like it was written in VB3, but like anything its a stupid bias.

 

The LT1 Edit layout may be better, I dunno. You can change the menu layout of Tunercat a bit (I have mine so 3rd column is A4 tables which I ignore), so for me it works perfectly. To remove tables you dont use altogether, you'd have to edit the $EE file and I've never gotten around to that.

 

http://www.wotelectronics.com to get a cable, then you just need the software.

 

LT1 Edit is $200, plus you still have to buy the cable.

 

I also like the idea of Tunercat being useable on other cars with other definition files, also it is not Vin locked like EDIT is, unless you pay $2000 for the pro tuner version. Anywho, you really have to decide for yourself, its clear to me - much of my bias is just on price alone, they both get the job done if you know how the engine works, thats the key. What is this sensor, how does it act with the other, what do these numbers mean, etc

 

This is not a programming tutorial, but I like it for giving an overview of the sensors:

http://members.aol.com/InjuneerZZ/ScanMast.htm

 

For hex editors Tunercat has the neat, automatic checksum calculator. One important thing to keep in mind, is that Tunercat/Edit do NOT store the T & M chip data in the same order, one has M/T the other is T/M, so you must open in Tunercat and save as LT1 before flashing, or use the free utility on the net ( http://www.carprogrammer.com has it somewhere ).

[80LS1T]

Ok how much do you have to know to reprogram a car? I know how the sensors work and what they do. I am also good with computer related things so will this be hard for me to understand? Basically do you have to be a computer porgrammer to know what all of the info on the screen means to reprogram the computer?

 

Thanks,

 

Guy

[Mudge]

Not too hard, I spent about a week reading up on techniques and such, just takes a little practice and its going to take some flashes anyway, same as trying to find the perfect carb jetting.

 

One of the easiest rules, tune where its weak, pay attention to that zone, look at the sensors. Start out with low end, then midrange, then work on your WOT stuff - to me WOT belongs on the dyno because of fuel concerns. After your dyno stuff leave the fuel alone and work timing any more if needed (like low throttle).

 

Fuel tuning other than closed loop low throttle, really belongs on the dyno, but there are ways to coming close with a little math. LJs site has info on that, I need to look for it myself. Since your going to stay speed density, VE tables are what you play with to get your BLMs close to 128, if they are close right now you can use VEMaster to help finish em off.

 

Timing I play with in small chunks, especially low throttle stuff. Its not like writing computer code or anything like that, but its not so simple that you just input lift/duration etc, you basically just need to learn to adjust the numbers to get your sensory output to where you want it.

 

Low map during cruise = high vacuum = good, so work timing to improve MAP, when it degrades go back to previous setting. If the car is idling rough, alot of that can be timing, can be fuel (overlap funktifying the O2 readings, or lean) overlap with the Hotcam should not be a concern. Some people run open loop 1200 RPM and below, you shouldn't need to. The tuning primers will help get you going on any concepts that may be confusing.

 

Usually I'd say its the larger cam stuff that gets kind of tough to tune down low, down low timing is either where people fail or work magic, or somewhere in between, mail order stuff for me (attempting to use as a baseline) was a sorry failure, the car was weak, very weak, timing sucked big time. So for me I used a tune off a friends car somewhat close to my setup, timing was almost spot on, tried playing down low to get more torque off idle (had amazing power down low but would run into ping ), 91 Craptane MTBE gas wasn't helping my cause, if only I had Texas gas. So your starting out with a good setup to learn on, great example baseline tunes to start with and a moderate cam profile should be fairly easy to work with and very forgivable especially down low. My own setup was my first dyno tune and really the first car I tuned with a computer setup, and I was almost done on the dyno by my 3rd pull, because I didn't really find any power playing with fuel much (well the ignition miss didnt help ), and didn't have enough time to get into much timing work, I was confident in my WOT timing and my down low is all street tuned.

 

I dont know how much spare time you have but the LT1 Edit list is great to jump on, I was on for probably over a year, thought about hopping back on but it would be yet another mailing list to consume the time that I already waste so well. You can set your subscription for web mail, or digest mode, so you dont have to recieve 100 emails a day, traffic varies from almost none to alot per day.

[Tim240z]

Also, LT1Edit is limitted to only one PCM. You cannot use it for a different PCM, so if you fry your PCM, or want to help a buddy tune his PCM, you're SOL. TunerCat is it for me!!

Tim

[80LS1T]

That's exactly what I wanted to hear Mudge! Sounds like I can handle it just fine! As for LT1 Edit I dont think I will got that route because like you guys said, you can only use it on one computer. I have a buddy who has a LT1 out of a Buick Roadmaster that he is getting ready to put in one of his camaros(he has like 7) or his monte carlo ss(1986 i think). So if I got TunerCat I could help him out too!

 

So what software do I need from Tunercat? Is there more that one version of the program?

 

 

Thanks,

 

Guy

[Tim240z]

There are two versions currently. The latest version allows you to use the application in Windows. The previous version had to be used in DOS, which if you were running Win2K, you were SOL, because it would not work in a DOS emulation window.

So what you have to do is:

Download the software from the TC website.

Send money for a license to TC. They will give you a registration number, which you type into the application.

Then you have to buy the correct 'Definition' file for your particular PCM. When they send you the file, you just copy it to the TC subdirectory.

You will also need a cable (from laptop to OBDI port). This can be purchased in 'kit' form or complete from AKM cables.com.

That's it really. Read the PCM a few times to make sure everything works ok (can't damage PCM by reading it). Save several copies of your original configuration. Then make the changes to the file offline, and then download it to the PCM. It is really easy to make the changes. It has switches for several parameters, and graphs and tables for others. You can either manually change the numbers in teh tables, or just drag points on the graph.

 

Very COOL STUFF!!!!

Tim