'Performance Proms' , also TPS enhancer snake oil, and other chip basics - TPI - Third Generation F-Body Message Boards

Drew ATX · 05-04-2002, 04:34 PM

I was wondering about something. I've been planning on getting the TPIS tps sensor enhancer for my car. But I've also ben planning on getting a prom from Jet or Hypertech. It's my understanding that the tps enhancer signals the computer at 60% throttle that I've got it at WOT. My question is, will a performance prom do the same thing or not? Would I be waisting my money buying both?

Ed Maher · 05-04-2002, 04:47 PM

You're wasting your money on both. Thje TPS enhancer is useless snake oil, big deal it brings the TPS up faster, that doesn't do anything special in the computer except maybe a little more pump shot (yawn)

As for a junk chip like hypertech or jet, instead buy the stuff to burn your own. You can duplicate what is in those for under $200, and have the potential to keep doing it as you learn more. But even if you just burn one chip you could beat jet, hypercrap, et al.

Drew ATX · 05-04-2002, 04:49 PM

Do you really think I could do better myself? I really have no idea what I would be doing. I'd be learning through trial and error.

Ed Maher · 05-04-2002, 04:57 PM

Thats just it. When i first got into PROM burning i happened to get a jet 305 chip for my car from a guy i knew. And i compared it to my stock chip. The ONLY differences were these:

- The torque converter clutch lock-up speed was raised to 40mph
- the timing table had a few numbers changed, just raising timing in a few spots.

As a matter of fact, i'll show you what i'm talking about, be back in a second.

Ed Maher · 05-04-2002, 05:14 PM

Here is a screenshot of tunercat, chip editing software. This is the stock main spark table for a 90-92 TPI 305:

And here is a comparison with a the 'performance' Jet chip:

the -1.8 means that the stock chip has 1.8' less timing than the jet chip. As you can see, all they did was add a few degrees of timing in the high load (high MAP values)

Anybody can do that, you can basically duplicate the effect without even buying PROM burning equipment just by turning the distributor except that works everywhere not just at WOT.

But yes, it really is as easy as changing a row of numbers in a 'spreadsheet' to duplicate a chip you'd spend hundreds for. The only difference is, you can then keep changing it as you learn more, and experiement to find best performance.

As for me, i tried running the Jet chip and my car ran like crap and pinged all the time. It was adding way too much timing at high RPMs. So i made a chip with less timing in the high RPMs and more timing in the low RPMs and i had a lot more pick-up off the line and it didn't ping

edit: well while it's here i might as well explain the table in case it isn't obvious to some. Like i said, it's the main spark table. Across the top are MAP values, which is like the opposite of vacuum. High MAP means low vacuum (high load, WOT, etc), and low MAP is high vacuum (idle, cruise). A typical stock L98 cammed 305 engine idles around 40kPa (18" vacuum) or so. Anyhow, down the side is RPMs. The number in front of you is how much timing the ECM sends to the distributor at those loads and RPMs.

If you're used to old style carb and vacuum advance distributor cars this should make sense to you if you look at it as the numbers across the top are like the vacuum advance, you can see that there is less timing at low vacuum, and more timing at high vacuum. And the numbers going down are your mechanical advance, adding timing as the RPMs go up. An important advantage here though is you can easily put in exactly the right timing at every rpms if you want to, squeezing every last HP out of it. Or you can just run a more traditional curve just as easily.

To get your total timing, these values are added to the initial timing in the distributor, and there is also another timing adder in the ECM for WOT.
WOT in the ECM is called PE or power enrichment. Think of PE like the secondaries of a carb, with an added shot of timing as well)

Speaking of which, WOT turns on around 50-70% throttle, which is why those TPS foolers are junk. There is no benefit in turning on PE a fraction of a second earlier, and once you're in PE, thats it, 80% throttle or 100% throttle the computer adds the same timing and fuel

Drew ATX · 05-05-2002, 01:13 AM

Wow! Thanks for all the help bro. :hail: I'm going to take your advice and just make my own chip. Thanks again for taking the time to post all of that and explain it.

Ed Maher · 05-05-2002, 10:42 AM

NP. We've been preaching about how poor these off the shelf chips are for a while now, but it never occurred to me to actually show exactly how little change there really is in there. And not only is there just those small timing changes, but in my experience those changes were exactly wrong for my application. If i had bought that jet chip as a performance replacement it would have gone into the trash it pinged so bad.

Since i've already been packing so much info into this post, here is some more advice to novices, a few basic features of PROM tuning that are easy and make the initial buy in cost well worth it, even if you don't try to be a guru and get heavy into tuning.

- Fan on temps. You can set the temp that each of your fans turn on and off. So this way no matter what thermostat you run you can keep your car cool in traffic in the summer without having to mess with any hard to reach sensors on the engine. Stock the fans come on until 220' or more. If you lower that to about 10' above your thermostat opening temperature you will see a big difference in how well your car can stay cool since it's not so close to overheating. And thats even with a stock 195 thermostat.

- torque converter lock-up points. Not a big issue in L98 cars, but most of the 305 bins i've seen lock up the converter clutch as low as 25mph. This gives you that lugging boggy feeling when driving at low speeds. The L98 cars don't lock the TCC until 40mph or so which is a much more reasonable value. There is also another TCC lock-up parameter that kicks in at WOT but thats a little more advanced of a topic.

- Idle speed vs. coolant. You know how you car idles faster when it's cold, then idles normally once warmed up. This is where you control exactly how fast it idles and at what temps. Those of you who like cold thermostats might be interested in this one, a 160' for example won't even get you to the normal idle speed in some bins. Basically all kinds of enable temps in the bin, but you don't need to play with most of them, but they can come in handy.

- injectors. Want to run high FP, or bigger injectors, no problem. All you do is figure out how much you're changing the relative injector size (for example going to 22s from 19s, you just multiply the injectoor constant by 22/19) or if you're changing pressure, the number you mutiply with is given by this formula squareroot{(new psi^2)/(old psi)^2}

-spark curve. This is the fun part, but you definitely have to be careful. The PROM gurus don't advocate playing with the spark curve until you have your fuel figured out, but most people aren't going to get that heavy into it. Even if you don't touch the fuel though you can find more performance just by tweaking the shape of the spark curve. Juust be careful and only make small changes. And keep track of what you're doing, and how it changed performace (you really need to be at the track or using a g-tech or similar to measure the difference in performance or you might just take yourself into detonation and never know it because of the knock sensor)

IMO the reasons above alone can justify buying the equipment even if you enever touch anything else, especially considering a barebones set-up is cheaper than some off the shelf junk chips anyway.

Now if i can find some free time maybe i'll condense this into a tech article or a sticky post

Synapsis · 05-05-2002, 02:32 PM

There's more than enough information packed into the PROM forum to get anyone started into PROM burning, IMHO. And it's also more effective use of your dollar. You could buy a 200$ JET chip, which probably won't net you much benefit at all, or you could buy a 150$ pocket programmer, 20$ in spare chips, and have total control over your car.

Spend the extra 30 bucks on beer to drink while you read Trax's prom burning article.

Tuned Port · 05-05-2002, 02:50 PM

ive browsed the PROM burning forum, and almost none of the topics made sense to me. for a novice, i think you would need a book or something to teach you the basics. and is $150 all you need to burn PROMs? i thought you needed like at least $500 in equipment

86Tra/maro · 05-05-2002, 09:01 PM

Tunedport,
Your right! I read & re-read the articles on computer tuning it doesnt make much sense to me either. My main problem is what parts do I need to buy to modify all of the above parameters (fuel , spark tables ,fan on/off temp ,Etc...) mention by Ed? A SPECIFIC (combo) of parts # of what to buy from a person who has been modifying his/hers eprom. For instance if ED uses pocket programmer, a particular program modifier, connection cables ??( i guess that what its called

) , & any other ED specific COMBO of parts would be a great help. Newbie programmers Have no idea of what combo of parts to BUY! U expert or experienced programmers made a very big list of most of the parts that can be bought. But as I said earlier, It would be greatly appreciated to help the NEW Guy make the right choice the first time around.

When I looked at the TunerCat software I was really surprised at all the different "smaller" programs that they were selling at $20.00 a piece ! I had no idea of what to buy! I was about to purchase all of the smaller programs but before i did i asked a question like: How can i buy all of these programs , cables ,eraser, chips ,etc... for $250.00?? Thats what I mean NEW PEOPLE DO NOT KNOW THE COMBO OF PARTS TO modify all of the timing ,fuel, fan on/off,ETC..
Hope I make sense.
njdaewoo

:hail: :hail:

Ed Maher · 05-05-2002, 10:16 PM

Since this is meant as an introduction thread, no heads will be cut here so long as you make sure you have read the whole thread up to this point, so don't worry about sounding dumb, i want to help people see how easy this all really is. Anyone caught making a wise *** remark in this thread will be shot as well, i want this to be a safehouse so i can figure out what i can do to help people with the basics.

Firstly, Tim (traxion) is in the process of updating the intro to PROM burning article. The 'new' version is http://www.xecu.net/timsiford/update.htm
Read over that, as well as what's below. If this thread clarifies some of what he says, or you see something confusing, post here and i'll talk to tim and see if we can re-work the article some more to make sure it's clear.

Here goes the barebones of what you need to get started...

1- http://www.xtronics.com/memory/EPROM.htm

Pocket Programmer from xtronics, PN I-PP2, $150

- this is what you need to actually burn the chip. Make sure they give you the windows software with it, very easy to use. To burn a chip all you do is load the buffer (like opening a file), hit the program button and when it's done hit verify to re-check to make sure that it wrote properly. To read a chip all you do is hit the move device button to load the chip into the buffer, and from there you save it. Really is that easy.

2- A bin editor program.

Most of us use tunercat to do our work on the chip. Total cost including the TDF (a file that tells the tuner software where the tables are in the chip) is $90.
If you are confused on what to get, all you need is the 'Tuner' software ($70) and the TDF $20) for your ECM and year (more on this later). All those other little programs are completely seperate and unnecessary unless you are VERY advanced.

There are also free editors, which do work quite well (they were mostly written and organized by theoriginal DIY guys), they just aren't as nice and polished as tunercat. But if you just want to change a few numbers and don't need every little feature then these will work fine for you. There are 2 major free programs, WinBin and GMEPRO
I'm not sure what and where the latest and best versions are to download so i'd rather defer this to someone who can point the way for sure. I do know you can find ECU files (like the TDF for tunercat, except for winbin) @ ftp://ftp.diy-efi.org/incoming/ as well as many other places. I'm sure the information is on the PROM board, but i don't have the time to sift through search results looking for links right now, sorry.

3- You need chips and a way to put them into the ECM.

As for chips, at this point, flash chips are the way to go since they don't require any erase time. These will be PN 29C256-12PC or 29C256-90PC, the only difference being the speed of the chip which doesn't matter sinc ethey are both fast enoiugh for our ECMs, the slower -12s being $1 cheaper or so. You can get these at www.jdr.com, just put the PN into the search window to find them. a few of these are all you need.

As for putting them in the ECM, there are a couple ways of doing this. Rather than beat type too much, i'll just defer to Tim's article here. In the how you do it section he describes the various methods people are suing to put their chips onto the stock memcal (thats the name of the whole blue 'chip' in the car, the actual chip sits on that. Unfortunately Tim's picture links are dead but i'm sure that will be remedied soon.

As for the ZIF sockets he mentions, you can also get them from www.jdr.com, just type in ZIF in the search, and you need the 28 pin style. I mention JDR for both these elctronics just because i have found they are usually in stock for these items we need. These can be purchased anywhere you can buy real electronics though as Trax mentions in the article.

And thats it. All you NEED to buy is a burner ($150) some chips and a ZIF socket (~$25). The free software (wWinBin or GMEPro) is more than capable of filling any novices needs. And as for putting the chip in the car, you do take a risk if you unsolder the stock chip to put a ZIF on it. It can be done, and is certainly cheaper than buying a spare memcal, but keep in mind you might need to buy a spare should things go horribly bad

(this isn't really different than most other car work though, i mean if you're porting an intake and you cut through you need to get it welded or geta new intake right, same thing here and a new memcal from GM is only ~ $50) Making or buying an adapter (such as craig moates http://ice.prohosting.com/moates/gmecm/hardware.htm has been selling, as well as 29c256 chips and ZIF sockets) is a safer and easier alternative, but then you're spending a little more money. You can also find these adapters on ebay from old jet chips (thats where i got the jet chip from, i'm using the adapter from it.) and also stock memcals to modify cheap as well.

Clear as mud?

Synapsis · 05-05-2002, 10:58 PM

Here's an example of one man's burning equipment. =) I've started with this setup and it's taken me as far as I've ever wanted to go.

Pocket programmer from www.xronics.com. $150
ZIF adapter and eproms from Craig Moates ~$60
A cable for reading data from the car ~$95
(forgot where I got the cable from)
Tunercat ~$90

Now you can build the data cable yourself for around 20-30$, and you can get free software to get the price down.

When I unsoldered my stock chip from the memcal, I destroyed the chip (not the memcal), so be careful for that. I bought a spare memcal for $45 from acdirect and keep it in the car just in case.

I didn't understand too much of what I was looking at the first time I edited chips either, and it can be overwhelming the first time. But I did find all the info off the PROM board and the diy-efi mailing list archives. The rest was experimentation.

And to quote Grumpy: Always document your changes!

BlazinOR · 05-06-2002, 01:45 PM

Ed, you should be commended for putting this up, and with a sticky. Thank you, this along with Glenn M's input has reignited my desire to get into the PROM burning arena.

Ed Maher · 05-06-2002, 01:52 PM

I threw this up as a sticky because i know most of the true novices are intimidated by the PROM board. Like i said above, i figured this would make a good safe-house to clear out the beginner questions so that hopefully such clarification can be built into the intro to PROM article.

I also thought it was important to actually show how little you are getting for your money when you buy one of the junk off the shelf pieces. Hearing over and over again that htey are junk is one thing, but i think actually seeing exactly what we have seen really drives home the point of how big of a waste it is.

86Tra/maro · 05-06-2002, 03:54 PM

Thanx Ed,
U really opened my eyes as a newbie to the programming deal! Like I said before I had no idea of what combo to buy. That was my main problem but now I have a real starting point.
My new question is can my same laptop be used as a portable scanner?
Thanx again ED & Synapsis!

Synapsis · 05-06-2002, 04:14 PM

Quote:

Originally posted by 86Tra/maro
My new question is can my same laptop be used as a portable scanner?

I've seen Pentium 90 laptops with 16 megs of ram run Craig Moates' software with no problems. I use a 500 Mhz Dell with 128 megs of ram and Datamaster in the car. I also burn my chips with it at the track.

monte-ss · 05-07-2002, 02:10 AM

Quote:

Originally posted by Tuned Port
ive browsed the PROM burning forum, and almost none of the topics made sense to me. for a novice, i think you would need a book or something to teach you the basics. and is $150 all you need to burn PROMs? i thought you needed like at least $500 in equipment

its true guys reading that stuff gets a little overwhelming, but if a particular topic makes no sense do a little research on it, a lot of these guys have been doing it a long time and refering to different things by the various names are like us that stick to this TPI board are used to some more basic things that you didnt understand when you first got your car, before you owned a TPI set up did you know what MAF or SD or ECM meant? or how to adjust your fuel pressure with an AFPR or even for that matter how to make your stock FPR adjustable? nope most of us didnt, and all those guys are just as willing to help, as long as your question isnt "hey how do I burn a chip" if its more along the lines of, "Im still learning, please explain" then they will usually jump right in, but they arent as fast to respond it seems as a lot of the guys here on the TPI board, you would think so since they are sitting at their computer tuning their cars! haha j/k Im still learning and this summer will break into the piggy bank and get all the goodies to get going myself.

Synapsis, whats the extra cable for?

Synapsis · 05-07-2002, 02:49 AM

It's the serial to ALDL cable to plug the computer (laptop) into the diagnostic port on the car to make it a scanner. The cable is based off the MAX232 circuit if you want to search and get the schematic. I believe I got it from AKM electronics, but don't quote me on that, it's been awhile. The cable is cheaper than a refurbished AutoXray, and the software you can use with it is a lot better as well.

wataru · 05-07-2002, 09:05 PM

I've been thinking of getting into prom burning since I found this site. I've read through Trax's introduction to prom buring and there are still a few questions I have. If anyone can help I would appreciate it.
#1 What is a definition file? Traxion said you can buy them for
$20 from Tunercat but does'nt really say what they are or maybe I misunderstood what he was talking about?

#2 He says that its only gonna be about $250 for the equipment but then at the end of the article goes into the fact that your really gonna need a scanner. Well thats an additonal $150 right their, and thats for the "cheap" hand held units that only read 1 data point /sec. My question is. Are the hand held units sufficient or do you really need to purchase a laptop and software and cable, ect. to take full advantage of prom buring?

Please keep in mind that I am really new at this

.
Thanks!! Barrett

Bort62 · 05-07-2002, 09:22 PM

Good Questions.

The Definition File, If I understand it properly ( and thats a big IF ) is what tells Tunercat wich ECM Your trying to edit.
'
So, You need the Definition file to match the ECM you wanna Write.

As for needing a scanner, all You need is a Cheapo Laptop and Craig Moates software ( free ).

Much better than any of those hand help scanners, the only thing that really compares is Diacom, But thats $$$

And, If all you want to do is simple flag changes and stuff, you Don't need a Scanner. Not right away anyhow.

Hope that helps.

wataru · 05-07-2002, 09:27 PM

Doh

. Thats right I remeber reading about it now. I did'nt realize thats what you call it.

Thanks for the help.
Later Barrett

monte-ss · 05-07-2002, 10:29 PM

does it have to be a laptop? I have an old computer and with a long enough cable and something to roll it around on shouldnt be a problem? just wondering, besides I have an auto xray (thanks to the generouse company of checker

)

Bort62 · 05-07-2002, 10:50 PM

Well, a Long cable and a Computer on a roller Cart would be great for in the driveway testing... but To get the full use out of a scanner, you really need to drive around with it logging data.

So Unless you have a Roller in your garage to Simulate load, the Desktop won't do you Much Good.

monte-ss · 05-07-2002, 11:09 PM

True, didnt think of that, unless I hadmiles and miles of cable!! or a generator in the trunk of the car,,,,, hmmmmmmmmmmmmm hehe:sillylol: guess Ill just stick to the Xray for now

Bort62 · 05-08-2002, 02:00 AM

You could prolly sell the Xray to a local guy, and buy an old laptop for the price.

You will get much more detailed information.

DAVECS1 · 05-08-2002, 09:52 AM

Alot of people recommend Craig's software and I have previewed it. It looks nice. My question is no one seems to comment on the Freescan software form Andy. Is it ok I downloaded it and so far I like it. I haven't been able to use either on my car because I am still waiting on a cable. Will Craig's software and Freescan both use the same cable?

Ed Maher · 05-08-2002, 01:07 PM

AFAIK moates software uses t