Alright I've got a stock 91 Camaro RS (305 tbi automatic), and from an earlier post I've learned that the stock chip or whatever for the tbi's doesn't accept mods very well (slow baud rate etc.). I don't know much about car computers, how do I mod the stock ecm? Should I just buy a new chip? I've heard other members give varying testimonies ranging from, dramatic increase in output, $200 down the hole. I'd rather figure out how to mod the stock ecm before buying a Hypertech chip or something. Thanks.

 

It would be a pain to mod the ECM. I'd stay away from that. You need to reprogram the EPROM. Not sure there is much gain from that in the case of a TBI

 

Not much to gain in moding the chip on a stock TBI engine, when you start putting different heads, intake, cam,headers or swapping to a 350 then you HAVE to modify the chip and fuel pressure so it will run well, don't even bother getting a premade chip.

 

So I should make most or all of my mods first (exhaust, intake, etc.), then worry about modifying the chip. Did I get that right? Also, on my car I know I'm going to have to upgrade the intake and exhaust manifolds, I don't have the money etc. to change the manifolds right now. Will I see any increase in horsepower if I put exhaust (Flowmaster) from the cat back w/out changing the manifolds? And can I change the exhaust manifold later w/ out having to make changes to the new exhaust system?

 

Do the exhaust first then add headers. I'd save my money for a standalone fuel system like DFI or the Holley one where it has the intake manifolds, etc. That way, you won't have to worry about a chip.

Feel free to ask Eileen Formato at www.fasterproms.com as they did my chip and will also give free advice and tell you what you can expect.

 

Thanks for the info, I'll check it out.

 

That price is obscene.

 

What did you expect for a custom job? You pay $200 + for something someone pulled off the shelf that may or may not work for your application. Further to that, for people like me who bought into it at $500 (less than that years ago), now I get reburns for $150 whatever I do. You buy your $200 chip and later (assuming it works good) try get a supercharger and change injectors and see how much more it costs you. They had to redo the entire process when I switched to my 383 and again when I switched injectors and other things that required a reburn.

 

If you stick with the basic bolt ons such as exhaust, open element, and ignition mods then you'll be fine just raising your fuel pressure a little. If you check on thirdgen.org in the tech articles theres the diy afpr, it takes about 30 minutes to complete.

Once you do heads, cam, and intake, basically anything letting a lot more air/fuel into the engine, then you'll need to burn your own chip. The stock TBI computer is pissy after doing this stuff (Id know lol), but the good news is burning chips is easy as hell. If you can download WinALDL, make a small cable, and multiply three numbers together then you can burn your own chips. Hell I didnt even make the cable, but then again Im a slacker

WinALDL
Then read Traxxion's tech article on thirdgen.org and then read his post about tuning non PE tables on the diy-efi board. That'll give you real solid footing.

 

I don't know about the TBI as I have a TPI. I had the Accel Superram Intakes (TB to manifold) and could feel a definate difference. Tried the AFPR but where it made a difference in WOT, the low end wasn't the greatest. Next, I did headers and there was another difference felt. AFPR didn't do much again. Each time I had my wife check it out. She is the most car illiterate person I know of so that is the best guide based on what she feels. After I had LPE do the chip it was much better. Again, it was wife tested.

Problem with AFPR is that it does it throughout the band. You may need more fuel on one end but not as much on the other but the AFPR doesn't care.

Besides, when I went to LPE to get them to custom my chip, I saw John get in the car personally no less than 8 times to make runs and he took several hours. This considering that it is a system he uses day in and day out tells me that if you want to get it just right, be prepared to do it for a long time. Being with him watching him do it and counting the hours spent to get EVERYTHING just right convinces me that it is not something done in an afternoon. Yes I have a degree in computer science and can read the chip program from his printouts and could understand it if I tried but why bother? How often do I need chips done? In the last 12 years of car ownership, I only needed to do 3 chip changes. I have better things to spend my time on.

 

I read Traxxion's article last night...very interesting.

The reason I'm interested in it is because it's cheaper to spend $500 off the bat to get the software to DIY and learn the programs, than pay someone everytime you have to make a change. It's very much like LT1-Edit. Pay $300 once, or pay Ed Wright or whoever $400 to do it once and an additional amount to make changes down the road.

 

You're only increasing your fuel pressure a tiny bit with the above mods, so the fact that it increases along the whole table doesnt matter too much. 14 psi is stock I believe, so really you only need to go up 1-1.5 psi, at least that was what I got best results with when my car just had open element and exhaust minus headers. If you're worried about it anyways, GM makes a vacuum adjustable fuel pressure regulator that you can say for say 11 psi at idle then 15 at wot, so as your vacuum changes your fuel pressure goes up. I think its $43 from gmparts direct, I can post the pn when I get back to my dorm.

Im not saying dont go to a place like LPE or have someone burn you a custom chip, if you dont have the time to do it then they offer a good service. But being in college I cant afford to drop $500 up front on a mail order chip, then and additional $150 when I want to change my cam and need a new chip. I dont mind dropping $150 on a pocket programmer once though, then $3 for a new prom when I need it.

 

www.fasterproms.com is nowheres near a mail order chip. Their first one to you is because it is just to get a baseline. With that in your car, you make runs when it is warmed up. They will check your warm start, cruise, wot and idle. Same for cold except that they will not do WOT. After that they send you another chip and you do readings again. After that they send you a final chip and when you are happy (ie no more tweaking) you send them a $500 check. If it needs more tweaking to get it in, it is on them but usually, it doesn't need more tweaking at this point.

In future, they will charge you $150 to repeat the procedure. First time it costs more because you are buying into the program. I believe they also do 4th gen mods on the chip.

Anyone who tells you they can get it in on the first time is smoking some good stuff.

True, when you change injector size, cam or heads in intakes, you can have it reopimized for the new stuff but how often do you change stuff? If you are doing testing on a daily basis, you will need to learn how to DIY. Like I said, 3 burns in 12 years hardly makes it necessry for me to learn something new and experiment with it all day long. Provided you get it dialed in just right, you can (and I do) drive my car year round and never need it changed.

 

No one called it a mail order chip. Those weigh in at a super deal of $300-350 lol, I dont think I'd trust one of those more than I trust my stock ecm.

And like I said, if you have the money and no the time its a good route to go. But I dont have money and I do have time lol. Plus I get a giddy nerdy like kick from playing with the computer. Im an aspiring Computer Science, so I guess we have at least that in common

 

I'd love to learn how to. What I need is an old motor to try it on. I just had my 383 built by LPE and paid around 5k for a short block and them to put my heads on when I was at that crossroads. Didn't want to toast my new motor with an "oops". Unlike a computer program, it is not as easy as formatting a disk or restoring data.