Tedd

1995 5.7 4WD auto E/OD GT4 Suburban:

I have had substantial gains by retiming the motor from a stock setting of 0° to 8° BTDC. But with the factory settings on the eprom it just isn't quite there. Now it seems I'm going to have to purchase hardware and software to burn my own EPROMs heavy sigh:

What are the reasons an after market chip (Jet stage 2) will not help? I have read many posts in the diy prom forum and while burning my own chips seems obtainable, I'm not sure if it will really be worth the effort, this is a 4wd Suburban for gosh sakes. I understand how ypu guys with 3500 lb cars are needing to get every 1/10th of a second out of your cars at the drag strip, but all I wanted was more torque for towing my boat!!! Now it looks as if i'll have to go back to school to learn how to reprogram my own eprom. I am not convinced that the benifit/effort ratio will be very high for this project of mine. Does anybody out ther burn chips for specific applications for fun and profit?

I am also curious about the specs on my factory cam (difference between what I had and what I now have) Is there a link or does someone know offhand what a stock 95 Suburban would come with, I would think it would be a different profile than an F-body cam.

have replaced the original 5.7 motor with a 355 c.i. split rear oil seal short block, a Crane cam [part # 113931] with intake lift at valve .440" and advertised duration of 266° and exhaust lift at valve .454" and advertised duration of 272°, a pair of 23° twisted wedge Trick Flow heads and Flow Tech shorty headers with O2 sensor coupled to 2 1/2" dual exhaust with dual cats and mufflers and no crossover tube. The motor is topped off with some 8mm ignition wires. The rest of the motor and car is bone stock.

Any way all help and responses are greatley appriciated and are dulet noted.

Thanks for all the previous responses so far

Brent

iTrader: (1)

The Jet 2 won't help because its not designed for aluminum heads and a larger cam.

Whether or not its worth the effort is really subjective. If you want to maximize your fuel mileage and torque then its worth it. If you want to prevent meltdown at WOT its worth it. If you don't care about these then its not worth it.

How much torque and mileage will you gain for your efforts? Well it depends on how far out of tune the factory PROM is for your new engine. The aluminum heads are gonna want more timing at part throttle and your gonna need more fuel at WOT for sure.

You'll probably have to look into a fuel pressure increase or larger injectors. A quick pull on a local chassis dyno with a Wide bad O2 sensor will tell you exactly how lean its running.

The factory cam is somewhere between 180-190 degrees @ .05 on the intake and 200 on the exhaust.


If you are gonna do PROM burning I'd start off by getting ALDL scan software that can datalog to a file for later evaluation.

Tedd

" Quote from Brent"
Whether or not its worth the effort is really subjective. If you want to maximize your fuel mileage and torque then its worth it. If you want to prevent meltdown at WOT its worth it. If you don't care about these then its not worth it.


Damn, I hate it when arguments are well worded logical and don't come to the conclusion I wanted to hear.


Thanks for the advice Brent. Why is the best way always the hardest way.
[2nd law of thermodynamics:Ya don't get somethin for nuthin!]

I suppose the first step I should take is aquiring win aldl software and an aldl cable for interface with my laptop. 2nd heavy sigh today

Of course I never do anything the easy way so why should this be an exception! As far as the cable goes, I'll be running Windows 98 or to be technically correct Virtual PC on my ibook. Thats right I'm the only one in North America who still uses an Apple At least when I hear people complain about the bill gates I can hold my head up in the knowledge that I have done my little part to bringdown the evil Microsoft empire. I have become quite adapt at running my Garmin GPS MApsource software on Virtual PC on top of the wonderfully simple and powerful Mac OS [how many wintel machines do you know that can run Mac OS on top of Windows?]Oh well thats another fight for another forum But back to the new and current dilema: Cable for aldl connector/ usb? I'll bet this will generate alot of smiles from you tried and true Windows users. And where do I get a copy of Win aldl?

Thanks again,
Tedd Edmondson

Brent

iTrader: (1)

WinALDL is here.

http://w1.601.telia.com/~u60113744/s...dl/winaldl.htm

Unfortunately, its not setup to work with your 95 'burban.

First thing I'd do is pull the glove box and find which PCM you have. Its either 16196395 or 16197427. Then I'd look for commercially availible scan software. I don't think any in the DIY community supports those particular PCMs. Ease, Diacom and Datamaster are a couple that come to mind.

Making these packages work with a MAC and OS emulation is something I know nothing about. I'm betting it will give you a ROYAL headache. A cheap wintel P100 - P133 laptop would fit the bill and cost less than the excedrin/aspirin purchases the other route will require.

Tedd

A cheap wintel P100 - P133 laptop would fit the bill and cost less than the excedrin/aspirin purchases the other route will require.

Yes I believe you are right about the older P100-133 wintel laptop, I will pursue that avenue.

I pulled out my ECM and the label on the prom is:
5068
1617
4895



I'll bet its not an F-body prom

what will win aldl do for me?

Seems like, if it is program to convert machine or assembley code into numerical data it would work for most proms.

Thanks Again,

Tedd Edmondson

Brent

iTrader: (1)

The three 4 digit numbers you listed are a date code and part number I believe. There is also a 4 digit alpha code ie (BJYM). This is the PROM id.

What are the part number(s) on the PCM case?

Winaldl won't do anything for you because it isn't setup to read your aldl data stream. The author would need your data stream info. I don't know where you'll get that.

The best bet is to get a aldl cable and software from one of the commercial sources. I think datamaster is the cheapest.

Tedd

Whoops


How about 16197427 BJYL

The other number was on the tape that covered the prom window.

Thanks,

Tedd Edmondson

Brent

iTrader: (1)

Ok, thats good news. The three scan softwares I mentioned will work on your 'burb and tunercat offers an editor that will work also.