Grumpy

It begins with, defining what you want to do. The more you can define what you want to do the easier the job gets. Saying you want a fast car is almost meaningless, you have to define fast. Want an 11 sec car?, is that on street tires, streetable tires, or slicks?. HP level?, or area under the curve?. What transmission?.
Oh, and what does your budget really allow you to afford?.

OK, got that figured out?. Next is what can you actually do, or afford to do?. if you want to go fast, and don't have much doe, then you need to get resourceful, and network. Learning to solder is almost a must, if you haven't mastered it, then your going to have to spend some money, or trade favors. It's really amazing what you can do if you really try to barter.... And in part why I'm into the DIY'er attitude.

So you have a car, and the desire to do something. I'm not going to spend much time in the mechanicals since that's not what this board is about. But, we'll look at the tuning, and most specifically the PROM end of things.

First you need a scanner. And to run the scaner means a laptop. Fab a cable or get one off of ebay. Then get familiar with normal is for your car. Learn what the BLs generally are, what the air and timing values are and what they mean.

Then go out and base line your car. Go to a test and tune, and run the car. Get used to data logging your runs, get guys who know what tuning is about to look at your logs, and learn which end is up. And learn how to drive your car consistantly. While ETs are an indicator, trap Speeds can be the most valueable data you can have. What the 1/8 and 1/4 mile speeds tell you is how the heat builds in the motor during a pass, it's just as valuable as having EGTs. In this case heat means, the combination of timing and fuel.

OK, now you have an idea of what the scanner says, and means. And a base line. Now, you can start thinking about actually starting to tune, and seeing what actually works. And in the low to moderate state of tune, it's real easy to learn the fine art of plug reading.

If you want to take the easy way out it'll cost you some money. EGT, a WB, and ECM bench are all ways to save time, and wear and tear on your engine. And the number way to save wear and tear on your engine is........ notes. Good note taking can save you told grief.

While there are few in the way of Universal Truths of Tuning, there are a few. Give the engine what it wants, forget what you *think* it needs, look at the data, study your notes, and the trends get apparent. Run with the least amount of timing consistant with max results. If there is no signifigant gain in adding 4d of timing, don't bother. To continue doing so, will probably mislead you into adding too much fuel. Then you'll have too much timing, too much fuel, changed the acoustic signature of the engine, and can fool the K/S. Then you'll be pucking up pieces of the piston crown out of the exhaust ports. Engines often *feel* better with too much timing, and too much fuel. Why?, the extra fuel serves to raise the CR ever so slightly and high CRs always lead toward crisp engine response, right up until you reach the detonation limit.

Now a lil diddy about WBs. First off they're not perfect. Like most sensors, they can be fooled. They can tell you based on the O2 content what the effective AFR is, but no gas analyser is going to be as accurate as accurately measuring the actual air, and fuel.
Run with the timing retarded, and the poor flame will generate a poor level of combustion effeciancy, and a false rich reading. Too much timing, and you get into having a false lean reading.

Prom burning does take some time to master. Just as successful engine building does. For some, it takes more effort then other, same as engine building. It's not rocket science, lots of average Joes have learned how.

Well, dang, Doc, just broke our crayon, so I'll have to stop for now...
HTH

funstick

simple striaght forward and to the point. im in total agreement with bruce. seriously well put

SATURN5

Printed and tacked to the wall......
Bob

JP84Z430HP

One thing to add..... When lost, don't be afraid of You'll find lot's of valuable info buried deep inside many posts on this board!

Captain C

Saved a copy to my computer! One question though, what's an EGT??? Exhaust Gas Tester??????

Cobra289

EGT = Exhaust gas temperature.

Well Grumpy you have my attention with the EGT.

Is EGT not kind of hype?
I know that the real profs they use it but what we can do our self?

Lest say I have one of those EGT and I see that my collector has 1290 deg. F what can I do with this value?

I know that there is a combustion that generates a temperature but how can be translated to our tuning?
I know that there is a relation between lean and rich conditions vs. temperature, but is the temperature build up not a matter of time? (It will take some time to get at this temp.) Not real time information.

My first impression is that this will be a good tool for endurance tuning.

I don’t know what is normal temperature for my engine combustion in a perfect tune.

Sorry that I have so many questions.
Regards,
Cobra289

Captain C

The EGT will tell you if you are truly rich or lean, not just a calculated AFR. What would be best is if you had a sensor on each header tube and not just on the collector. That way you could program each individual injector for greater overall individual cylinder efficiency. (Sequential injector firing needed as a minimum)

Due to the port design/configuration of some heads/intake ports some individual cylinders flow better than others. In the past, especially with carbs, people used to design the lobe lift/duration on their racing cams for the individual port. i.e. different lift or duration depending on the flow test results on the cylinder in question.