383 tuning help

[myburb]

The prongs on the chips are very thin and I tended to get one bent trying to put it in. The zif allowes you to just drop the chip in and flip the lever and you are done. If you want to get the tune really good you will tweak and data log a LOTA LOTA times. The only problem with the zif is it makes the chip sit up higher. Moates does have a low profile zif. What some do is use the zif while you are tuning and when you get the tune done then you can carefully insert the chip without the zif and then the cover on the case will fit ok. That adapter you have looks like it does a similar job to the g1. With the g1 you retain your limp. Not sure if yours does.

[dktool]

The prongs on the chips are very thin and I tended to get one bent trying to put it in. The zif allowes you to just drop the chip in and flip the lever and you are done. If you want to get the tune really good you will tweak and data log a LOTA LOTA times. The only problem with the zif is it makes the chip sit up higher. Moates does have a low profile zif. What some do is use the zif while you are tuning and when you get the tune done then you can carefully insert the chip without the zif and then the cover on the case will fit ok. That adapter you have looks like it does a similar job to the g1. With the g1 you retain your limp. Not sure if yours does.

This ^^^

I originally started with the low profile zif for the sake of the low profile and cover clearance, what I found was that I was R&R'ing the chip so much that the lesser quality and more difficult lever operation was causing some grief so I went with the higher profile / quality zif with the metal lever, sooooooo much better !
With the taller zif the chip guides into place very easy and the large lever is easy to lock even with my gigantic fingers.
I can reach down and remove the chip without leaving the captain's chair.

I will someday put the low profile one back in and the cover on but I still find I like the ease of pulling / installing the chip and still play with the tune even after getting it REALLY good. (I never leave thing's "well enough", got to have tinker-time)

1 year ago I didn't even know this tuning was possible, now I am comfortable with what I do. I will say that based on the steep learning curve I am glad I went simple and didn't go the APU1 route. For me, stopping and pulling the chip and re-burning a change is close enough to "on the fly real time tuning".

[C2500]

Thanks for that experience with the zif guys. Dktool so what did you use for doing the re-burning?? I was going with APU1 cause it looks like its all there to do what I need to..
I’m still trying to figure out turner pro..I don’t have it yet but doing a lot of reading and don’t understand all the symbols are with the $B or whatever $ that is....Thanks

[myburb]

The apu doesn't have to be used emulating. I just data log with mine, decide what I need to change and burn a chip with the apu.

[myburb]

In ref to tuner pro and the process, it is a litte steep on the learning curve at first. Then it is kind of "bingo" and it all starts to fall in place. With the $, they are the mask which is relevant to your vehicle. In your case it will be $OE or $OD depending on what transmission you have.

[dktool]

Thanks for that experience with the zif guys. Dktool so what did you use for doing the re-burning??

I went cheaper (my nature) bought the following from Moates;

http://www.moates.net/aldu1-and-cabl....html?cPath=64

http://www.moates.net/burn2-chip-programmer-p-197.html

http://www.moates.net/g1-memory-adap...-etc-p-32.html

http://www.moates.net/hdr1-memcal-header-p-52.html

http://www.moates.net/s2-aries-28pin...cket-p-44.html

http://www.moates.net/c2-sst-27sf512....html?cPath=26

http://www.moates.net/s4-aries-28pin-lowprofile-zif-p-46.html?cPath=26

[myburb]

while we are passing info to get you going, here is a pigtail extension I made so I could mount the pcm under the front seat but leaving the truck wiring intact.

[C2500]

Looks like a good idea thanks!!

[daveosx]

C2500
The computer tuner guys I think will have you covered.
However lets look at the basics first.

You are not getting what you expected to.
First lets check the timing
Are you running pump gas or REC90 race gas
On modern pump gas up to 10% ethanol you can set your total advance to 38 manually by bringing the motor up to 3000 rpm for 30 seconds and then set timing to 38 degrees. Then disconnect the timing bypass under the dash and check timing at idle should be about 10-16 degrees. On race gas the same, on REC90 set it down to 35 and 10.
Then check your vacuum on a 383 even with a medium cam the vacuum should be greater than 26 inch HG.
If lower increase fuel pressure bit and check again you want to get the highest vacuum you can obtain at idle.
Now if you put a vacuum pump on the EGR valve and pump it up the idle should get funky and vacuum go down release the vacuum pump and it should recover.
If not then yank the EGR and replace, on the 2500 you need the EGR to protect your top ring lands.

If the old motor was puking oil your cat and even the resonator can be clogged if the same pull the O2 sensor and put a adapter in with a 0-10psi gauge with a long hose take the truck out run it normal and look at the pressure gauge it should not exceed 2 psi if so replace exhaust before you ruin your new motor.

Another issue that a lot of truck owners have is the lame fuel pump on the trucks since the stick motors were only 200 HP the bean counters put the cheap fuel pump in 36 dollars at GM dealers.
I changed mine out to an AC Delco EP376 and set the fuel pressure at 18PSI.
Now the truck is crisp and pulls all of its 200 HP working ;-)
Before complete failure mine had no symptoms and the previous owner did not notice.
When I changed mine the fuel pressure was below 1 psi I measured on a digital gauge so swap out the pump.

Once all good then look into the tune.

I have played with the 7.4L 2inch TBI unit no good for less than 400 CI it tends to dribble instead of squirt at idle and low rpm and you get a bad BOG even if you raise the enrich table all the way. The bigger TBI was designed for the BBC not the SBC and kind of sucks on a small block.
The stock TBI unit with all of the Mods is good for 670CFM the 383 naturally aspirated is good for 450HP under 6000rpm.
With 6lbs of boost easy 600hp.

To get the 450HP hour available the intake and fuel system has to support 9.16Gallons of Gasohol per hour at 14.2:1 and 130 gallons of air per hour In and out.
Full rich 110 Gallons per hour full lean 156.6 Gallons per hour.
You need 55.62 PPH of gasohol to make 450HP.
The stock injectors new flow 55PPH.
Lots of guys are putting the 7.4L injectors (92PPH) in and trying to get an acceptable idle they dribble at low pulse width and actually are limited to about 5300 RPM until full open.
They are quite a bit slower reacting and the minimum injector off time is relatively longer so poor economy slower throttle response.

It reminds me of when the dominator carbs came out and a bunch of guys upgraded their 650 double pumpers on stock SBC to 1000 cfm Dominators because more was better. I actually got a couple of those pink slip titles back in the day.

Remember Nascar makes 900 to 1100 HP on 104 octane pump gasoline from a mandated 348 cubic inches through a 13/16 throttle restrictor plate.