Official Bro's 1992 FS Chebby Thread
Nutshell tired LO3 transplanted with a 350 .040, Vortec heads, L98 cam, 74# injectors, Edelbrock Performer intake, shorties and NV3500 approximately four weeks ago.
Quote from my "Intro" thread...
Quote:
Originally Posted by
stew86MCSS396
As stated above bro's truck is a 1992. Started just fine on the oem '299 computer but very rich. Swapped to '747 ecm w/ 5.7 manual truck bin EGR delete and changed BPC to 115 for 74# injectors. Much better smell at the exhaust. Didn't put a scanner on it and sent him home with that. I know, I know what am I waiting for. There's way more on the table since we're talking peanut cam vs. L98. He just notified me he had issues climbing a grade. My thoughts for hit it out of the ball park tune is to start with a L98 cam bin, however closest thing to that would be '746 Caprice cop car. Only wiring difference between the two, is the IAT/MAT sensor. Tried comparing the VE tables and very different. Internet searches had varying opinions of what the IAT does. Am I wrong to think I can import the '746 map into a '747 map? Another possible route is take the deleted EGR wiring repin A4 to C12 and run with the '746 sans EGR and BPC change. I know it still needs to be tweaked for the vortec heads but just wanted to kick some ideas around before the week ends and I won't see him til next week.
Update...scratched the '746 idea although I'm open to comments about it. Turns out the climbing^^^ issues was all in the tune. Managed to get some data logs and corrected all the BLMs to 128+/-4. Also dumped first LT1 spark map I could find like copy and paste. Performance improved like night and day. Last data log after the LT1 spark map, BLMs varied as low as 110 to stoich. Bro is stoked with that tune but I know it's not perfect. He has a 2" TB in the mail and told me we'll take care of it then. It's been a very rewarding experience so far and thanx to all you experts that I've learned from!!! Stay tuned for the next update and the floor is open for comments.