Tinbender59

hello friends, now that I'm getting back to some sort of post Covid normal, I want to get back to my TPI projects that I have acquired. first up is my 1976 GMC Sprint, she has an LT1 converted to TPI was on a 411 but after $2000 and unresolved Long Term Fuel Trim issues, I pulled TPI, ECU and wiring off for a complete re-evaluation and review. found a couple of major issues, ( one of which Jim at TPIS solved for me by just explaining the issue). currently waiting on price quotes from Jim on 2 - 7730 systems ( I have the TPI hardware), before I start throwing wrenches at it again. Price will dictate 7730 or 411 again. the 411 system is a proven system, I ran this exact system in a 1997 K1500 for 5 years and got 22 mpg consistently.

the second system will go in our 1979 motor home she has a 400cui/ TH400 and could use a new carb. so I decided to put my second TPI on it instead, It could use the extra torque. lol

as stated above I am waiting on a price quote before I dig into them. I hope to video the process and post it on my YOUTUBE page.

the LT1/TPI with a Lunati cam, headers, 1.6 rockers and stock WS6 block, put 287 ft tq @ 20000/ 268 hp @ 4600 on the ground with a jacked up tune. what will it do running correctly?

ULTM8Z

Despite its age and limitations on non sequential injection and stuff like that, the 7730 with 8D is actually a pretty good system. It's amazing how much fidelity GM put into that system for fuel and spark tuning... especially with guys like 84Elky, Rbob, and the other gurus on this board to break it all down for us and continue to support the platform.

Tinbender59

Yes you are correct, a little known fact, above 4k the LS ECM's revert to batch fire as the injectors can't be fired fast enough to maintain sequential above that.

Fast355

iTrader: (2)

That is not correct! The only time a LS PCM operates in Batchfire is without a cam signal.