Why is the secondary injector circuit so complicated? - ZR-1 Net Registry Forums

XfireZ51 · 10-24-2022

Basically, GM didn?t want to or could not develop another ECM for a limited run of units like the ZR-1. There are many similarities between the L98 programming and the LT5, although the LT5 uses Speed Density instead of MAF for some obvious reasons, ie a new MAF would have been required. Controlling the secondaries using the ECM would have required additional injector drivers, again necessitating a significantly modified or new ECM. So the injector relays are a less expensive alternative while using the primary injector as simply the ?trigger?. Then u cut the PW by 50% whenever the secondaries are engaged. Voila!

10-24-2022	#2
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,669	Re: Why is the secondary injector circuit so complicated? Basically, GM didn?t want to or could not develop another ECM for a limited run of units like the ZR-1. There are many similarities between the L98 programming and the LT5, although the LT5 uses Speed Density instead of MAF for some obvious reasons, ie a new MAF would have been required. Controlling the secondaries using the ECM would have required additional injector drivers, again necessitating a significantly modified or new ECM. So the injector relays are a less expensive alternative while using the primary injector as simply the ?trigger?. Then u cut the PW by 50% whenever the secondaries are engaged. Voila! __________________ [SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX