Originally Posted by jbc426
I'm building a fresh 493" EFI'd pump gas RB motor that had 10.2 to one compression. I had been running the mechanical DC carbs, but am switching to a Holley HP unit with coil-on-plug and a Wilson ported Victor single plane with their throttle body.

Does anyone know how much I can bump up the compression using pump gas while injecting straight methanol controlled by the Holley computer? I've heard I can run at least 11 to 1, but have never used methanol injection before.


It depends on how much methanol you spray, the more you spray, the HP ECU will pull fuel out to get the AFR where you set it. if it rattles add more Meth

1968 Charger COLD A/C Hilborn EFI
512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim
2020 T/A 392 Stock 11.79 @ 114.5