jims hot tune

[Sawzall]

Another mail order tuner did my LQ4. When my knock sensors failed, the timing went to -15 degrees under a load and the buggy would fall on it's face. When cruising it ran normally. I have never seen another engine act that way but I don't have much experience with LS engines. I think my engine does pretty good for a stock LQ4 but a friend has an identical powertrain in his buggy except for gearing, (Mine is 5.13 and his is 4.56), and his engine is a lot crisper and seems stronger with a Jim's Performance tune compared to mine.