[Vegas69]

Originally Posted by SSLance

More tuning on the Holley. Found and corrected several issues which created the touchy throttle and have it MUCH better now. Super easy to be very smooth on throttle now. Also added some enrichment on MAP rate of change which it didn't have before, helped tremendously with tip in power. Can't wait to race it again Sunday.

Video for attention...



Had a pretty scary hung throttle while testing yesterday. Had a green light with no traffic in front so made a pretty hard hit in first and second gear, then the throttle hung wide open going to third. Pedal was on the floor so I immediately hit the key to switch it off. After I caught my breath while still coasting, I started it again with same result. Once stopped I pulled air cleaner but didn't see the culprit, fiddled with throttle cable and all seemed good so I started it again and it was fine. Once I got it back home, I discovered this...



The screws holding the throttle position sensor had come loose, one completely gone and the other finally loose enough that the shaft jumped the slot in the sensor and the sensor held the throttle open. Yes, the replacement screws got a dose of loc-tite upon reinstall and yes, throttle application is much smoother now.

I was running a datalog during the hung throttle...finally got up the nerve to look at it.

The green line is RPM... At least I know my rev limiter works now...

This may be the answer you are looking for. A long rev limiter hit is tough on your bottom end, especially with cast pistons. When I had my ZL-1 built, my engine builder preferred I raise the rev limiter vs. bounce it off repeatedly.