Post by acr on Jan 5, 2011 14:18:31 GMT -6
The following is a FWIW reort on my experiences using Damon's "White Paper Dual Quads" article. I've had my Carter AFB 2x4's installed & running for two or so months but didn't get to tune them until the last few days. I took my time, did things just as Damon listed them & I'm happy with the results.
1. Setting/sychronizing the idle on both carbs as directed made a BIG difference.The idle was smoother & an annoying intermittent idle/low speed miss is gone.
2. When adjusting the mixture screws I didn't have to turn them very far from the inital two turns out from the bottom & I made very small adjustments as I did this. One screw required 3/4 of a turn from the original two out & the other three 1/4th turn. Per the article, I went back over these again but moved them very little.
3. I used my vacuum gauge to do this & had used the same gauge on my car when I had 1x4 AFB. After final settings the idle was much smoother & the vacuum gauge reading was steadier than before.
4. My RPM drop from park or neutral is much less now, less than 200 RPM from park to drive, around 100 RPM from neutral to drive.
I hope this info is helpful to someone, i'll post more after a thorough test drive. Also my set up is on a weekend driver street car. .
FOLLOW UP: I just drove the car about 4 miles, start up was much easier, idled better & ran good. I still have a slight stumble or hesitation that occurs from a stop or at lower/mid driving speeds. It occurs when I first tip in the throttle. I also still have tuning to do, the metering rod springs test, linkage not opening all the way, check my plugs for color, etc.
1. Setting/sychronizing the idle on both carbs as directed made a BIG difference.The idle was smoother & an annoying intermittent idle/low speed miss is gone.
2. When adjusting the mixture screws I didn't have to turn them very far from the inital two turns out from the bottom & I made very small adjustments as I did this. One screw required 3/4 of a turn from the original two out & the other three 1/4th turn. Per the article, I went back over these again but moved them very little.
3. I used my vacuum gauge to do this & had used the same gauge on my car when I had 1x4 AFB. After final settings the idle was much smoother & the vacuum gauge reading was steadier than before.
4. My RPM drop from park or neutral is much less now, less than 200 RPM from park to drive, around 100 RPM from neutral to drive.
I hope this info is helpful to someone, i'll post more after a thorough test drive. Also my set up is on a weekend driver street car. .
FOLLOW UP: I just drove the car about 4 miles, start up was much easier, idled better & ran good. I still have a slight stumble or hesitation that occurs from a stop or at lower/mid driving speeds. It occurs when I first tip in the throttle. I also still have tuning to do, the metering rod springs test, linkage not opening all the way, check my plugs for color, etc.