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View Full Version : Edelbrock tuning help



Jeremy
08-18-2005, 04:25 PM
I have an edelbrock 750 on my 400 pontiac. I am running a 068 cam with 6x-4 heads. Everything is in good working order and I feel tuned correctly.

My problem is the transition from the primaries to the secondaries. If I go to full throttle in first as if on a run on the strip, there are no problems. The car is fine on full throttle and the A/F ratio is correct. Around town, the rods and jets are were they need to be. Driveability and part trhottle response is good. If I try to floor it from about 2000 rpms, the car bogs for a bit and then starts pulling hard again. It just seems to take too long for the car to recover from the secondaries opening. My guess is that the secondaries are coming in too soon for my relatively heavy car. I know they are mechanically linked, but was hoping someone would have some tricks to slow down the air valve over the secondaries.

Please chime in or ask more questions if needed to help me dial it in. While some may not think it is the best performance carb, it is what I have. Other than this problem I am very happy with it in that it is reliable, easy to tune, and offers good off idle and part throttle driveabilty.

Thanks.

MarkM66
08-19-2005, 08:19 AM
Have you tried moving your pump arm to a different hole?

Jeremy
08-19-2005, 10:29 AM
I have tried moving the arm but it made the car way too rich on the primary side. This was before I got the jetting correct on the primaries. I'll give it a try as it could be a lean bog. I just thought it was too rich from the secondaries opening.

Jeremy
08-19-2005, 06:26 PM
Thanks for the input. I realize it was a simple fix, but I guess I had been working on it all summer and just needed a fresh, outisde opinion. I went to the biggest pump shot and the car is how I want it and where I thought it should be. Throttle response is much better under all conditions, although the initial transfer from idle is a little abrupt. I think the throttle is just a little stiffer now as there is more resistance from the pump.


Thanks again.