mechanical or vacuum secondaries?
Thread Starter
Racer
Joined: Sep 2005
Posts: 453
Likes: 1
From: Austin TX
mechanical or vacuum secondaries?
So everywhere I read, the manufacturers recommend the use of a vacuum secondary carb on vehicles with automatic transmissions.
I purchased a 750 mighty demon mechanical secondaries for use with my 406 and 700R4 tranny. The transmission will have a 2000 stall. Do you guys think I made the wrong choice with the carb? Should I exchange it for a vacuum secondary carb? Or will I be ok?
I purchased a 750 mighty demon mechanical secondaries for use with my 406 and 700R4 tranny. The transmission will have a 2000 stall. Do you guys think I made the wrong choice with the carb? Should I exchange it for a vacuum secondary carb? Or will I be ok?
Melting Slicks
Joined: Dec 2000
Posts: 2,041
Likes: 0
From: Wichita, KS
I have a mechanical secondary Speed Demon on my 406. I'm never going back to a vacuum secondary carb on a hot rod again! One of my friends had a pro tuned vacuum secondary Demon on his 383. He swapped my carb on one day and went out the same day and bought his own.
That said, the mechanical secondary carb is a bit harder to tune correctly. If I wanted to cruise I'd be happy with a vacuum secondary carb. In fact the vacuum secondary carb that my buddy pulled off of his car may find it's way on to my wife's 302 powered '50 Ford over the winter.
That said, the mechanical secondary carb is a bit harder to tune correctly. If I wanted to cruise I'd be happy with a vacuum secondary carb. In fact the vacuum secondary carb that my buddy pulled off of his car may find it's way on to my wife's 302 powered '50 Ford over the winter.
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
I am a big fan of mechanical secondaries. I put them on everything from a lowly 302 ford to a pair on my blown bigblock.
With mechanical secondaries the carbs are usually set up a little on the rich side. Just lean them out for street driving and you know when the secondaries open, no guess work.
I think you bought the right carb.
With mechanical secondaries the carbs are usually set up a little on the rich side. Just lean them out for street driving and you know when the secondaries open, no guess work.
I think you bought the right carb.
