Six Pack 4 spd race question?

Posted By: ragtop

Six Pack 4 spd race question? - 10/09/12 12:48 AM

When Drag racing a stock 340 Six Pack, 4 spd.,
do the secondaries(outboard carburetors)totally close,
(not power shifting)between gears? If so, will that effect E.T. much?

Posted By: JackGTX440

Re: Six Pack 4 spd race question? - 10/09/12 01:01 AM

I'd say no, because on the 440 six packs I've driven, it takes them a second to close anyway. Kind of a spooky feeling the first couple times you let off the throttle. Lol

Posted By: scatpacktom

Re: Six Pack 4 spd race question? - 10/09/12 01:54 AM

I would agree with Jack

Posted By: 6PACMAC

Re: Six Pack 4 spd race question? - 10/09/12 03:15 AM

When non power shifting and you close the throttle in between shifts, yes they do close. Then it takes time for the out board to open again, by which it's time to shift again. And drag racing is all about not wasting time, like waiting for the out boards to open wide again. Things are different when power-shifting though

. 6 pacs like autos. I run my 6 Pac bee without the springs for the secondaries, which seems to make it quicker when not power shifting. My car is more responsive with a 850 double pumper.

Posted By: Big Squeeze

Re: Six Pack 4 spd race question? - 10/09/12 04:30 AM

Quote:

I would agree with Jack

Tommy...you're killing me...

when letting off the throttle the linkage closes the end carbs, and they typically take a split second to open back up....IMHO the ONLY reason to have a 4-speed is to power shift it...and YES it will be slower if you don't power shift...

and if you're gonna be a weenie and grannie shift it you may as well go all the way and put a girlie-matic in it....

Posted By: Mr.Yuck

Re: Six Pack 4 spd race question? - 10/09/12 12:30 PM

Quote:

I'd say no, because on the 440 six packs I've driven, it takes them a second to close anyway. Kind of a spooky feeling the first couple times you let off the throttle. Lol

I kind of have to agree with that, because mine seems to wait a split second at the strip to quit.... the 1st few times at the track I thought my throttle cable was caught up.
That said power-shift the mofo.

Posted By: scatpacktom

Re: Six Pack 4 spd race question? - 10/09/12 01:14 PM

While I understand the mechanics of it Wayne I also know that I go through the traps and get off the throttle the car will pull a split second longer. It's long enough that the thought of being in the beach goes through your mind. For me that is long enough to be in the next gear.Lol

I still say they do not COMPLETELY close... on me anyway

Posted By: Big Squeeze

Re: Six Pack 4 spd race question? - 10/09/12 01:19 PM

Quote:

I still say they do not COMPLETELY close... on me anyway

OK......If you actually let up on the throttle all the way, they have to close completely........

on the 6 Pack cars I've tried grannie shifting, when I went back to WOT, there was a noticeable amount of time that the carbs were opening back up......which is a rush killer.....

but like mentioned, maybe it'd be better without springs in the end carbs (I've never tried that)...

Posted By: scatpacktom

Re: Six Pack 4 spd race question? - 10/09/12 01:51 PM

Really it has more to do with can the throttle return spring overcoming the open six barrels at 6000 rpm or above. We know we let off the throttle and we know it still pulls. So that could indicate the return spring is not quite doing its job properly. So to some degree "Your results may vary" All depends on your spring tension.