6 pack worth it ?

[gzig5]

6 pack fuel injection.  Best of all worlds, except cost.  WOW factor, power, economy, and mild behavior.

https://www.hotrod.com/articles/dyno-tested-self-tuning-six-pack-efi-system-mopars/

https://www.manciniracing.com/fi4406pakfui.html

[FSHTAIL]

In my experience, the 4bbl made more power..

There are several dyno shootout articles where they tuned the 6 pak for all it's worth then swapped to a 4bbl and it made more power, better drivability characteristics, then to a self learning EFI setup and the power was pretty damn close to the 4bbl that made more power than the 6 pak.. 

I had a Tri Power 71 Dodge Demon GSS and the carbs were just a pain in the ass, it's not worth the hassle... 
If its a garage weekend warrior that came original with it, sure, it makes sense.   

If you want a bit more out of your car, the 4bbl is rock solid.       4150's are my favorite.. 

It's just my opinion and several others, we could ALL be wrong if your opinion differs. 

[72 Challenger]

In my experience, the 4bbl made more power..

There are several dyno shootout articles where they tuned the 6 pak for all it's worth then swapped to a 4bbl and it made more power, better drivability characteristics, then to a self learning EFI setup and the power was pretty damn close to the 4bbl that made more power than the 6 pak.. 

I had a Tri Power 71 Dodge Demon GSS and the carbs were just a pain in the ass, it's not worth the hassle... 
If its a garage weekend warrior that came original with it, sure, it makes sense.   

If you want a bit more out of your car, the 4bbl is rock solid.       4150's are my favorite.. 

It's just my opinion and several others, we could ALL be wrong if your opinion differs.

Have you got a picture of the GSS demon?

[dodj]

build a multiport EFI usin 4 coils & crank trijjer

Way off topic........
I know little about FI other than the cost keeps me using a carb.... Why four coils? 

[340Challman]

Not really. They work well when dialed in but with a modern 4 barrel on a modern manifold you can achieve even better results and easier.

Not true at all, that is strictly 
The same car with a six pak will outrun the 4bbbl car, hands down.
The tuning is not rocket science, it's just no one want to follow the process for success

If you have never owned or drove a properly set up six pak car you are clueless

I'm not disputing your position, I'd just like for you explain why you feel that is the case. If an engine is nothing more than an air pump, I don't see how having 1000 cfm of vacuum operated carburetion is going to give any more performance if the engine can only move 650 cfm. If the outboards were mechanical, then I could see how you are going to dump extra fuel, but you are still limited by the amount of air the engine can draw. More fuel just means a rich condition. 

[autoxcuda]

 

To me the coolness factor is enough.  My Roadrunner is a V code and, even though it's taken me awhile to get them setup properly, is a real nice cruiser than is as wild as I need it to be when you get into the secondaries.

Only advice, if you don't have equipment already, just buy them brand new from Holley.  Most of my problems dealt with trying to us OE carbs that had forty years of modifications.  Date stamps and part #s be damned if it's not originally a six pack car.

In one of the stock NHRA classes there was a racers with a pink T/A 340 6-pack they changed the car to 71 340 Challenger with single carb and went faster.

The 340 intake is limiting at a point in HP. Big modern single planes 1000+ cfm carb move beyond the capability of a stock 340/440 6-pack intake.

The original Carter AVS and AFB's on Mopar HP motors 66-71 were performance limiting with small CFM. Some factory literature say the 440 AVS was 750 cfm, but that seems doubtful compared to modern 750 cfm carbs.

Just like the factory "10.25:1" compression that never actually measures up to that. Because the head cc's are always large.

[FSHTAIL]

Wasn't the stock carb on a 71-73 340 4bbl equipped Cuda's a 850cfm? 

Or is this a typo? 

Would this have been a thermoquad?

https://www.allpar.com/mopar/mopar340.html

How many CFM's were the 340-6pack carbs individually and all together?

[Chryco Psycho]

340 had the Tquad from 71-73 with 800 cfm , true .
6 packs were measured differently , with higher vacuum when testing CFM , so the center carb was 350 cfm & the outboards were 500 cfm each but when test at lower vacuum as a 4 bbl the 6 pack was around 850-900 cfm total .

All of today engine run multiple coils , gen 3 hemis run 8 coils on top of the plugs same with LS1 , you can do what is called wasted spark so you connect 2 wires to each coil such as cyl #1 & 6 , the coils are trigger every 90* as the crank damper goes past the pick up , this fires 2 plugs - 1 in combustion cycle & one in exhaust cycle at the same time  , you can just run 1 coil & trigger it 8 times for each cylinder so 3 different ways to do it .

[MOPAR MITCH]

One thing to consider, is the overall weight difference.

I've weighed my complete 6-bbl setup, with the T/A air cleaner... 60 pounds total.

I've weighed my complete LD340 setup, with a Holley 3310, and ~12" diameter open air cleaner (not the factory air cleaner), and that comes in at 30 pounds total.

So, the 6-pack setup adds 30 pounds over an aluminum mfld 4-bbl setup.  For handling concerns, the 4-bbl setup is better as that's ~30 pounds off the front end.. less weight in the front = better handling, etc.

I had my 6-pack off the car for about 20 years of hard-core SCCA national AX racing (class E/Street Prepared) because every way possible to lose weight was better for performance.

As I've gotten back to the car shows more lately, the #1 question I was always asked was "... where's the 6-pack?".   So, I eventually put it back on.. all with PROMAX parts.  My 6-pack runs near perfect... awesome response!   In recent years, I've been doing more HPDE/HSAX track events and i feel the 6-pack gives me plenty of power, and probably more than my 750 4-bbl setup.  Plus, I get all the glory of "WOW" from the spectators in the race pits during the race events, as well as back at the shows.  The long distance, wide open track events really allow me to open up the 6-pack for all its worth!   Also, i like the sound of the 6-pack better than a 4-bbl when stepping into it!

IF I were to return to national competition with autocross racing (pylon SCCA SOLO racing), I'd definitely put the lighter weight 4-bbl back onto the engine (maybe next time with an upgrade to the Eddy RPM Air-Gap instead of the LD340)... primarily for the reduction of that extra 30 pound penalty with the 6-pack.

[340Challman]

Cool! @MOPAR MITCH I think it's awesome that you auto X your T/A. That's what they're made for right? My A66 Challenger has a six pack setup, 4 speed, Dana 60 with 4.10's, no p/s, no p/b. For nothing other than factory suspension, she handles well for a 1970 muscle car. 

[MOPAR MITCH]

T/Anks 340 man!    If you want the most fun, try to get your car out onto a road course track (manual steering still OK on such a track)... another subject.

[340Challman]

T/Anks 340 man!    If you want the most fun, try to get your car out onto a road course track (manual steering still OK on such a track)... another subject.

I don't have the nerve to put my Challenger on a track and push it. 
I raced GT-4 back in 82 & 83 at St.Louis Intl Raceway. I don't know what they call it now. That was before they tried to bring in NASCAR and ruined the track. I had a Datsun 510. Loved racing and loved that car. Could never get any sponsors and ran out of money though.

I used to frequent Oak Park back in the day. Didn't know there was a track anywhere around the Chicago area. Where do you play?

[HP_Cuda]

Funny how no one has talked about Volumetric efficiency?

Besides the fact that you can buy a rather large cfm 4 barrel carb.

Lot's of considerations here.

[340Challman]

Funny how no one has talked about Volumetric efficiency?

Besides the fact that you can buy a rather large cfm 4 barrel carb.

Lot's of considerations here.

I didn't mention it, but that is how I came up with 650cfm. A 440 @ 6000 rpm and 85% volumetric efficiency is 650cfm. 1350 total cfm for a six pack that 1000cfm is vacuum operated. The outers will flow 300-350cfm max combined, if you rev the hell out of your motor. Most motors from the good ole days are horribly over carbureted which hurts performance rather than improve it. Fortunately the outers being vacuum operated shouldn't run you too rich, unless they're setup wrong. Just like a certain appendage on the beloved female of our species, bigger isn't necessarily better. 

[Chryco Psycho]

And yet you increase carb size & the car runs faster as I have proven so many times & with the right combo also become far more effcient