Done with six pack

[charger1972]

I have had a sixpack setup on my car for years now.Allways thought it was pretty fast.....until.I drive my car to work on Saturday's,and on the way home last week a little yellow German car(i don't know what it was,they all look alike to me)took off from a stop light pretty fast so i did too.Once i opened it up,she started to break up so i backed off.Its had this problem for awhile thought it was the fuel pump not being able to keep up but now I'm not too sure.So I'm almost home and i run into my nephew with his 2001 ford mustang, 5 speed pipe kit and  flowmasters "cause he wanted it louder"otherwise his car is stock.Anyway,he starts getting on it from a roll and i can barley keep up.Now i know something is up.So on sunday i put a Holley street dominator and Holley 3310 4 barell i had laying around and its like night and day,and that's without tweeking it at all.So from what iv read on here the proform carbs are the best choice for performance.So my question is,what cfm and should i run a double pumper or vac secondaries .Here is my combo--69 440 lunati voodoo cam 60303 that Ron firefighter  recommended,hooker headers three inch ex no tails,electric fuel pump 3.55 gears 4 speed firecore wires and firecore distributor from Ron ,old style msd 6a .So that's my story,hopefully not to long for everyone but along with looking for advise i needed to vent a little.Thanks for any advise,Jim.

[Cooter]

Yep, been there, done that with multiple carbs...PITA! Of course, i can already here the "Six pack lovers" coming out in droves to defend their 1350 CFM set ups...

I'd go with a nice 650-700 Double pumper Holley. Might blow the tires away with that 4-speed, but shouldn't take too long to learn..

[cdr]

http://www.summitracing.com/parts/QFT-Q-950/
this is what i would run

[FLG]

Nice 750 proform should do the trick 

[firefighter3931]

Nice 750 proform should do the trick 

  with the 4speed you can definately use the double pumper !  The PF750 has small venturies but flows quite well so your throttle response and WOT performance will be well balanced. 

Hi Jim 



Ron

[Ghoste]

I do have one question though, was the breaking up part something new?

[charger1972]

Not new,but every time i did something to fix it like timing or jetting or re building the fuel pump for the fifth time it would seem to move.Before it would only do it at higher rpm ,then off the line.They are old carbs, i did rebuild them(years ago).The four barrel carb just seems to respond better.Ill keep the sixpack and maybe someday try it again,but for now i cant let all these tuner cars in my small town walk all over me.And Ron,that distributor is pretty cool.switched to the lighter advanced springs and could feel the difference,thanks!

[Chryco Psycho]

I use the Proform race series double Pump no choke , i would pick the 850 personally

[firefighter3931]

Ron,that distributor is pretty cool.switched to the lighter advanced springs and could feel the difference,thanks!

Jim, where have you got the timing set at ?

I'd recommend 17* at idle and 35-36* total all in before 3000 rpm. 

The PF750 race series carb flows 830cfm and has nice, small, radiused venturies and that will equal strong throttle response as well as top end power. Another member has that same carb on a build almost identical to yours ; same cam/headers etc...except he has a set of Eddy RPM heads and his made right at 500hp on the dyno. That carb will be perfect for your needs, inmo 


Ron

[charger1972]

Ron,iv got it at about 14 and at 3000 its kinda hard to see i might have to mark everything better or take off my big chrome jc Whitney shroud so i can see better.Maybe some timing tape for the balancer?It just seems hard to see it.

[charger1972]

I use the Proform race series double Pump no choke , i would pick the 850 personally

The pro form seems to be the one to get.Is your engine stock?850 seems big but then i guess not compared to the sixpack.

[FLG]

Im using the same Carb (race series) for what should be a bit over 500hp 440

[Brightyellow69rtse]

i got the 303 cam aswell in my 440 and run the 750 proform race series. im very happy with it 

[chargermike]

wanna sell the six pack set up. i would love to have one.

[charger1972]

I thought about selling it,but its to soon.I'm to emotionally attached.

[Cooter]

Six Pack and twin four set ups are like Trophy wives...The tend to impress, but require high maintenance.

[Ghoste]

Lol, sounds like a good t-shirt slogan.

[Cooter]

Lol, sounds like a good t-shirt slogan.

How bout you send me $25.oo and I'll be sure and put your shirt in the mail??

[Ghoste]

You must think we're on the old Charger site.

[GOTWING]

just a FYI a dead stock 2001 Mustang GT 4.6 5spd. with 3.27 gears will run 13:80's so isnt that about what a dead stock six pack car runs on street tires??

I bought a yellow 99 GT for my now X girlfriend and i took it to Delmar and raced it all the time, dead stock with street tires i got best of 13:79 @ 99mph. with bolt on's i got 13:11 that was with 3.73's JBA headers,X-pipe,70mm throttle body,pauls hp chip,pullys,k&n,drag radials.

[charger1972]

just a FYI a dead stock 2001 Mustang GT 4.6 5spd. with 3.27 gears will run 13:80's so isnt that about what a dead stock six pack car runs on street tires??

I bought a yellow 99 GT for my now X girlfriend and i took it to Delmar and raced it all the time, dead stock with street tires i got best of 13:79 @ 99mph. with bolt on's i got 13:11 that was with 3.73's JBA headers,X-pipe,70mm throttle body,pauls hp chip,pullys,k&n,drag radials.

If i could barely keep up with a modern v8 car,i would be ok with that.But his car is a v6 and mostly stock exept for duals and cold air intake.

[Chryco Psycho]

I use the Proform race series double Pump no choke , i would pick the 850 personally

The pro form seems to be the one to get.Is your engine stock?850 seems big but then i guess not compared to the sixpack.

I have used them on a number of engines , they respond extremely well stock or upgraded , I generally stick with 2x the CI & they work very well . Nothing I build is stock , there is always some port work & cam upgrades even if the engine appears dead stock .

[Tom Q]

A properly tuned six pak car will outrun it's  4bbl equal and not have problem after problem. I have run then for 35 years. Six paks have a bad reputation because people get frustrated with them.  They are stone reliable!

There is comprehensive guide  to set up and tune a six pak that has been posted here and on moparts too many times now. Over the years I compiled many peoples information into it and i have a lot of time invested in getting it to read right. There is at least one minor error about the pwr valve selection in it that the brainiacs on moparts have pointed out to me, but at this point i am not taking the time to copy edit any further as people would rather nit pik on the web boards than be helpful.   This is the reward for being nice and gracious to those who need technical support.

So i will leave you with this note as i am sure some one who lives here can post up the guide.
Rather than further blacken the stellar reputation of the six pak, I suggest you try tuning it properly and enjoy it.
No 4bbl set up will make the car run any better.  Be careful with the advice given here by others less informed

[Ghoste]

You say it's on here Tom?  I took a quick search for it and couldn't find it, you don't recall the thread title by any chance?

[Troy]

http://www.dodgecharger.com/forum/index.php/topic,93373.msg1063015.html#msg1063015

Troy

[Ghoste]

Thanks Troy, I should have left the word "tuning" out of the search.

Oh, and excellent post Tom.

[charger1972]

A properly tuned six pak car will outrun it's  4bbl equal and not have problem after problem. I have run then for 35 years. Six paks have a bad reputation because people get frustrated with them.  They are stone reliable!

There is comprehensive guide  to set up and tune a six pak that has been posted here and on moparts too many times now. Over the years I compiled many peoples information into it and i have a lot of time invested in getting it to read right. There is at least one minor error about the pwr valve selection in it that the brainiacs on moparts have pointed out to me, but at this point i am not taking the time to copy edit any further as people would rather nit pik on the web boards than be helpful.   This is the reward for being nice and gracious to those who need technical support.

So i will leave you with this note as i am sure some one who lives here can post up the guide.
Rather than further blacken the stellar reputation of the six pak, I suggest you try tuning it properly and enjoy it.
No 4bbl set up will make the car run any better.  Be careful with the advice given here by others less informed

I love my sixpack,the reactions when i pop the hood,when a kid stares at the 440 sixpack badges on the hood,the noise they make when they open up.But i have read the tuning posts and tweaked them over and over,re jetted them and so on.It runs great, just doesn't perform like i think it should.I'm a mopar or no car kinda guy,and will never say anything bad about that set up and I'm not done with it,just putting it on hold for now.

[Ghoste]

Still, it seems strange that if you had it set up to kill that just switching to a stock Holley (and I'm only assuming the 3310 was not dialed in) that it was like "night and day".   Not that I don't think you'll extract greater performance from a well adjusted Proform, it just seems like there is something else wrong with that Six Pack.

[charger1972]

I totally agree with that.But i will have fun with a new set up and over the winter maybe screw around with the sixpack carbs some more.I don't plan on selling it,even though that would cover the cost of a new carb.

[Cooter]

What was it Ron said a few threads back???


Something along these lines..."There's NO WAY IN HELL a stock (IE 440 SIX PACK, even with it's SLIGHTLY larger cam), will EVER need 950 CFM and actually use it."


Why would a "Stock" 440 need 1350 CFM? Too much carb., too little motor IMO. Yes, they perform "ok" when tuned properly, but then again so does a 750 Holley on a Victor intake.

[Ghoste]

With vacuum secondaries it shouldn't draw more than it needs when properly set up anyway should it?

[BSB67]

The 6 pack is truly the best balance for street cars up to about 550 hp, and will still work well above that. The small 2 bbl/dual plane intake drives nicely and the WOT and the 950 cfm gives up little to nothing to the single plane 750 or 850 4bbl.  You simply cannot discuss quality of induction system and carbs, or carb size, without including the intake manifold.

[Ghoste]

Thats kind of where I thought its advantage was, less about airflow and more about distribution.

[FLG]

Heres my question,

2 identical cars, both 440's with the same specs. One setup with a factory 6 pack perfectly tuned, one setup with a proform or similar dp'er and a good flowing manifold but something not far from stock looking...CH4B for example, or one of the better flowing stock mopar intakes from a 71 440.

1/4 mile and dyno wise, which car would make more hp and be faster, and by how much? Taking all other variables out of the equation (driver error, wheelspin...etc)

[BSB67]

Heres my question,

2 identical cars, both 440's with the same specs. One setup with a factory 6 pack perfectly tuned, one setup with a proform or similar dp'er and a good flowing manifold but something not far from stock looking...CH4B for example, or one of the better flowing stock mopar intakes from a 71 440.

1/4 mile and dyno wise, which car would make more hp and be faster, and by how much? Taking all other variables out of the equation (driver error, wheelspin...etc)

Lets pretend they 60 ft the same...okay?

On a slightly modified 440 (400-425 hp ish) The 6 pack would have 1 mph ( i.e. .1 sec quicker) and about 5 more hp verses the CH4B with a good carb.  Add a 1" open spacer or mill the divider down for the CH4B and it would probably be a wash.  The gap will get wider as the hp goes up.

Verses a cast iron intake with a large Holley, 2 mph and .2 sec.  Peak power is still only 10 hp lower.  But the average power for the 4 bbl is down more because the iron manifold power drops like a stone at 5200 rpm where the 6 pack continues to pull decent power well past peak power and allows higher shift rpm, and a greater area under the hp curve (average power from 3600 to 6000 rpm).  The power gap gets bigger faster as hp goes up.

I have conducted a lot of track testing with several cars in this power range with different induction systems and is the basis for my opinion.

[FLG]

Thanks for the info 

Based on that, besides a numbers matching resto or just for looks.....i personally would than just throw on a nice Aluminum manifold and a dp'er and call it a day.

[oldschool]

What was it Ron said a few threads back???


Something along these lines..."There's NO WAY IN HELL a stock (IE 440 SIX PACK, even with it's SLIGHTLY larger cam), will EVER need 950 CFM and actually use it."


Why would a "Stock" 440 need 1350 CFM? Too much carb., too little motor IMO. Yes, they perform "ok" when tuned properly, but then again so does a 750 Holley on a Victor intake.

Why would a "Stock" 440 need 1350 CFM?

the six pack is not really 1350 cfm, as compared to the way they rate a four barrel. they rate 2 barrel carbs differenty.

[BSB67]

Thanks for the info 

Based on that, besides a numbers matching resto or just for looks.....i personally would than just throw on a nice Aluminum manifold and a dp'er and call it a day.

Right.  From a cost perspective it does not make a lot of sense.  It does take time to understand the 6 bbl and get it sorted out, they are harder to work on, fuel line access is a pain, need to remove carbs to access jets and more.  Every time I would tear into the carbs at the track, I would wonder if everything would get back together trouble free.

But to add to my previous post, when I put my 6 pack on my 508 cu in motor, it was only 10 lower in average power from a SD, with open spacer, and 950 4150 carb, without turning a screw, and made more power under 4500 rpm.  Again, the versatility of the 6 pack from 350 hp to 550 hp is phenomenal.

[Ghoste]

Very informative, thanks.   You don't have the six barrel setup on there now though, do you?

[BSB67]

Very informative, thanks.   You don't have the six barrel setup on there now though, do you?

No. 
440-2D with the 950.  It runs about even with the SD and 4 hole open spacer.  SD with a little more peak, but same average.

[ACUDANUT]

Six Pack and twin four set ups are like Trophy wives...The tend to impress, but require high maintenance.

I agree 100 percent.

[Cooter]

Why would a "Stock" 440 need 1350 CFM?

the six pack is not really 1350 cfm, as compared to the way they rate a four barrel. they rate 2 barrel carbs differenty.

According to the factory rated Carb CFM, it's 1350 with all three 2BBLs added together at WOT....Maybe the factory make a BooBoo?

[Ghoste]

I thought the way they were measured was different than the four barrel?  The factory was using the highest number available for marketing why would they rate them measured at the same vacuum as the four barrel if it gave a lower cfm?

[Cooter]

Don't make no nevermind no how, as if a "Stock" 440 only uses around 650 CFM, then it don't matter if they's "Only" around 900 CFM in a Six Pack, it's still too damn much.

[Ghoste]

No, but that wasn't your question.  Although I will ask this again, would it ever see that 950 capability interfere with vacuum secondaries?  The center one was "rated" at 500 so it would be used almost always, no?  The outer two would only come in as an "on demand" feature and shouldn't be doing anymore than improving fuel/air flow balance across the engine?  Yes, there are better carb intake systems for sure but as far as a stock setup which improves performance and gained a big marketing plus in 1969, it's a pretty sweet way to go I think.
Isn't that why so many Six Pack cars became ultra dogs on the street when backyard carb scientists altered them to either tip the outers in sooner or worse yet, make them mechanical?

[c00nhunterjoe]

Ah yet another "how much cfm is too much" debate..... I don't see how 950 cfm iss too much for a mildy modified 440 (cam,intake,exhaust) when there are plenty of articles with dyno tests on the 383 that showed an 850 dp made the best combo on a mild 383, yet you guys are saying a 650 or 750 is the max you will need on a 440.  Granted a lot of factors decide how much carb you need and if you are running a bone stock,8:1 engine through an iron intake then no, you don't need a big carb, but if you have a little compression, decent flowing heads, an intake matched to you cam\head\comp combo, then I can't see how a 950 is too big on a modified 440 when every dyno sheet comparison has showed otherwise.

[BSB67]

I purposely stayed away from this last time.  But I'll give it a shot.

It seems that everyone talks about "cfm" as some ultimate measurement, where in reality, it is a number that has no meaning by itself.  For a 4 bbl, it is actually XXX cfm @ 1.5" hg.  So a carb can, and will flow more or less than the advertised number depending on.....wait for it.....the pressure drop.  Guess what, our type of engines (street/drag) usually do not pull 1.5" hg at WOT.  At WOT, the carb will create a pressure drop across the venturi, which in effect restricts air flow (but provides the necessary pressure drop to meter the fuel - can't have your cake and eat it to).  It is absolutely incorrect to say that an engine only wants XXX cfm.  What is accurate to say is that an engine will only TAKE xxx cfm @ x.x" hg.  This part is important....if you reduce the pressure drop, the engine will TAKE more cfm.  Of course there is the point of diminishing returns...i.e. the carb is too big.

So let me give an example:  We run an engine on a dyno and it makes 550 hp.  The carb is a 950.  The dyno instrument tells us that the engine actually had an air flow of 800 cfm during the pull.  Wow.  I guess the motor only wants 800 cfm.  So we put a 800 cfm carb on and do another dyno pull.  Hmmm.... it only made 535 hp, and now the air flow is only 725 cfm.  This happens because the engine is pulling less than 1.5" hg.  So for the first pull the engine was pulling 1.1" hg, and on the second pull, the engine was pulling 1.25" hg, caused by the more restrictive smaller carb.  Of course the engine made less power because it pulled less air.

2 BBl carbs are rated at 3" hg.  So to compare them to a 4bbl you need to convert the 2 bbl rate cfm to 1.5" hg.  In the case of the 1350 cfm @ 3" hg 6BBL, the flow rate at 1.5" hg is actually 955 cfm (i.e. measuring it like a 4 bbl.).

[Ghoste]

In other words, advertised cfm is much like advertised duration with cam specs.

[BSB67]

In other words, advertised cfm is much like advertised duration with cam specs.

Actually, it is like every flow situation....they are always defined as" certain flow at a certain pressure", same as oil pumps, fuel pumps...etc..

[Ghoste]

Acually I meant more the validity of just comparing numbers across the board and assuming that all things were equal.  What you said but just the comparing part.

[BSB67]

Sure.  A lot of numbers fly around in this hobby without proper context.  Dyno numbers and head flow are a couple more beauties.

[c00nhunterjoe]

I purposely stayed away from this last time.  But I'll give it a shot.

It seems that everyone talks about "cfm" as some ultimate measurement, where in reality, it is a number that has no meaning by itself.  For a 4 bbl, it is actually XXX cfm @ 1.5" hg.  So a carb can, and will flow more or less than the advertised number depending on.....wait for it.....the pressure drop.  Guess what, our type of engines (street/drag) usually do not pull 1.5" hg at WOT.  At WOT, the carb will create a pressure drop across the venturi, which in effect restricts air flow (but provides the necessary pressure drop to meter the fuel - can't have your cake and eat it to).  It is absolutely incorrect to say that an engine only wants XXX cfm.  What is accurate to say is that an engine will only TAKE xxx cfm @ x.x" hg.  This part is important....if you reduce the pressure drop, the engine will TAKE more cfm.  Of course there is the point of diminishing returns...i.e. the carb is too big.

So let me give an example:  We run an engine on a dyno and it makes 550 hp.  The carb is a 950.  The dyno instrument tells us that the engine actually had an air flow of 800 cfm during the pull.  Wow.  I guess the motor only wants 800 cfm.  So we put a 800 cfm carb on and do another dyno pull.  Hmmm.... it only made 535 hp, and now the air flow is only 725 cfm.  This happens because the engine is pulling less than 1.5" hg.  So for the first pull the engine was pulling 1.1" hg, and on the second pull, the engine was pulling 1.25" hg, caused by the more restrictive smaller carb.  Of course the engine made less power because it pulled less air.

Thank you.   

[c00nhunterjoe]

In other words, advertised cfm is much like advertised duration with cam specs.

Comparing the 2 barrel vs a 4barrel cfm numbers would be the same as comparing hydraulic cam to mechanical cam specs. 

Advertised cam specs vary from manufacture to manufacture based on where they are measured at.

[firefighter3931]

Here's some data to chew on....several builds coming off the same dyno, with the same dyno operator (Dwayne Porter) using the same correction factors. Translation ; the results are DEAD NUTS reliable....no overinflated magazine bullshit ! 

I've yet to see one of these magazine beauties make it into a car to back up the horsepower claims with a timeslip. I guess that makes me a skeptic....oh well it is what it is 

From another post i made in Cooters thread a week or so ago :


Here are some engine combos with dyno numbers/CFM @ peak HP to illustrate ;

(1) 446 E-head > 535hp/540tq with 830cfm dp'er (Proform 750DP) = 760cfm
(2) 493 E-head > 563hp/592tq with 850cfm dp'er (Holley 4781 850DP) = 785cfm
(3) 572 Indy head > 715hp/720tq with Quickfuel1050 (4150) dp'er = 930cfm
(4) 572 Indy head > 722hp/725tq with Holley 1150 Dominator = 960cfm

The comparison between number 3 & 4 are interesting ; this is my 572 and we tried to see if the engine really wanted more carb. Despite a 100cfm increase in carb sizing, going from a 1050 (4150) to an 1150 Dominator it only made an additional 7hp even though the engine was ingesting 30cfm more air. What I learned from this was that throwing more carb at it doesn't allways translate into bigger numbers....and lots of air equals a small amount of power if the engine doesn't need it. In most cases if the carb is sized appropriately going bigger will just soften up the throttle response and make the driving experience less enjoyable. 

I can say that the smaller 4150 Quickfuel 1050 was waaaay more responsive than the Dominator. Smaller venturies mean increased airspeed and sharper throttle response.....allways has, allways will ! 

I'm not even sure that 7hp would even show up on the timeslip at 4100lb raceweight and there was no way i was going to trade off a razor sharp throttle to find out.   


**So if after reading all that you're still convinced that your stock or mildly modified 425-450hp Big Block still needs an 850 carb then i guess my response would be..... good luck with that. 



Ron

[Cooter]

Well, I think I'm gonna try all three mentioned (700 DP, 800 DP, and 850 DP) on the dyno just to see what is what for this(my) 440. If it likes more carb, ok, fine, but if it doesn't, ok fine...

I was just thinking a modded 650 DP might be a little small for a modded 440. I guess we's bout to find out.

[ACUDANUT]

Yea, a 650 is too small for a 440.

[c00nhunterjoe]

I won't argue with your numbers, but on the same note, I know what I have seen with my own eyes in this area. I know what my local cars have tried and run.

I also know what worked on my car. I ran a 650dp for a long time because that is what everyone said was the biggest I could go. My cousin (who builds race engines) talked me into a run of the mill 4779 750dp. The power difference was enough I could feel. I have never dynoed my car so I can't quote you numbers.  After pulling the properly tuned 650 for the 750, the only things changed were the jets and the primary squirter was changed from a 24 to a 31. The response it quick and crisp, I lost nothing in the upsizing.

On the same note, for the same reasons quoted above about numbers being tossed around on the internet, I have not bought a holley 850 to try for several reasons. I know its a lot of carb, I know what I have read though. My 750 runs great so I am skeptical to buy another carb.

[mauve66]

my 6pak on my "little" 383 worked great, never had to change anything out of the box other than a power valve and accel pump and that was after moving to 2 different states and 2 years of running and upgrading the cam, maybe it could of worked alot better, maybe it was too much CFM for the motor but it ran a LOT better than the stock carb that came on it in 66, yea the car was completely bone stock when i got it.

[XH29N0G]

Just a thank you to those who have written the detailed explanations for whys and hows of dynos, carburators and CFM.  This teaching is great for someone like me who is reading this thread and learning.

[firefighter3931]

Well, I think I'm gonna try all three mentioned (700 DP, 800 DP, and 850 DP) on the dyno just to see what is what for this(my) 440. If it likes more carb, ok, fine, but if it doesn't, ok fine...

I was just thinking a modded 650 DP might be a little small for a modded 440. I guess we's bout to find out.

It never hurts to test while you have the engine strapped to the dyno....that way you know for sure what the engine wants/needs for best performance. 

I'll be interested to see what the results show. 

Ask the dyno operator to supply cfm numbers when he prints out your dyno sheets...that is valuable data 



Ron

[JB400]

I don't see what all the hype is about the six pack setup.  Back then, Chrysler wanted to win everywhere at any cost.  Win on Sunday, sell on Monday.  NHRA rules were like NASCAR and SCCA.  Run what you sell on the street.  It might not be practical now, but it was fun back then.  Still fun now.

[BSB67]

Well, I think I'm gonna try all three mentioned (700 DP, 800 DP, and 850 DP) on the dyno just to see what is what for this(my) 440. If it likes more carb, ok, fine, but if it doesn't, ok fine...

I was just thinking a modded 650 DP might be a little small for a modded 440. I guess we's bout to find out.

It never hurts to test while you have the engine strapped to the dyno....that way you know for sure what the engine wants/needs for best performance. 

I'll be interested to see what the results show. 

Ask the dyno operator to supply cfm numbers when he prints out your dyno sheets...that is valuable data 



Ron

A couple of data geeks here.  And I'll gladly pile on if we're spending Cooter's money.  Seriously, maybe we should start a collection to help finance Cooter's  data collection?  Dyno time is not cheap.

If my 750 DP wasn't on a car, I'd send that to you to try as well.  I have a 1" phenolic spacer that I'll send you if you're interested.  They always seem to affect the results.

The operator may have a standard data package that he gives with his service, or he might ask you what you want.  With the air flow, get the DP, mass fuel flow, VE and BSFC.  In the heat of the pulls, you won't look at this stuff much, but when you look back, you will want it.  Also, they usually only give the corrected results, I like to get the actual results and the corresponding atmospheric data.  He should be able to give you average power and torque for each pull real time, and that is the data you need for dyno engine tuning and evaluating your changes, FWIW.

[bobs66440]

Six Pack and twin four set ups are like Trophy wives...The tend to impress, but require high maintenance.

I don't know. I have a Eddy dual quad setup and never had to do anything to it. Works perfect. Though I have to agree, a good single carb setup is hard to beat. 

[Cooter]

I just hope my builder/machinist has an up-to-date Dyno that records and prints out all the info required here. Not real sure if his 1200 HP Engine dyno will give that, but we will see.

Nah, I hoping for a deal for referring about 50 people in the last year to him, so hopefully it won't cost me much. I'm doing it for more of a curiosity/braggin rights thing than anything else.

[charger1972]

Got my proform carb the other day in the mail.Came home from work and went straight to garage to install it.About 11:30 at night i took off for a test drive(my neighbors must love me)and what a difference!That's a great carb ,very responsive.Was a used one off eBay,but only a month old.Took the bowls off before i put it on to see what jets were in there...74 primary 84 secondary.Does that seem a little to much?I'm not sure ,it definitely runs strong.Thanks for all the advice and for any further advice,starting to cool down here in NY so not sure how much more tweeking i can get in before the snow comes.   

[JB400]

Glad to hear it works for you. Are you going to do anything about the metering blocks and the carb base?  Kinda tacky on an orange car in my opinion.

[Cooter]

750 CFM?
Why was Ebay seller selling? Sorry, but I'm always kinda suspect when buying used carbs.

[BSB67]

If that carb has 1 3/8" venturi then that jetting is similar to what I have found to work on other 1 3/8" venturi carbs of the same style.  Maybe a little fat on the secondaries.

[charger1972]

750 CFM?
Why was EBay seller selling? Sorry, but I'm always kinda suspect when buying used carbs.

He said he sold the car and kept the carb,didn't need it anymore.Normally id be a little hesitant to but he had 100% feed back and it looked good in the pictures so,i gambled it was OK.

[charger1972]

Glad to hear it works for you. Are you going to do anything about the metering blocks and the carb base?  Kinda tacky on an orange car in my opinion.

Like what?All iv seen is purple and pink or whatever color mine is.Black would look cool but from what i have seen only the street carbs have black bases and plates.Maybe polish them?

[ACUDANUT]

How old does that e-bay carb look.? Price ??

[charger1972]

How old does that e-bay carb look.? Price ??

He said a month old,looks like new.He had a buy it now for 375 so i jumped on it.

[ACUDANUT]

375.00 IMO is waay too much.  Is it a DP or what ?

[firefighter3931]

375.00 IMO is waay too much.  Is it a DP or what ?

Not too much at all for a 1 month old carb that sells for $550.00 

I'd call that a score 


Ron

[firefighter3931]

Got my proform carb the other day in the mail.Came home from work and went straight to garage to install it.About 11:30 at night i took off for a test drive(my neighbors must love me)and what a difference!That's a great carb ,very responsive.Was a used one off eBay,but only a month old.Took the bowls off before i put it on to see what jets were in there...74 primary 84 secondary.Does that seem a little to much?I'm not sure ,it definitely runs strong.Thanks for all the advice and for any further advice,starting to cool down here in NY so not sure how much more tweeking i can get in before the snow comes.   

You should install the holley throttle adapter (pn 20-7) to get the right throttle ratio....it'll run even better than it does now ! 

I knew you'd like that carb ! 

Have  a look at the plugs to see if it's running rich 


Ron

[Ghoste]

And you should be able to get it tweaked before the snow flies.  It might be getting cool but its still only September. 

[charger1972]

Got my proform carb the other day in the mail.Came home from work and went straight to garage to install it.About 11:30 at night i took off for a test drive(my neighbors must love me)and what a difference!That's a great carb ,very responsive.Was a used one off eBay,but only a month old.Took the bowls off before i put it on to see what jets were in there...74 primary 84 secondary.Does that seem a little to much?I'm not sure ,it definitely runs strong.Thanks for all the advice and for any further advice,starting to cool down here in NY so not sure how much more tweeking i can get in before the snow comes.    

You should install the Holley throttle adapter (pn 20-7) to get the right throttle ratio....it'll run even better than it does now !  

I knew you'd like that carb !  

Have  a look at the plugs to see if it's running rich  


Ron

I have never seen one of those 20-7,i just looked it up.Pretty cool,i usually just weld something together to make it work.But i don't think its opening full throttle so that should help.Ill order one when i order a new air cleaner.

[Cooter]

Let us know when you get that thing lined out, as there are a few looking at the Pro Form carbs hard. Guesswork/hearsay is great, but nothing beats real world tuning results.

[FLG]

Let us know when you get that thing lined out, as there are a few looking at the Pro Form carbs hard. Guesswork/hearsay is great, but nothing beats real world tuning results.

Plenty of real world results, me and Ron right off hand....i know theres a bunch of other members too.