I did do some tuning yesterday, but I forgot to read the plugs. I'll get them read this week, planning on driving from 2500 ft to 7500ft this coming weekend and I think my current jet might be alittle too rich for that altitude... kinda jealous of those TBI guys now...
Pony Carb Customer Service
- Thread starter MPGmustang
- Start date
MPG, any updates on mpg's? 
(Cool! See MercuryMarc's post on venturi enlargement in viewtopic.php?t=36105, and viewtopic.php?t=36108&highlight=5200 )
Heroic mods should be reserved for old HAMB spec carbs, not new Pony Carb pieces. Scott would have a coronary if he knew that you'd hit his finest grade anular discharge vaporizer with Marc's weapon of choice... :smash: :splat: :fume: :boom:
:deadhorse:
This works if you've you'd like to do a small fraction of the type of research that a Ford engineer or dyno tuner would do. You have to be a bit of a tuning fanatic. Venturi enlargement works to gain power by lowering turbulent air speed through the venturi to a lower level when there is insufficent carb area. It's based on a combination of David Vizards 70 and 80's work on modified SOHC Pinto 2 liter engines, and Webers idealised port on port carburator air speed. There is a critical 'turbulent' air speed for maximum power with any carb and engine combination. Venturi enlargement works only when you recalibrate fuel air ratios to suit, and if you don't go too large in relation to the throttle plate diameter. In the two barrel world of staged Holley-Weber 5200, 6200's 6500's and staged or asynchronos Weber DGAS/DGV et al, you can go balistic with up to 160 thou (4mm) enlargement from stock, but on other carbs, you can make it a pile of rubble with as little as a 60 thou skim. Thats as little as 1.5 mm. You have to return the section shape to a similar type as before the enlargement, requiring extra dexterity and time.
On some carbs, you'll need JB Weld or Devcon filler to fix up any casting break-throughs, and you might need brass inserts if you hook into a drilled passage. If you have a spare carb, you can experiement, and get an improvement like Marc did, but you always need a narrow or wide band O2 sensor, ColorTune, plug reading skills and some kind of standard load test to quantify the impact of the mods.
Don't know why you'd want to ruin a great remade factory improved carb with addo and marc's tool, but the above link will certainly do the damage.
Oh yeah, Marc later changed to a Carter 1-bbl carb since the bog and stutter problems from float level and calibration were giving him a headache..
Heroic mods should be reserved for old HAMB spec carbs, not new Pony Carb pieces. Scott would have a coronary if he knew that you'd hit his finest grade anular discharge vaporizer with Marc's weapon of choice... :smash: :splat: :fume: :boom:
:deadhorse: 
This works if you've you'd like to do a small fraction of the type of research that a Ford engineer or dyno tuner would do. You have to be a bit of a tuning fanatic. Venturi enlargement works to gain power by lowering turbulent air speed through the venturi to a lower level when there is insufficent carb area. It's based on a combination of David Vizards 70 and 80's work on modified SOHC Pinto 2 liter engines, and Webers idealised port on port carburator air speed. There is a critical 'turbulent' air speed for maximum power with any carb and engine combination. Venturi enlargement works only when you recalibrate fuel air ratios to suit, and if you don't go too large in relation to the throttle plate diameter. In the two barrel world of staged Holley-Weber 5200, 6200's 6500's and staged or asynchronos Weber DGAS/DGV et al, you can go balistic with up to 160 thou (4mm) enlargement from stock, but on other carbs, you can make it a pile of rubble with as little as a 60 thou skim. Thats as little as 1.5 mm. You have to return the section shape to a similar type as before the enlargement, requiring extra dexterity and time.
On some carbs, you'll need JB Weld or Devcon filler to fix up any casting break-throughs, and you might need brass inserts if you hook into a drilled passage. If you have a spare carb, you can experiement, and get an improvement like Marc did, but you always need a narrow or wide band O2 sensor, ColorTune, plug reading skills and some kind of standard load test to quantify the impact of the mods.
Don't know why you'd want to ruin a great remade factory improved carb with addo and marc's tool, but the above link will certainly do the damage.
Oh yeah, Marc later changed to a Carter 1-bbl carb since the bog and stutter problems from float level and calibration were giving him a headache..
Thanks for the wealth of info and links on venturi honing xctasy! I'd like to get ahold of an affordable wideband setup myself at some point in the quest for rickwrench type mileage numbers/efficiency, and I've got at least one old 1100 that would make a suitable experimental unit. I want to swear that Pony Vaporizer venturi is a foreign material (a plastic of some sorts...another reason I wished I had taken time to crack mine open before returning it for updates) which might mean it's inserted instead of integrally casted like the originals...maybe there's an option to pick up a spare venturi via PC 
...although I've found you have to be careful on how much info you share with those folks...they're not too big on outside the box ideas.
...although I've found you have to be careful on how much info you share with those folks...they're not too big on outside the box ideas.
I saw the initial write up of the Pony Carb 2100 series triple set up for 289's. They modify things heavily, and are good at it. Scotty is probably trying to protect his investment from backyarders.
I've been working with mechanical engineers and technicians for 25 years, and they don't often have a great sense of love to those of us who muck around with there staple diet of revenue. Dark looks are a common occurence because they don't know if your a great prospect or a gremlin waiting to bite them on the butt.
See ya
I've been working with mechanical engineers and technicians for 25 years, and they don't often have a great sense of love to those of us who muck around with there staple diet of revenue. Dark looks are a common occurence because they don't know if your a great prospect or a gremlin waiting to bite them on the butt.
See ya
Frankenstang":1o68uyt9 said:MPG, any updates on mpg's?
Yeahi gained .75 mpg from tire sizes... 205/70-14 to 195/70/14
I noticed I was pulling in a LOT of AIR through the engine, and effectively fouling up my breather cap :x
so i took off the PCV valve and put a cap on it. still testing, maybe i should check before I plug in the electric fans?
oh and i'll get your plug readings tonight.
:rolflmao:MPGmustang":12w9gzci said:
careful...that could get messy...maybe your pcv has failed/opening too much or stuck openMPGmustang":12w9gzci said:
My breather cap needs a change...use to clean them with kerosene, but now it might be greener to pitch & replace.
So xctasy, this 'colortune' of which you speak
Are you recommending that in conjunction with a wideband or possibly in lieu of?http://www.youtube.com/watch?v=B_ksmZLch0w
Wonder if my hyfire CD box would make for interesting lighting...I know the CD is probably not doing much for me since I never really top 3,500 much, but it was a cheap additon that I still want to test mpg/efficiency of...once the carb is back to a predictable baseline.
dang, just realized I forgot to read the plugs... :roll:
Frankenstang- pertaining to the PCV far the I have noticed that I have alot richer/lower idle, and some smoke coming out the breather caps... I just hope that the oil stay's cleaner, this last change was black/black and black.. usually not a good sign.
Frankenstang- pertaining to the PCV far the I have noticed that I have alot richer/lower idle, and some smoke coming out the breather caps... I just hope that the oil stay's cleaner, this last change was black/black and black.. usually not a good sign.
So xctasy, this 'colortune' of which you speak
http://www.youtube.com/watch?v=B_ksmZLch0w
Either will help. Wideband best, color tune cheapest
Thanks xctasy...I thin I remember some reference to the 'see thru' spark plug, but didn't know much more about it 
EDIT: (typos :arg: )Did you plug the pvc line at the carb? I would just want to be sure I had it setup for fresh air free flowing in and crankcase nastiness out. Be interested to hear if your mpg's appreciated after the updates.
Good luck
MPGmustang":3esy3m5q said:
MPGmustang":3esy3m5q said:
EDIT: (typos :arg: )Did you plug the pvc line at the carb? I would just want to be sure I had it setup for fresh air free flowing in and crankcase nastiness out. Be interested to hear if your mpg's appreciated after the updates.
Good luck