F-BIRD'88 wrote: ↑Fri Jul 20, 2018 1:45 pm
You should get yourself a radar gun or a Vericom (VC200) ...or later
to evaluate your street blast perf tuning. The butt dyno can be very deceiving. You can measure perf gains/// losses over any test length
Either standing start or rolling start test between speed a and speed b etc.
Or distance a to distance b. Cheap used....
Google search for HP Tuners Track Addict and see how that turns your iPhone or Android into a data recorder with the GPS and accelerometer in the phone. Drag race, oval race or road race, it records and replays showing your track position and elapsed time on a satellite image of the track simultaneously with a ton of information synchronized and superimposed with the video it records, and it can synchronize with other video cams using Bluetooth and also will trigger your GoPro when you go on and off the track. The basic app is a free download and the bells and whistles are cheap. This app and several others like it replace a data system that cost as much as $30,000 30 years ago.
At a race last Saturday I asked a friend's 16 yr. old son to find an app that recorded lap time and he searched the web, found this HP Tuners Track Addict app (he already has tuning skills and knows HP Tuner well, we got his nose out of video games by saying, "Here, tune the fuel and spark tables in your dad's truck."), downloaded it, figured it our and had it working in the race car in about a half-hour.
427dart wrote: ↑Sun Jul 15, 2018 10:53 am
Is what my engine seems to be telling me. Since we have a couple days of lower humidity 85 degree weather,I was doing more tuning on my vac. secondaries on the dual 650 Holleys.
First test was to remove my .060 sized orifice from the sec. pots and go from the weakest White to purple spring. This gives the full sized .081 hole like having no check ball. Did this on both carbs and but zip tie on secondary diaphragm rod with just enough tension to let it slide.
Result in a 3000 RPM roll in 2nd to 3rd gear up to 5500 RPM was no bog and not quite the strong mid range pull...didn't notice tires breaking loose in middle of 2nd. gear. Zip tie inspection shows about 1/2 open on secondary throttle.
Second test this morning was back to White spring in front carb only since it is easier than the rear carb and same full .081 vac. orifice.
Result was no bog or sense of secondary flopping open just a stronger pull with the rear end of Mustang doing a slight slide to the right at mid point in 2nd gear. Felt real good in 3rd gear.
May switch out the rear carb spring back to the original weak White spring and see how it goes but this seems to be telling me at 2950 lbs and with only a 3.50 gear on 275-50 M/T drag radials the 427 wants all it can get as soon as possible.
I WOULD run a pair of 650 mechanical secondary carbs IF somebody made them with the short 4160 bowls and a passage way for the secondary accelerator pump shot. Doing the race only Center Squirter won't work that well on the street due to excess fuel puddling in secondary barrels everytime you work the primary throttle during part throttle.
Anyway it runs really strong on the street which is where I'm at now days. Note my test area is a industrial park road with fresh new pavement.
I have dual Holley 4224 center squirters and the run great on the street with minamal mods
A63BA89D-D57A-4DAB-BF4E-95840781688B.jpeg
You do not have the required permissions to view the files attached to this post.
427dart wrote: ↑Sun Jul 15, 2018 10:53 am
Is what my engine seems to be telling me. Since we have a couple days of lower humidity 85 degree weather,I was doing more tuning on my vac. secondaries on the dual 650 Holleys.
First test was to remove my .060 sized orifice from the sec. pots and go from the weakest White to purple spring. This gives the full sized .081 hole like having no check ball. Did this on both carbs and but zip tie on secondary diaphragm rod with just enough tension to let it slide.
Result in a 3000 RPM roll in 2nd to 3rd gear up to 5500 RPM was no bog and not quite the strong mid range pull...didn't notice tires breaking loose in middle of 2nd. gear. Zip tie inspection shows about 1/2 open on secondary throttle.
Second test this morning was back to White spring in front carb only since it is easier than the rear carb and same full .081 vac. orifice.
Result was no bog or sense of secondary flopping open just a stronger pull with the rear end of Mustang doing a slight slide to the right at mid point in 2nd gear. Felt real good in 3rd gear.
May switch out the rear carb spring back to the original weak White spring and see how it goes but this seems to be telling me at 2950 lbs and with only a 3.50 gear on 275-50 M/T drag radials the 427 wants all it can get as soon as possible.
I WOULD run a pair of 650 mechanical secondary carbs IF somebody made them with the short 4160 bowls and a passage way for the secondary accelerator pump shot. Doing the race only Center Squirter won't work that well on the street due to excess fuel puddling in secondary barrels everytime you work the primary throttle during part throttle.
Anyway it runs really strong on the street which is where I'm at now days. Note my test area is a industrial park road with fresh new pavement.
I have dual Holley 4224 center squirters and the run great on the street with minamal modsA63BA89D-D57A-4DAB-BF4E-95840781688B.jpeg
Running 1 to 1 linkage with the tunnel ram? They work great once you get the idle circuits leaned a bit.
pdq67 wrote: ↑Sun Jul 15, 2018 12:33 pm
Install a GOOD Q-Jet and then spend some time tuning the rear top air door!
pdq67
Or better a pair of qjets run in a Six pack configuration.
(Front carbs primaries are not used, nore exposed to the plenum.)
4 big secondaries with central small responsive primaries.
A pair of edelbrock afb's could also be run in this Six Pack configuration (6 venturi) on a 4 bbl intake.
F-BIRD'88,
Have you actually ran this configuration before?
Just the back barrels of the front Q-Jet and all of the rear Q-Jet??
How did it run if you have?
Very interesting design concept in my book.
Kinda like running four 2GC two barrels on a flat cross-ram intake with each one of them set 90 degrees off so that a barrel is over each cross-ram throat and not set like a regular in-line 3x2 set-up. Think an old modified, "Man-A-Fre", 4 two barrel carb'd intake....
Or better a pair of qjets run in a Six pack configuration.
(Front carbs primaries are not used, nore exposed to the plenum.)
4 big secondaries with central small responsive primaries.
A pair of edelbrock afb's could also be run in this Six Pack configuration (6 venturi) on a 4 bbl intake.
F-BIRD'88,
Have you actually ran this configuration before?
Just the back barrels of the front Q-Jet and all of the rear Q-Jet??
How did it run if you have?
Very interesting design concept in my book.
Kinda like running four 2GC two barrels on a flat cross-ram intake with each one of them set 90 degrees off so that a barrel is over each cross-ram throat and not set like a regular in-line 3x2 set-up. Think an old modified, "Man-A-Fre", 4 two barrel carb'd intake....
pdq67
Again, have you actually ran this set-up?
pdq67
Sorry for not responding...work gets in the way of life...
No , I have not run this setup yet. I keep an eye out for 2 of the older
pre1975 4MV Qjets (or say 2 of the old Mercruiser marine engine Q jets) as I think these are the best to work with for this.
Ya it is interesting, with tons of potential.
Last edited by F-BIRD'88 on Sat Jul 21, 2018 1:23 pm, edited 1 time in total.
F-BIRD'88 wrote: ↑Fri Jul 20, 2018 1:45 pm
You should get yourself a radar gun or a Vericom (VC200) ...or later
to evaluate your street blast perf tuning. The butt dyno can be very deceiving. You can measure perf gains/// losses over any test length
Either standing start or rolling start test between speed a and speed b etc.
Or distance a to distance b. Cheap used....
Google search for HP Tuners Track Addict and see how that turns your iPhone or Android into a data recorder with the GPS and accelerometer in the phone. Drag race, oval race or road race, it records and replays showing your track position and elapsed time on a satellite image of the track simultaneously with a ton of information synchronized and superimposed with the video it records, and it can synchronize with other video cams using Bluetooth and also will trigger your GoPro when you go on and off the track. The basic app is a free download and the bells and whistles are cheap. This app and several others like it replace a data system that cost as much as $30,000 30 years ago.
At a race last Saturday I asked a friend's 16 yr. old son to find an app that recorded lap time and he searched the web, found this HP Tuners Track Addict app (he already has tuning skills and knows HP Tuner well, we got his nose out of video games by saying, "Here, tune the fuel and spark tables in your dad's truck."), downloaded it, figured it our and had it working in the race car in about a half-hour.
which one of you guys will figure out how you can video the secondaries opening and superimpose the recording of the acceleration G on the video frame by frame? Do you think that will help determine the best opening rate?
427dart wrote: ↑Sun Jul 15, 2018 10:53 am
Is what my engine seems to be telling me. Since we have a couple days of lower humidity 85 degree weather,I was doing more tuning on my vac. secondaries on the dual 650 Holleys.
First test was to remove my .060 sized orifice from the sec. pots and go from the weakest White to purple spring. This gives the full sized .081 hole like having no check ball. Did this on both carbs and but zip tie on secondary diaphragm rod with just enough tension to let it slide.
Result in a 3000 RPM roll in 2nd to 3rd gear up to 5500 RPM was no bog and not quite the strong mid range pull...didn't notice tires breaking loose in middle of 2nd. gear. Zip tie inspection shows about 1/2 open on secondary throttle.
Second test this morning was back to White spring in front carb only since it is easier than the rear carb and same full .081 vac. orifice.
Result was no bog or sense of secondary flopping open just a stronger pull with the rear end of Mustang doing a slight slide to the right at mid point in 2nd gear. Felt real good in 3rd gear.
May switch out the rear carb spring back to the original weak White spring and see how it goes but this seems to be telling me at 2950 lbs and with only a 3.50 gear on 275-50 M/T drag radials the 427 wants all it can get as soon as possible.
I WOULD run a pair of 650 mechanical secondary carbs IF somebody made them with the short 4160 bowls and a passage way for the secondary accelerator pump shot. Doing the race only Center Squirter won't work that well on the street due to excess fuel puddling in secondary barrels everytime you work the primary throttle during part throttle.
Anyway it runs really strong on the street which is where I'm at now days. Note my test area is a industrial park road with fresh new pavement.
I have dual Holley 4224 center squirters and the run great on the street with minamal modsA63BA89D-D57A-4DAB-BF4E-95840781688B.jpeg
Winner winner^. I have my GoPro... I can try this in the next few days...
Here is a thought... I have noticed with my truck that I needed a set of Brown springs on the street with regular radial tires to keep from bogging. Basically when you mat the throttle it lights the tires up instantly... The engine acceleration rate is super fast...
When I took Casper to the track with Drag Radials... Something funny happened! Hooked up the engine acceleration is no-where near where it was with street tires. So the Secondaries were slow to come in...even though the 4300lb truck ran 7.67 @ 90 mph in the 1/8th it was done with a 1.70 60'. You need a much lighter spring if you hook the power up!
Next time I go to the track I plan on swapping springs and I want to add the brass tube to ad the opening rate. Once I get these carbs dialed in.... I will compare them to my tricked out 4224 Center Squirters!
Don't be fooled by the seat of the the pants feeling for secondary spring choice. When I did my tuning on my teeeked 735 (OEM bbf) Holley (after doing much seat of the pants tuning and dialing in, the default silver spring ended up with the best et and mph at the track on my car. The "butt dyno" is decieving.
The butt Dyno doesn't apply here... On street tires I must run Brown springs in the pots to keep the Secondaries from just flopping open! But when you put slicks or in my case drag Radials on. The engine revs at a much slower rate thus allowing you to run a lighter spring to get the Secondaries open sooner! I had my GoPro mounted in my engine bay to video this.... While running down the track my Secondaries was very slow to open and never reached " Full Throttle". When we ran the engine on the engine Dyno we had to put the lightest springs in the pots to get the Secondaries to come in at a somewhat normal rate....
A very good buddy of mine...said you keep jacking around with those vacuum Secondary carbs...you are wasting your time! Put those 660's on there and you will see what a difference they will make! He has been drag racing for 40 years! His current car runs 4.30's in the 1/8th so he knows his stuff...
F-BIRD'88 wrote: ↑Fri Jul 20, 2018 1:45 pm
You should get yourself a radar gun or a Vericom (VC200) ...or later
to evaluate your street blast perf tuning. The butt dyno can be very deceiving. You can measure perf gains/// losses over any test length
Either standing start or rolling start test between speed a and speed b etc.
Or distance a to distance b. Cheap used....
Great idea. When my son was into Hot Wheels as a child, Hot Wheels sold a radar gun that seemed accurate. Seems it was about $20?
NHRA SS/G
1970 AMC AMX - 390 4-speed
Advanced Clutches - Red Line Racing Cams
There are several apps that use the accelerometer in your smart phone to calculate wheel HP and 1/4 mile performance. For the folks who don't bother with short attention span racing, the Track Addict app uses the GPS to record your laps and draw a track map, from which you can extract segment times.
I expected one of y'all to have already done it by now, videoed your secondaries opening with the HP data.
