60 ft issues
#3075896
09/09/22 08:29 PM
09/09/22 08:29 PM
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Joined: Jun 2014
Posts: 3,105 Md.
carnut68
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What could cause my slow 60 ft times? Mid 1.50's Here's my set up. 68 Barracuda fastback about 3400 w/me. 446 w/indy EZ standard port M1/ Proform 950. 590 cam. ATI 5200 convertor, torqueflite. 430 gears w/spool. Superstock springs clamped on front half 1 clamp on back and Calvert 9 way shocks. CE 3 way on front w/5 in travel. Hoosier Quick time Pro's 27x10.50 15. 17lbs air. Car doesn't spin, leaves straight. Engine is snappy. What am I missing?
America First!
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Re: 60 ft issues
[Re: carnut68]
#3075902
09/09/22 08:42 PM
09/09/22 08:42 PM
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Joined: Aug 2003
Posts: 43,007 Bend,OR USA
Cab_Burge
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[quote=carnut68 What am I missing? [/quote] the reason it is slowing ,down correct AKA, have you thought about the air density altitude change effects on your car? If you have it tune lean for summer heat and humidity it will get a lot leaner in better air Does it miss or nose over anywhere during the run? Another thing to consider is how many runs on the slicks, are they balling up and going away? How much 60 Ft ET are you losing? How about the 330 and 660 ET?
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: 60 ft issues
[Re: Cab_Burge]
#3075912
09/09/22 08:55 PM
09/09/22 08:55 PM
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Joined: Jun 2014
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carnut68
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[quote=carnut68 What am I missing? the reason it is slowing ,down correct AKA, have you thought about the air density altitude change effects on your car? If you have it tune lean for summer heat and humidity it will get a lot leaner in better air Does it miss or nose over anywhere during the run? Another thing to consider is how many runs on the slicks, are they balling up and going away? How much 60 Ft ET are you losing? How about the 330 and 660 ET? [/quote] Cab, my 60's have never been good. Tires might have 25 passes. No videos, yet. There are some pic's on Mason Dixons website. If I go tomorrow hopefully I can get a good video. The car feels good. It doesn't do anything stupid.
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Re: 60 ft issues
[Re: carnut68]
#3075943
09/09/22 11:17 PM
09/09/22 11:17 PM
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Joined: Oct 2006
Posts: 1,262 New York, USA
Chargerfan68
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What was the best mph? And avg mph? Any idea on HP? Dyno numbers?
1.50 60Ft. , 10.75@ 127MPH Hauling 3900 LBS.
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Re: 60 ft issues
[Re: Chargerfan68]
#3075982
09/10/22 06:53 AM
09/10/22 06:53 AM
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carnut68
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What was the best mph? And avg mph? Any idea on HP? Dyno numbers? Best MPH 126.1. Best ET 10.82@ Cecil County. Avg 122@ Mason Dixon. WAG on HP 550. No Dyno.
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Re: 60 ft issues
[Re: Wirenut]
#3075988
09/10/22 07:25 AM
09/10/22 07:25 AM
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Joined: Jun 2014
Posts: 3,105 Md.
carnut68
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The video needs to be closer and slow motion. I went through a similar thing but my car was losing 60 and I couldn’t get it back . If you search me you will find the thread . In short I ended up getting cal tracs and double adjustable shocks all the way around . In the long run Ingot it back to 1.40 . This year had the converter freshened no other changes and it’s 1.35 and .10 faster overall .
Video will help greatly. If I go today I'll try to get a better video. The thing should 60 in the 1.40s. If I was having traction problems I would consider Cal tracs and better shocks. As for my convertor It only has about 25 passes on it, and have considered it possibly being the issue.
Last edited by carnut68; 09/10/22 07:29 AM.
America First!
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Re: 60 ft issues
[Re: carnut68]
#3075993
09/10/22 08:07 AM
09/10/22 08:07 AM
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Joined: Mar 2006
Posts: 9,791 MI, usa
dvw
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Realize that 60ft without spin or excess chassis movement is a pure function of power. Weather, converter, engine set up. Engine can be broken down into carb, cam, intake, heads, ignition just to start. Suspension and traction at this stage are not the issue. Doug
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Re: 60 ft issues
[Re: dvw]
#3075995
09/10/22 08:17 AM
09/10/22 08:17 AM
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carnut68
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Realize that 60ft without spin or excess chassis movement is a pure function of power. Weather, converter, engine set up. Engine can be broken down into carb, cam, intake, heads, ignition just to start. Suspension and traction at this stage are not the issue. Doug That's a good perspective. Knowing how well your car works I'll take that as good advice. So I think what your saying is I'm lacking some power. Possibly in the tune?
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Re: 60 ft issues
[Re: carnut68]
#3076031
09/10/22 12:07 PM
09/10/22 12:07 PM
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Joined: Dec 2021
Posts: 1,072 Loudoun County, VA
Brad_Haak
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My friend Mike sent me a short video of your car from Friday night a week ago. I don't have anywhere to post it, though. My thoughts: - the whole car sits up rather high, typical of what I think of with bracket cars on Super Stock springs; not seeing much pitch rotation - your front dampers may have 5" of travel, but I don't think you've got 5" of extension travel from the static ride height, unless you are using shock extensions and have trimmed down the upper control arm bumpers - CE shocks don't move very freely; a set of Calvert's "loose as a goose" 90/10s might be a better option that won't break the bank Questions: - you mentioned it's a 5200 ATI; at what RPM are you leaving? - where is your ignition set for initial & total timing? - have you tried any different accelerator pump cams from what the Proform carb came with? - have you measured the available front suspension travel from the static ride height? - have you tested how the car responds from leaving off or slightly above idle vs stalling up against the converter?
2021 Challenger 6.4L Scat Pack 1320 (2022) 100% stock: 1.680, 11.894 at 113.75 (DA 175 ft) wheels, tires, air filter: 1.714, 11.833 at 115.80 (DA 310 ft)
1973 Challenger 452 ci street/strip (2008) pump gas, DOT radials: 1.454, 10.523 at 126.44 (DA 514 ft)
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Re: 60 ft issues
[Re: carnut68]
#3076055
09/10/22 01:46 PM
09/10/22 01:46 PM
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Joined: Jan 2005
Posts: 2,540 Milwaukee WI
TRENDZ
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I assume you have a transbrake. What rpm are you launching at? You say no tire spin. That may be one of your problems. Dead hooked on a slick leaves you “stuck” with your hard ratios. Induce some spin to get your engine in a higher rpm range. Effectively this will change the ratio the engine “feels”. My opinion would be to raise launch rpm and stiffen the shocks. Maybe change the caltrac bar angle to induce some spin.
"use it 'till it breaks, replace as needed"
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Re: 60 ft issues
[Re: TRENDZ]
#3076090
09/10/22 04:41 PM
09/10/22 04:41 PM
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Joined: Aug 2003
Posts: 43,007 Bend,OR USA
Cab_Burge
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If it is spinning it ain't moving forward as fast as it can Watch some of the ultraslow motion vids on Top Fuel, Funny cars and Pro Stock cars, they don't spin when leaving the starting line They wrinkle the sidewalls as they go forward without spinning
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: 60 ft issues
[Re: TRENDZ]
#3076165
09/10/22 09:48 PM
09/10/22 09:48 PM
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Joined: Jan 2003
Posts: 14,478 So. Burlington, Vt.
fast68plymouth
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I’d do a cranking compression test on a few cylinders(with the carb at WOT).... primarily to gauge the relationship between the compression ratio and the camshaft. What are you running for valve lash?
Have you done a low speed, high gear, flash stall test? Are you getting an honest 5200 out of it?
Frankly, I’d consider 5200 to be on the lower end of what I’d want for that combo.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: 60 ft issues
[Re: carnut68]
#3076177
09/10/22 10:34 PM
09/10/22 10:34 PM
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carnut68
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To answer a few questions. The flash stall is 5200. Valve lash is .020 cold. Initial timing was 27idle 35 total. Tried 37 total today,it picked up. Tried leaving off idle ...leaves harder. Up on convertor [footbrake] 2500 and 3500 no big difference. Leaves softer. Put a known good carb on today and it picked up everywhere, but 60 ft. Went to Keystone for tnt. Typically it's slower there than Mason Dixon [elevation] but I was 3/10ths quicker today. I had the best 60 ft 1.51 leaving off idle, 17lbs air. The car really responded to 37 degrees total timing and the carb swap. Picked up 4 mph from the first run. 119 to 123.7. A friend who was there said there's about 8 in separation on the rear suspension. We did a compression check shortly after the engine was put together all the cylinders were around 205.
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Re: 60 ft issues
[Re: carnut68]
#3076178
09/10/22 10:40 PM
09/10/22 10:40 PM
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Joined: Jan 2003
Posts: 14,478 So. Burlington, Vt.
fast68plymouth
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I’d try opening up the lash .004-.005 and see if that impacted the 60’ time
For perspective on the stall speed....... the Normal T/A 8” Race converter for a 440 bracket race engine would flash about 5600. That configuration was derived long before there were Indy heads.......... so it was lotsa stall....... with small heads. Typically, the trend would be to increase the stall speed as the heads got bigger.
My take on the 8” of rear separation is........ it takes(wastes?) energy to wind the springs up that much. If the car didn’t lift so much........ maybe it would use that energy to move forward instead.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: 60 ft issues
[Re: fast68plymouth]
#3076184
09/10/22 11:07 PM
09/10/22 11:07 PM
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Joined: Jun 2014
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carnut68
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I’d try opening up the lash .004-.005 and see if that impacted the 60’ time
For perspective on the stall speed....... the Normal T/A 8” Race converter for a 440 bracket race engine would flash about 5600. That configuration was derived long before there were Indy heads.......... so it was lotsa stall....... with small heads. Typically, the trend would be to increase the stall speed as the heads got bigger.
My take on the 8” of rear separation is........ it takes(wastes?) energy to wind the springs up that much. If the car didn’t lift so much........ maybe it would use that energy to move forward instead. Now to figure how to close that separation. Clamps? Shocks? Cal Tracs?
America First!
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Re: 60 ft issues
[Re: carnut68]
#3076187
09/10/22 11:19 PM
09/10/22 11:19 PM
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Joined: Dec 2021
Posts: 1,072 Loudoun County, VA
Brad_Haak
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Two screen shots from a fuzzy video showing staged and right after the green. Noticeable front extension, but it doesn't look like 8" of rear separation to me... maybe 3-4"?
Last edited by Brad_Haak; 09/10/22 11:26 PM.
2021 Challenger 6.4L Scat Pack 1320 (2022) 100% stock: 1.680, 11.894 at 113.75 (DA 175 ft) wheels, tires, air filter: 1.714, 11.833 at 115.80 (DA 310 ft)
1973 Challenger 452 ci street/strip (2008) pump gas, DOT radials: 1.454, 10.523 at 126.44 (DA 514 ft)
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