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Correction factor and tuning question #2708424
10/19/19 09:44 PM
10/19/19 09:44 PM
Joined: Oct 2006
Posts: 820
New York, USA
Chargerfan68 Offline OP
super stock
Chargerfan68  Offline OP
super stock

Joined: Oct 2006
Posts: 820
New York, USA
I went to the track Friday and got a few runs in. I did 2 runs with exactly the same tune, and then after looking at the plugs, i jetted up slightly for the last 2 runs.

1050 dominator - 89 pri/ 96 sec.
Run1: 11.06 @ 123.98. 1.544 60 ft
Run 2: 10.93 @ 124.05. 1.525 60 ft

91 pri/96 sec
Run 3: 11.07 @ 124.48. 1.604 60 ft
Run 4: 10.90 @ 124.18. 1.500 60 ft


After correcting for density altitude, the 1st 2 runs correct to faster mph than the last 2 runs. so, my jetting change with the weather made the car pick up. But, in theory, it actually went slower with those changes. Not sure i fully understand what happened.


1.50 60Ft. , 10.75@ 127MPH Hauling 3900 LBS.
Re: Correction factor and tuning question [Re: Chargerfan68] #2708532
10/20/19 12:03 PM
10/20/19 12:03 PM
Joined: Aug 2003
Posts: 33,766
Bend,OR USA
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Cab_Burge Offline
I Win
Cab_Burge  Offline
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Joined: Aug 2003
Posts: 33,766
Bend,OR USA
Originally Posted by Chargerfan68
I went to the track Friday and got a few runs in. I did 2 runs with exactly the same tune, and then after looking at the plugs, i jetted up slightly for the last 2 runs.

1050 dominator - 89 pri/ 96 sec.
Run1: 11.06 @ 123.98. 1.544 60 ft
Run 2: 10.93 @ 124.05. 1.525 60 ft

91 pri/96 sec
Run 3: 11.07 @ 124.48. 1.604 60 ft
Run 4: 10.90 @ 124.18. 1.500 60 ft


After correcting for density altitude, the 1st 2 runs correct to faster mph than the last 2 runs. so, my jetting change with the weather made the car pick up. But, in theory, it actually went slower with those changes. Not sure i fully understand what happened.

Theory on many things affecting racing of all types is just that, theory.
That being said stick with the basics like what the spark plug looks like and what the time slip says from your changes up work
Don't worry about maxing out the tune with theory involved and worry about why you weren't able to match the theory results tsk twocents
Run 3 looks like it spun the tires and then went faster every where else on the track up

Last edited by Cab_Burge; 10/20/19 12:03 PM.

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Correction factor and tuning question [Re: Cab_Burge] #2708540
10/20/19 12:53 PM
10/20/19 12:53 PM
Joined: Jan 2003
Posts: 12,490
So. Burlington, Vt.
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fast68plymouth Offline
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fast68plymouth  Offline
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Joined: Jan 2003
Posts: 12,490
So. Burlington, Vt.
Not what you’re asking.......

I assume this is the stick car?

Looks like you’re giving up something in the middle.
My friends stocker(4 speed) will ET slightly better than that 10.90 with slightly less mph than your 124....... and a very similar 60’ to your 1.50.

The moroso chart shows 124 is good for a 10.69.

With the small motor in the car he’s gone 10.80@123.

Run #3....... a bit of tire spin often shows up as a higher trap speed.


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: Correction factor and tuning question [Re: Cab_Burge] #2708583
10/20/19 02:25 PM
10/20/19 02:25 PM
Joined: Oct 2006
Posts: 820
New York, USA
Chargerfan68 Offline OP
super stock
Chargerfan68  Offline OP
super stock

Joined: Oct 2006
Posts: 820
New York, USA
Cab,

I saw films of the 1st and last runs. The first run dead hooked. No tire spin at all. And the last run made 1 revolution and hooked which is ideal. I think thats why it 60 ft better. I do have an adjustable softlok in there to dial in some slip at the gear changes with centrifugal weight. The 3rd run i had clutch slippage at all gear changes according to graph. Shift recovery rpm was way higher rpm than normal. Not sure how i ended up with mph in 8th and 1/4 with what i saw on graph.

Last edited by Chargerfan68; 10/20/19 02:26 PM.

1.50 60Ft. , 10.75@ 127MPH Hauling 3900 LBS.
Re: Correction factor and tuning question [Re: fast68plymouth] #2708584
10/20/19 02:32 PM
10/20/19 02:32 PM
Joined: Oct 2006
Posts: 820
New York, USA
Chargerfan68 Offline OP
super stock
Chargerfan68  Offline OP
super stock

Joined: Oct 2006
Posts: 820
New York, USA
Dwayne,

Yes, this is the stick car with the M1 dominator manifold replacing the Victor. The M1 is without the 1-1/2” open tapered spacer i ran on the Victor. Also, i put on the flat stock looking fiberglass hood replacing the 4” sixpack scoop fresh air hood. I just radiused the upper plenum area and portmatched to the heads. Old setup usually ran 10.80’s at 126 mph. So i lost about a tenth and about 1-1/2 mph with this change.

But, that is with 4 runs with this setup, comparing to about 50 or so runs of tuning with the older setup

Last edited by Chargerfan68; 10/20/19 02:35 PM.

1.50 60Ft. , 10.75@ 127MPH Hauling 3900 LBS.
Re: Correction factor and tuning question [Re: Chargerfan68] #2708588
10/20/19 02:50 PM
10/20/19 02:50 PM
Joined: Jan 2003
Posts: 12,490
So. Burlington, Vt.
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fast68plymouth Offline
I Live Here
fast68plymouth  Offline
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Joined: Jan 2003
Posts: 12,490
So. Burlington, Vt.
You had to know it was going to lose something.
It’s less difference than I would have expected.


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: Correction factor and tuning question [Re: fast68plymouth] #2708648
10/20/19 07:04 PM
10/20/19 07:04 PM
Joined: Feb 2005
Posts: 3,960
Prospect, PA
BSB67 Online content
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BSB67  Online Content
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Joined: Feb 2005
Posts: 3,960
Prospect, PA
Originally Posted by fast68plymouth
Not what you’re asking.......


Run #3....... a bit of tire spin often shows up as a higher trap speed.


That has been my experience too


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