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Re: Big end stablity
[Re: Al_Alguire]
#893727
01/02/11 05:42 PM
01/02/11 05:42 PM
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Joined: Feb 2009
Posts: 1,532
off the grid
340B5
pro stock
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pro stock
Joined: Feb 2009
Posts: 1,532
off the grid
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Max caster(w/stock front suspension) will help a lot.
Yeah, it's got a smallblock.
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Re: Big end stablity
[Re: Al_Alguire]
#893728
01/02/11 05:49 PM
01/02/11 05:49 PM
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Joined: Jan 2003
Posts: 32,394
Quicktree
I Win
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I Win
Joined: Jan 2003
Posts: 32,394
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Quote:
IMO go to a wider wheel, IMO an 8" wheel is to narrow for the 10.5 tire. Get the front end alignment checked at ride hieght. Also from that launch picture I think I would want to stiffen the extension on the rear shocks if you can. Would like to see some launch video..
 combine that with low pressure it's an accident waiting to happen.
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Re: Big end stablity
[Re: Quicktree]
#893729
01/02/11 06:02 PM
01/02/11 06:02 PM
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Anonymous
Unregistered
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Anonymous
Unregistered
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Do 1 thing at a time. Raise air pressure in rear 1st and then go from there. If that doesn't help then I would loook at your front suspension. Idler arm and then front end alignment at ride height.
Your 8" rim isnt the problem.
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Re: Big end stablity
#893730
01/02/11 06:30 PM
01/02/11 06:30 PM
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Joined: Mar 2008
Posts: 553
Kentucky
clovis
OP
mopar
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OP
mopar
Joined: Mar 2008
Posts: 553
Kentucky
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http://www.youtube.com/watch?v=yhPWI8Egkushttp://www.youtube.com/watch?v=NfMQXqlml2UThese were my first passes on both days, so the launch is at around 1800 for both. The car 60fts much better when I leave at around 2800. Both these passes were low 1.60 60ft. By the end of the day I can usually get the car into low 1.50's.
'75 Plymouth Duster
Phase I 451 906/590/2-660 10.75/126
Phase II 451 Stage VI/590/1050 9.82/135
Phase III 383 906/Victor-Pump gas 11.30/119
"For by grace you have been saved through faith. And this is not your own doing; it is the gift of God,"
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Re: Big end stablity
[Re: 69CHARGERMD]
#893732
01/02/11 08:54 PM
01/02/11 08:54 PM
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Anonymous
Unregistered
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Anonymous
Unregistered
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With those ET 's and 60 foots, you should be able to drive it with 1 finger.
I'd like to see the front raised up another 2" and check your idler arm and get a race wheel alignment. Tire pressure up front 37-38 ibs.
rear tire pressure 12.5 psi.
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Re: Big end stablity
[Re: 69CHARGERMD]
#893733
01/02/11 09:19 PM
01/02/11 09:19 PM
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Joined: Mar 2008
Posts: 553
Kentucky
clovis
OP
mopar
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OP
mopar
Joined: Mar 2008
Posts: 553
Kentucky
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The first video was my first pass with the 590 cam and the fourth pass with the 660's. So by the last pass on 11/21 (6 passes later)we were able to get the jetting and shift point adjusted to post the 10.75. When I finished that pass, I temped the tubes and had three 200* below the others and after I saw the video I could see the puffs of smoke at launch. The motor was pulled this past Friday and tore down, thus the purpose of the original post in that I wanted to know if trying to go 10.0's on an 8" rim and 10.5" tire was a bad plan.
'75 Plymouth Duster
Phase I 451 906/590/2-660 10.75/126
Phase II 451 Stage VI/590/1050 9.82/135
Phase III 383 906/Victor-Pump gas 11.30/119
"For by grace you have been saved through faith. And this is not your own doing; it is the gift of God,"
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Re: Big end stablity
[Re: clovis]
#893734
01/02/11 09:25 PM
01/02/11 09:25 PM
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Joined: Jan 2003
Posts: 4,852
KENTUCKY
69CHARGERMD
master
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master
Joined: Jan 2003
Posts: 4,852
KENTUCKY
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According to the Wallace calculator,,,with that ET,,,a "good" 60' should be 1.49
I dont think your too far off,,,,,
I have a set of Weld Pro Star 12" rims sitting in the garage,,,not sure if they would work for you,,,( you mentioned 10" rims )
I had some improvement with my 60' after adjusting the carb shooters,,
I run 13.5-14 lbs in my slicks,,,anything less,,,and the car "waffles" around at the top end,,,
see ya at Bowling Green this year,,,
Doug
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Re: Big end stablity
[Re: pressureangle]
#893736
01/02/11 10:18 PM
01/02/11 10:18 PM
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Joined: Mar 2008
Posts: 553
Kentucky
clovis
OP
mopar
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OP
mopar
Joined: Mar 2008
Posts: 553
Kentucky
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The alignment was the last thing we did. First, we replaced all the bushings, ball joints and ends, then we swapped out the front shocks, and then lowered it to get the five inches of travel. I let it sit for a few days, then we did the alignment. When doing the alignment we jacked up the front of the car to mimnic the car being under power and set everything there.
My plan is to raise the front to get about an inch between the top of the tire and bottom of the fender and then lower the rear to get more of even stance without so much rake. Then go back and align it again.
Doug, we only have about eight weeks before the first test and tune.
'75 Plymouth Duster
Phase I 451 906/590/2-660 10.75/126
Phase II 451 Stage VI/590/1050 9.82/135
Phase III 383 906/Victor-Pump gas 11.30/119
"For by grace you have been saved through faith. And this is not your own doing; it is the gift of God,"
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Re: Big end stablity
[Re: clovis]
#893737
01/03/11 02:01 AM
01/03/11 02:01 AM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
The alignment was the last thing we did. First, we replaced all the bushings, ball joints and ends, then we swapped out the front shocks, and then lowered it to get the five inches of travel. I let it sit for a few days, then we did the alignment. When doing the alignment we jacked up the front of the car to mimnic the car being under power and set everything there.
My plan is to raise the front to get about an inch between the top of the tire and bottom of the fender and then lower the rear to get more of even stance without so much rake. Then go back and align it again.
Doug, we only have about eight weeks before the first test and tune.
If you raise the front your only reducing the front
end travel.... lower the back if you want... also
what bushings did you use on the front, some of the
poly bushings are very stiff and dont move well
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Re: Big end stablity
[Re: theman440]
#893739
01/03/11 08:27 AM
01/03/11 08:27 AM
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Joined: Jan 2003
Posts: 2,922
A shed in England
Tig
master
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master
Joined: Jan 2003
Posts: 2,922
A shed in England
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We swapped from 8.5 to 10 inch rim using the same 29.5 x 10.5 tyre. I don't recall that making a lot of difference stability wise. What did help was correct rear tyre pressure, stiffer extension damping on the front shocks and a good aligment job with plenty of positive castor. HTH's 
'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials.
9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge.
RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
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Re: Big end stablity
[Re: theman440]
#893740
01/03/11 08:57 AM
01/03/11 08:57 AM
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Joined: Mar 2008
Posts: 553
Kentucky
clovis
OP
mopar
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OP
mopar
Joined: Mar 2008
Posts: 553
Kentucky
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When I raise the front I will do it to the extent I can keep 4.5-5" of travel, as I have a little more now. That is why I waited before doing the alignment, as after we lowered it to get the 5", the car settled a little more.
We used Moog parts for everything on the front if I remember correctly.
How are you guys testing for the binding?
The smoke is from three cylinders being down.
'75 Plymouth Duster
Phase I 451 906/590/2-660 10.75/126
Phase II 451 Stage VI/590/1050 9.82/135
Phase III 383 906/Victor-Pump gas 11.30/119
"For by grace you have been saved through faith. And this is not your own doing; it is the gift of God,"
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Re: Big end stablity
[Re: sr4440]
#893742
01/03/11 09:45 AM
01/03/11 09:45 AM
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Joined: Jan 2003
Posts: 9,999
Frostbitefalls MN (Rocky&Bullw...
gregsdart
master
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master
Joined: Jan 2003
Posts: 9,999
Frostbitefalls MN (Rocky&Bullw...
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Be careful to recheck bump steer if you change caster. One affects the other, and if you go with the max caster it may be enough to cause problems. I have six degrees in mine, with about 1600 lbs on the front. It is hard to turn, and from what I feel in the wheel, less will be plenty for a door car .
Last edited by gregsdart; 01/03/11 01:07 PM.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: Big end stablity
[Re: Locomotion]
#893743
01/03/11 12:52 PM
01/03/11 12:52 PM
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Joined: Jan 2003
Posts: 16,925
NC
440Jim
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,925
NC
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Quote:
As mentioned before, the wider rim allows more air, which stiffens and prolongs the life of the sidewall and helps maintain a fuller contact patch.
The increase to 10" rims will help the traction issue too. Recommended
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