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CAL TRAC PRELOAD QUESTION #1056438
08/18/11 11:52 PM
08/18/11 11:52 PM
Joined: Dec 2003
Posts: 1,400
Wi.
old_racer Online content OP
pro stock
old_racer  Online Content OP
pro stock

Joined: Dec 2003
Posts: 1,400
Wi.
Hi,
was racing at the Nats and a guy came up to me and asked how I had my cal tracs set, I have the whole set up, they're mono spring etc. rancho shocks, I'm a 11:00 nostalgia SS car, my car's best is around 1.46 .60ft, most of the time around 1.49 to 1.51, during class run off with similar cars et, I look at others .60ft and mines good if not better than theres. any way the guy said he talked to another racer who's running good and has 2 turns of preload on his bars, and I'm running with about 2 flats on the bars, two full turns seems like a lot. it seams like it would bend the springs quite a bit to get 2 full turns on the bars. just wondering what others use and what works for them. maybe I'm missing something.
thanks
Russ

Re: CAL TRAC PRELOAD QUESTION [Re: old_racer] #1056439
08/19/11 12:11 AM
08/19/11 12:11 AM
Joined: Oct 2003
Posts: 2,537
PORT ALBERNI , BC., CANADA
superwrench Offline
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superwrench  Offline
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PORT ALBERNI , BC., CANADA
I got 2 flats on the left....4 flats on the right. Seems to hook the best there. 3700# Challenger with 1.46-1.47 to 1.52-1.53 depending on the track. Hits the tire hard. Ranchos on 8.

Re: CAL TRAC PRELOAD QUESTION [Re: superwrench] #1056440
08/19/11 02:38 AM
08/19/11 02:38 AM
Joined: Mar 2009
Posts: 2,457
Sydney,Australia
tex013 Offline
top fuel
tex013  Offline
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Posts: 2,457
Sydney,Australia
i have a 1/4 turn each side,as per a call to Caltracs.
pulls straight,never had cause to try anything else
i have found the ranchos work best for me on #9,1.54-1.57 60
Tex


New best ET 10.259@129.65 .
New best MPH 130.32
Finally fitted a solid cam,
stepped it up a bit more
3690lbs through the mufflers
New World block 3780lbs 10.278@130.80 . Wowser 10.253@130.24 footbraking from 1500rpm
Power by Tex's Automotive
Re: CAL TRAC PRELOAD QUESTION [Re: tex013] #1056441
08/19/11 08:46 AM
08/19/11 08:46 AM
Joined: Dec 2005
Posts: 1,494
Shelby mi.
J
JAKE68 Offline
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Shelby mi.
Once you have your side to side set up and done trying different pre loads is part of the tuning you do for your car. what it likes. There is some nhra stockers that put up to 2 full turns of preload after it was set up.


JAKES AUTOMOTIVE
Re: CAL TRAC PRELOAD QUESTION [Re: old_racer] #1056442
08/19/11 11:17 AM
08/19/11 11:17 AM
Joined: Jan 2003
Posts: 13,319
Marion, South Carolina [><]
an8sec70cuda Offline
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Marion, South Carolina [><]
I only run a 1/4 turn on both sides. Bottom hole, shocks on 9.


CHIP
'70 hemicuda, 575" Hemi, 727, Dana 60
'69 road runner, 440-6, 18 spline 4 speed, Dana 60
'71 Demon, 340, low gear 904, 8.75
'73 Chrysler New Yorker, 440, 727, 8.75
'90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt
'06 GMC 2500HD LBZ Duramax
Re: CAL TRAC PRELOAD QUESTION [Re: old_racer] #1056443
08/19/11 11:43 AM
08/19/11 11:43 AM
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
B
BradH Offline
Taking time off to work on my car
BradH  Offline
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Val-haul-ass... eventually
IIRC, 1/2 p-l on driver side, 1/2 + 1/3 on passenger side, 5-way Ranchos on #3, bottom hole ==> 1.45-1.46 60-fts on 275/60R15 ET Street Radials.

Re: CAL TRAC PRELOAD QUESTION [Re: an8sec70cuda] #1056444
08/19/11 11:45 AM
08/19/11 11:45 AM
Joined: Sep 2006
Posts: 1,440
central ohio
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nss guy Offline
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central ohio
At beech bend, I changed from 2 flats on rt. side to having the pin just touching the spring on both sides with drivers weight in and motor running when setting them. I was 1.44-1.47 with the car "detuned"

Re: CAL TRAC PRELOAD QUESTION [Re: JAKE68] #1056445
08/19/11 12:11 PM
08/19/11 12:11 PM
Joined: Jan 2003
Posts: 4,852
KENTUCKY
69CHARGERMD Offline
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KENTUCKY
Quote:

put up to 2 full turns of preload






This will soften up the hit I assume,,,

Sounds like it varies alot with the individual car,,,

I have heard leave a "nickel" size air gap,,,all the way up to lots of preload...as far as ways to adjust them.

Jake, ( and Jim ) ,,what are you running for rear tire pressure ?

thanks,

Doug

Re: CAL TRAC PRELOAD QUESTION [Re: 69CHARGERMD] #1056446
08/19/11 02:25 PM
08/19/11 02:25 PM
Joined: Dec 2005
Posts: 1,494
Shelby mi.
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JAKE68 Offline
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Shelby mi.
We run about 14.5lbs. WE have right now with driver 1/2 turn preload with 35lbs more on right side. 3550#w dr. 1.29 60's 10.5w

Last edited by JAKE68; 08/19/11 04:44 PM.

JAKES AUTOMOTIVE
Re: CAL TRAC PRELOAD QUESTION [Re: superwrench] #1056447
08/19/11 02:44 PM
08/19/11 02:44 PM
Joined: Feb 2007
Posts: 6,295
U.S.
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moparniac Offline
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U.S.
Quote:

I got 2 flats on the left....4 flats on the right. Seems to hook the best there. 3700# Challenger with 1.46-1.47 to 1.52-1.53 depending on the track. Hits the tire hard. Ranchos on 8.




When running that much preload you should switch to the upper hole and start flush! Upper hole hits the tire the hardest . The hardest you can hit a tire with caltracs is top hole and lots of pre load .. Lower hole no pre load is the softest ...


Mopar Performance
Re: CAL TRAC PRELOAD QUESTION [Re: an8sec70cuda] #1056448
08/19/11 02:50 PM
08/19/11 02:50 PM
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U.S.
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moparniac Offline
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Quote:

I only run a 1/4 turn on both sides. Bottom hole, shocks on 9.




Chip I think it was you that asked over winter about switching to double adjustables vs the single ranchos! Best I got with ranchos was 1.46(not many passes before lifter broke) and first time with the afco doubles was 1.40 on bottom hole and same preload! Flush on drivers side and 2 flats pass side... I'd love to tune this thing up your 60s


Mopar Performance
Re: CAL TRAC PRELOAD QUESTION [Re: 69CHARGERMD] #1056449
08/20/11 08:34 PM
08/20/11 08:34 PM
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Posts: 1,440
central ohio
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nss guy Offline
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central ohio
Quote:

Quote:

put up to 2 full turns of preload








Jake, ( and Jim ) ,,what are you running for rear tire pressure ?

thanks,

Doug




Doug,
I run between 12.5 and 13.5 psi, M/T 29.5 x 10.5 bias
20-24 psi when running hoosier 30x9 radials and yes the radials are about tenth quicker!

Jim

6787417-BG2011.jpg (29 downloads)
Re: CAL TRAC PRELOAD QUESTION [Re: nss guy] #1056450
08/20/11 08:45 PM
08/20/11 08:45 PM
Joined: Jan 2003
Posts: 4,852
KENTUCKY
69CHARGERMD Offline
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69CHARGERMD  Offline
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Quote:

I run between 12.5 and 13.5 psi




Thanks Jim,,,,
I was running 14 lbs,,,but the car was "on ice" off the line,,,dropped it to 12 lb,,,and it took care of it,,,thanks,,,,see ya at Norwalk.

ps,,nice sig pic.







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