Calculating optimum shift points?

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DriveWFO
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Calculating optimum shift points?

#1 Post by DriveWFO » Mon Apr 23, 2007 2:04 pm

Any idea on how to go about finding my best shift points? Or at least get in the ballpark.

383ci with 260/264 @ .050", 106 LSA, 106 ICL.
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sunsation540
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#2 Post by sunsation540 » Thu Apr 26, 2007 12:22 am

type of trans and gear hyd solid ? make some diffrences.. however start shift points at 6400. w /solid 6000 w /hyd make 2 passes per rpm move up 200 rpm at a time until it slowes down... you may need to short shift 1-2 strech 2-3 so it can cross at peak if you have a dyno sheet that helps.. with the cam @50 should make good power around 6500/ due to the math they split at 5250 heavy cars need torque and light cars like HP there is no magic bullet lets race!
make a plan and stick to it !!
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sc racing
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#3 Post by sc racing » Thu Apr 26, 2007 9:17 am

In my experience with my own cars Ive always seem to run a little faster by short shifting,regardless of peak hp or peak torque #s.Just my combo I guess.
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DriveWFO
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#4 Post by DriveWFO » Thu Apr 26, 2007 12:59 pm

I'm running a mechanical roller setup. Race weight is 3350#. With 3.73s & 28" tires, I'm trapping right around 6000. Not ideal, but when I spray the car, it's gonna trap at a lot higher rpm.
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1320racer
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#5 Post by 1320racer » Thu Apr 26, 2007 5:26 pm

For me, I can't short shift. Tried it and the car slowed. My car likes to be shifted at about 8000 rpm.
78 Malibu, 357 SBC, Dart pro 1 230cc, custom solid flat tappet, Ron's fuel Alcohol Injected,
1.76 Glide, TCI 8" group 12 flashin to 5700, Ford 9" with 5.14 gears, 28x9 MT slicks. 3077# race ready.
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sc racing
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#6 Post by sc racing » Thu Apr 26, 2007 8:05 pm

Some like high......some like it low.
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1320racer
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#7 Post by 1320racer » Thu Apr 26, 2007 9:46 pm

sc racing wrote:Some like high......some like it low.
Exactly!! Just try differant points to see where your car "wants" to be shifted.
78 Malibu, 357 SBC, Dart pro 1 230cc, custom solid flat tappet, Ron's fuel Alcohol Injected,
1.76 Glide, TCI 8" group 12 flashin to 5700, Ford 9" with 5.14 gears, 28x9 MT slicks. 3077# race ready.
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1320racer
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Joined: Fri Dec 08, 2006 6:43 pm

#8 Post by 1320racer » Thu Apr 26, 2007 9:50 pm

side note to my last post..... my duration at .050" on that cam is 264 and 276.
78 Malibu, 357 SBC, Dart pro 1 230cc, custom solid flat tappet, Ron's fuel Alcohol Injected,
1.76 Glide, TCI 8" group 12 flashin to 5700, Ford 9" with 5.14 gears, 28x9 MT slicks. 3077# race ready.
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dadnova
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#9 Post by dadnova » Sun Apr 29, 2007 9:29 am

A dyno test will really help you in this decision. Or try a computer dyno simulation with all the proper info input, this should get you in the right area of your tourqe curve. You just have to try different things at the track to find out what you and your car like.
I launch hard off trans break and short shift while my son takes off on foot brake and reves higher in each gear. The funny thing is we both run within a 1/2 a 1/10 of each other every time. GO FIGUER. :?:
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