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Discussion Starter · #1 ·
With the upcoming 1/4 mile Outlaw 10.5 races at Atco, 1320X (MIR) and Englishtown, I am going to purchase a new center section as my car is set up for only 1/8 right now with 3.89 gears.

Twin Turbo Big Block Big Chiefs, Bruno Lenco (2.10 first gear), 3165lbs with driver, 8400 +-rpm shift, 33" tires. 22% trans slip in the 1/8 estimate 13% in the 1/4.

Race calculators can not take place of experience.

Best test pass so far 5.0 @ 157.

How much does a 10.5WX33 grow in height?

Stuck between a 3:40 and 3:50 gear ratio.?

Thank you,







 

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RIP Dave - YB will miss you
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Why are you changing?????????If you can spin your engine to 8500 that should be what 210-215 mph with a 33 10.5W.

I've got 4.10's in my small block single 10.5 car.
 

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Discussion Starter · #4 ·
1) On the 5.0 , 157mph test pass RPM was 7259 from Racpac.

Tire Height: 34.5
Trans Ratio: 1:1
Gear Ratio: 3.89
Conv slip %: 22% Solved for
MPH: 157 actual
RPM: 7259 actual


2) Calculated at 210 mph with only 15% slippage RPM would be too high.

Tire Height: 34.5
Trans Ratio: 1:1
Gear Ratio: 3.89
Conv slip %: 15% estimated
MPH:210
RPM: 9153 Solved for


3) With 3.40 and a very wishful 220mph.

Tire Height: 34.5
Trans Ratio: 1:1
Gear Ratio: 3.40
Conv slip %: 15% estimated
MPH: 220
RPM: 8381

Seems most guys who run a powerglide with a 1.86 or 1.90 first gear use a 3.50 rear gear. Bruno/Lenco has 2.10 first gear.

Is it normal to have this much slippage?

Not really a lot of difference between 3.40 and 3.50 just wondering?

Thank you



 

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If Daniel is driving just leave the 3.89's in it, because he'll lift before the finish line. Ha Ha. Just messing with him.
 

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I run a 3.60 gear in my small block 10.5 car,at 203 it went through the traps at 8200
 

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I would bring that converter in. Of course if thats not an option I would error on the side of cuation and go with a 3.40. As you take ratio out the converter slip will go up.
 

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8500........awsome!!! :)

Stellar ride bro!
 

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Discussion Starter · #11 ·
Ash:

Running M/T's, their tech department said the tires grow a maxium of 1.5 inches at 150 mph for a total height of 34.5". Ran our first 1/4 mile pass this weekend 7.6 and ran out of gear at 1000' with the 3.89's, data logger showed 14% conv slippage.
 
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