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Gears make it go.

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Old Feb 11, 2007 | 10:51 AM
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Default Gears make it go.

Yes that is an old saying and the creedance of many a hot rodder.

Using the comparison to my Trans Am with its 350 Turbohydramatic transmission 1st gear ratio of 2.52 and the rear end ratio of 3.08 : 1 the net result is a gear multiplication of 7.76.

A stock Bonneville with its 4T65 1st gear ratio of 2.92 and final drive ratio of 2.93 the net result is a gear multiplication of 8.56. This roughly equivalent to the T/A having a final rear ratio of 3.42 gears.

Now if you replace the Bonne gearing with a 3.29 rear gears, that is equivalent to 3.81 gears in the T/A.............and if you go with the 3.69 gears, that is equivalent to running 4.11'* in the T/A.

.....it'* no wonder Todd has trouble with traction in 1st gear.

Gears make it go

I know in the T/A that switching from 2.73 gears to 3.42 gears.......or from 2.41 gears (stock in my Formula) to 3.08 gears.....a 30% bump in output torque.....it shaved a full second off the 1/4 mile.

I know that this will not happen for my Bonne for some time, only to be justified by a complete trani overhaul, but Kudos to those who have done it.
I'm sure they can feel the difference in the butt meter.
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Old Feb 11, 2007 | 03:56 PM
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that is why i say use the shortest slick that is wide enough to do the job.
Paul we are hampered because we can't use a 15" wheel, if we could get a
15" wheel to fit, then we could use a short (22") tall slick for the track and
the stock size (27") tall tire for the street, best of both worlds.

ROD
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Old Feb 11, 2007 | 04:44 PM
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See what you can find in your fantastic land of the auto plenty.

The best I could do is a 26" on 16'*.
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Old Feb 11, 2007 | 06:14 PM
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Originally Posted by rrounds
that is why i say use the shortest slick that is wide enough to do the job.
Paul we are hampered because we can't use a 15" wheel, if we could get a
15" wheel to fit, then we could use a short (22") tall slick for the track and
the stock size (27") tall tire for the street, best of both worlds.

ROD
I totally agree, and I think that'* partially why my car is quicker than it should be. I'm runnin' some pretty small tires right now. We can use a 15" wheel, ya just gotta swap over to the GP brakes. I talked to Todd about that, he said the computer has issues with the different tire sizes, but if a guy could seduce the computer into working, you could get a race tranny with the 2.93'* for mileage, then run 22" slicks on race day and have insane acceleration.
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Old Feb 11, 2007 | 06:37 PM
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Or 3.29'* daily driver and then roll down to the other tires for the track.
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Old Feb 11, 2007 | 06:47 PM
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Originally Posted by chadow427
...I totally agree, and I think that'* partially why my car is quicker than it should be. I'm runnin' some pretty small tires right now...
Haro, don't burn up those tires too soon when you get the car running again
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Old Feb 11, 2007 | 07:06 PM
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here ya go Paul,

D.O.T. Drag Radial
Tire Size: P335/35R17
Tread Width: 12.5"
Diameter: 25.4"
Circle: 82.0"
Recommended Rim: 11-13"
Measured Rim: 12"
Section Width: 13.5"
Tire Weight: 25
522-17335

it'* a little WIDE .......
but if you still can't hook em up :(

Tire Compound: D-1
Tire Overall Diameter: 33.8''
Average Roll Out/
Circumference: 105''
Tire Tread Width: 16.8''
Tire Section Width: 20.1''
Wheel Diameter: 16''
Required
Wheel Width: 13-16''
Tire Weight: 38.0 lbs

i'm sure you won't spin those.

ROD
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Old Feb 11, 2007 | 08:58 PM
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Good ones Rod.

If I had some 12 or 13" wide rims.

The 255'* on both the drag tires and the road tires are on stock 7 - 7 1/2" wide wheels. :(
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Old Feb 11, 2007 | 09:56 PM
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hey, you asked i delivered ! ! !
now go get some rims.
even though it might be hard to find
16"(WIDE) rim'*. GOD that would look like
and people would say
and then you would show them your

ROD
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Old Feb 13, 2007 | 10:18 PM
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Don't forget that with only 16 psi in these tires, the effective rolling diameter is about 21"
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