What gear to use

[prplcar]

I need help to figure out what gear will give me the best results for my combo. I have a 493hp, 522lbt 440 in a 3190lb Savoy. The trans is a manual shift 727 with a 3000 stall converter, and a 8.75 rear with 3.23 gears. On the street it's fun and will run 13.5's all day at the track. I think it is capable of more, but don't know enough about the gear to converter relationship so I can help not hurt. I run 26.5 tall tires on the street and 30's on the track, also I have to drive the car 80 miles at highway speeds to get there. Is there a math formula or am I good to go with what feels right? I was thinking of 3.91's.

 

[Hemi Rebel]

What rpm is the engine at going through the traps? Is it done or does it still pulling? 391's would probably be a good gear. Then play with tire size after that.

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http://www.coastdriveline.com/htmlfolder/calculator2.html

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What is your mph in the quarter?

 

[dvw]

4.56 will be the quickest. 4.10 will work well. You have a problem if it only runs 13.5@3190lbs with 493 hp though. even with 3.23 that should put you in the low 12s.
Doug

 

[prplcar]

98 mph and 5300 rpm. Still pulling all the way down the track.

 

[dvw]

98 mph and 5300 rpm. Still pulling all the way down the track.

98 in the 1/4? If you made 493 HP you have a serious problem. I'm assuming the 3190 lbs is without driver. Even with 3.23 it should be way quicker. Before a gear change lets investigate why it's not quicker. How about some info?
Doug

 

[wstrowig]

Think about what rpm range you want your car to be running at the end of the race and/or on the highway, then calculate backwards, so to speak. There are math formula's to calculate what you are wanting to know. I used to have them all written down. Just remember, engine speed is measured in revolutions per min. and speed is usually measured in miles per hr. You can't compare apples to oranges. It's easier to convert everything into common units (seconds), then do the math. I'll break it down further if you want. Good Luck!

 

[prplcar]

Power numbers are from engine dyno, car has not been chassis dyno'd yet. 3190 is the car and 5 gallons of gas, with driver and helmet 3430lbs. I am using a performance tuned distributor with a blue box right now, not sure if the orange box is worth it. I am looking to upgrade to MSD streetfire box and wires. Carb is a Thunder series AVS 800cfm, I have left it alone except for adjusting when secondaries kick in. I will try alittle more tuning and increase the pump shot this season.

 

[Budnicks]

Even a 3.73:1, 3.91:1 decent street/strip gear {or middle of the road 4.10:1 to 4.30:1, even a 4.56:1 with a taller tire, probably even better, might not be as Hwy or street friendly, might have to do 55-65mph getting there} will all no doubt wake it up more, get better 60 ft times, help move it out quicker, much of the ET is made up in the 1st 120 ft, might need to go with better stickier tires maybe even taller & wider tires, with a lower gear, to hook & go efficiently... You have other issues thou running only 13.50's with that kind of power, a decent properly tuned 440 stock, in that weight of car should do that easily, I suspect carb & ignition tuning... Then do suspension & shocks, make the car work for you... I'm "Not" trying to bust your chop, just point you in the right direction... Good luck either way...

 

[prplcar]

Tires and suspension are good already, Mickey Thompson drag radials and super stock leafs with traction bars. I was breaking parts in last time at the track and not loading the converter completely. I launched at 1800rpm instead of 3000rpm, that is nodoubt a big deal.