3.72s or 4.10s ?
08-02-2001, 10:15 PM
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Car: 1990 Formula
Engine: treefitty
Transmission: stick
3.72s or 4.10s ?
I'm thinking about swaping gears. Which would be better of the two? I wanna improve my ET. I plan on getting srteet-slicks of some sort. Please, look at my mods. I have a T5.
Keepin mind; drivability and gas millege is not an issue.
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1990 Formula
Factory:TPI-305/Dual Cat(230hp),5 Speed,3.42 rear.
Dealer instaled:Aluminum Drive Shaft
Mods:SLP air foil,K&N Filter, Accel:wires,coil cap,rotor.Hypertech Thermomaster chip,Stat,Fan switch,TES headers,MSD6AL,AFPR(50), Harwood fiberglass hood,Original GM "Notchback GTA" hatch.
Flowmaster 3" Cat-back exhaust,TB coolant bypass,B&M Ripper shifter, Centerforce dual friction clutch, Ported Plenum, March Power/Amp Pulleys. (???HP)
DIRECT LINK TO PICS OF MY CAR. NO WEB-PAGE. http://community-2.webtv.net/MZavraz...A90/page9.html
08-04-2001, 10:31 PM
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Location: 51°N 114°W, 3500'
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Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
Gear choice depends on a lot of things. Tire size, weight of vehicle, engine rpm range and red line rpm. Chances are you'll be happy with 3.73 gears.
Changing gears changes the torque multiplication to the rear wheels. You'll feel more accelleration from the increased torque however top end speed will decrease. Chosing a gear ratio for the street is different than a race car. A low first gear and 4.10 gears will usually create too much torque and short street tires will never hook up.
Drag racers will try to stuff as much tire, especially the height, into the fenders as they can. Then they determine what gear ratio will get them down to the end of the track so that there is no more usable rpm at the finish line.
Since you intend to use the car on the street, the typical tire height is 26". If you put 4.10 gears in and went to 27 or 28" tall tires you would still get the torque multiplication of the gearing but not lose as much high rpm speed.
------------------
Follow my racing progress on Stephen's racing page
and check out the race car
87 IROC-Z SuperPro ET Bracket Race Car
461 naturally aspirated Big Block
Best ET on a time slip: 11.242 altitude corrected to 10.89
Best MPH on a time slip: 121.52 altitude corrected to 125.89
Altitude corrected rear wheel HP: 497.9
Best 60 foot: 1.546
Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association
87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley
Changing gears changes the torque multiplication to the rear wheels. You'll feel more accelleration from the increased torque however top end speed will decrease. Chosing a gear ratio for the street is different than a race car. A low first gear and 4.10 gears will usually create too much torque and short street tires will never hook up.
Drag racers will try to stuff as much tire, especially the height, into the fenders as they can. Then they determine what gear ratio will get them down to the end of the track so that there is no more usable rpm at the finish line.
Since you intend to use the car on the street, the typical tire height is 26". If you put 4.10 gears in and went to 27 or 28" tall tires you would still get the torque multiplication of the gearing but not lose as much high rpm speed.
------------------
Follow my racing progress on Stephen's racing page
and check out the race car
87 IROC-Z SuperPro ET Bracket Race Car
461 naturally aspirated Big Block
Best ET on a time slip: 11.242 altitude corrected to 10.89
Best MPH on a time slip: 121.52 altitude corrected to 125.89
Altitude corrected rear wheel HP: 497.9
Best 60 foot: 1.546
Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association
87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley
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