I hate it when this happens... *UPDATE*

PKRWUD · 09-09-2001, 01:46 PM

Sprint cars, for the most part, race on dirt ovals that are 1/2 mile or less. They are powered by either 360ci or 410ci Methanol burning engines that obtain their peak power (650hp - 950hp) between 7000 and 8000 rpm. They are designed to be driven at WOT, and don't have the time or the need to be shifted. Their success is largely due to their gearing. Their drivetrain consists of the engine, a U-joint that mounts to the end of the crank on one side, and has a yolk on the other, a splined driveshaft, and a quick change rear end. The rear end has a one piece axle that attaches to both rear wheels, and has a ring gear mounted to it which connects with a forward facing pinion gear (mounted behind the axle). The pinion shaft and the drive shaft ends are both splined, and sit on top of each other, at the of the back of the rear end. Two matched gears are slid onto their ends, which make the final gear ratio, and allow for gear changes in less than 3 minutes. For example, the Sprint car I crew for has a 4.86 ring and pinion. Last night, the track conditions called for a 6.76:1 final ratio at the wheels, so I installed a matching set of quick change gears in the end, with a 32 tooth gear on the pinion shaft, and a 23 tooth gear on the drive shaft. Our track is a 1/5 mile oval, and with a 6.76:1 final drive ratio, that keeps the engine between 6k and 8k rpms around the entire track.

Below you can see a Winters quick change rear end. The polished plate with the anodized nuts at the rear is the quick change cover. If you draw a line forward from the bottom of that cover, you can kinda see the torque tube that covers the driveshaft.

BTW, if you've ever wondered why Sprint cars always have to be push-started, it's because they don't have starters. With no transmission, there is no flywheel, and thus, no ring gear for the starter to engage.

There are a few Sprints that have 2-speed trannys, but they are only used on tracks that are larger than 1/2 mile and usually paved.

Take care
~Chris

------------------
Retired Moderator
MustangNet

My site: JimPorterRacing

RACECAR spelled backwards is RACECAR

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[This message has been edited by PKRWUD (edited 09-09-2001).]

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09-09-2001, 01:46 PM	#5
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	Sprint cars, for the most part, race on dirt ovals that are 1/2 mile or less. They are powered by either 360ci or 410ci Methanol burning engines that obtain their peak power (650hp - 950hp) between 7000 and 8000 rpm. They are designed to be driven at WOT, and don't have the time or the need to be shifted. Their success is largely due to their gearing. Their drivetrain consists of the engine, a U-joint that mounts to the end of the crank on one side, and has a yolk on the other, a splined driveshaft, and a quick change rear end. The rear end has a one piece axle that attaches to both rear wheels, and has a ring gear mounted to it which connects with a forward facing pinion gear (mounted behind the axle). The pinion shaft and the drive shaft ends are both splined, and sit on top of each other, at the of the back of the rear end. Two matched gears are slid onto their ends, which make the final gear ratio, and allow for gear changes in less than 3 minutes. For example, the Sprint car I crew for has a 4.86 ring and pinion. Last night, the track conditions called for a 6.76:1 final ratio at the wheels, so I installed a matching set of quick change gears in the end, with a 32 tooth gear on the pinion shaft, and a 23 tooth gear on the drive shaft. Our track is a 1/5 mile oval, and with a 6.76:1 final drive ratio, that keeps the engine between 6k and 8k rpms around the entire track. Below you can see a Winters quick change rear end. The polished plate with the anodized nuts at the rear is the quick change cover. If you draw a line forward from the bottom of that cover, you can kinda see the torque tube that covers the driveshaft. BTW, if you've ever wondered why Sprint cars always have to be push-started, it's because they don't have starters. With no transmission, there is no flywheel, and thus, no ring gear for the starter to engage. There are a few Sprints that have 2-speed trannys, but they are only used on tracks that are larger than 1/2 mile and usually paved. Take care ~Chris ------------------ Retired Moderator MustangNet My site: JimPorterRacing RACECAR spelled backwards is RACECAR HEY !!! Are you ASE Certified ??? If you are, ask me about iATN. The best tool you'll ever have, and it's free !!! [This message has been edited by PKRWUD (edited 09-09-2001).]