4:10s to 3:73s

TbirdSC93

Registered User
I currently have 4:10s in my car and it is very quick off the line.....but I have a horrible time getting traction. Would going to 3:73s help in getting better traction? Or would it result in reduced performance?
 
They would help with traction but not that much. Tires are going to be your biggest improvement. Do you run it at the track or is it just for street playing?
 
Over the summer we experimented swapping my 3.73 gears out with Chris Wise's 4.10s. I know this doesn't make much sense, but I actually got better traction on the street with the 4.10s. Where the 3.73s would tend to snap the tires loose, the 4.10s turned just enough slower to grip the pavement and squirt the car forward.

I'm reffering to nailing the throttle from a 25-40 mph roll, not a standing start. From a stop both gears feel about the same on street tires..meaning that with more than 1/3 throttle, you just sit there with tires spinning instead of moving.

The 4.10s were better on the track (with slicks), but I didn't like them on the highway or the street and we swapped the pumpkins back so I've got the 3.73s again. Chris's car ran pretty much the same ET and MPH with 3.73s as it did with 4.10s, but his rpms were lower thru the traps.

So it really depends on what your looking for.

David
 
I use it for street playing right now but would like to run at the track....just seems like a I lose a lot of good power thru roasting the tires. I'm using 245/50/zr16 all the way around.

Thanks for the info dave....I was worried about spending the money on it and then it not being any different or slower.

I guess Ill just stick with my 4:10s and save my $170 for something else.

What are some techniques for your best launches on the 4:10s and do you know what RPMs he was at when he finished his run
 
What are some techniques for your best launches on the 4:10s and do you know what RPMs he was at when he finished his run

I assume your talking about launching at the track, because I can't launch my car on street tires no matter how wide they are. I've got Nitto 275-40-17s on the back and they spin very easy from a stop with either gears. The average Chevy Cavalier can jump me by a car length at a street light unless I'm really light on the gas.

On the track was using M/T ET streets 26 x 11.5 x 16 with about 19 pounds of pressure and I launched the same way with both gears. Put it in "D" and spin the tires long enough for the car to upshift from 1st to 2nd and from 2nd to 3rd. Then pull it down into 1st and goose the throttle to remove any loose rubber. There should be a pretty large cloud of smoke if you do it right.

Holding the brakes on the line and raising the rpms to about 1200 seems to work best for me. I've got a 2700 stall converter so it still gets plenty of slippage and torque off the line. With the nitrous, I did the same thing and it would just spin the tires real bad. I've now got a set of M/T ET Drags that are real sticky and I was able to pull as low as a 1.587 60ft. launching on the bottle. Haven't tried them yet on the motor only.

For the street/strip use I would suggest you get a set of BFG drag radials. They are just as sticky as the ET streets when properly heated and they are much more stable with lower tire pressures (down to 10 psi). I don't street race or I would have them on my car.

Chris was turning about 6400 rpms thru the traps with a non locking converter, 4.10s and 26" tires.


David
 
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I know stock its not good to run that high of RPMs....What needs to be done to run that high of rpms? Better torque converter and lighter driveshaft?
 
What needs to be done to run that high of rpms?

Build an engine that makes peak power higher in the rpm range. Cam and heads are the main things, built up balanced lightweight bottom end helps a little. Intake, exhaust and feul systems must also be able to keep up. I think the stock driveshaft is okay, but the converter probably shouldn't be revved that high.

I think the bottom end on a built and balanced engine like mine is good for about 7000 rpms, it's the valvetrain that gets risky past 6500. Since the blower can't keep up much past 6000 rpms (pulls more power than it makes) there isn't much point in revving any higher.

Chris is now running 28" tires and his RPMs are down about 300-400 thru the traps.

David
 
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