Speedo Calibration

[cobraaph]

As part of a rear end rebuilding, I am having 3.73 gears installed when the traction-lok is serviced. Does anyone know if a new gear should be installed at the transmission or some other calibration needs to done so that the speedo reads correctly?

Thanks for any input.

Al Hermans

[SNAKEYE]

New gear on sender unit that plugs into the left side of the tranny. Simple replacement job.
I went to 4.10 rear gears. Got the speedo gear from Steeda. Looked it up on their website. Total cost a salty $25+/-! Depending on your tire size (if modified) the correction may be off a bit, but nothing like the uncorrected 15%+/- you have without any correction!

[cobraaph]

Thanks for the info. I'll look for that gear. I'm running 275/40R17's so the diameter should be close to stock.
Al

[Poisonous98]

Good info....I have stock gears now, but have considered 3.73 myself. How do the 4.10s workout for daily driving?

[SNAKEYE]

Originally posted by Poisonous98
Good info....I have stock gears now, but have considered 3.73 myself. How do the 4.10s workout for daily driving?
First, the car has always had the 4.10's since I own it, so however it was with the 3.27's is unknown to me. I can say this though, there's no need to ride or slip the clutch in first gear to get things moving!
Second, obviously gas mileage suffers, but then I don't know any better. I get 17-18 on trips and 15 everyday. Ive forgotten exactly what RPM's in 5th gear are at various speeds, but something like 2700 at 65 seems about right. My automatic '98 New Beetle does more than 3 grand at 65. It has about 1/3 the HP and only gets about 23 MPG! And it's boring!
Third, with a Vortech up front adding more than 100HP over stock the 4.10's bring up the revs very quickly. Don't spend much time in first gear at WOT! Or second gear for that matter.
I put in a shiftlight, set at 6200 RPM to allow me some reaction time. Shift points come at around 35MPH for first, 60MPH for second, and 90 for third. Never pushed it to the 120MPH level.

[cobraaph]

Just got the car back with the 3.73's installed. These gears rock! Definitely woke the car up. Screw CAFE, these gears should have come with the car.

Al

[Poisonous98]

Well Snakeye, I get about the same gas Mileage with 3.27s now. I like the stock ratio.....except 5th gear is worthless in the 1/4 mile. It feels like I need to shift to fifth, but then it drops out on me. 3.27 is good for the interstate and highway...sucks at the strip.

[SNAKEYE]

Originally posted by Poisonous98
Well Snakeye, I get about the same gas Mileage with 3.27s now. I like the stock ratio.....except 5th gear is worthless in the 1/4 mile. It feels like I need to shift to fifth, but then it drops out on me. 3.27 is good for the interstate and highway...sucks at the strip.
If you're only getting 15 MPG with 3.27's you must be riding around in second gear most of the time! I don't drag race the 1/4 mile, and I never had but the 4.10 rear gear, so I guess I'm astonished that you get to 5-th gear in a 1/4 mile. Or am I misinterpreting what you are saying? I would have thought that with stock rear gears you'd be pulling through the 1/4 mile in 3-rd gear?
But, like COBRAAPH, until you experience the difference the gear change makes you just can't appreciate the blast!
Drive on.