Solution: Speedo calibration, details inside Options

[snapshotgt]

It looks like my speedo is reading on the high side. I am using the e153 tranny out of a 99 Solara. I also have bilstein struts, tein springs and 7th gen GTS wheels with 205/50/16 tires.

Four sources of evidence of possibly reading high:

1.) GPS is reading ~10mph slower

2.) OBDII reader from the solara is reading ~5mph slower

3.) I can be crawling at a snails pace and it reads obviously high

4.) When slowing down to a stop, needle can make un-flowing drops down in speed, does not look very accurate.



Please post your thoughts and suggestions. I'm looking to fix this and get it as accurate as possible. Anyone running with a e153 tranny swap please post your experience. Thanks-

[Silver94CelicaOw...]

My E153 speedo sensor doesn't read spot-on either, it indicates that I'm going 5 MPH faster than I actually am going.

My GPS also indicates this, and the trap speeds at the drag strip on Friday also indicated that my theory was true....I crossed the 1/4 mile mark on my first run and my speedometer was at around 110 MPH and I got really excited. ...Until I realized it was actually 104, not 110.


I think it comes down to one thing, really. Tire size. The Camry's and Solaras came with much larger wheels and tires than our Celicas. Thats what the speedometer is calibrated to, and thats why it will read faster. I think the best way to fix the issue would be to get a speedo sensor from an ST205 or an MR2 with an electric speedo sensor and switch out slave gears on the sensor to the one from your Solara transmission so it meshes properly.


Then you'll have an accurate reading.


EDIT: Even though you have 7th gen wheels, you still went down a tire profile and up a wheel size from stock, which makes it roughly identical to the OEM Celica size.



-Corey

This post has been edited by Silver94CelicaOwner: Apr 29, 2008 - 12:00 PM