speedometer calibration

[zulater]

Ok I've been searching around and cannot find a real solid answer.
Is there a way to re-calibrate the speedometer when switching tire sizes? It was easy on my old cable driven camaro you just put in a reducer when you changed gears/tires.
Is there anywhere to change the vss output? Is there a reducer you could put inbetween the gear on the transmission and the vss?
going from stock size to the grabbers 215/65-16 and will be about 8% off.
Thanks.

[zulater]

could it be as easy as just getting a forester VSS since they come stock with 215/65-16 so that it would be closer? Exact would be ideal but information is minimal at best.

[zulater]

anyone?

[zulater]

2003 bajas came stock with 225/60-16 which miata tire calc says would be 1.4% too slow for the grabber 215/65-16.
I may look into a VSS for the baja and see what it would do. Maybe talk to a subaru tech.

If anyone has any info I would still gladly appreciate any help

[zulater]

well...

Has anyone tried an Electronic Ration Adapter?
http://www.abbott-tach.com/era.htm

[rollo]

Very unusual for a thread like this to go unanswered.. apparently you got us stumped :D

My guess is that most people just compensate in their heads.. or maybe just don't pay much attention to that gauge anyway :D You could also get an alternate source (GPS seems easiest) and use that as an absolute guide. Not the most elegant solution though.

[zulater]

Very unusual for a thread like this to go unanswered.. apparently you got us stumped :D

My guess is that most people just compensate in their heads.. or maybe just don't pay much attention to that gauge anyway :D You could also get an alternate source (GPS seems easiest) and use that as an absolute guide. Not the most elegant solution though.
Yeah I have the "quick and dirty" method figured out but I'm that guy that can't leave it well enough alone and has to have it fixed and work properly.
Quick and dirty is slits of post it notes on the speedometer indicating the new positions of every 10mph by using GPS/rpm=speed calc to "set" them.

[rollo]

I hear you man. I've spent months fruitlessly searching for ways to fix things that most people would just leave alone and deal with.

Actually that is another option - redo the gauge face...

[zulater]

Yeah but that will not fix the odometer :/

[rollo]

Ha.. good point. I think that ERA thing looks like a good option.

[SportyMark]

I used to use the Abbot ERAs all the time on Mustangs when I woudl do rear ratio changes. They can be tricky to get calibrated but once done right are spot on.

[2002maniac]

Somebody should give the foz or baja vss a try.

[zulater]

Somebody should give the foz or baja vss a try.
From what I've found out you have to crack open the case to change the gears. The actual vss is the same but the gears are different from what I have found.

[SueBee03wrx]

I just talked to a subaru tech today at our local 4x4 shop, and he said there are many fix's for it on the internet, im runnin the same set of tires and they were really interested in the set-up of the cars we are doing. But yea, it would be nice to keep the odo in correct alignment with relitive speed and distance, figuge that % differance into your oil milage and warrentys as well. If the warrenty company figures out that you didnt get it done right they can void any and all warrentys and they dont have to re-fund the money in the cases that you bought the warrenty with a used car purches.

[SueBee03wrx]

I'm also finding nothing for the Subaru make with the exeption of the one posted above. This is a great topic to investigate and hopefully overcome. I'll kepp lookin' with ya.

[stauff]

Has any one used one of these with any luck? I have one on my other car and it works great. Once I get my bigger tires I think I am going to pull it off my other car and test it.

http://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=126/category_id=311/home_id=59/mode=prod/prd126.htm