4.44 Swap done, now speed issue?

[svxfiles]

Originally Posted by SSSVX

Good info, OT.

Just wonder how accurate for the spdo from a manual swap?

The six speed with the 3.545 rear should be perfect!

[Tuck]

Would not the speedo reading be a function of the gear ratio driving the speed sensor? As I understand it, the sensor is nothing but a rev counting switch.

Tuck

[svxfiles]

Originally Posted by Tuck

Would not the speedo reading be a function of the gear ratio driving the speed sensor? As I understand it, the sensor is nothing but a rev counting switch.

Tuck

Speedo only counts axle rotations.
So, now that you have more torque you COULD fix it with a taller tire,
a 245/45/17 at 25.68" tall would put you at being off 2.4%.
Pretty darn close.
Reads 102.4 at an actual speed of 100.

[Michael Blue]

Huh, that makes sense. Still sucks that it was not only not disclosed, but incorrectly disclosed, lol!

Anyways, when I go 18"s, what sizes should I be looking at to at least mostly correct this?

Thanks!

[svxfiles]

Originally Posted by Michael Blue

Huh, that makes sense. Still sucks that it was not only not disclosed, but incorrectly disclosed, lol!

Anyways, when I go 18"s, what sizes should I be looking at to at least mostly correct this?

Thanks!

As a Gearhead with 4.44s I know that at 3000 rpm I am going 72 mph when the torque converter is locked up.
So I watch the tachometer more than the speedometer when I am checking my speed.

ALL vehicles have speedo discrepencies, unless its a POLICE CAR and none (of the 4.44 conversions that I have personally done) were ever off enough for me to worry or think about.

When I drive the 93, (stock gearing and tires) the speedo is absolutely correct.
When I drive Di's Silver 92 (stock gearing and 225/45/16s) the speedo is off 3mph at all speeds. 10-100
When I drive nicks Black 96, (4.44s and 225/45/16s) I am off about 6 or so %, but since its my sons car, thats cool with me! I don't need the boy speeding!
And when I drive my Claret, (4.44s, 225/45/17s and a supercharger )
I just watch for the POLICE! And mt tachometer, Your Honor Sir.



I do not think that anyone has actually put the pieces together for this puzzle, and it SHOULD have been me to figure it out.
The reason I say this is that I have four 4.44s here at home and have built more than twenty of them, and I never thought it was a problem.

I am sorry for anyone for whom this a problem, but when we got the first 4.44running I/we could not think of anything else.
Tom


The truth will set you free.

[svxfiles]

Originally Posted by Michael Blue

Anyways, when I go 18"s, what sizes should I be looking at to at least mostly correct this?

Thanks!

An 245/45/18 at 26.68" tall would be very close, and very big!
At 0.17" shorter than an Outbacks 205/70/15 you would read 100.6 at an actual 100.

If everything else is working properly and perfectly.
However there is usually some discrepancy in the speedo sensor, or the speedometer head itself, a poor ground, whatever.
So it could still be off.

[Tim]

I think mine is off by like 3-5 mph at most judging from my GPS

[Michael Blue]

Sounds like mine is likely off more than most, at least, if you can believe those roadside radars, lol!

Oh well.

[porschekiller]

the '04-'06 forester has 4.44 with 215/60-16s. this would equal 235/45-18. you would practically eliminate understeer as well.

Originally Posted by Michael Blue

Huh, that makes sense. Still sucks that it was not only not disclosed, but incorrectly disclosed, lol!

Anyways, when I go 18"s, what sizes should I be looking at to at least mostly correct this?

Thanks!

[Evil One]

With 4.44s and 225-50-16s I am reading 3 mph high @ 70 mph according to the roadside radar.


jim

[porschekiller]

235/55-16 would correct the speedometer and the understeer. they're oe on camaro rs's.

Originally Posted by FOMOGO

With 4.44s and 225-50-16s I am reading 3 mph high @ 70 mph according to the roadside radar.


jim

[pavanbabut]

I know that I am coming late to this issue after being bugged a lot with this issue after my 4.44 swap. Later I just ignored it, now since I am seeing many members with 4.44s are noticing this issue, thought I would do some research and found this from Dakota Digital SGI-5, 'wonder if anyone tried this. Reasonably cheap at ~$75 and you can adjust it close to 1MPH. From their description, I think now I understand why my cruise control is also working not in a smooth way it used to on stock tranny as with the ABS.

Would like to hear some feedback on this, if anyone is using it.

-Pavan

[LetItSnow]

Being me, I'd rather put the correct speed sensor in than change the tire diameter!

FWIW, my speedo is rock solid on per my GPS at all speeds I've traveled, even with the swap.

[kis86]

mine is 4mph off at any speed according to my gps. I've just gotten used to making the adjustment in my head, just like on a motorcycle. The cycle is 10% off, and the car 4mph :P

Still no idea why my car speedo is off though!

[williamshuck]

My Speedo



Another idea is to take a Speedo Healer and attach it to your car. They are designed for motorcycles but work on the same concept. The car sends pulses to the healer, which sends slightly slower or faster pulses to the speedo. You set the margin of error on the healer and you're good to go. You just have to do alot of precise measurement making sure your margin of error is corrrect. I recommend 2 different GPS readings.