Z3 Transmission speedomter/rpm questions

[USAF EP3]

He would need a ridiculously large tire size to get an error of 10+mph on the speedo. And given that the most common sizes on our cars are 16" and 17" wheels, the diference made by tires on those size wheels is minimal and not enough to make a 10mph difference.

[Ba82Ep3]

Agreed. My point was its a variance that wasnt mentioned... either when comparing car speedometer to car speedometer side by side, or what one person said they had when compared to what another person had at X RPM. Add that to individual speedometer inaccuracy when compared to tachometer inaccuracy (KPro will show how far off your dash tachometer is), you have enough variance to equal about 7 or 8 mph when measured between several different cars.

Individually its not a lot... when compared between several different inaccurate setups it can be a good amount. A radar gun would be most accurate.

I wish i knew a solid way to know without visual inspection if you were screwed or not on the gears. : (

[cyllarus]

He have to be running some really really small tires to show a 12% speedo inflation, and have changed the tires at the same time as the tranny.

[ryboto]

* off topic, where did you get your z3 tranny internals and how much did it cost. I'm looking at this as my next upgrade.

Thanks for the info, people on FB seemed to think the ECU gets the signal and then sends it to the cluster. The VSS is supposedly the same as the original EP3 VSS, so it would indeed be for a 4.4D, not the 4.7 of the 6spd that's in it.

I got mine off K20A.org, I think I ended up only paying $1100 shipped with the VSS? Probably could have offered less if I could have picked it up

KPro adjustments will not affect your speedo. Only the tune and its results...

Like I said, people on FB were telling me it was possible to fix through the ECU.

[ryboto]

He have to be running some really really small tires to show a 12% speedo inflation, and have changed the tires at the same time as the tranny.

Yea, even with the stock tire, I'm seeing that difference. Speedo is 12% lower than it should be. Tach is right where I expect it to be when I drive with the GPS and check my actual speed.

[USAF EP3]

Thanks for the info, people on FB seemed to think the ECU gets the signal and then sends it to the cluster. The VSS is supposedly the same as the original EP3 VSS, so it would indeed be for a 4.4D, not the 4.7 of the 6spd that's in it.

I got mine off K20A.org, I think I ended up only paying $1100 shipped with the VSS? Probably could have offered less if I could have picked it up




Like I said, people on FB were telling me it was possible to fix through the ECU.

The EP3 VSS sensor is for a 4.7 FD. The stock EP3 tranny has a 4.7 FD. Only the 02-04 RSX Base and Type S models had the 4.3 FD.

[Ba82Ep3]

The VSS just sends a voltage signal, it doesnt display it. If i remember right there is no physical difference between the RSX and the EP3 speed sensor... regardless of the FD difference...

[USAF EP3]

The VSS just sends a voltage signal, it doesnt display it. If i remember right there is no physical difference between the RSX and the EP3 speed sensor... regardless of the FD difference...

The teeth are different on the bottom of the mechanical portion that rides on the ring gear of the diff. Also the fact that they are two completely different part numbers between the RSX sensor and the EP3 sensor.

[Ba82Ep3]

Silly rabbit... the part number difference is because of the Acura/Honda badging. lol So many parts have different numbers but are ideally the same when compared.

Think about it... the VSS ring on the diff can go from diff to diff regardless of the FD. The rings position in relation to the VSS sensor isnt changed by changing the FD. Why would there be a need for a different gear on the VSS for either FD?

IF there is a difference i would imagine it to be electrical... as that would be cheaper to manipulate for mass production than mechanical variances between models. From what i remember though, there is no difference between the two.

[USAF EP3]

Silly rabbit... the part number difference is because of the Acura/Honda badging. lol So many parts have different numbers but are ideally the same when compared.

Think about it... the VSS ring on the diff can go from diff to diff regardless of the FD. The rings position in relation to the VSS sensor isnt changed by changing the FD. Why would there be a need for a different gear on the VSS for either FD?

IF there is a difference i would imagine it to be electrical... as that would be cheaper to manipulate for mass production than mechanical variances between models. From what i remember though, there is no difference between the two.

Well who knows. He's still having the problem and the only thing that would make sense would be the VSS. He doesn't have much else to try to fix the issue.

[Ba82Ep3]

Agreed. I wish trans internals were easy to identify without teardown... it makes it hard to be sure you arent being taken when buying used. : (

[USAF EP3]

Agreed. I wish trans internals were easy to identify without teardown... it makes it hard to be sure you arent being taken when buying used. : (

Honestly, he really didn't get had. He got what the seller told him what it was. An RSX-S trans case with 06-11 K20Z3 trans guts. The problem lies within his speedo reading incorrectly. His revs and speed are spot on with what mine are. around 3700-3800 RPM at 80MPH in 6th gear. That's the tall .659 ratio 6th borrowed from the TSX with the 4.7FD of the 06-11 K20Z3 trans.

[cyllarus]

I can attest, and demonstrate that the 2 sensors ARE different, and indeed send a different signal.

I've got both in my garage and can swap and shoot vid if you disagree.

I agree with Ba* though, i bet the difference is in the pulses / rotation, NOT in the number of teeth.

[usedep3]

I can attest, and demonstrate that the 2 sensors ARE different, and indeed send a different signal.

I've got both in my garage and can swap and shoot vid if you disagree.

I agree with Ba* though, i bet the difference is in the pulses / rotation, NOT in the number of teeth.

This. I agree. I believe the 2 sensors are different. I had an issue with the speedo being off after I rebuilt my tranny. It turned out it was the VSS. I had 2 laying around and must've pick up the wrong one when i was frankenstein-ing the tranny back together..

[Ba82Ep3]

Yes please if you dont mind. Makes me wonder if i have the wrong VSS myself, there wasnt a VSS specification for K swapped chassis with ITR trans (that i found anyways).

I know physically they cant be different (gear and ring). Ive been through enough trannies to know that for a fact.