Going 4.444 next week!

[Chiketkd]

Originally posted by SVXRide
Chike,
couple of things to keep in the back of your head tomorrow:
1. My "baseline" back at the end of June was 158-159hp (air temp was ~80degF)
2. Assuming a 30% loss through the drivetrain you get the following:
a. 230hp@ flywheel = 161hp@wheels
b. 235 = 164.5
c. 240 = 168
d. 245 = 171.5
3. The AWD dyno at AA is a DynoJet (rollers in the floor)

-Bill (shooting for options c or d...but realizing his engine now has 186k on it....)

Good info Bill, and I guess you answered Porter's question. I also feel that you should be somewhere between c and d tomorrow despite 186K on your motor... Personally, I'm hoping for 165 at the wheels tomorrow.

Porter, I'm not sure whether a Dynapack is supposed to be more accurate than a Dynojet, but SVXRide and I will be doing all of our dyno runs at Altered Atmosphere (both tomorrow and in the future). I plan to re-dyno my car in February/March after getting the ECUTune Stage 1 for OBDII cars.

-Chike

[SVXRide]

Chike,
If I remember right, the Dynapack actually attaches to the hubs (you remove the tires) so, theoretically at least, it should provide a more accurate reading (no slippage between the tires and the rollers). I believe LAN also used a Dynapack for his dyno runs during the early Stage 1 chip development effort.
-Bill

[Chiketkd]

Originally posted by SVXRide
Chike,
If I remember right, the Dynapack actually attaches to the hubs (you remove the tires) so, theoretically at least, it should provide a more accurate reading (no slippage between the tires and the rollers). I believe LAN also used a Dynapack for his dyno runs during the early Stage 1 chip development effort.
-Bill

I remember that. Good point.

Either way, the Altered Atmosphere dyno is one of the most reputable ones on the East Coast. Shiv Patak of Vishnu used that as the site for a huge EVO VIII dyno meet last year...

The numbers tomorrow should be very interesting. A Stage 1 v4 w/ green filter and a stock engine w/ STI filter...

-Chike

Originally posted by oab_au


Could not get the pics to open. But as it uses the clutch instead of the band, the normal 4eat TCU won't do it.

I remember someone posting a scan of the later TCU, and there were a few changes. They now use another sensor on the input shaft to relate the load that the converter has on it. A bit vage on it now, but if you can get the pics to open, I'll check it out.

Harvey.

Edit: it was in a .post by NormadTW called 'third gear only'. Looks like it will need the TCU from the doner car.

Can you expand on this? The TCU won't work at all, or it will work but AWD will be non-functional?

Will the car be drivable even in a reduced state with the SVX TCU?

The pics are in Adobe Acrobat PDF format btw... you can download the free reader at www.acrobat.com

Thanks Harvey!

[drivemusicnow]

any more of the SVX p/o ? or the the diagram from the legacy b4?

[oab_au]

Originally posted by Porter


Can you expand on this? The TCU won't work at all, or it will work but AWD will be non-functional?

Will the car be drivable even in a reduced state with the SVX TCU?

The pics are in Adobe Acrobat PDF format btw... you can download the free reader at www.acrobat.com

Thanks Harvey!

Yes mate the early box uses the band. The Timing and control for the 2nd to 3rd change is contained in the valve body. This controls the band release and the high clutch applacation.

The later box useing a clutch instead, has the timing and applacation of the change controled by the TCU. Its a case of the operation of the box is removed from the valve body to the TCU.

If you look at the diag. there is a solenoid for this clutch and another speed sensor on the torque converter. This is used to sense the load on the box, to time the change over between the two clutches.

It really will have to have the TCU to suit the later box.

Harvey.

[drivemusicnow]

would the WRX 4eat tcu work? it being a "newer" model trans also... i'm not sure what exactly is changed besides a general program. Subaru uses "learning" tcus, so even the programs shouldn't be that far apart.

probably has higher shift points too.. however the redline would stay the same.. that could make for an interesting time.

The WRX shift point with the 4EAT (USDM) should be similar to the SVX... 6500rpm or so.

I'm interested to know whether the WRX unit would work... hmmm...

I may call SoA and talk to some folks.

[Chiketkd]

Originally posted by Porter
The WRX shift point with the 4EAT (USDM) should be similar to the SVX... 6500rpm or so.

I'm interested to know whether the WRX unit would work... hmmm...

I may call SoA and talk to some folks.

The WRX 4EAT TCU should definitely be a good option to look into. The wiring may be a pain...unless you can find a junkyard with one that'll be able to sell you both the TCU and complete wiring harness...

-Chike

Originally posted by oab_au
I reckond you need the TCU out of a Aust, UK, or European SVX. Not out of a JDM model, they have speed limiter, which you would just hate

Why would that matter? Doesn't the ECU do the speed limiting?

[Chiketkd]

Originally posted by THAWA
Why would that matter? Doesn't the ECU do the speed limiting?

Good question. As far as I know the ECU does have the speed limiter, however, the speed of the SVX is calculated from the rotations of the input shaft running through the transmission. That's what the electronic speed sensor (mounted on the passenger side of the 4EAT) is monitoring...

I'm just not sure where the data from the speed sensor goes to directly. The TCU must use it to control gear changes, but then the ECU must use it as well to control the ABS system...

-Chike

The Vehicle Speed Sensor signal passes from the transmission to the instrument cluster, then from the instrument cluster to the ECU, then from the ECU to the TCU.

On the SVX the signal may split before the ECU, but on the later cars the above is true.

[Earthworm]

Originally posted by Chiketkd
the speed of the SVX is calculated from the rotations of the input shaft running through the transmission. That's what the electronic speed sensor (mounted on the passenger side of the 4EAT) is monitoring...

It won't be the input shaft because otherwise our speedos would be off if we change diffs. I was always under the understanding that the speed was measured in the front diff.

[mbtoloczko]

Originally posted by Earthworm
It won't be the input shaft because otherwise our speedos would be off if we change diffs. I was always under the understanding that the speed was measured in the front diff.

This is correct for the 4eat. On 5MTs, the speed sensor is spun by the 3rd/4th driven gear cluster. Not central to the thread, but just wanted to point it out for accuracy.

[Earthworm]

Thanks for the clarification!