[kamiraa]

For tuning on a dyno where does everyone get the RPM signal to feed into the dyno computer?

Are you tapping into the RPM signal wire going back to the ECU, or do you clamp onto some wire at the igniter? Or just one of the signal wires at one of the coil packs?

 

[Sound Performance]

green long wire inside of the ignitor connector.

 

[kamiraa]

green long wire inside of the ignitor connector.

Do you just clamp to it Larry, or do you need a physical hard connection to the conductor?

I'm in the process of making a custom harness for the engine, and if a physical connection to the conductor is required, I'm thinking about splicing the wire to a lug, and putting a cap on it. For easy access.

If just clamping, I can just leave portion of that wire exposed and not wrap that wire.

 

[Sound Performance]

Do you just clamp to it Larry, or do you need a physical hard connection to the conductor?

I'm in the process of making a custom harness for the engine, and if a physical connection to the conductor is required, I'm thinking about splicing the wire to a lug, and putting a cap on it. For easy access.

If just clamping, I can just leave portion of that wire exposed and not wrap that wire.

Most dynojets just clamp around it and pick up the signal inductively.

 

[kamiraa]

Thanks Larry

 

[Sound Performance]

You're welcome!

 

[Hukhuksupra]

Why off the igniter and not of the coil from #1 directly?

What does it mean if you are loosing signal for the trq?

 

[Nick 95 6sp]

...What does it mean if you are loosing signal for the trq?

They dyno measures horsepower and if you don't know the RPM's you can't derive the torque. Keep in mind that HP and TQ are always locked in by the relationship:

 

[Hukhuksupra]

Thanks i never really thought to use the relationship and associate it with the RPM pickup. Much appreciated.


Now why not use the #1 coil wire instead of the igniter wire?

 

[isifmobile]

They dyno measures horsepower and if you don't know the RPM's you can't derive the torque. Keep in mind that HP and TQ are always locked in by the relationship:

Dynos measure torque, not horsepower. The equation is right, but that means it calculates horsepower from variables it knows (torque and RPM).

 

[Nick 95 6sp]

isif,

you're right...the dyno computer knows how fast your wheels are turning the drum so that's where it starts with "wheel torque" even though it has no idea how fast your engine is rotating.

 

[isifmobile]

Either way without rpm you can't plot hp or like you said, torque against it engine speed. Thought plotting against wheel speed should still work.

 

[Horacio Ramos]

The green wire is the number 1 coil wire. Its just easier access at the igniter box.

 

[Hukhuksupra]

Yes, it is the same wire, but would it not be a stronger signal at the coil directly. Thats what i meant when I asked why not use that.

 

[Hukhuksupra]

Does anyone know if dynojet settings need to be adjusted for a 2J. Maybe revolutions or something. My buddy keeps losing his torque signal. Car pulls strong making 820rwhp but the torque signal never comes through properly, its always choppy.

 

[rotortuner]

Yep i know dynojets measure hp and torque is calculated. I have had the same issue, with the dyno not picking up the ignition signal and I only get HP vs speed.

CJG

 

[isifmobile]

^^^
How do they do that exactly?

 

[Hukhuksupra]

Anyone have a solution to this?

 

[Veepster]

dyno's measure torque(either by load cell or munging rate of acceleration of rollers or combo of both) and it also collects roller RPM and engine RPM. it uses the roller RPM and engine RPM relationship to understand the gearing and remove it from its internal calculations.

and as described previously it calculates HP by knowing torque and engine RPM.

rotortuner.....the X and Y axis labels are determined by the dyno operator. they can choose to put anything on those. the industry standard is RPM as X Axis(horizontal) and torque and HP as Y axis(vertical). you definitely want the Y axis to be the same for torque and HP. if they are not it makes the graph difficult to read. For tuning I prefer to have the X axis as "time" it makes it easier to tune, but when I print out graphs I change to RPM on the X axis..

dropping torque signal? I see mention of this....what you are doing is not dropping the signal but dropping torque! assuming AFR's are correct this momentary drop in the graph you see is ignition failing usually. YES it could be other things but almost impossible to determine without knowing specifics of vehicle. Knock will also show up as drops in torque. lots of factors to look at but it usually is ignition...

good conversation!

 

[Hukhuksupra]

Yes correct you are dropping torque, but why. We made numerous clean pulls and the dyno did not read the torque, it jumps up and down. His car pulled 840rwhp and the torque signal was lost no hiccup. My car did the same thing on the dyno, no torque and smooth pull. We even put a secondary reader on his car, moved the ground etc etc and still lost signal.


How many revolutions are you setting the dyno at, 360 degrees or 720? We tried both and nothing. Even a bone stock mkiv lost signal. Another friend with an SRT-4 Neon did not lose the signal.
Any ideas?