GSXR Coil Polarity

[Devastator]

HD coils?

[Rikard]

I cruise at 70-80 KPa and 19:1.

I thought that your heads would melt at such AFR. Lots of timing i guess?

HD coils?

Harley Davidson Twin Cam coils

Rikard

[Piledriver]

I'm on the edge of overcooling at 19:1 whenever ambient temp is <80F.
Max temp and burn speed is ~ stoich. (~14.1-14.3:1 on E10, 14.7:1 is for pure isooctane that no gas station on earth sells)

Either side of stoichiometric burn speed and temps drop dramatically.
19:1 requires a LOT of timing or the EGT gets stupid. VERY slow burn.

I actually PULL some timing at lower temps (ab)using the cold timing table to help things warm up.
(starts off +10 to ~120F to assist cold start/initial warm up, then I go -5 until 200, -3@200, 0 at 240.

My CHT under the plugs reads ~300 (calibrated TC/temp compensated) when the CLT reads ~260F at 3600 RPM ~70 MPH.
(The delta varies with RPM/fan speed no direct TC to MS at the moment, work in progress)

It only helps fuel economy so much, I think I really need a couple points more compression and a 5th gear to have a really high mileage setup.

[Redline Weber]

The current HD coil (our coil) has an internal magnet in the steel.

That coil is MORE powerful than a LS-2 (GEN-IV) coil.

What method of secondary current measurement can be used for an ion sensing system
with a "twin post" coil OR a "single post" coil with internal secondary ground ?

Our coils, some, feature a separate secondary ground return wire for ion sensing purposes.

Lance

[Piledriver]

The current HD coil (our coil) has an internal magnet in the steel.

That coil is MORE powerful than a LS-2 (GEN-IV) coil.

What method of secondary current measurement can be used for an ion sensing system
with a "twin post" coil OR a "single post" coil with internal secondary ground ?

Our coils, some, feature a separate secondary ground return wire for ion sensing purposes.

Lance

The Delphi twincam coil is 2 physical coils in one package with a common ion sense 80v curcuit, and a single ion current output. (Not a "twinpost" waste spark coil)
Setup to fire 180 out pairs it gave a pretty decent signal. HD AFAIK used the ion sense only for knock detection.

[Rikard]

Pile, a bit OT but did you get the ion sensing to work? If so, did it work well? It seems to me to be the best way of controlling advance.

Rikard

[Piledriver]

Pile, a bit OT but did you get the ion sensing to work? If so, did it work well? It seems to me to be the best way of controlling advance.
Rikard

I got a signal I could easily make out at WOT.
Anywhere else---not so much.

Direct pressure sensing using TI pressure sensors is where I'm looking now, Beru is building them into glow plugs, 2010+ TDis have them, amongst others. It ONLY outputs pressure signal, coil ringing/flamefront etc has no effect, ~0-5v out.

In the midst of a very interesting thread on msextra about ion sensing...
http://www.msextra.com/forums/viewtopic ... 0&start=90

I am actually considering dual plugging (2 new holes) a pair of heads and jacking one of these in the std location in an adapter.

The sensors themselves are dirt cheap, hopefully some devious individual will start putting them in plugs for <<$1500 ea.

[Rikard]

Looks like an interesting thread. I will have something to read this evening

Could you use the direct pressure sensor to run close loop advance?

Rikard

[Piledriver]

Looks like an interesting thread. I will have something to read this evening

Could you use the direct pressure sensor to run close loop advance?

Rikard

If you built a separate ignition controller, as the gentleman in the "DIY ion sensing" paper did.
(I don't want to murder his last name trying to spell it)

OEMs to date mostly use the ion sense as an advanced knock sensor, as it ignores acoustical noise.

It can do more, but has its limits.
I suspect one could do it much easier with direct pressure sensing, the TI MEMS pressure sensors probably cost OEMs a buck or so in 1000s, and it puts out a nice ~noise-free signal ready for direct measurement.

[Rikard]

My electronic skills is limited so I don't think I should try to make an ignition controller...
But I would love to have the ability to use the ion sensing as a knock sensor and a camshaft sensor. Combined with Pile's flywheel solution the install would be really clean.

Rikard

[Redline Weber]

The MOST simple way is to use Crankshaft Acceleration.

We do this with our ECU's

Lance

[Piledriver]

You cannot read cylinder pressure or knock by reading crank acceleration.
(although it could be used for misfire detection, and is by many OEMs for decades)

Engine phase, yes. Cylinder pressure//knock (subject of discussion) no.

[Steve Arndt]

Subject of discussion is coil polarity actually, at least that is what my screen says.

[Piledriver]

OK, it drifted into ion sensing, but regardless coil polarity also cannot be determined by crankshaft phase sensing.

Some OEMs have done crank phase sensing via the coils in a waste spark setup, measuring IIRC discharge current, easier to fire on the exhaust stroke, but we are drifting even farther off topic per usual.
(not always a bad thing)