Project Update Part VI - Megasquirt Graph

[ae1969]

Part V update

Well..........

Finally have the system figured out.

Nice clean revving all the way to redline. Idles like a kitten,
Warmup and acceleration enrichment dialed in. Timing as aggresive as its gonna get for now.

So we have full boost at 3K.

This is a screen shot of the Megalogviewer. You can graph every sensor. So nice for diagnosing issues.

The last hiccup I had were RPM spikes on the upper end but I managed to get rid of that by using plugs with resistors.

Next week I am hoping to receive a new wideband and knocksensor and will finish auto-tuning (you plug in AFR values and this thing TUNES your car for those values )and enabling knock sensing.

The next item will be using xtau. That will take a number of posts to explain.

But anyways.....I am so excited at the awesome driveability the car has now...... I can't imagine why anyone sticks with motronic.

I have an autox this weekend and will log all my runs.....

[Mike Markota]

Very nice to see. I've been reading the topics on this with much interest...

[IanS]

Full boost by 3k, thats faster than John's MAF I believe

I saw your post on msefi.com about knock sensing. Good to see someone's testing that code

Its nice that the new MS2 beta code has wheel decoding. Its too bad it doesn't have second wheel decoding. But I think microsquirt with its two VR sensors and two spark outputs will cause the MS2 code to advance towards a plug and play solution to do wasted spark on a 944.

[ae1969]

Originally posted by IanS
Full boost by 3k, thats faster than John's MAF I believe

I saw your post on msefi.com about knock sensing. Good to see someone's testing that code

Its nice that the new MS2 beta code has wheel decoding. Its too bad it doesn't have second wheel decoding. But I think microsquirt with its two VR sensors and two spark outputs will cause the MS2 code to advance towards a plug and play solution to do wasted spark on a 944.

So you lurk on msefi........ hehehehe thats how I started.

With megasquirt........... you have to take little bites and learn and understand.

Grippo ...bowling and lance and countless others have SOOOOOOOOO much knowledge its scary!!!

I picked up a knocksense from boris. It will be tuned for ~100 mm bore. The trick then will be determining what voltage 0-5V is generated when knock occurs. That will be a challenge but the test mule is ready for it.

I will probably advance the 3000-3500 rpm cells at idle (no load) and set megasquirt to listen. I should be able to make it knock with no load...........rev.........advance........rev..... ...advance......... Knock (or boom).

Once I have the voltage spike that is required for knock to be detected.....VOILA. PLUG and play knock sensing.

So much fun.

That TAU stuff is SOOOOOOOOOOOOO over my head.....but we will give it a shot.

Take care.

P.S ........Johns MAF for me was giving me full boost at 3K as well. I don't think I will get it under that....... but we'll see.

[IanS]

I do lurk. I have posted a few times, but only when I've read something recently of relevance. I don't have enough knowledge to contribute any true information to the discussion.

Impressive, I thought 3200rpm for full boost was the number tossed around for the stage 2 turbo.

One comment about knock sensing. When I log the knock voltage on my 1.8T, the voltage goes up substantially with RPM without the timing being pulled. I don't know if that is a function of the 1.8T knock sensor circuit or not. But its possible that a voltage which qualifies as knock at 3000rpm may not be knock at 6000rpm. Maybe something to ask boris?

[JustinL]

So, what was the deal with those high boost stutters? Weak spark?

I'm curious to see how fast that monster is now that it's smoothed out! It'll be a good weekend for squishing Boxsters and bimmers. I've also gotta show those SVT cobras that our old cars aren't so slow

Justin

[ae1969]

Originally posted by JustinL
So, what was the deal with those high boost stutters? Weak spark?

I'm curious to see how fast that monster is now that it's smoothed out! It'll be a good weekend for squishing Boxsters and bimmers. I've also gotta show those SVT cobras that our old cars aren't so slow

Justin

I had to pick up a set of resistor plugs!!! noisy signal thats all! Rpm spikes ........ nothing to do with advance whatsoever.

IT feels sooooooooo gooood. I am holding myself back from raising boost or increasing advance......

Gonna finish the turbo timer wiring tonight......

[ae1969]

Originally posted by IanS
I do lurk. I have posted a few times, but only when I've read something recently of relevance. I don't have enough knowledge to contribute any true information to the discussion.

Impressive, I thought 3200rpm for full boost was the number tossed around for the stage 2 turbo.

One comment about knock sensing. When I log the knock voltage on my 1.8T, the voltage goes up substantially with RPM without the timing being pulled. I don't know if that is a function of the 1.8T knock sensor circuit or not. But its possible that a voltage which qualifies as knock at 3000rpm may not be knock at 6000rpm. Maybe something to ask boris?

Over 5000 rpm the mechanical noise is so high that I have recently read that stock system shut off knock sensing.
I see that on my MS ver 2.67 that they have a range that knock sensing is active..........a low and a high point.

I may be able to detect knock properly at the lower RPMS but may have issues if I try to sense knock at high RPM at WOT.

As I remember TEC recommends to shut off Knock over 5K as well and to control with proper timing. Even thought they can set the system to detect between 600-8000 rpm as I recall...

THe truth is that majority of knock will probably occur as you are getting on load. Peak torque etc......
Timinng becomes very flat past 3500 rpm for the 951.

[CJFusco]

Ae, is megasquirt a "piggy-back" system that uses the stock computers, or is it a stand-alone?

BTW, clean out your PM box

[JustinL]

Originally posted by CJFusco
Ae, is megasquirt a "piggy-back" system that uses the stock computers, or is it a stand-alone?

BTW, clean out your PM box

It is a stand alone computer. Alex is running it this way with no DME or KLR. I'm running mine as a fuel controller which drives the injectors directly without any input from the DME. My DME and KLR are still installed to control ignition.

[Mike B]

Very nice Alex...I'm thinking you could start up your own cottage industry suppling the stuff that is need for all of us 951 guys. Lord know this is over my head!

[CJFusco]

Yes, it's over my head, too... but, since stand-alone makes a lot more sense for the 951 engine I am building in my garage than trying to find a stock DME, stock KLR, stock AFM, all the stock sensors, and fabricating a wiring harness (not to mention the eventual chips, MAFs, etc.), I am taking notice.

[JustinL]

Grinning like idiots that our megasquirted cars actually survive track duty!

[ae1969]

Originally posted by JustinL
Grinning like idiots that our megasquirted cars actually survive track duty!

I forgot your girl had a camera! I can't believe she got me!

HEHEHE.

Yes it survived...... bouncing it off the rev limiter a few times. She gained 10-15Km/hour down the straightaway!.
I was usually only able to hit ~160K down that straight last year (top of third).......and now she would hit 170-175....

Lets just say I had butterflies on my first event. I was a little scared coming down that straight.......and realizing I had to shift in to fourth..........and then hammer on the brakes. I think my nervousness showed blowing through the gates on my last two runs.

The car ran very strong and smooth. No issues when it was warm and flying. I still need to play with my cold start. It is actually very tricky to adjust your stepper and warmup enrichment etc. .... but its getting there.

Only managed a 1:06 which put me in the pack with the newer cars. Whereas Justin was at the top of the pack. Shocking all those new cars.

Its funny how you forget the little things from one year to the next........ such as how your brakes feel coming down from 100+mph into a 90 degree turn.....or the amount of turn in you can have before the backend comes around.

I am just happy it held together.