Almost there, help me get the Briggs'nSquirt'nSparkon 100%

gielamonster · Post by **gielamonster** » Sun Apr 16, 2006 12:13 am

Its a mammoth "UPS" battery, about 60lbs. I did have a meter on it today, it was over 12V unloaded. I forgot to check it loaded, datalogs don't pick that up unless I have them set to do it, hunh?

I threw a charger on it today, so it should be fine on Monday when I'm back at it.

djandruczyk · Post by **djandruczyk** » Sun Apr 16, 2006 7:40 am

gielamonster wrote:FYI, I got things restarted in EFI today after two months of learning how to use our dyno on a stock carbed/magneto'd engine and also working hard on designing and fabbing a decent EFI intake manifold/restrictor.

I was a little disturbed to find that the engine was back to its old bad habits again. Reset after reset after reset. I solved the initial issue I had after updating to the lastest MSnS-E firmware (029o), and switching back to the old working setup on 029f firmware doesn't solve anything.

Anyone have some ideas on how I can seek/destroy these resets? Anyone live near Dearborn MI and want to come down and give my setup a once-over?

I posted more details of the latest problems in this thread (troubleshooting forum since I think my reset issue isn't necessarily -extra related).

Please let me know if you have any ideas that might help. Thanks.

How are you getting your ignition signal from the mag? can you put an oscilloscope o nthe ignition input to see if it has a really high voltage spike that might be getting through causinga board reset. Where are all your circuit grounds being tied to? (they should go all to one spot as close to the battery negative terminal). How close is you ECU physically to sources of noise on the motor (magneto, plug wires, etc) ?

gielamonster · Post by **gielamonster** » Sun Apr 16, 2006 1:26 pm

The trigger wheel is from a 12-1 wheel and a hall sensor. Last time I scoped it, the signal was beautifully clean. All grounds are tied to the same ground point, but its a decent distance away from the batt - terminal. The ground path is through a thick, welded steel frame though, so I assume that its pretty decent.

The ignition is completely magneto free now, I'm using IGBTs and plain single-pole coils. Looks like this...

http://www.msefi.com/viewtopic.php?p=102214#102214

Right now the harness is dangerously close to some hazards and the ECU is about 18 inches away from one of the coils.

I'm going to work on rerouting/packaging some of that, but I'm also starting on the "real" harness this week.

gielamonster · Post by **gielamonster** » Wed May 10, 2006 10:08 am

Dr. Photon wrote:what sort of power supply are you using to run this rig? you might want to scope out the main +12v line to see if it's "extra funky" or not.

So I scoped the 12V line feeding the coils, injectors, and ECU and found it looks very "funky". It stays a rock solid 12V under a certain RPM, then it appears to start dipping instantaneously to zero volts, although not in a regular pattern. The dips/spikes definitely coincide with poor running. I thought it might be a bad main relay so I jumpered it out. The problem didn't appear any better on the scope, but I was able to get it running almost "hiccup" free. I'm thinking that the way I've mounted my relays (on their side, to a metal cart with lots of vibration from the oddfire VTwin) might be causing them to vibrate so much that its switching them on and off mechanically, even though they're engergized electrically?

I'm going to try some fresh relays that "dangle" from the harness instead of a hard-mount to the cart and see if things stay fixed today.

The good news is, if this turns out to be the problem I can now swap out the "backup" ECU we've been using and start using an MS again.

Post by **jsmcortina** » Sat May 13, 2006 7:17 am

Picked this snippet up from an old post I'd saved

Bruce Bowling wrote: Finally, the 0.01 uf capacitor on the IGBT collector to ground is a real good idea, this shunts extreme high frequency spikes to ground that would otherwise cause potential problems with processor resets, etc. And the best thing to prevent resets is by keeping the high-current paths away from the digital paths in the layout.

This component never made it onto the V3 board and isn't shown in the MS1/Extra diagrams.
Might be worth a try in your application as it is cheap and easy to do.
The capacitors need a few hundred volts rating.

I forget whether I fitted them to my Megasquirt or not and I'm not going to pull it off the car and dismantle right now to find out...

James

gielamonster · Post by **gielamonster** » Wed May 17, 2006 1:53 pm

I wanted to put up the latest news with our Briggs'nSquirton. Its in the car and running great (not a day too soon, we trailered it up to competition this morning). The good news is I swapped out the relay and ignition switch wiring I was using for all new carefully assembled stuff and all issues dropped off the map. The bad news is that we had the "other" ECU installed when I did that, so it earned the rights to power the car this year.

While I'm really disappointed that all of my MS work won't be showcased on this year's car, I'm quietly content to know that it could. We have a Garret GT12 in hand already and will be force feeding our '07 motor starting in a month or two. There's no way we'll be using anything but a MS for management, so at least all the work wasn't in vain.

I'm heading up to competition after work today. We're team number 14, a flat black with gloss black striped vtwin-thumper powered oddball. Last year we finished 39th/140 teams with about 18 hp down to 0hp in left turns. This year we're dyno'd at over 30 hp and its available all the time. We have our sights set much higher in the rankings. Wish us luck!

gielamonster · Post by **gielamonster** » Mon May 22, 2006 12:07 pm

Well the competition results are in. We placed 31st overall, and we're still not sure how our engine compares to the field. We struggled with misfires and reduced output for much of the event. We think the heavy rains on Friday waterlogged our IAT sensor and had us running overly rich. Things dried out on Saturday, but we suffered even worse performance. We had a problem with insufficient charging so we installed a second battery for increased reserve (assuming we'd be running in total-loss mode) and didn't start/idle the car at all before the race. What we should've done is fully warmed up the car on an auxillary battery and then sent it onto the course warmed and ready to race. It took about 3 laps (3 km) for the engine to warm up and clear out enough to get out of its own way. By about 7 laps in, it was running at nearly full throttle and definitely a faster pace than the cars we were on course with. Our second driver's 11 laps were about the same as most of the 10-20th place teams.

I'm learning from my mistakes of this past year and getting started on the 07 motor right away. At this point we're unsure of which powerplant we'll be using. We'll likely choose between a turbocharged version of our current Briggs engine, a conventional 4 cylinder powerplant, or possibly one of the new single cylinder options that are becoming very popular.

I wanted to thank everyone in the community for your support throughout the past few months. I've received excellent service from a number of the vendors on this site, along with many individual users. Its been a lot of fun and a lot of learning, I've really enjoyed myself.

Dan