Not for Nuthin' But Close! - Page 9

Marty Knox · 11-29-2020, 07:48 PM

Quote:

Originally Posted by Glenn Briglio

What is the compression ratio of this engine? What fuel being used ? Fuel table would be cool.

The advertised compression ratio is 10.00:1.

Doug Hoven · 11-29-2020, 10:03 PM

The combustion chamber design has some hemispherical properties, so more timing didn't seem to do any good. The fuel is 100 octane unleaded Sunoco 260GTX. The only fuel settings I can mess with are power enrichment (only active in closed loop), and injector pulsewidth multiplier vs manifold vacuum. For this reason I decided to run the car in open loop at all times and take control over the amount of fuel going in. With it in closed loop the ecu kept commanding the afr to be richer and richer and I couldn't get it under control. Attached are photos of both the injector pulswidth multiplier and the minimum spark table.

Glenn Briglio · 11-30-2020, 07:57 AM

Ok cool.......what can you adjust in open loop? Can you monitor a/f ratio?

Doug Hoven · 11-30-2020, 08:36 AM

Yes and No. There is an afr shown in the data log, but it shows that it is the commanded ratio by the ecu. However, when I started to mess with fuel, it did start to show leaner values. The 02 voltage is also shown, and is somewhere around .8 - .9 going down the track.

jmcarter · 11-30-2020, 09:35 AM

Just FYI that Mike Cashman has posted pics of the car in the FB Stock and Super Stock Racing group, assume the pic has Doug and Billy in it. Very cool little ride.

Doug Hoven · 11-30-2020, 10:41 AM

Quote:

Originally Posted by jmcarter

Just FYI that Mike Cashman has posted pics of the car in the FB Stock and Super Stock Racing group, assume the pic has Doug and Billy in it. Very cool little ride.

That's not me next to Billy. That's the guy that was running the staging lanes.

Glenn Briglio · 11-30-2020, 10:47 AM

Quote:

Originally Posted by Doug Hoven

Yes and No. There is an afr shown in the data log, but it shows that it is the commanded ratio by the ecu. However, when I started to mess with fuel, it did start to show leaner values. The 02 voltage is also shown, and is somewhere around .8 - .9 going down the track.

.8-.9 is what in afr?

Doug Hoven · 11-30-2020, 10:56 AM

Quote:

Originally Posted by Glenn Briglio

.8-.9 is what in afr?

After some research, this is about 12.8-12.9 in terms of afr.

jmcarter · 11-30-2020, 11:00 AM

Thanks Doug, I’m learning!

lvd2340 · 11-30-2020, 12:01 PM

Threads like this are always my favorite.

11-29-2020, 10:03 PM	#82
Doug Hoven Member Join Date: Feb 2018 Location: Jersey Posts: 209 Likes: 189 Liked 807 Times in 160 Posts	Re: Not for Nuthin' But Close! The combustion chamber design has some hemispherical properties, so more timing didn't seem to do any good. The fuel is 100 octane unleaded Sunoco 260GTX. The only fuel settings I can mess with are power enrichment (only active in closed loop), and injector pulsewidth multiplier vs manifold vacuum. For this reason I decided to run the car in open loop at all times and take control over the amount of fuel going in. With it in closed loop the ecu kept commanding the afr to be richer and richer and I couldn't get it under control. Attached are photos of both the injector pulswidth multiplier and the minimum spark table. Attached Thumbnails

11-30-2020, 07:57 AM	#83
Glenn Briglio VIP Member Join Date: Nov 2002 Location: Massapequa Park,NY Posts: 1,280 Likes: 1,888 Liked 965 Times in 306 Posts	Re: Not for Nuthin' But Close! Ok cool.......what can you adjust in open loop? Can you monitor a/f ratio? __________________ 1989 Camaro Iroc-Z I/SA B&B Auto Machine Shop.

11-30-2020, 08:36 AM	#84
Doug Hoven Member Join Date: Feb 2018 Location: Jersey Posts: 209 Likes: 189 Liked 807 Times in 160 Posts	Re: Not for Nuthin' But Close! Yes and No. There is an afr shown in the data log, but it shows that it is the commanded ratio by the ecu. However, when I started to mess with fuel, it did start to show leaner values. The 02 voltage is also shown, and is somewhere around .8 - .9 going down the track.

11-30-2020, 09:35 AM	#85
jmcarter VIP Member Join Date: Dec 2008 Location: Richmond Hill GA (and Port Ludlow WA) Posts: 4,284 Likes: 2,336 Liked 3,122 Times in 962 Posts	Re: Not for Nuthin' But Close! Just FYI that Mike Cashman has posted pics of the car in the FB Stock and Super Stock Racing group, assume the pic has Doug and Billy in it. Very cool little ride. __________________ Jim Carter 2340 Super Stock 2340 SST/2340 Stock Set another place at the table

11-30-2020, 11:00 AM	#89
jmcarter VIP Member Join Date: Dec 2008 Location: Richmond Hill GA (and Port Ludlow WA) Posts: 4,284 Likes: 2,336 Liked 3,122 Times in 962 Posts	Re: Not for Nuthin' But Close! Thanks Doug, I’m learning! __________________ Jim Carter 2340 Super Stock 2340 SST/2340 Stock Set another place at the table

11-30-2020, 12:01 PM	#90
lvd2340 Junior Member Join Date: Jul 2006 Location: Western Mass Posts: 60 Likes: 16 Liked 4 Times in 2 Posts	Re: Not for Nuthin' But Close! Threads like this are always my favorite. __________________ Billy Kirpens Jr / Pro ET / Street ET 123J @ Lebanon Valley Dragway Stock/Super Stock 123A