Dyno Tuning the 12A - assistance?
07-13-07, 08:26 PM
#27
Did you receive an AFR graph to go along with the hp/tq graph? While your average may be 11.5, did it vary across the rpm range or happen to follow the hp line in the upper rpm range? It would be nice if you could monitor/log fuel pressure throughout the run too.
Your afr's are more in the range for a turbo, too rich for NA.
Your afr's are more in the range for a turbo, too rich for NA.
07-13-07, 10:04 PM
#28
OldSchool
Thread Starter
Join Date: Jan 2007
Location: Hotlanta
Posts: 80
Likes: 0
Received 0 Likes
on
0 Posts
We had a sniffer in the pipe but it wasnt datalogging with the dyno software. It was a standalone gauge. I just eyeballed it during the runs. It varied b/w 11.3 - 11.6 under load. I agree - its pig rich.
I'm hoping just some smaller secondaries should do the trick. Along with the direct fire ig. Is 20 more hp too much to ask?
I'm hoping just some smaller secondaries should do the trick. Along with the direct fire ig. Is 20 more hp too much to ask?
07-13-07, 11:37 PM
#29
You might be even richer than the reading. The tailpipe sniffers have a tendency to pull in outside and read a little leaner than what the engine is really running. I would weld an O2 bung where the 2 exhaust ports meet in your system and test again. You don't need to do this on a dyno, street/track tuning is fine for leaning out the carb.
There's 2 things that concern me about your graph. 1. The torque curve shouldn't fall off as quickly, it should be much flatter. 2. After 5k, both lines are too erratic. While it may be partially due to ignition, I suspect fuel flow is a problem too. Once it's leaned out, that part of the curve may even out.
There's 2 things that concern me about your graph. 1. The torque curve shouldn't fall off as quickly, it should be much flatter. 2. After 5k, both lines are too erratic. While it may be partially due to ignition, I suspect fuel flow is a problem too. Once it's leaned out, that part of the curve may even out.
07-14-07, 06:59 AM
#30
OldSchool
Thread Starter
Join Date: Jan 2007
Location: Hotlanta
Posts: 80
Likes: 0
Received 0 Likes
on
0 Posts
When you suggest fuel flow - do you mean FP or the jets?
I've been kicking around the idea of a cockpit AF gauge. Not sure which has the best bang-for-buck. The AEM is the most common (not sugg its the best).
I've been kicking around the idea of a cockpit AF gauge. Not sure which has the best bang-for-buck. The AEM is the most common (not sugg its the best).
07-14-07, 10:34 PM
#36
OldSchool
Thread Starter
Join Date: Jan 2007
Location: Hotlanta
Posts: 80
Likes: 0
Received 0 Likes
on
0 Posts
Nikki's do best b/w 2.0 and 2.5lbs
My ignition has been hacked up - and I need some help unraveling the mess.
1. There are two wires going to the coils from the firewall. One blue, other black. I assume power and possibly ground?
Also, the two wires from each of the igniters are hacked as well. Only three wires out of the four make it to the coils. The larger wire on the trailing coil is cut and isnt connected.
Thx
My ignition has been hacked up - and I need some help unraveling the mess.
1. There are two wires going to the coils from the firewall. One blue, other black. I assume power and possibly ground?
Also, the two wires from each of the igniters are hacked as well. Only three wires out of the four make it to the coils. The larger wire on the trailing coil is cut and isnt connected.
Thx
Thread
Thread Starter
Forum
Replies
Last Post
HalifaxFD
Canadian Forum
126
05-09-16 07:06 PM
