Full tune or monitor?
02-07-2013, 02:02 PM
#1
Full tune or monitor? Here is my situation, I am running a SD tuned procharged LS2 with a forged bottom end on 93 pump. I have since added a 75 shot of nitrous and I have been logging for KR and AFR doing 3rd gear pulls. AFR typically "lean spikes" to 13-14 for about .6 seconds before the fuel system can catch up and then ramps down from 12.5 at 4000 RPM to 10.5 at 6500 RPM. The reason for the ramp is that the base procharger tune ramps in more fuel as RPM increases because that is how a centri blower makes power. I have only seen 1 degree of KR on one pull when the lean spike was more severe and lasted longer due to higher nitrous bottle pressure.
Now, I can either strap it down and monitor KR and AFR or get a full tune to possibly get rid of the ramp such that AFR stays more consistent. Either way I plan to pull a plug for reading after the dyno pull. So do you think it is worth retuning or just check to see what is there now and go from there? The retune is more hassle and expensive but if it saves a motor well worth it...
Now, I can either strap it down and monitor KR and AFR or get a full tune to possibly get rid of the ramp such that AFR stays more consistent. Either way I plan to pull a plug for reading after the dyno pull. So do you think it is worth retuning or just check to see what is there now and go from there? The retune is more hassle and expensive but if it saves a motor well worth it...
02-08-2013, 10:19 AM
#3
Hehe, yep three times already. Check out the thread I made in the nitrous section for plug pics. Besides that "lean spike" is pretty small (14AFR) and not long lived (.6 second) and I feel like more fuel jet will just leave me fat every where else.
02-08-2013, 10:44 AM
#4
Hmm, Do you have a progressive controller? The type we use, have a pwm blend it can do, It would fix it pretty easy. You could also just fix it in the tune if you are able to flash it.
Any time you are boost, if you are 2 lbs or 20lb, it is better if you are just straight to the 11s with 0 ramp. It will run safer. 12.5 is to lean, and 10s are to rich.
Just tune it to be flat at what it is needed is going to be the best safest choice.
As for the nitrous issue, Maybe you need to tune it via the injectors instead of a wet kit, That or make a separate tune for nitrous only and fix the Ve,maf in the area where it is lean, or pe table.
Any time you are boost, if you are 2 lbs or 20lb, it is better if you are just straight to the 11s with 0 ramp. It will run safer. 12.5 is to lean, and 10s are to rich.
Just tune it to be flat at what it is needed is going to be the best safest choice.
As for the nitrous issue, Maybe you need to tune it via the injectors instead of a wet kit, That or make a separate tune for nitrous only and fix the Ve,maf in the area where it is lean, or pe table.
