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Hey guys, Junior,
I've got a general question on tuning strategy with an A/F gauge and EGT probes.
Simply, the two don't seem to agree with each other sometimes! The agree when doing a big pull - get a nice 13.5 to 13.2 on the A/F, and nice 1150F EGT's on both holes. Sweet, no issues there.
Now when running at light throttle loads, I get nice low EGT's - errrr.....600-700F I think, but the A/F is going crazy, ready way lean 15.5 - 17.0, and even sometimes right out of the range of the wideband. Am I in danger of a burndown at low RPM/low throttle?
-2007 M1000 with 2008 reflash
-speedwerx y pipe
-stock pipe
-BDX power valve delete
-slp can
-BDX intake
-boondocker box
Sorry I don't have my current #'s handy but have some -'ves in the low ranges, mostly zeros through the mid range, and some +8, +10's in the HI for the higher RPM's.
Any thoughts greatly appreciated
Pistonbroke
So you are saying A/F numbers of mid 13's at full throttle is OK? I was trying to keep it below 13.It is not uncommon to see A/F number go high under low load or deceleration. EGT temps in the 600-700 range are very low, provided your probes are mounted in the appropriate location, about 4 ½” from the piston skirt (2-2 ½” from the exhaust flange). It sounds to me like you’re on the right track. When under a full throttle load on a NA sled I look for A/F numbers in the mid 13s. When cruising in the mid with little to no load I’ll often see A/F numbers in the 14s, 15s, even 16s. Being able to back this up with low EGTs should give you even more confidence.
Hope this helps, let me know.
Thanks,
Junior
It is not uncommon to see A/F number go high under low load or deceleration. EGT temps in the 600-700 range are very low, provided your probes are mounted in the appropriate location, about 4 ½” from the piston skirt (2-2 ½” from the exhaust flange). It sounds to me like you’re on the right track. When under a full throttle load on a NA sled I look for A/F numbers in the mid 13s. When cruising in the mid with little to no load I’ll often see A/F numbers in the 14s, 15s, even 16s. Being able to back this up with low EGTs should give you even more confidence.
Hope this helps, let me know.
Thanks,
Junior
So you are saying A/F numbers of mid 13's at full throttle is OK? I was trying to keep it below 13.
Thanks
Im just getting my boondocker installed and since this engine is not
a purchased pk that comes w/BD# as baseline I will be starting with
(guessing) my oun base line. it is a F7 BB to 800cc with rave style
ex valves,vreed,Fatazz pipe,y pipe, ported case ,ex ported and transfur
tunnels opened a little. so my question is the # at 3000 there
is no need for a Hi setting and 6700 no need for a low, but you
would have a low setting at 78 and 8100 to add fuel after letting off
from a pull. ?? and how much do you add for a low setting ?
BTW in has the 06 reflash. more ?? to come Im sure
Junior,
Is there any reason to have a fuel number in the low load range on the 7200 thru 7800 settings. I have been noticing that when I let off my numbers get really high after a long pull. Should I add some numbers to the low load? I have zeros in there right now. Thanks
I just bought a boondocker nitrous kit from Justin at Code Red, do you happen to have any base line numbers for tuning? I run anywhere from 0ft to 4000ft.
Also I was thinking of maybe getting a o2 gauge to help with tuning. What brand and where would you recommned where to get it.
You can put numbers in the lo and mid at the top rpm ranges like 7800 or 8100, to add fuel when you let off. Some guys feel like this is necessary, and it’s common practice for racers, or dyno runs. But beware, adding numbers in these areas can also add to much fuel on a deceleration, causing the engine to load up when you let off, than grab the throttle and go again.
Thanks,
Junior
In response to the last couple of posts I also have twins and the BD box on my racin station 800 M7 and I can tell you that most of the issues are not with the box but with the twins. I had a buddy running the SLP twins and the pure logic and he had the same inconsistency problems. We are both good at tuning but the twins can be a pain sometimes. I have changed numbers a ton, checked wash, brought the bore scope on the mountain etc and one day its spot on and the next it is not with the twins.
Maybe Junior can give us some more insight on tuning with twins.