Tune need changing?
Tune need changing?
Senior Member
Joined: Nov 2001
Posts: 3,652
Likes: 0
From: Charlotte, North Carolina
TTT.
Bobby (Whitelightning),
I'm bringing this to the top to help us get the answer to your question. I have the Breathers here now if you need it.
Mike,
For Bobby's 4 LB pulley, Single Blade, Full Exhaust, XCalibrator tune, etc. etc., I think these are the most important, is it recommended that he have a Crankcase Breather?
Thanks for the Great Tune Mike, you outdid yourself on Bobby's Lightning.
Tim@Chikenears
Bobby (Whitelightning),
I'm bringing this to the top to help us get the answer to your question. I have the Breathers here now if you need it.
Mike,
For Bobby's 4 LB pulley, Single Blade, Full Exhaust, XCalibrator tune, etc. etc., I think these are the most important, is it recommended that he have a Crankcase Breather?
Thanks for the Great Tune Mike, you outdid yourself on Bobby's Lightning.
Tim@Chikenears
Former Sponsor
Joined: Mar 1998
Posts: 13,385
Likes: 4
From: Virginia
Hi WhiteLightning,
Glad you're enjoying your new custom tuning!
Yes, we *do* like to see a proper screw-in breather cap used to replace the oil fill cap on the passenger side cam cover, to help release a bit of the additional crankcase pressure from the increased boost levels - and no, we will not need to change anything in your tuning to accommodate that.
What happens is, there is the *potential* for unmetered air to enter the motor via that type of breather *only* during conditions of extremely low engine load - like at idle, or on decel, basically - we have found from a lot of testing & datalogging that at cruise, for example, this just isn't an issue. And if it actually did result in unmetered air actually getting into the *combustion* chamber (hard to do) and actually affect the A/F ratio at those low loads, then the PCM will automatically correct for that as it's in Closed Loop. The O2 sensors pick all of that up and the PCM corrects to stoich in closed loop, no problem.
Now in the 2003 & newer Lightnings (and almost all of the 2001 & up Lightings as well), really nothing needs to be done - now there have been a few of the earlier Lightnings (pre-2001) where once in a while we'll see that a slight change needs to be made for airflow not measured by MAF, and we do that tiny adjustment on *all* our Lightning tunes for those earlier Lightnings anyway - just like we go ahead and make the changes required for a higher stall speed torque converter, in case one is ever installed. And the changes we make for a breather cap on those earlier Lightnings are very small, and don't cause any problems if the breather cap is not installed (and virtually all of our customers with raised boost run a breather cap), so that isn't a concern, either.
Bottom line - you'll be fine.
Glad you're enjoying your new custom tuning!
Yes, we *do* like to see a proper screw-in breather cap used to replace the oil fill cap on the passenger side cam cover, to help release a bit of the additional crankcase pressure from the increased boost levels - and no, we will not need to change anything in your tuning to accommodate that.
What happens is, there is the *potential* for unmetered air to enter the motor via that type of breather *only* during conditions of extremely low engine load - like at idle, or on decel, basically - we have found from a lot of testing & datalogging that at cruise, for example, this just isn't an issue. And if it actually did result in unmetered air actually getting into the *combustion* chamber (hard to do) and actually affect the A/F ratio at those low loads, then the PCM will automatically correct for that as it's in Closed Loop. The O2 sensors pick all of that up and the PCM corrects to stoich in closed loop, no problem.
Now in the 2003 & newer Lightnings (and almost all of the 2001 & up Lightings as well), really nothing needs to be done - now there have been a few of the earlier Lightnings (pre-2001) where once in a while we'll see that a slight change needs to be made for airflow not measured by MAF, and we do that tiny adjustment on *all* our Lightning tunes for those earlier Lightnings anyway - just like we go ahead and make the changes required for a higher stall speed torque converter, in case one is ever installed. And the changes we make for a breather cap on those earlier Lightnings are very small, and don't cause any problems if the breather cap is not installed (and virtually all of our customers with raised boost run a breather cap), so that isn't a concern, either.
Bottom line - you'll be fine.
