lean spool or not to lean spool

evonut270 · Oct 30, 2009, 06:41 PM

iv heard people tuning with and without lean spool active but id like to see who does and doesnt use it when tuning on here.id like to see your reasons for both too please.

03whitegsr · Oct 30, 2009, 09:02 PM

because it's awesome.

Raceghost · Oct 30, 2009, 10:00 PM

I only voted no for I finally figured out how to turn it off...lol. Been tuning with it on and thought it was off. Besides, you can come back to it, later, if you so desire. I think it is one of those things that can be done after timing and boost. I beleive you have to adjust your AFR's when utilizing it as well. So theoretically, could be done after everthing else...though I could be bonkers.... Someone set us straight?

Thanks in advance,

Jim in Tucson · Oct 30, 2009, 10:09 PM

Good question. I'll be looking forward to all of the replies.

FWIW, I've have my EVO tuned by three professional tuners. All three said that lean spool should be left active. Two said that only lazy people tune with lean spool turned off. One of these tuners is an Evom vendor and very active on these boards.

awddyno · Oct 30, 2009, 10:18 PM

I have yet to tune with lean spool off. What I have done instead was change the lean spool stop rpm to be higher. I know the AFRs drop about .3 to .5 when it reaches the lean spool stop rpm. So far I don't see an advantage turning it off but maybe someone can educate me as well. I'm always willing to learn.

mchuang · Oct 30, 2009, 11:14 PM

Quote:

Originally Posted by awddyno

I have yet to tune with lean spool off. What I have done instead was change the lean spool stop rpm to be higher. I know the AFRs drop about .3 to .5 when it reaches the lean spool stop rpm. So far I don't see an advantage turning it off but maybe someone can educate me as well. I'm always willing to learn.

This is also what i did.

Evo_Kid · Oct 31, 2009, 01:42 AM

I tune with it off because its keep the AFR more consistent, from gear to gear and overall, when its turned off.

merlin.oz · Oct 31, 2009, 05:13 AM

Always use lean spool here, but then I always change the base values and the tune values as well as the main 3D map.

nothere · Oct 31, 2009, 07:11 AM

my thinking is with a car that sees road race lapping, where the turbo is always boosting or the car is braking the last thing you want is to introduce more heat.
so I have lean spool off.

beside the fact, I like to put the afr in one place and have it there.

Biggy VIII · Oct 31, 2009, 10:41 AM

Evo_Kid, nothere +1

l2r99gst · Oct 31, 2009, 10:44 AM

I've always tuned with lean spool on.

EvoIan · Oct 31, 2009, 02:47 PM

I left mine on because I figure its an extra margin of safety... Consistency of AFR's definitely suffers tho

nothere · Oct 31, 2009, 03:16 PM

Quote:

Originally Posted by EvoIan

I left mine on because I figure its an extra margin of safety... Consistency of AFR's definitely suffers tho

what is your reasoning?

Evo_Kid · Oct 31, 2009, 03:51 PM

Quote:

Originally Posted by nothere

what is your reasoning?

I believe his reasoning is how the system works.

Its not really "lean spool" per say, its more like "richen up as you beat on it". Thats what "lean spool" does, as you beat on the car, it makes the AFR richer for safety.

Having it off makes it so the AFR stay what you tuned the car for.

JohnBradley · Oct 31, 2009, 03:59 PM

I like to be able to control fueling during spool and keep it consistent out the top. Some fuels do not play well with lean spool. E85 will lose power and torque at 13.0+ during spool. We saw this on Lucas' car the other night...sometimes it needs to be rich to be happy (12.0)