Lean spool for turbo freaks

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joe 90
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Re: Lean spool for turbo freaks

Post by joe 90 » Sun May 20, 2018 4:35 pm

ptuomov wrote:
Sun May 20, 2018 9:18 am
joe 90 wrote:
Sat May 19, 2018 7:13 am
It must be called "lean spool "for a reason?
If you're adding excess fuel it's not lean so therefore lean spool doesn't use excess fuel.
So what’s your answer, does lean or rich spool the best in terms of maximizing acceleration?
As I said above in a previous post, richer than lambda 1 but not as rich as full power rich.
If you flood it with fuel so that it runs dirty , it'll run like crap.

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Re: Lean spool for turbo freaks

Post by ptuomov » Sun May 20, 2018 4:47 pm

joe 90 wrote:
Sun May 20, 2018 4:35 pm
ptuomov wrote:
Sun May 20, 2018 9:18 am
joe 90 wrote:
Sat May 19, 2018 7:13 am
It must be called "lean spool "for a reason?
If you're adding excess fuel it's not lean so therefore lean spool doesn't use excess fuel.
So what’s your answer, does lean or rich spool the best in terms of maximizing acceleration?
As I said above in a previous post, richer than lambda 1 but not as rich as full power rich.
If you flood it with fuel so that it runs dirty , it'll run like crap.
And how about ignition timing?
[b]Paradigms often shift without the clutch[/b] -- [url]https://www.youtube.com/watch?v=cxn-LxwsrnU[/url]

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Re: Lean spool for turbo freaks

Post by joe 90 » Mon May 21, 2018 1:59 am

ptuomov wrote:
Sun May 20, 2018 4:47 pm
joe 90 wrote:
Sun May 20, 2018 4:35 pm
ptuomov wrote:
Sun May 20, 2018 9:18 am


So what’s your answer, does lean or rich spool the best in terms of maximizing acceleration?
As I said above in a previous post, richer than lambda 1 but not as rich as full power rich.
If you flood it with fuel so that it runs dirty , it'll run like crap.
And how about ignition timing?
I've already mentioned that too.
You even quoted my reply.
......................................................................................................
Lean spool?

There's more than one way to do it.


If you run extra rich (11s) when you don't need to , you kill the power output.
So keep it lean, normal lean, in the 12s or 13s......pull back the ignition timing a bit.
You lose a bit of power but the boost goes up quicker.


Everything has a downside, the downside to this sort of thing is failed turbos.

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Re: Lean spool for turbo freaks

Post by vwchuck » Thu Jun 07, 2018 9:43 am

This is a turbo engine 12-13 AFR burns holes in pistons.

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Re: Lean spool for turbo freaks

Post by ptuomov » Thu Jun 07, 2018 9:45 am

vwchuck wrote:
Thu Jun 07, 2018 9:43 am
This is a turbo engine 12-13 AFR burns holes in pistons.
Even at the rpm band where the turbo is just spooling and wastegate is fully closed under WOT?
[b]Paradigms often shift without the clutch[/b] -- [url]https://www.youtube.com/watch?v=cxn-LxwsrnU[/url]

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Re: Lean spool for turbo freaks

Post by vwchuck » Thu Jun 07, 2018 9:49 am

By running rich and retarding the timing you are effectively turning the exhaust system into a burn chamber and spinning up the turbo earlier than you could with only the engine. You are spinning up the turbo from the delta P that you created due to burning fuel in the exhaust. This is VERY hard on the turbine......
I think the OP is looking for a safe fix to increase boost when the engine is out of the power band. In this case you really can't unless you go to a sequential turbo setup where you feed a small turbo with a larger one. It is a plumbing and control nightmare but will give you torque down low and make you come on boost much sooner.

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Re: Lean spool for turbo freaks

Post by vwchuck » Thu Jun 07, 2018 9:52 am

ptuomov that isn't the operating condition. He said he is full throttle at low RPM trying to do a pull on the highway. I would definitely run it rich there.

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Re: Lean spool for turbo freaks

Post by ptuomov » Thu Jun 07, 2018 10:17 am

My car has a 5.0L V8, makes peak power at about 6200 rpm, and makes about 2 psi of boost 1400 rpm. So I don’t really have a problem with the car (not this problem anyway). I’m just trying to understand what’s optimal and why.
[b]Paradigms often shift without the clutch[/b] -- [url]https://www.youtube.com/watch?v=cxn-LxwsrnU[/url]

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Re: Lean spool for turbo freaks

Post by vwchuck » Thu Jun 07, 2018 2:40 pm

Oh didn't even realize you are the OP...so this problem doesn't even exist?? Great....

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Re: Lean spool for turbo freaks

Post by ptuomov » Thu Jun 07, 2018 2:55 pm

vwchuck wrote:
Thu Jun 07, 2018 2:40 pm
Oh didn't even realize you are the OP...so this problem doesn't even exist?? Great....
More is never enough and too much is just right! ;-)

If I learn something useful in this thread, I'll surely try it out. So it's not wasted effort.
[b]Paradigms often shift without the clutch[/b] -- [url]https://www.youtube.com/watch?v=cxn-LxwsrnU[/url]

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Re: Lean spool for turbo freaks

Post by gruntguru » Thu Jun 07, 2018 10:05 pm

vwchuck wrote:
Thu Jun 07, 2018 9:43 am
This is a turbo engine 12-13 AFR burns holes in pistons.
It's a low compression engine and its off-boost. You could probably run 14.7 there if you wanted to.

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Re: Lean spool for turbo freaks

Post by joe 90 » Fri Jun 08, 2018 2:00 am

vwchuck wrote:
Thu Jun 07, 2018 9:43 am
This is a turbo engine 12-13 AFR burns holes in pistons.
Only when you do it wrong.

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Re: Lean spool for turbo freaks

Post by vwchuck » Thu Jun 21, 2018 7:48 am

Only a fool would run it there for the irrelevant 10 horsepower gain. Just turn the boost up 1 psi more

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Re: Lean spool for turbo freaks

Post by joe 90 » Thu Jun 21, 2018 6:17 pm

The idea is to only run it like that while the turbo (s) spool up (to make boost) which shouldn't take any more than a second or so.

A 12 or 13 to doesn't and never has burned holes in any pistons, not when you're at lowish load and not making boost.

It's the detonation or pre ignition resulting from that lean AFR combined with low octane and the timing wrong which does it.

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