Free "boost cut"
05-20-2019, 04:15 PM
#1
Free "boost cut" Well its free if you have Hp tuners or efi live. I know some maybe of you are going to say its not a good idea to do this, but bear with me. Its does work, to and extent...so far...
I had posted a while back about adding a bunch of fuel past the boost that i'm safe with. Got mixed opinions. So I picked 12psi to be my max. I went right past that in my boost enrich table and added a bunch of fuel. And I've hit it a few times. Its feels like the engine loses a bunch of power for a second and I let off, quickly glancing at my wideband, seeing it was flashing 9.xx meaning its pig rich, and it hit like 15 psi. Why tho? Well my china wastegate failed on me and locked shut. Nice. That could have ended real bad. So theres reason 1 for me. Ive since replaced it with a Tial wastegate.
Second reason. I recently upgraded my down pipe to a much better flowing setup. Now I get even more boost by 1-1.5psi at peak. Well I hit it then too. I felt it and let off, saw 13.5psi. Ive passed my max boost a couple times while dialing in my boost controller, so I feel like its saved me. I guess if The boost were to go really really high and the fuel didnt drown it but actually matched the boost, well i'd notice a huge power increase and let off. I never try to be a hero....any little thing out the norm, I let off. What say you?
I had posted a while back about adding a bunch of fuel past the boost that i'm safe with. Got mixed opinions. So I picked 12psi to be my max. I went right past that in my boost enrich table and added a bunch of fuel. And I've hit it a few times. Its feels like the engine loses a bunch of power for a second and I let off, quickly glancing at my wideband, seeing it was flashing 9.xx meaning its pig rich, and it hit like 15 psi. Why tho? Well my china wastegate failed on me and locked shut. Nice. That could have ended real bad. So theres reason 1 for me. Ive since replaced it with a Tial wastegate.
Second reason. I recently upgraded my down pipe to a much better flowing setup. Now I get even more boost by 1-1.5psi at peak. Well I hit it then too. I felt it and let off, saw 13.5psi. Ive passed my max boost a couple times while dialing in my boost controller, so I feel like its saved me. I guess if The boost were to go really really high and the fuel didnt drown it but actually matched the boost, well i'd notice a huge power increase and let off. I never try to be a hero....any little thing out the norm, I let off. What say you?
05-20-2019, 05:12 PM
#2
you can pull timing too via a NC hobbs switch put in line with the ground side of the IAT
above a certain psi, the opens and the IAT reads -38* F
go into that cell in the IAT timing table and pull whatever timing you want
I found that was a little safer than dumping unburnt fuel on a hot turbine wheel (although doesn't make as many cools sounds)
above a certain psi, the opens and the IAT reads -38* F
go into that cell in the IAT timing table and pull whatever timing you want
I found that was a little safer than dumping unburnt fuel on a hot turbine wheel (although doesn't make as many cools sounds)
05-20-2019, 05:36 PM
#3
you can pull timing too via a NC hobbs switch put in line with the ground side of the IAT
above a certain psi, the opens and the IAT reads -38* F
go into that cell in the IAT timing table and pull whatever timing you want
I found that was a little safer than dumping unburnt fuel on a hot turbine wheel (although doesn't make as many cools sounds)
above a certain psi, the opens and the IAT reads -38* F
go into that cell in the IAT timing table and pull whatever timing you want
I found that was a little safer than dumping unburnt fuel on a hot turbine wheel (although doesn't make as many cools sounds)
05-21-2019, 02:13 AM
#5
If you are not using meth injection, cutting fuel is a better option. Everybody worries about going lean, but beyond a certain point you no longer have enough fuel to do any damage, no matter what your timing is set to. You really do need to have an extremely hard transition for this to work, though. Otherwise you could go lean with enough fuel to damage something.
05-21-2019, 05:55 AM
#6
If you are not using meth injection, cutting fuel is a better option. Everybody worries about going lean, but beyond a certain point you no longer have enough fuel to do any damage, no matter what your timing is set to. You really do need to have an extremely hard transition for this to work, though. Otherwise you could go lean with enough fuel to damage something.
05-21-2019, 10:22 AM
#7
if you are not using meth injection, cutting fuel is a better option. Everybody worries about going lean, but beyond a certain point you no longer have enough fuel to do any damage, no matter what your timing is set to. You really do need to have an extremely hard transition for this to work, though. Otherwise you could go lean with enough fuel to damage something.
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05-22-2019, 08:27 AM
#10
I do have overboost protection in my controller, which is great if I don’t have a wastegate malfunction. I mean usually that’s what causes a overboost mostly anyways (besides creep) and if a line pops off the wastegate, then you have no control either. At least if I dump fuel (and when I say dump fuel, I mean add enough to where is just pig rich but not flooded out) then it’ll alert me something is wrong.
05-22-2019, 09:31 AM
#11
10 Second Club
iTrader: (2)
A fuel cut will work. I’ve hit my fuel cut rev limiter without damage enough to know that will work. For what you are trying to do I would go with ddnspider on this and tune for the correct afr under all conditions while pulling timing as a safety net.
05-23-2019, 03:08 PM
#18
9 Second Club
05-23-2019, 03:46 PM
#20
9 Second Club
Let's be fair though...the sort of person to do that...would probably set up any failsafe incorrectly too.
