Loud popping/backfire

[GGorman]

I have a custom tune in my Supra. On the dyno everything went fine as usual. The tuner asked for a street log in third gear from 2500 rpm through 4th. In third at around 5000 rpm it omits a loud backfire or pop and I let off for fear of damage. New plugs are gapped correctly. Before he sends me a revised tune, has this happened to anyone else?

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[Thraxbert]

This happens on any sufficiently high-performance vehicle letting off of high RPM. If it happened before you let off, that might be a sign of the tune's fuel mix being a little lean (consult with your tuner).

 

[razorlab]

This happens on any sufficiently high-performance vehicle letting off of high RPM.

uhhhhh. A loud backfire when you let off is normal for a high performance car? No. Incorrect. It might be true on horribly tuned ones.


OP: Do you have a log from when this happens?

 

[GGorman]

https://bootmod3.net/log?id=6711513a0b2f342232341856

Here it is above. And the big pop is before I let off the gas. Otherwise it runs smooth. Currently an E30 blend in the car.

 

[razorlab]

https://bootmod3.net/log?id=6711513a0b2f342232341856

Here it is above. And the big pop is before I let off the gas. Otherwise it runs smooth. Currently an E30 blend in the car.

HPFP crashed from maxing it out. 126* is the max angle, you hit WAY past that. Too much boosty for ethanol level.

 

[Thraxbert]

uhhhhh. A loud backfire when you let off is normal for a high performance car? No. Incorrect. It might be true on horribly tuned ones.


OP: Do you have a log from when this happens?

uhhhhhhhhhhhhh ?

Any car is going to run rich instantly coming off 4K+ RPM to nothing. There's going to be overrun. It's going to pop, crackle, bang, whatever. Feel free to spend the next hour of your life pointlessly nitpicking the definition of "loud backfire."

 

[razorlab]

Any car is going to run rich instantly coming off 4K+ RPM to nothing. There's going to be overrun. It's going to pop, crackle, bang, whatever. Feel free to spend the next hour of your life pointlessly nitpicking the definition of "loud backfire."

Still incorrect. Injectors drop, car goes lean because no fuel is needed, no combustion, no pop, boom, etc on a properly tuned car.

I know you like to double down on your incorrect statements, but let the people that know things help the OP out.

 

[kingdooksdb]

 

[Jmanlevan]

HPFP crashed from maxing it out. 126* is the max angle, you hit WAY past that. Too much boosty for ethanol level.

I'm always amazed at the knowledge you have when I stumble upon your posts, Bryan.

 

[GGorman]

Yeah you ain't kidding!

 

[Loco38SUP]

I'm always amazed at the knowledge you have when I stumble upon your posts, Bryan.

Don’t inflate his head bigger than it already is FFS.

-RJM

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