Knocking ... What to do
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Knocking ... What to do
Hello All,
I just noticed last weekend. It started on the high way in fifth gear after 100 mile continuos drive, when I stepped on throttle and about 4000 rpm, boost started to go up about 5 - 10 psi, I felt/heart knocking, of course I backed off right away, then I tried again, same happened. I went home, poped the hood, the turbo was glowing red in the night. The weather did get a lot colder lately in MN, and I might have premixed a bit too much with 2 cycles (1 ounce/gallon) along with MMO (half that maybe) along with 91/92 octane.
The car got 720 pri and 890 sec, Rtek 1.7 and SAFC supporting a BNR stage III at 15 psi, what can I do to correct it? Does the glowing turbo tells me anything?
Thanks
-X
I just noticed last weekend. It started on the high way in fifth gear after 100 mile continuos drive, when I stepped on throttle and about 4000 rpm, boost started to go up about 5 - 10 psi, I felt/heart knocking, of course I backed off right away, then I tried again, same happened. I went home, poped the hood, the turbo was glowing red in the night. The weather did get a lot colder lately in MN, and I might have premixed a bit too much with 2 cycles (1 ounce/gallon) along with MMO (half that maybe) along with 91/92 octane.
The car got 720 pri and 890 sec, Rtek 1.7 and SAFC supporting a BNR stage III at 15 psi, what can I do to correct it? Does the glowing turbo tells me anything?
Thanks
-X
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Originally Posted by NMJ87T2
Correct me if I am wrong, but the 1.7 is set for 550primaries and 720 scondaries?
#6
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Sounds like the timing is retarded a bit if your turbo is glowing red after highway driving.
Check the timing first just to make sure, then figure out why you are over boosting so bad.
If you really are knocking, I'd suggest light driving until you get it figured out.
Also, check your fuel system, those are some big injectors for the stock pump also, have you upgraded your fuel pump and replaced your fuel filter?
Check the timing first just to make sure, then figure out why you are over boosting so bad.
If you really are knocking, I'd suggest light driving until you get it figured out.
Also, check your fuel system, those are some big injectors for the stock pump also, have you upgraded your fuel pump and replaced your fuel filter?
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#8
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I don't not whether anyone has similar setup, and how you all tuned your car for winter. Just blur it out, say using the ideal gas equation we got pV = nRT and this translates to rho = pM/RT. Now with R and P constant, since the sensor for the SAFC is tied to the boost sensor, and with constant Moles, then rho (density) is inversely proportional to temperature. Say rho1 ~ 1/T1, and rho2 ~ 1/T2, such that between 20 degree C and 2 degress C, there should be about 6% change in air density.... does this lead to 6% compensation in fuel? I am on the right track? This means, originally, if my compensation was set at -24% at 20 C, now this is equivalent to -18% at 2 C? That much? Or I am wrong somewhere?
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Yeah, kinda. The sensor up front is a velocity sensor and a temp sensor. The ECU uses that to gauge air density. There is also a temp sensor after the turbo that the ECU uses to figure out the correct density and fuel charge. Everything should be automatically adjusted by the ECU minus any changes made via the SAFC.
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Originally Posted by camman
glowing turbo means hot exhaust. hot exhaust means lean fuel mixture.
That could be caused by the knock though. I think knock triggers ignition retard.
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