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

 

Correct me if I am wrong, but the 1.7 is set for 550primaries and 720 scondaries?

 

"Knocking ... What to do"

Waiting for the Knock knock jokes to start showing up............

 

550cc primaries minimum, 720cc secondaries minimum with rtek 1.7

 

Thats what JUST the Rtek can control. With a piggyback fuel controller you can use larger

 

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?

 

Yes, the fuel pump is a walbro 255

 

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?

 

I will try it out ...

 

If only it was a piston engine ... straight 30 FTW...

 

i dont speak spanish....

 

The compensation should be built into the Rtek anyways.

Something else is happening here I believe.

 

Also, the safc is connected to the AFM, not the boost sensor. I'm pretty sure the AFM bases its signal off of the amount of air coming in, automatically compensating for air density changes due to temerature change.

 

glowing turbo means hot exhaust. hot exhaust means lean fuel mixture.

 

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.

 

Or the timing is EXTREMELY retarded letting the charge burn mostly in the exhaust as opposed to the engine.

That could be caused by the knock though. I think knock triggers ignition retard.

 

What would happen if one of these temp sensor is not hooked up or are not operating correctly? The MAF anf boost sensor is the same thing for turbo cars?