alexdimen

iTrader: (13)

You're not wrong, but you're not right either. It depends. This was a tightly built engine and already had 800 miles on it. RPMS were and still are kept low.

Plus, I've already discussed this. Post #5.

alexdimen

iTrader: (13)

I figured. I guess whether or not detonation will occur depends on other factors than just pressure. Similar to the flow VS pressure debate?

Wade

iTrader: (1)

I got similar overboost with just a downpipe as well. You might consider lowering your boost on the primary turbo with pills/valves or the hallman, and set your secondary boost close to max, but not so high it hits fuel cut. The stock ECU will allow for a little spiking, but bogging the engine at 3500 in 5th gear is one of the few situations where you would run into this problem (and a situation I'd try to avoid, anyway).

Lots of people over the years with lightly modified cars have run 12-13 psi. To cause detonation with a setup like that would take some effort or another problem with the car. If you want to use a Fuel Cut Defensor or a basic computer (piggyback like PMS, or reprogrammed stock ECU) you can get around the fuel cut problem and run about 12psi pretty safely in my opinion. The stock ECU runs rich enough to tolerate it (typically the stock ECU maxxes out wideband meters at 10:1), and after all, it's only an extra 2psi.

Wade

alexdimen

iTrader: (13)

Yeah, I figured. I had decided to put the engine through it's paces and that was the only way I could think of to test prolonged maximum boost without speeding too horribly.

Thanks for the other info. I hope it doesn't start another stupid debate, though. Personally, I'm going to stick to 10.