This past month I got my FD back on the road after blowing my old engine. I'm trying to make sure it doesn't happen again. My question is, if the previous owner put in an aftermarket intake (apexi power intake), and if he didn't have the computer re-mapped for the extra air it lets in, would this have caused it to lean out and distroy the engine?
I already got myself a nice boost gauge to ensure it wasn't an overboost condition that caused the apex seal to snap in half. Any other ideas I should watch for?
Oh yeah, car only had 100Km (60,000 miles appx) on it.

 

It is unlikely that adding only an intake would cause you to go lean enough to destroy an apex seal. You should check your fuel system. Plugged filter, broken pump or stuck injector are all possibilities. Apparently, the plugged filter is the most common case.

 

With the rebuilt engine, I was thinking of putting in a new fuel filter anyhow.

 

The consensus on this forum is: As long as the boost stays at 10psi after adding the mod, there is very little additonal risk of blowing the engine. In practice, 11 and even 12psi is fairly safe, although that leaves little margin. If your boost is where it should be for that ECU, you're fine. What kind of ECU, and what amount of boost is it mapped for?

However, other things like a clogged fuel filter, bad fuel, or sticking injector can cause lean regardless of the ECU tuning. I would make certain these are working properly.

Dave

 

Stock ECU. I'm assuming that the previous owners didn't ever have it changed. With my boost gauge, I've only seen a minor amount of boost for I'm not gunning it yet. Still breaking it in, but it's so tempting to floor it and see what the max is!!! (don't worry, after that much $$ I'll wait)