So hey all I'm new to the forum and didn't find an answer to my question with a little bit of scouring so I'm just gonna post and see if anyone has any ideas or a post to point me to.

I have an AP1 with a built F20C that has been rotrex supercharged via a used kraftwerks kit with a 90mm pulley installed. I was driving home one evening cruising at about 80 when I suddenly heard a "thwoomp" sort of noise and lost all throttle response. Pulled over and had it towed home. There was a bit of oil on the ground where I pulled over but did not see any damage to the engine then or during later inspections and also did not hear any of the telltale noises like grinding or clunking or any of that. I did later notice that the boost bypass(no BOV) valve was stuck open as it was pretty old and worn by this point and the hose had popped out where it connects to the silicone adapter that mates up to the SC itself. I got it home and when I turn it over it sounds like nothing is happening in the cylinders. No combustion. (video for reference regarding the sound) I pulled the coil packs and turned it over to find there wasn't any spark happening. I'm pretty sure I grounded it correctly as I had my old man present and he is a very skilled mechanic(primarily aerospace). Does anyone have any ideas on what could potentially be wrong here? Sensor? Wiring? Coil packs? I'm at a complete loss. I have not taken it to a shop yet as I'm trying to avoid doing that. Any advice would be greatly appreciated.

 

Do the cylinders have compression? Numbers okay?

 

I have not done a compression check but my question is more about the fact there isn't anything happening in the combustion chamber. Even with bad/low compression there would be the sounds of it trying to start and there are none. The engine only has a couple thousand miles on the rebuild with forged internals, a brand new oem crank, and built up valve train. Very unlikely it is a compression issue.

 

Quote:There was a bit of oil on the ground where I pulled over but did not see any damage to the engine.
where did it come from then ?

 

My first thought was to pull the spark plugs and check to see that one isn't broken. What if the oil was from the blower itself? Perhaps your best bet (if not a broken spark plug) is to take the supercharger off and try to start the engine then.

 

I was wondering about it being from the blower as well. I will try your suggestion in the coming months and let you know if that changes anything. In case youre wondering why so long its because I don't keep the car at home(I live in Seattle and it will be vandalized/stolen) and it is stored about 30 miles away and this summer I don't have a lot of free time as I have a bunch of things going on that prohibit driving just to work on the car so I will keep you posted.

 

Hey no worries. Better safe than sorry so take your time and work on it when you can.