fd3s95

Hi Guys,

Few weeks ago I was driving my car, I was pushing a bit honestly, moments later I saw that the knock sensor read a high parameter compared to the normal.
The car started to run bad, like if she started to have misfire, I've been able to drive till home. Once at home I removed the sparks in the front rotor and this is the sound


The engine has been rebuilded around 8000kms ago, the car it's fitted with a Re Amemiya V Mount, hks intake, have the Apexi ecu and stock sequential turbos. I always run 100 octane and 2 stroke oil

Another thing I noticed is that the car start without major problems (cold and hot engine) but when isn't warm the engine wouldn't go over 5000rpm and if revving, smokes like a crazy. Otherwise when it's hot, the engine arrives until 8200rpm without problems and almost not smoking at all.
Following here a video of the start-up

I know that probably I blew an apex, but before open the engine is there anything to try?

Thank you

DaleClark

iTrader: (55)

Yep, the first video sounds like a broken apex seal. You can hear "HIGH-low-low-HIGH-low-low-HIGH-low-low" - with a broken apex seal, compression bleeds from one rotor face to another. This leads to a rotor with 2 low compression faces and 1 high compression face.

To be certain, do a compression test. You can use a piston engine tester, that's fine for letting you know for 100% if you have a broken seal. Rotary testers are great but they mainly show the overall health of the motor. Right now you just want to know if you have a broken seal.

Don't go further on things until you do a compression test. If it's fine, go further, but don't waste your time.

Dale

gracer7-rx7

iTrader: (16)

I'm curious how much boost you were running and whether your fuel injectors, fuel pump and ECU can support those levels.

fd3s95

Ok I'll get a compression tester and will do this test, I'll let you know
thank you

I was running with 0.8 boost, stock injectors and stock fuel pump. From what I know the my ECU can manage this setup

DaleClark

iTrader: (55)

.8 is around 12psi. With the stock fuel pump you are pushing your luck and obviously something gave.

You have the PowerFC which is great but if it's untuned you were really pushing your luck. Blew my first engine on an untuned PFC. The factory map on the PFC has a lot of spots that need help.

All that said, the other symptoms sound normal. The PFC won't let you cold rev it to redline which is good, you shouldn't be doing that in general. Also the smoke when cold is normal, a cold car is richer and you now have 2 rotor faces that aren't properly compressing the mixture so you get a lot of unburnt fuel.

The car will most likely start, run, drive, and make power just fine. It's possible you damaged a turbo, it's common to have an apex seal piece go out through the turbo and chew up a blade. But it is possible the piece embedded itself in the rotor so you can't know without taking apart and inspecting.

Again, compression test then move forward.

I HIGHLY HIGHLY recommend getting a Datalogit, a wideband, and the FC-Tweak software. Using that you can easily build a safe, reliable, and powerful map for the PowerFC all by yourself. I made a post recently about it if you want to learn more.

Dale