I just got my Haltech installed on my 87 TII (fmic, T04, street port and free flowing exhaust) and was running a real rich base map ( the one for the s4 with T04 from Hitmans website) and was trying to tune it with my friend. I had already tuned it real good for idle and free reving. I was running the lowest boost (12psi) I can with my boost controller and was trying to tune the on boost off boost transition with my egt gauge and a/f gauge. It felt fine and the car was running real good, real strong and smooth but the 02 gauge was showing it runnign lean for a sec. before boosting but I read that is normal. Anyway, I was still trying to richen it up a little for saftety until I find someone with a wideband I can borrow to fine tune everyhting. I made a run through 3rd, everything was fine and I was only shifting at 5.5k. When I slowed down to make a turn and down shifted, it felt like I had it in 5th coming out of the turn because the motor bogged down reall bad and I hardly had power. I got it almost back to my house ( less then a mile) when I took it out of gear it died. Started it up and it made a real loud knocking noise, idled low, bad vibrations. Drove it the rest of the way home, wouldn't boost, excelerated real bad. No power. Anyway, I did a compression check and the front housing was 20-20-20; overall 75. Rear was 25-25-25; overall 110. So it looks like I blew it Sucks.

Anyone have any ideas as to why it blew when I was making a turn ?! And why would it making the knocking noise and vibrate after it stalled and I started it back up?! I'm guessing the knocking noise is because of a blown seal...? That sound right?? If so, did it break when I made the run then come loose at low rpms? Why didnt it start knockig right away?? Sorry for the long post, but this is my first blown motor and I just want to understand a little better what the hell happened.
Thanks,
Ryan

 

What kind of turn was it(L or R) and how much gas was in the tank?

Steve

 

sounds just like you blew an apex seal, or maybe 2 of em

 

left turn at about 10-15mph. half tank of gas. running premix at 1:100 ratio if that matters...

 

What do you mean, two seals on the front rotor? I thought 100-115psi was good compression and the rear was about 110...??

 

Compression does not matter when you have predetenation, it can be brand new and have that happen.

BTw I feel you pain, last week I blew to apex seals in the rear rotor.. Due to a low rpm detenation..