street ported series 5 NA, 6500k miles on a reman with carbon apex seals, high volume oil pump, shimmed relief valve (85 PSI), new injectors, platinum plugs, header, presilencer, cat back, ignition box, and air filter.

i installed myself, and followed breakin to the proverbial 't'. the engine made great power, with a wide powerband 4k to 8k.

recently, i have noticed a considerable drop in torque from 4 to 5.75 os so when the VDI kicks in, wether i am at wot or atleast 50% into the pedal. I advanced the timing about 1.5 deg, and it seemed to smooth out the distinct torque hit at 5.75.

i doesnt feel like the engine makes as much power as it did before the torque loss. also, i dont think its a bad apex seal since the engine behaves as it always has after 6k.

it just seems the engine is weaker in the lower rpm range.

any ideas?

 

You have carbon apex seals, those seal best at high RPM's. Rev it up to 8k and see how she pulls, if you have FCD rev it to 9k and I bet she still pulls. And don't worry about detenation!

 

Hmm... Forget what I told you I challenge you to a duel! My 7 against yours

 

bump

 

Maybe the 6-ports? Stuck? Opening late?

 

i hadnt thought of that, ill look into it.

 

i have the same problem with no power in the range of when the vdi should be switching over. it just seems flat.

my 6 ports are a little sticky though i have noticed.

do non-functioning/weak 6 ports cause the vdi switching over to make less power?

 

bump