I have a 2003 evo 8 full bolts minus o2 housing stock turbo on e85 at 28.5psi. Would i benefit from upgrading my stock wastegate to a fp 25 psi one or is my stocker fine?? Or just go o2 dump? And would i also benefit from upgrading my stock platic bov to a synapses?

 

Oh yes replace that plastic DV with the JDM IX metal one or a synapse. The plastic ones leak like a sieve. I guarantee you have boost leaks from that alone. Replace all the clamps with t-bolt ones as well.

I think you will find you will hold boost much better and will have to retune because of the change

Either an FP or Forge wastegate actuator will be fine...21-25 psi 21 will not overshoot like a 25 psi actuator might so i'd go with that. Again it will need retuning so id change both items, do a boost leak and then retune.

 

Does your turbo have the 9.8cm, or the 10.5cm turbine housing? All 2003 turbos came stock with the 9.8, but most people upgraded to the 10.5 piece.