I?ve run the turbo and I?m not really feeling boost hit until around 5000 hence why I?m asking. I would have thought simply the significant difference in the compressor map would indicate a large performance difference.
Many have run similar setups as you with much lower boost threshold. Difference is they tuned theirs. With dynos and data and stuff.
Start at stage 0. Set the static timing of everything properly. Cam and ignition. By the book. Leave adjustable cam gear at 0. Test for and fix all vacuum, exhaust and boost leaks. THEN start the engine with boost set to wastegate pressure. Where does boost come on? Creep up to 18psi or whatever.
You are running a t-cam, right? T-cam is not a performance cam. This may be your problem. You are probably cam restricted. Get a real cam. An A or a K cam may help, many use them in turbo engines, and they are much more common in canada than the usa. Many canucks pull them and sell them to yanks. There are better cams but not in a junkyard. The cam lift, duration and its overlap can really make a difference to spool time. First thing to make sure is that the turbine is seeing ALL the exhaust energy it can. No exhaust leaks. An intake manifold to head or manifold to turbo exhaust leak is bad, and will for sure effect the turbo spool. You have an ebay manifold, is it flat? You can not assume new gaskets are good. How could you hear an exhaust leak with the straight pipe in your face anyways? You can also lose boost after the turbo. This was discussed in the other thread.
Have you TESTED for boost/exhaust leaks? Have you driven it with the leaks fixed? Do you have any dyno runs or data logs to see whats going on? This is what building a serious engine entails. Play around without data and you are going to break stuff. Usually the stuff that will break cost more than the dyno runs would have. With a straight pipe out the hood, and high boost, you will NEVER hear the detonation before it damages things. Its hard to hear for the inexperiences with a normal exhaust. It can only take a few seconds running too lean at 18psi to melt a piston, or break a rod........
Lastly, are you sure the turbo doesn't have the wrong wheels in it right now? Why was it such a good deal? Perhaps it was a good deal because the exhaust turbine is a little too small and is letting exhaust bypass it or something.
Also, you already have an 8 page thread on this topic. No need to start a new one, just ask this question in there. Considering the fact that you were blowing into the intake pipes with your mouth to look for leaks, and skipped the cam a tooth then started the engine to see what would happen, I would take the turbo to a shop to get the wheels looked at/changed.
