I would also assume ANY exhaust modification would have an impact on boost in the upper RPM ranges, though headers would be more of an impact than anything else.

I am not super technical on boost/FI setups, but I will explain this part the best I can.
With using an open setup like I did, though we still hit 8PSI, you could lose pressure overall but the idea is running the system at a more efficient manner. Meaning you lose pressure but still maintain power, this allows you to push tuning and other aspects of the kit farther hitting the same PSI (8 per the original kit) and increase power at a more efficient rate.

Dreamer is absolutely right. It is not just about making peak boost but making efficient power. Ideally you want to make peak #'s at as minimum boost as possible. I honestly think if Dreamer had gone ahead and retuned the setup for long tube headers there might have been some gains. I have the F.I. Long Tube Headers on my naturally aspirated setup and they provide a big increase in torque throughout the powerband.

I was thinking about doing the cog set up but I think I am going to see what kind of boost I will get if I just increase the size of the pulley on the back side of the kit that's the pulley connecting directly to the blower pulley

On my mustang vortech setup just a 10% increase in the crank pulley jumped boost up from 12 to 14 on the top end but even better is boost was up all over the rpm range

I am seeing 8psi at 4000rpms and 14 psi at 6500rpms on my Stang
That's with a v2 vortech

928 impeller +. Water meth. And that pulley size increase a solid 13-14 psi on the top end could be possible I.e if you can keep belt slippage at a min.

More boost on the top end more boost you see on the lower end

Problem if they crack valve cam thing most of use would have to lower the boost on our cars less we want a new motor

don't hold your breath for a vvel crack. Last I know of only UpRev has been working on it, its been a tedious and slow procedure (I even heard they blew a motor in the process) and I think there was mention they didn't see any real gains from it (not sure if they tested it with forced induction). I wonder, if someone ran a full standalone setup could they then control VVEL? As it stands there is an ECU for all the "normal" tuning parameters and VVEL has its own control unit. Maybe a standalone could do the job of both.

Personally, the fact that GTM isn't working on it means that Sam believes that he can make plenty power working around VVEL. Moreover, I don't think GTM wants their S/C kits making more than 500-540whp because it would take away from the TT market share. The real loss doesn't come in our limitations on peak HP but torque. Quoting HP numbers is great but no S/C kit is going to anything more than 400tq. That seems to only be possible by TT kits which are mechanically more complex, create more heat and cost more.

Thats what I read till the thread disappeared, It wasnt you was it, I feel for the guy, There where some other things writen that did not make sense( But we can leave that closed)..
I hear what you are saying about making power, That was always the case with my turbo cars. make the most effecient power you can, Try not to just run high PSI to make power cause at some point you just spinning hot air,

No not my car, I believe it was a G37 not a Z.

ok cool, I wasnt sure if I read that on here or over on myg37?

It was on here for awhile but after a lot of trash talk started it was taken off, especially without the owner posting everyone was just throwing BS around.

I know, thats some of the BS I was reading and then the thread disappeared I dont blame them for removing it, Not one bit, The whole thing was rediculous,

I remember that thread, turned into a mess eventually. I would never pick up a car running high compression, stock internals and forced induction without a new tune after exhaust modifications had been added.

Aftermarket headers can't be used with GTM's stage 2 s/c kit. The compressor is so big that it won't fit with long tube headers, I'm not sure if you could modify the headers someway to still use them, it seems like Sam's general tone is that you should not be running long tubes with the SC kit. I think the single turbo setup done by another forum member completed by JTran Studio's uses the long tube headers with his single turbo setup. I love the headers, its a same there seem to be so many obstacles mating them with the quality S/C kits that are coming out for the z34.

Does the 9psi pulley require a new belt? My local shop is telling me no but want to confirm before ordering.

Nope.

Can you guys provide input on 9lb pulley vs 928 impeller upgrade? Planning to do one or the other (not both-stock motor). For the money and performance which would be the better option?

Either way, swap to topgunz's air to air setup if you want your motor to live.

Yeah, do both and make a lot more power, safely. You have already made a big investment for a supercharged car. Add a fraction of that more into it and make some serious power.