What works/doesnt work with the GTM stg 2 SC?
 

I often see people selling parts when they add an SC saying "wont work with my new kit" Im stockpiling parts so that ill have everything I want/need when i do sc my Z. With that being said, what aftermarket parts are compatible? I normally see others selling their LTH's saying they wont work...why wouldnt they?

the Stage 2 compressor is pretty big and the engine compartment is a tight fit. To make it fit GTM includes new motor mounts. No one has tried it with the stage 2 kit and I'm pretty sure LTH's would require modifying the headers and then of course there is the continuous debate of too much exhaust flow and how it doesn't mix with VVEL etc. If you plan on going with the SC kit then the supporting parts you should acquire are an upgrade clutch and flywheel with a csc kit and a 2.5" catback system. Intakes are not necessary.

^well said.

Dont the LTH's mimic the stock headers?

LTH replace the catalytic converters and creates "smoother" exhaust flow. They are like headers with straight pipe to the CBE.

What you're reading on the forum relates to the stage 1 system. The Rotrex supercharger that is being used in the stage 2 (c38-91) system is big unit (biggest charger Rotrex offers) with a 4.5" inlet. That helps flow a lot more air into the engine which you won't lose as much boost if you're running a non-restrictive exhaust (long tube headers, ect).

With the stage 1 and a non-restrictive exhaust a lot of people were getting Valve Overlap (both sets of valves, intake and exhaust, open up at the same time) because the air would be forced into the intake, but wouldn't be given enough time for combustion process and was just being pushed out the exhaust side. People were losing 1 - 2lbs of boost because of it and that's why they were selling off their parts.

At the end of the day, VVEL is the main reason for this issue. I think the cam duration is around 300 which is extremely aggressive for a street car, but the ECU is able to keep the idle in check. When your cars warmed up and you listen to it, you can hear a slight lope.

physically, i really don't think the LTH will fit with a stage 2 GTM SC kit, the position of the intake air filter is right below the rear portion of the header, and the intake piping also take up additional space. because of the design of the LTH, with 3 pipes running all the way until the meeting point that goes into the Y-pipe, i personally don't think it will clear the air filter.

I do agree. Some claim to argue differently. Your statement is 100% true.

That makes sense...So then stock headers with test pipes would be ok as far as fitment? Since the test pipe is exactly the same as the cat pipe...
with test pipes being installed, are people having boost drop off? or tuning problems?

I have test pipes and there great with the setup

Did sam make the most rwhp with stock cats, stock headers and stock exhaust ?

You shouldn't go stock cats, just my 2 cents

From looking underneath my car with the stage 2, which is a G sedan not a Z, there is space for any kind of test pipe, since the air filter doesn't extend past the flange of the header. However, i do wonder if there is any short header like the stillen or megan racing that will fit with in the space above the filter and intake pipe. Altho this may not benefit since there is no heat shield on these headers which means the intake will take in more hot air and the intake pipe that leads to the SC unit will be baked, but this can be easily solved if someone wraps it.

I actually have a set of art pipes (v2 with the ceramic coating) that i will be swapping with my berks HFC, to test out both fitment, and change in output. I'm currently in the process of making some gaskets and will have to tune the car slightly when everything is install. Hopefully i will have full results by the week of 20th-25th.

Let me know how it goes with the ART pipes. I have them with my Stage 1 GTM SC, and was hoping I wasn't gonna have to get rid of them if I upgraded to Stage 2.

Did you upgrade your transmission lines?