I personally would keep the stock cats. I removed my HFCs and the 9psi pulley btw.

The car feels much better with stock cats.

If you plan to run the 9psi pullley make sure to upgrade the injectors from 600CC to at least 725CC with UPREV GT MAF to accommodate the added boost. I had issues because I maxed out my fuel running the stock MAF and standard 600CC injectors with the 9psi pulley. I will go back to the 9psi pulley in the near future but after I purchase those two things (Injectors/UPREV GT MAF) and get a retune.

 

I also have the 9lb pulley, and upgraded to 1000cc injectors and put in the uprev MAF's. Thinking of maybe putting back the stock cats but... dunno, because I will need a re-tune then and dont want to waist the cash.

How often do you guys go through your small blower belt? how many KMS? I am at about 40,000km and have some good cracks in it. I will be replacing it soon.

 

Every dyno is different so take that with a grain of salt, You shouldn't have to get the 9PSI pulley to make 400WHP or just over that's all in the tune. I wouldn't get the 9 PSI pulley. Take it to the track and see what you run and trap.

 

Put the OEM cats back in, I just did and my power came right back! Overall a much stronger power curve with additional torque.

 

What fittings any lines did you order?

 

Nice! You went from stock cats to HFC's back to stock cats. I went from HFC's to stocks only and noticed a difference.

 

I ordered the NA fittings from them also and just built some hoses

 

For those using Test Pipes vs Stock Cats.

 

So how do I increase power with the supercharger? My tuner, himself, is confused about this. He says all the supercharged vehicles he tested made more power with test pipes and long tube headers. I wanted to get the 9lbs pulley, but he said it will only add about 12 hp since I'm making 12hp/psi. He doesn't even want to retune the car for that much power.

 

The standard Stillen kit with an aftermarket exhaust will be all you will need. If you want to upgrade the kit, there is not a lot of room for growth but swapping the injectors from 600CC to 725CC/GTR spark plugs along with UPREV GT MAF and a 9psi pulley with an upgraded heat exchanger from Frozen Boost will get you some extra ponies. What I will not advise is to swap out the Vortech impeller which some members have done but the stock block may not hold up with that much boost.

Play it safe and upgrade only those things and retune and you will make great power I am sure or you can wait for the "High Boost Kit" from Stillen that's coming soon

 

Try a different tuner, with the stock 8PSI kit I saw 420+

 

I went back to the 8psi pulley and upgraded to GTR spark plugs and the frozen boost heat exchanger. I will visit a dynojet next week and see how she does.

I should have went ahead and got the damn ID 725CC injectors with UPREV GT MAF but I ran out of mod money for now

 

About upgrading the injectors and getting the uprev GT MAF. Do you by any chance have a dyno sheet before and after the injectors and MAF? Because from what I was explained. The 9psi pulley will increase fuel requirement by 6% and my car is already quite rich with the 600cc injectors and stock MAF. What do you think about this statement?

FYI I already have an Ark catback exhaust.

 

Exactly, although I don't expect 420hp, because it was on a mustang dyno plus mine is AWD, but shouldn't I be able to atleast break in to the 400's?

 

The stock injectors (600CC) with stock MAF can be tuned on the 9psi pulley, but your fuel will be maxed out. I did this exact setup but switched back to the 8psi for that same reason until I upgrade injectors/MAF to support the higher boost. Until Stillen themselves releases the High Boost Kit, I will stay with the 8psi pulley.

I don't have dyno #'s but check out this vendor who has made some great power with a few 370z's and the Stillen SC.

http://www.the370z.com/search.php?searchid=6224838

I agree with bachelor, maybe go to a different tuner to get retuned.