Mad A

Thanks for all the input guys and sharing your personal experiences. From my experience with other platforms and a twin turbo g35, you don't really lose power if you go with a well designed more free flowing exhaust path with forced induction. You may lose some low end torque, but make up for it in the mid and high range.
I gained about 15 whp with test pipes on a jwt TT g35. A buddy of mine kept ruining his Berk HFCs on his supercharged setup, but that was because he was running rich with his tune.
I don't want to go with test pipes for this car, so it's stock or HFC. I may just stick with stock if people are saying HFCs will go bad simply due to the high exhaust gas temperatures...
Anyone install high flow cats sometime after installing his supercharger? Power gains with a re-tune? Did the high flow cats go bad quickly?

milkcow500

If you don't want to go test pipes, I'd suggest going with ceramic core catalytic converters, which can handle the high heat. They have flow on par or better than that of HFCs. The only thing is that they tend to be a bit pricey at 200-300+ per cat.

Mad A

Any bolt on ceramic core cats available for the g37, or will I have to have them welded on to some piping?

milkcow500

Not that I know of. If you find one let me know haha.

Q50SC

618whp on full e-85 11.7 1/4 on continental 275/35/20. Headlift at 14.5psi, had to upgrade to L19s. No other changes to the stock block or trans. Now at 79k miles daily driven.

Mad A

Wow, that's pretty amazing! Where in Texas are you located? I'm in DFW. I want to relocate my MAFs like you did and just use that same large filter directly on the supercharger. Do you have a part number or link for that filter?

milkcow500

You are better off installing IAT sensors in the plenum than relocating the MAFs.

Filter: K&N RX-4130-1

Mad A

Thanks for the input. Now that I think about it, I'm going to get tuned by Seb, and he will tune it using their MAP sensor, so there probably is zero benefit from moving the MAFS past the blower anyway. Would you agree?

Edit: but my MAFs have to go somewhere if I am ditching the stillen intake portion that goes into the blower... right?

milkcow500

You could just delete the MAFs, since he is going to be disabling them anyways. You can still benefit from IAT sensors in the plenum though because he can use it a reference point when tuning via SD.

Q50SC

He is correct, I started out with MAF relocation and upgraded to a 4 wire map sensor that has the IAT build in. I purchased it through Boost Logic in Austin.

Mad A

Ok, I've make a custom pipe and relocated the MAFS properly, where each sees 50% of the air flow.


My question now is as follows. I'm ready to put the filter directly onto the supercharger. The current silicone coupler has two hoses going in. On the driver side I believe is the hose feeding re-circulating from the by-pass valve, so I'm not concerned about that one. What about the one on the passenger side/left? What do I do with that once that coupler is gone and I just have the filter on?

Q50SC

I put a filter on that tube. No issues with the tune or idle.

Mad A

Thank you for confirming that! Do you know what diameter the filter was?

Lastly, did you have to remove the SC to do the work?

Q50SC

I picked up a little universal filter from advance auto part. I didn't buy a complete kit as it wasn't available for the Q50s so mine didn't come with a boot or intake tract.

Javi2380

Maybe i should of started my on forum/topic but im thinking of the stillen sc but i wanted to know since my 08 g37s coupe just hit 110,000 miles on it with no major issue and all and most maintenance done would anybody still sc it. I really dont care just want peoples opionion and advice. Either way im getting this kit next year.