Need a little advice. So here's the deal, looking to add next mod. Current list below.

Engine:
Stillen air box w/ K&N filter
OEM z-tube
MD iso thermal plenum spacer
transgo shift kit (need to install)

Exhaust:
Tanabe medalion y back (puchased due to leak in OEM)

Suspension:
Stillen sway bars
Powergrid endlinks

Dress: JDM clears, full led conversion inside and out, nifty shift boot and razo shift ****

I think I want HFC and Y pipe, or maybe just one or the other. I'm worried about losing low end torque as this is my daily driver and I like to have that around town. I would get MD art pipes but i have to be concerned about emissions in my state. If I get HFC and keep OEM Y pipe perhaps it's enough back pressure to maintain most of the low end torque or maybe not ?Maybe just get HR Y pipe? Maybe both? I am definitley getting osiris tune after this either way.

So what do you think HFC and Y pipe, one or the other, or something completley different I'm not thinking of? (could get coils but want more power!)

Thanks for your advice!

 

The largest restriction in your exhaust system is the OE cats. Keeping it legal a pair of BERKS HFCs will give you another 10HP. Check our MARKETPLACE, Henry @ Mr.Wong has the best price delivered. My BERKS are in the mail, should have them installed by next Saturday....can't wait! Gary

 

^ Thanks Gary! Good luck with the Berks! Let me know how you like them.

 

Hey guys how do hfc affect the sound?

Is it really loud afterwards?

 

^^ It does increase the sound ... But not as loud as testpipes... When i put in my HFC it was a completely different tone / sound

 

It makes it a deeper meaner sounding. I remember the day i got mine i couldnt stop revving the engine lol.

 

^ ^ are hfc and test pipes really only useful if you have FI?

I am wondering why someone would want increased flow without also increasing gas input.
If you change your headers, cats, air intake what should one do on a mostly stock g35 to increase the amount of gas being pumped in ... to avoid running too lean.

upgraded injectors?
ECU upgrade?

assuming FI is not desired

 

^ hahaha nice. I am saving up for ART pipes just because I want that low end torque as this is my DD also... I think an extra 100 over Berks is worth the increase in HP/TQ

 

just through about it a little more, will the stock 2004 ECU adjust the fuel/air mixture ?
I remember reading in another thread that only 06+ will auto adjust (when I was looking into MREV2)

 

^^I agree ART pipes are the way to go but I have to pass emissions. I hope I won't lose to much low end torque with HFC.

 

It will allow you to pass emissions only if they dont have a sniffer.

 

How will I know if they have sniffer?

 

When i got HFC it help with low end torque. i drive a 07 6mt, i think with a tune it should help gain it back.

 

The bolt ons won't lean out the car enough to cause detonation. The ecu will throw more fuel to account for the lean condition. Obviously if you want to max out the hp from your mods, you will need a tune.

 

I ssy keep the stock cats and just go with the HR y pipe. You'll get more hp and keep your low end tq.

Only bad part of having hFC is that you smell the unburnt gas coming from the exhaust.