Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum - View Single Post - G25-550 Exhaust Housing Question

Ryan_H · 08-15-2023, 08:34 AM

Hi All

I'm building a street S14 with an SR20DET VVT (not VVL!) for the weekend here in the UK that will do occasional track work.

I want something very driveable and responsive and with a bit of punch. I've come to the conclusion the G25-550 works best for me.

Now here's where I could use advice.

I want to keep the setup simple, so ideally I want to use the T25 exhaust housing that is available for it so I can mate to a PSM Flex Cobra downpipe and maintain the low mount position. I also want to keep it internally gated.

There is a T25 5 bolt housing compatible with the Flex Cobra with an AR of 0.64. The next one along is a VBand at 0.72.

My question is, what's your gut feel of the 0.64 AR in terms of power output?

I presume it'll break 350hp at the flywheel which would be fine for my needs but what could it realistically do, your input is appreciated.

And secondly, is anyone here running a G25-550 on an SR20DET (in any config) and would you mind sharing your feedback? I have tried to search for it on here but come up short.

Thanks

Ryan

Edit - to add, the motor is built and has Tomei USA 258 IN/EX Cams. I have, I believe, Nismo 555cc injectors but I can swap these out for whatever.

08-15-2023, 08:34 AM	#1
Ryan_H Leaky Injector Join Date: Jun 2020 Location: United Kingdom Posts: 116 Trader Rating: (1)	G25-550 Exhaust Housing Question - And your general experience Hi All I'm building a street S14 with an SR20DET VVT (not VVL!) for the weekend here in the UK that will do occasional track work. I want something very driveable and responsive and with a bit of punch. I've come to the conclusion the G25-550 works best for me. Now here's where I could use advice. I want to keep the setup simple, so ideally I want to use the T25 exhaust housing that is available for it so I can mate to a PSM Flex Cobra downpipe and maintain the low mount position. I also want to keep it internally gated. There is a T25 5 bolt housing compatible with the Flex Cobra with an AR of 0.64. The next one along is a VBand at 0.72. My question is, what's your gut feel of the 0.64 AR in terms of power output? I presume it'll break 350hp at the flywheel which would be fine for my needs but what could it realistically do, your input is appreciated. And secondly, is anyone here running a G25-550 on an SR20DET (in any config) and would you mind sharing your feedback? I have tried to search for it on here but come up short. Thanks Ryan Edit - to add, the motor is built and has Tomei USA 258 IN/EX Cams. I have, I believe, Nismo 555cc injectors but I can swap these out for whatever.