So I know that someone has probably asked this question but what is the max HP a 08 G37 Sport Coupe, RWD, 6 speed manual, can hold with stock trans and nothing too crazy with engine modification besides getting it up to said HP

I'm far from an expert. That said, I've heard the gearbox should be gucci up to around 1,200 HP. It's become a pretty desirable gearbox for manual swaps across lots of chassis partly due to its availability, and its HP tolerance.

From 400 whp you need an upgraded clutch.
I had the same transmission in a 350Z.
Clutch held fine but started to slip after I got to 400 whp.

PalmerWMD wrote: ↑

Tue Apr 27, 2021 4:55 pm

Clutch held fine but started to slip after I got to 400 whp.

Dope! Thanks for that input.

What mods did you do to get to/over 400 HP, if you don't mind me asking? I have a G35 manual now. I plan to get a used engine from PickAPart, and rebuild it. I would like to build it stronger, then add boost. Probably twin turbo. The only thing I am thinking about adding to the new(er) engine is the G37 HR valve springs which I hear will support higher revving.

HollywoodJackson wrote: ↑

Tue Apr 27, 2021 7:06 pm

PalmerWMD wrote: ↑

Tue Apr 27, 2021 4:55 pm

Clutch held fine but started to slip after I got to 400 whp.

Dope! Thanks for that input.

What mods did you do to get to/over 400 HP, if you don't mind me asking? I have a G35 manual now. I plan to get a used engine from PickAPart, and rebuild it. I would like to build it stronger, then add boost. Probably twin turbo. The only thing I am thinking about adding to the new(er) engine is the G37 HR valve springs which I hear will support higher revving.

Sorry I didnt respond more timely.
I had a Vortech Supercharger, plus AAM hiflow cats, and of course a uprev retune on the dyno.

Did not bother with intake or catback.
The mild pulley gave me 370-380 whp and the smaller puller gave me 411whp.

With the smaller pulley I could tell my clutch was past its capability but it held up fine with the milder pulley.
Later got a Nismo clutch and all was well even at 411whp (which I figure was probably 470-475 crank hp )

I staid with the stock fuel system and started running out of fuel at higher rpms so brought down the redline with the uprev for engine safety.