I have the 3.91 gears in my 350z. I was thinking of adding a Vortech SC or Stillen SC but don't know if its a good idea since I changed my ratio. What do you guys think?

 

I am doing the swap soon. It is definitely beneficial. Turbo cars will benefit from longer gears because they make peak boost earlier in the power band than do SCers. Shorter gears such as the 3.9 are beneficial to SCers because it gets you into the powerband quicker.

Just my

 

Traction will be a b*tch, but yeah, it's been done.

 

That's what drag radials are for... anyway, from a roll it will be great. From a dig it will be... interesting...

 

I would personally swap in the 3.3 pumpkin if I had 450+whp....but that's just me.

 

I have the 3.3 and I hate it. It's great for driving around town, but that's it. Some people may like it, but I'm not one of them.

 

Agreed.

 

i think the 3.9 gears will benefit the vortech and procharger. Not sure on the HKS SC, but the stillen I'd tend to say no to because it already has a mountain of torque down low

the vortech and procharger really start building all it's power around 5000-5500 rpms and pretty much hold it until almost redline. The 3.9 gears will drop the rpms to around that 5000-5500 rpm mark when you shift so you'll always be in your max power.

With a turbo where peak boost/torque comes in at 3500-4500 rpms or so, the 3.3 gears help because it drops the rpms down into that peak area a little better than if you had the stock or 3.9 gearing. Of course you're losing some gearing multiplyer power with the drop though.

IMO the 3.9 is a win/win situation for the vortech and procharger kits other than the usual lower mpg loss on the highway. Since they don't create much boost at 1-2k rpms, launching with the 3.9 won't be much crazier than if the car was NA


a light flywheel will accellerate you thru the boost also whereas with a turbo setup it'll accellerate you too, but you'll be accellerating away from your peak torque once you go past 4500 rpms. The combo of light flywheel, 3.9 gearing and a SC IMO seems to be more efficient and complimentary to each other than a turbo setup on this car, though the turbo will still probably be faster

 

ANyone with the 5AT have the 3.9 gears and the Vortech SC? I have thought about this as a possibility. I just got the 6MT pumpkin installed and am looking for maybe more acceleration. Any input is greatly appreciated.

Zach

 

I have the 3.5 rear gears on my AT5 . Ive never really had a good chance to test it out with the 400whp [ Mustang dyno ] motor . But it seemed to fit pretty good...actually on the edge of being to much gear . Im going for even more boost with the new set up and believe it will be to much and I have the AT5 rear end ready to go back in if needed . Going to the 3.9 with any thing over 375whp IMPO would just not make 1st gear usable at all .

 

Hi Booger,

How about a second Gear start... with 3.91 and a Six Speed MT - it could be done. But you would have to shift to 5th for a quarter mile.

Wld350Z is experimenting with Greddy TT, 6MT (Version 09 Build) and 3.91 Final.. (He said he had to try it. Cusco's LSD )

Every time I've driven the car with 3.5's the shift points were TOO ! Close together.. And the traction was not there. - I'd think it needs a 3.3 final.. that can cross the line in fourth gear in the 1/4 mile.

Oh well it will be fun to see what a Greddy TT - NOX - and 3.91's feel like.


Here is a link to the TurboNetics BBQ with very cute girl models..

https://my350z.com/forum/southern-california/144753-turbonetics-cover-girls-56k-warned.html

Cheers Amy -

Opps Here is page two

https://my350z.com/forum/southern-california/144759-turbonetic-s-cover-girls-2-56k-warned-tanya-win.html

 

AmyCroft

I was just commenting on Zach's question about an AT5 with the 3.9 . A second gear start is not doable with an AT5