I am in the process of getting some mods done to my Z. Intakes, full exhaust, tune and LSD.

I was thinking while I am getting the LSD installed I might as well throw in gears to save on install cost.

Does anybody have experience with 3.9 gears on an HR with bolt-ons and a tune? Good or bad?

I say 3.9 because from what I understand that will be a good compromise of performance vs drive-ability. However, this will not be a daily-driver, a weekend cruiser with some track time.

Thanks.

 

the 4.08 compliments the HR nicely, is less expensive and more readily available

 

^^^ +1 Upgrade to the 4.08's. Just last weekend I installed the 4.08's in my HR. They are perfect for the HR motor...especially if your car is not a DD. Mine is and they are still great. You may lose 1 mpg or so, but my car really pulls strong now for a NA car.

If you ever plan on going FI, I wouldn't do the gears. If you plan on staying NA, I would add HFC's or test pipes to your list, so that you can do the tune once the majority of your bolt-ons are done.

The 4.08's made a world of difference...go with those.

 

I have 4.08's and I love them. It will make the car shift a little stiffer but it is easy to get used to. This mod made the biggest difference out of all my mods I have installed. Since the 4.08 are made by nissan I felt a little better about how they would fit versus 3.9. gears. My car is my DD and I don't see any reasons this would compromise it ability to do so.
Hope this helps

 

The 3.9's are made by Nissan as well, they just are not from a US market car - no one is going to spend the time and money to tool up for ring and pinions for this car. Costs far too much and the ROI would take forever.

 

I got the 3.9s like....2 years ago and I love them. at the time there were no FI options for the HR, but from what folks were saying at the time, going to a gear like the 3.9 would still be 'ok' with a supercharger but not work so well with a turbo. My plan was to go supercharger when it became available, and if the 3.9s were too much then I would go back to the stock.but till then Id use the 3.9. I thought for me the 4.08 would be too much period..so the 3.9 would be a safer shoice.

I didnt have any trouble finding them online (I thought I read somewhere that they were from the Xterra in Japan or something), I got the install kit and in fact I had Nissan install them when I got the Nismo exhaust put on. They gave me a year warranty on the work too since it was indeed a NIssan part.

http://www.vividracing.com/catalog/c...3-p-20063.html Dont remember if I got them there..but the description sounds familiar

 

lol because they copied our description word for word

http://www.z1auto.com/prodmore.asp?m...ne&prodid=1726

it's from a Japan-market-only sedan

 

might be the worst ever reason to go supercharger instead of turbos just because you have 3.9 FD. i'd go back to stock or a 3.3 FD and go turbos 100 times out of 100.

 

I do not see the purpose of changing the final drive ratio "unless" you have a specific need such as drag racing or autocross.

 

Ok, thanks. That does make since. I have always heard that 3.9's were not nissan so I guess I assumed as well that they were fabricated from the ground up.

 

Ok...

So if some one would just clarify this for us...

(Refering to only HR motors)

Would it be safe to say that it is not best to go with 4.08 or 3.9 if you plan on going forced induction, however; the stock or 3.3 final drive ratio would compliment a supercharger or turbo setup much better...

 

Yes

 

That isnt the reason I want supercharger over turbo. It was the reason I chose 3.9 over 4.08 at the time. I always wanted a supercharger because Im not looking to build, I dont need to go over 400whp and want something more drivable and more reliable. I got the 3.9s because at the time there werent any options for FI, so I figure in the meantime may as well get the 3.9s, enjoy them, and they may still work out when I went SC.

 

haha yes! Now i remember I did buy from you guys. Its been a few years sorry!