First I have to give props to Tadashi and Howard at Technosquare Inc for doing the install. The turn around time was only a day and I left with absolutely no problems at all.

First Impressions - All I can say is WOW. I have the diff locked at 60% and so far it has been great just for daily driving. No obnoxious clunking of any sort. Now I feel more confident going into and exiting corners faster. The gears definitely helped in the acceleration department. By the time Im out of the corner, I am already in the peak of the power band. I noticed that I am shifting gears a lot sooner than usual which means my MPG will definitely be go down. I noticed that my RPM is at 3500 at 80 MPH than the usual 3000 RPM. All well worth it. I've only driven the car today so we'll see how it does after I push it harder after the break in. I cant wait to get back out to the track!

 

Why wouldn't you have had Performance do it for you??

 

We can do it here but we would have to out source it so eithe way it wasnt going to be done directly at Performance. Plus, Technosquare has done plenty of final drive jobs and plus theyre really close to my house. Just made sense this way.

 

Ah, ic.

 

3.7 gears? Call me an idiot, but what am I missing? When did this FD ratio show up on the scene and what's the difference in acceleration characteristics between this and the 3.9 gears?

 

The 3.7 ring and pinion I put in my car is a factory OEM NISSAN part out of another vehicle. Compatible with the R205 rear end, the ring and pinion dropped right in. Difference in driving characteristics between the 2? I wouldnt be able to compare as I havent had a chance to drive the 3.971 yet. Maybe Ill test drive Rickdogg's car and do a comparison. All I know is that the acceleration was a notciable difference and I wont lose so much top end speed with the 3.7.

 

Interesting. I'm about to drop in the 3.9; I didn't figure I'd ever get above 150, anyway...

So what difference can you feel on the street between the Cusco RS and the OEM VLSD? I wish I could afford to do the diff. now too...

 

I was consiering the 3.7. You guys sell them right? Ahh. here it is.
http://www.mynismo.com/products/?id=5568

From what I've read, the difference in performance form the 3.9 and 3.5 is approx. 10% faster acceleration. I know it probably doesn't work this way but I'm guessing 5% with the 3.7.

 

sounds nice Andy - I wish I went with the cusco RS back when I bought my LSD instead of the nismo


at 80mph, the 3.7 should be around 3050-3100 rpms in 6th gear depending on the tire diameter. 3500 seems really high, that's higher than my car with the 3.9
What are your tire sizes Andy?



top speed of the 3.9 is still around 165ph at 6600 rpms depending the diameter of your tires

 

The 3.69 FD is used in a few FM AWD vehicles. AWD FX35 FX45 M35X not sure about the G35X.

Howard, Richey, and Tadashi rock.

 

Very interesting Andy. I also plan on using the 3.7 final drive (with cams) and a redline adjustment to 7200 RPM. I did the math, and the shift points should be around the same MPH as stock.




BTW...the 3.7 final drive (38100-0C760) comes from the QR25DE Nissan Frontier.

 

Do you have to drive in figure-8's to break-in the new differential?

 

Im running 255/35/19 and 275/35/19. I thought it was a bit high in RPM's too, but in 6th gear at 80mph, I am shy under 3500 RPM's. My rev limiter is at 7500 RPM's so Im not too worried but I thought it was rather strange. Either way, the car definitely accelerates faster than stock. I know I should be doing some burn outs and figure 8's top break the diff in but I dont like doing that kind of stuff on public roads. Maybe a nice canyon run after I get back from Ohio will help the break in.

 

Yeah, that's why I was confused when you said the RPMs were so high in 6th, compared to what they are saying it should be for the 3.9 gears. That's really odd.

 

Hey andy you said that the 3.7 dropped right in. So Im assuming then that you didnt need to replaced any bearings or shims or anything at all correct? I am thinking about doing this to my 06 revup. Will it drop right in as well with out anything else?

 

What can you expect this type of setup to run you? I have an LSD setup in my near future and I'd like to know what options there are.

Thanks!

 

Why did you go with the Cusco instead of the Nismo? I'm torn between the two right now. I like the Cusco because it's quiter, but I like the Nismo because I can install it myself and it's easy to adjust locking %.

 

yeah it is. I was telling Andy how my 3.9 at 80MPH reads at about 3300. I don't think the wheel/tire combo would make that much of a difference unless you are running 22's since our cars do not need the speedometer adjusted to compensate for different gear ratios

 

Anyone have a calculator for mph based on tire size and gearing with the stock transmission? I think I want to do these mods in the near future.

 

im torn between the 2 actually also. I need a lsd in the near future.