What does a proper break-in procedure entail? What worked for you?

http://www.ringpinion.com/technicalhelp/ContentFrame.aspx?FilePath=~%2FContent%2FParts%2FRingAndPini ons%2F%2FNew_Gear_Break-In.inc

i did a bit of browsing through this thread, as i am interested in installing these gears along with quaife LSD, but before I get involved in it I have a couple questions that I didn't find...or didn't see at least.

It seems the general consensus is that the 4.08 gears are great for the HR engine (because of the higher redline and whatnot)

But what about the revup engine? would the 4.08 gears be as beneficial? or would the revup engine benefit more from the 3.9 gears?

where do you guys buy these gears? Z1 seems to have reasonable pricing but they don't answer e-mails maybe they're already on christmas holiday.

Tomei makes also final gears, but are they really worth extra buck?

(Tracking and drifting 50/50 and my Z is sc (hr))

408 is for na z's. Unless you drive around on slicks or 305 wide drag radials then 408 would be a waste in a sc z. No traction. Z1 answers emails like a week later then went you send them.

Any thoughts on 4.08 on a NA revup with manual? I saw someone ask a few posts back with no real input.

I had them on my 06, you can tell the difference with acceleration and was certainly fun to spin tires in 1-3/4. I bought a new Z recently and probably will not be doing this mod. Saving for that turbo :icon21:

4.08 FD/Stock Diff
 

Hey guys, not trying to bring up an old thread here but I have a question. I have a bone stock, 35th Anniversary (minus K&N drop-in filter which I don't count as a real mod ha.) I've had my car for a little over a year and put 22,000 miles full of grins and giggles. But, the time has come where I just can't leave it alone. I don't want to change anything more than what I have to because I think a bone-stock 35th Ann. could be a nice collector's item in the future once all of the others are heavily modded, riced out, or wrapped around a tree.

The 35th Ann. if you aren't familiar with it (I assume anyone who's opinion counts on here is aware of this but just to make it clear) has the DE Revup and stock Vicious LSD.

My question is this: Would I probably be okay if I kept the stock diff and just dropped a set of 4.08s in the rear end? I drive it mildly-spirited at most times as I'm over the burnout/donut stage in my young life but still "lay into it" sometimes. I'd just like some more low end grunt, and I don't do any auto-x and have only taken my car to the strip a couple of times with no plan to make a race car out of it.

Money is fairly tight and will be for the next couple of years until I land an engineering job, so if an aftermarket diff is absolutely crucial for my car and relatively normal driving habits, I'll just toss the idea out the window.

P.S. I know I don't have any posts (maybe a few but I'm not real sure), but I wouldn't consider myself a noob to the car world, so please don't roast me if at some point this question has been asked an I overlooked it in the 46 pages of this thread.

Thanks guys!

I would recommending buying a spare pumpkin to build then swap in...

If you plan on keeping it mostly stock having a known good spare will help...especially in a jam !

If you put 22k miles on your car in a year im going to guess most of that was on the highway. I would think your best leaving your gears stock if you put that kinda mileage on the car. What is the cruising rpm on the highway like 3k rpm+

By "soar" do you mean just another cheap stock pumpkin to "build" and then just keep my VLSD for when/if S#!T hits the fan? Thanks for the response!

Actually, I hardly ever go on the highway, believe it or not. I just drive to random scenic spots here in Arkansas which I can normally get to by city streets and then scenic/curvy roads. I just love driving! Thank you for your input though, I appreciate it!

You got it. I would keep my stock differential and buy a used one to build or get an already built used one. Their are a few in the marketplace bolt in ready for about $1000. The parts to build it yourself will probably be little more. I think the added acceleration would be a enjoyable mod.

I hope someone chimes in with what rpm the car cruises at on the highway im curious.

I'll definitely check out the marketplace. As to the cruising RPM, I'm pretty sure there's a thread on this somewhere that I ran across during my research for this little project. I'll see if I can find it.

Any come up with the rpm's for 6th gear about 70mph cruising? With the 4.08 gears vs the 3.9s thanks.

Otherwise stock 2005. 4.083 gears at 70mph=3050 or so rpm (one needle width past 3000). At 75mph it is 3250 exact.
I've got stock tire size.
Any other rear end ratio can be figured from this data. 3.9 gears at 75 should be 3104 rpm.

Where is everyone buying their pinion shim sets from? Im in the middle of installation and the factory shim is too thick.

I don't think they make sets. I put my gears together and made an educated guess which one I needed. I then went to my local dealer and bought two different shims that were close and got lucky that one guess was right.

Pretty sure you can get them from Z1 dont know how long the trip to Kuwait would be though.
https://www.z1motorsports.com/advanc...ferential+shim

I'm willing to buy stock ring and pinion if somebody is willing to sell one cheaply!