6MT with 3.53s?
 

Any of you 6 speed FI guys try switching to a 3.53 rear end? I really think it would make the car a lot more fun to drive on the street, and better for the track. If you have, I would love to here your input. I did a search and couldnt find anything.

I think Mr.Squeeze did. I'll have to check his build thread to be sure.

Here is the post from Mr.Squeeze.

http://www.the370z.com/forced-induct...ml#post2175330

He used gearing from an auto 350z, 3.3 final drive.

I talked with OS Giken last year at Sema and their reccomendation was to use the Auto final drive for our cars. I am more inclined with that idea or a custom Final drive for FI... I would love a 200mph+ final drive :D

Thanks man! :tiphat:

200mph would be fun however my goal is to get more usable power. I don't see why an auto guy wouldn't wanna trade straight up. Gonna make a post in the socal section.

Go with the 3.3 Final drive you will love it I have it in my car. After I put the 3.3 in my car it felt so much faster from the load. 350z guys have been doing it for year's. The 3.53 comes stock in all 350z's when any of those guys go for high whp turbo they switch to the 3.3.

You can use what i posted below as a reference it's all the final drives that we can use in our car's just look at the 7500 redline to get a idea for the 370z.

STOCK 3.357 Gear-- ECU REFLASH 3.357 ---HR Engine
6600 Rpm Redline --------7200 Rpm Redline----------7500 Rpm Redline

First------40mph ------First-----44mph-----------First-----46mph
Second ----66mph ------Second----71mph-----------Second----74mph
Third------94mph-------Third----102mph-----------Third----107mph
Forth-----120mph-------Forth----131mph-----------Forth----136mph
Fith------152mph-------Fith-----166mph-----------Fith-----173mph
Sixth-----192mph-------Sixth----209mph-----------Sixth----218mph

STOCK 3.538 Gear-- ECU REFLASH 3.538 ---HR Engine
6600 Rpm Redline -------7200 Rpm Redline-----------7500 Rpm Redline

First -----38mph ------First-----42mph-----------First-----43mph
Second ----62mph-------Second----68mph-----------Second----71mph
Third -----89mph-------Third ----97mph-----------Third----101mph
Forth ----114mph-------Forth----124mph-----------Forth----129mph
Fith -----144mph-------Fith-----158mph-----------Fith-----164mph
Sixth ----182mph-------Sixth----199mph-----------Sixth----207mph

No Reflash 3.7 Gear-- ECU REFLASH 3.7 ----HR Engine
6600 Rpm Redline ---------7200 Rpm Redline---------7500 Rpm Redline

First -----36mph-------First ----40mph-----------First-----41mph
Second ----59mph-------Second----65mph-----------Second----68mph
Third -----85mph-------Third ----93mph-----------Third-----97mph
Forth ----109mph-------Forth----119mph-----------Forth----124mph
Fith------138mph-------Fith-----151mph-----------Fith-----157mph
Sixth-----174mph-------Sixth----190mph-----------Sixth----198mph


No Reflash 3.9 Gear -- ECU REFLAH 3.9-----HR Engine
6600 Rpm Redline ----------7200 Rpm Redline-------7500 Rpm Redline

First ------35mph-------First ---38mph-----------First-----39mph
Second -----56mph-------Second---62mph-----------Second----64mph
Third ------81mph-------Third----88mph-----------Third-----92mph
Forth------103mph-------Forth---113mph-----------Forth----117mph
Fith-------131mph-------Fith----143mph-----------Fith-----149mph
Sixth------165mph-------Sixth---180mph-----------Sixth----188mph


No Reflash 4.083 Gear-- ECU REFLASH 4.083--HR Engine
6600 Rpm Redline ------------7200 Rpm Redline---------7500 Rpm Redline

First ------33mph--------First ---36mph----------First-----38mph
Second -----54mph--------Second---59mph----------Second----61mph
Third ------77mph--------Third ---84mph----------Third-----88mph
Forth ------99mph--------Forth---107mph----------Forth----112mph
Fith ------125mph--------Fith----137mph----------Fith-----142mph
Sixth -----158mph--------Sixth---172mph----------Sixth----179mph

Great info thank you. Is the 350 stock 3.3 a direct bolt in? I hope I will be able to hook 3rd at least after the swap!

Go to a junk yard grab one from any 350z/g35 should be easy to find from 03 and up.Just make sure it has LSD by turning the stub by hand the other one should spin in the same direction.

Or you could just get a open diff and put a good LSD in it. I am getting a spare to do the same.

Did you have any issues with cruise control or synchro rev when swapping to the 3.3? This is something I'd definitely like to do!

Rev match works without a problem cruise won't work in 6 gear I have to use 5 gear for it to engage I rarely use cruise.

Direct swap man fits like a glove very easy.

So just swap the whole pumpkin ?

Yes the pumpkin

:icon14:

Great thank you man. I will look for an open diff so I can swap my OSG into it

No SRM here and I wouldnt mind losing cruise for tons more usable power. Did you make yhe swap before your built motor? I cant even get my car to hook 4th so I really see this as being a neccesity for the TT guys

Will this work also for g37? Also would it require to re-tune again?

I don't see why it would but don't quote me on that. I also would imagine you would wanna take a look at the tune as you will load up the motor more. Also just a guess im sure mr.squeeze can chime in more

Yes it will fit the G37 without a problem. I didn't get tuned right away it was fine when I went back to re-tune that was because I added the F.I 3 inch exhaust.


I swapped once my motor was built this was something I knew I was going to do. With the right set up alignment tires car not slammed I was hooking very good in the summer 570whp 2 gear from around 40mph or so.

Cool man appreciate you chiming in. Its on my to do list..

I would have to give up my SRM to go with a new final drive, which I would hate.

completely? he said SRM still worked I thought. Now I am wondering if my OSG diff will fit in that pumpkin..

REV match still works you will not have a problem with it at all.






You can use just make sure you get one that's made for a auto.

Putting this on my to-do list.

Think I found a diff from a 2005 G35, listing says AT (3.357 ratio), (locking). That's what I need right? Is this a DIY type install?

That will fit without a problem , if your going to DIY make sure you have help lifting the differential its heavy.Also if your going to just swap make sure it has a factory LSD by turning the axle stubs.

It may still operate, but it will be not be matching correctly. Changing the final drive would change the RPM/Speed ratios, which the SRM computer uses to compute the rev match. As far as I know, no one has figured out a way to change those values upon going to a different final drive.

Cool. I'll have to flip through the service manual. Maybe I'll buy the unit and get R/T to install it for me when I go for my tune.

Thanks!

I share your concern, it wouldn't be correct. This is what has held me back so far from changing my FD.

One of us around here should find time to put together a spreadsheet to display exactly how far off it will be. Perhaps in most cases, it might still come in a lot closer than the typical throttle bump from a heal/toe downshift anyway. I am not sure a few hundred RPM would make a noticeable difference.. but if there are scenarios where we are looking at 1200+ RPM off, it could become annoying or counter productive to leave SRM on.

I will say this much I have had it on my car since July of last year and my down shifts still seems smooth when down shifting. I use rev match all the time it may use the computer to compute speeds .

I will also say and its s fact my car is much faster with the 3.3 than the 3.7 its perfect for my power level . With the shorter gears was shifting way to much and traction is much improved in my opinion any Z over 550 whp .

That's good to hear. I totally agree regarding the better match of long gears with FI, particularly turbos. On my last turbo car, the short gearing was my #1 complaint. We should try to make a spreadsheet just to see what the effect is. My guess is that it is not that significant if you aren't having serious issues.

Where did you source your final drive gears?

I still think even with the 3.3 the lower gears are still to short 1-2, I however do love 3-4 gear now.

I got the whole differential from a local junk yard for $200. I plan on getting another one from them just rebuild and put a good LSD in it.

If you cant find any at a local junk yard look on Ebay.

Can anyone with 500+ rwhp comment on traction improvements by only changing from the factory LSD to an aftermarket LSD? As far as just pure straight line traction, I wonder how much can be unlocked in the diff. The way my tail wags around, I dont think I am getting any one-wheel action in a straight line, but it will often go one-wheel on me if I am trying to do donuts.

Here is a comparison chart between stock 3.692 and 3.3 ... if my math is correct.
http://farm9.staticflickr.com/8366/8...761d32ac_b.jpg

What car was the diff off of? A 370Z? Just curious where the new gears come from. Sorry if I missed this above.

I run the 3.53 with a Quaife ATB LSD, cruise and SRM work perfect (about 100rpm off). I'd agree that over 500whp the 3.3 FD is probably best, but the SRM will be ~300-400rpm off (same as going to 4.08) and as Squeeze mentioned, cruise won't work.

Why does cruise not work? Is it because of the speed/rpm mismatch? I would think the computer would just hold a speed.

Esforteen - where did you get your setup and would you recommend it?

From my experience and going from a 3.7, 4.08 and 3.9 ratios(why you ask? ..long story) that if your concerned about the few extra RPM needed for a downshift....... blip the throttle after Rev match has done it's thing.

Phunk: the stock LSD is a piece of crap. I use a Cusco RS 1.5 80% and when it locks it locks well. But it is noisy on low speed turns and likes to clunk at low speeds.
Beware though, as it will snap rear axles with drag radials.

I want to do this but I cant see my OSG lsd fitting in the new pumpkin..

I put it together myself: used 350z open diff, quaife ATB LSD for an open diff, new bearings, seals, and shims from nissan. It took about 4 hours to put it together and properly shim the diff, if you're mechanically inclined It's a fun project. I love this setup, but going for 600whp I could probably use more gear lol.

As for the cruise control with the 3.3, I believe the issue is related to the RPM's being off since Squeeze mentioned cruise works in 5th gear for him.