I need help!!!! I can't decide! This is where I'm at...

My next 2 mods are clutch/flywheel and rear gears...
I'm on 65k miles now and still have the original Master cyl, and I know it's going to need done soon.... So I wanted to do that next. But with my bigger heavier vossens I put on, my car feels a little sluggish now... I'm not sure if a stage 2 southbend clutch and lightweight flywheel would make up for the rims, and make my car faster than it was on the sport 19s or not... (Anyone know the answer to that??) Which will cost $1,500... I believe I can get rear gears and have them installed for that... I love the look of my vossens so I won't change that. But if the clutch/fly won't make that car quicker than it was before by at least a small margin, I want to do the gears first. Which leaves me to my next dilemma...

3.91s or 4.08s...
I have a 2010 6mt S coupe...
Meisterschaft full catback
KWv3 coilovers,
20x9/20x10.5 Vossens wrapped in 255s with 285s in the rear.

With the GTHaus exhaust it's quiet while cruising now with no drone (contrary to popular belief) but it does get loud at about 3200 rpms... So with the 4.08s I wonder if it will be too loud at 80mph for road trips...also the mpg from what I read on 370z forums lose 1-2mpg.... Which isnt horrible, but not ideal. Top speed will suffer as well... But I have no idea how much. I have a friend with a long private super flat and straight concrete road that we run on and sometimes do get faster than 130 mph... We also do 40 rolls out there sometimes, would 4.08s put me near redline in 2nd at 40mph?

The 3.91s are more attractive because less top speed loss, lower rpms while driving, less mpg loss... However, I'm wondering if 3.69 to 3.91 is even worth it?

I need help! I'm so torn and have no idea what to do...
Also, anyone know some trust worthy shops to do the swap in either Houston or Austin?

Thanks for any and all opinions and input!

EDIT:

I was told these would work:
http://www.thenismoshop.com/Nissan-F...-G35_p_69.html

I was also told I would need:
http://www.thenismoshop.com/Nissan-r...37_p_1399.html

Is this all I need? Are there better options? Thanks!

 

Clutch/flywheel won't make your car faster.

 

I didn't really mean faster I guess... I suppose quicker? Make up for lost acceleration with a lighter flywheel, resulting in less internal spinning mass. Or are you saying it won't help in that manner either..?

Edit: I'm mainly focusing on the gears though, as even if I change the clutch and flywheel first, this is still my next mod.

 

Your car will Rev quicker with the clutch/flywheel giving the illusion of increased power, but in the end your at the same place. Go all out with 4.08 gears and a new diff and that may clear up a few lost hp in the drivetrain

 

I vote 4.08 gears. Can't help too much because I'm not 6MT and have not done my gear swap.

I might, however, get a 6MT differential at first and just try it with the 3.6 gears. I would rather have the 3.9 gears though. I'm still not so sure myself.

When do you plan on doing this mod?

 

Yeah, I went on the 370z forum and there's a lot more info about 4.08s on there and that's pretty much what I've decided to go with... I drove around in 5th at 3200 rpms to see how loud it would be, and it's just a soft hum, not bad at all. The 1-2mpg highway loss isn't too bad for me... If I wanted great mpg I would have bought a civic. Top speed is no longer a concern as many Z guys hit 160+ with only minor mods. I really want to get this done mid to late April. I just need to make sure there's nothing else I need aside from the two links up there, and fluid obviously... Then find a reputable shop in Houston or Austin that won't charge an arm and a leg...

 

I know this may be a shot in the dark but do you know if this will work for a 5AT? I know i need to get a diff from a manual as its larger to accommodate for the gear change and that will supposedly fit fine on my car. But will the kits you provided the link for work as well? I'm guessing it will but wasn't sure if anyone knew for sure.

 

7at go with 3.9 or 3.69, 6 speed go with 4.08. I put 3.9 in my 7at and it was the best thing I have done to my car.

 

A lightweight flywheel should help free up a few hp at the wheels. Not much, but it's there.

If the engine revs quicker that's a result of the gained power due to reduced rotational mass. If it sweeps through the powerband faster, the car will be faster.

 

I've had 4.08 gears on my previous car, got it done together with a new aluminum driveshaft and these two mods together were the best bolton mods out of everything I've ever tried on NA car and I've tried a lot of mods.

 

4.08 gears FTW

 

Any idea of what shops do this install on the G37/370Z?

I'm in Las Vegas, so anywhere within a 4-5 hour driving range is fine.

Have read about whine problems due to incorrect preload problems, so really only interested in shops that have performed multiple installs.

 

Seb at Specialty Z does all my work..he is in Chatsworth, CA

 

Yea they do fantastic work. I'm actually going to them sometime next month for my tune.

I've talked to sebastian in detail about the gear swap and they are very familiar with it and completely understand and know what they are doing with this mod.