JWT vs Southbend Clutch/flywheel set-up
 

Hey guys, I'm going to be replacing my CSC with the Zspeed HD CSC and am looking to also replace my clutch/flywheel while the transmission is open. I've looked around the forums on this site as well as a few others and have narrowed my choices down to either the Southbend stage 2 daily kit with either the 19lb Steel flywheel or the 14.5lb aluminum flywheel (I'm leaning towards going with the aluminum one) OR the JWT HD clutch/flywheel (15.4lb flywheel). I have full bolt-ons with 4.08 gears and am looking for the best performance (acceleration) and reliability. I dont really track the car, but i want whichever set-up I go with to be able to handle a track day if I decide to do one. Any experience/advice would be GREATLY appreciated!

An aluminum flywheel will make a lot more noise than a steel one. Both will make a lot of noise, but the aluminum will be worse. If that's a concern at all, go with the steel one.

The noise is not a concern for me, just reliability.

Maybe also look into southbend steel flywheel. It's 23lbs and maybe better for street use since not as light as the others. Videos I seen also show it's not as noisy.

I can't see reliability being any different between the two aluminum flywheels.

I'm mainly looking to see if there are any issues with tracking an aluminum flywheel as well as advice on which kit is better between the Southbend and JWT

I have the ss southbend kit and aluminum flywheel for about 10k drives great and feels fantastic. Got it all from joe at zspeed he has great service!

What stage southbend do you have? I'm looking at the stage 2 daily. Also, how does the aluminum flywheel feel? Noticeably better acceleration? Any loss in torque feel?

South Bend Clutch SS Street Kit with Aluminum Flywheel Pre-Order

Revs ridcoulously faster, if you notice anything, its not much at all, the benefits far out weigh the cons, they also have a slient disk that helps with the noise, but it is really not that bad, if you have an exhust you can not really hear it much. It is also worth a call to Joe at zspeed, if you tell him what you are doing with your car he will suggest the right clutch for you.

use to have a jwt aluminum flywheel. diff. feel faster acceleration. drove for a couple of thousand miles on it but was way to noisy for me so i ended up selling the flywheel, will be trying out the south bend flywheel next(19lb). when inside the car while idling wont notice it too much if you have music on, but if you are on the outside sounds like throw out bearing took a dump

as a JWT owner, i have to say its the best clutch i have ever driven, easy to drive, no slip, and much better than the stock clutch imo

the flywheel does rattle real bad at times but i usually dont notice it unless i have AC on and no radio playing, i like the weird looks i get from it though, like the what is wrong with your car that makes it sounds like a diesel truck(not exaggerating there either)

since you're dropping the tranny id suggest looking into a short shifter as well

Bryan what is going on big guy. Thi sis C4...lol I have to say JW FTW...... JTran will tell you the same thing.

Whats up man! So you are really happy with it? Noticeably better acceleration/faster rev? How bad is the extra noise?

:ughdance:Not too much big guy. No complaints about it. Acceleration/rev seems faster, but I also had the F. I. RHFC's & Stillen Gen 3 put on at the same time. I had to break the clutch in for 500 miles and keep the reviving from one gear to the next under 3k (a little hard to do). OH you will definitely notice the noise, but it’s not OMG WTF is this. It is not terrible sounding, but you will get use to it too. You have to remember that you installed a HD aftermarket clutch & flywheel.

I'm still trying to decide which setup I want. im still running my factory clutch with 433whp..hahah. surprisingly its still holding up. I think I might for the JWT setup, but I really want to SZ setup but 1575.00$ is a lot.

UPDATE: I went with the Southbend Stage 2 daily with 14.5lb aluminum flywheel and couldn't be happier :)

Been running JWT products in my VQ's for over 8 years, Awesome! Everyone on here seems to lean towards Southbend, either way, they both have great reviews and customer service.

I just upgraded to the southbend stage 2 daily from ZSpeed with the 19 lbs steel flywheel and cannot believe how much better it drives. Now just need to put some break-in miles on it before I can really test it out.

Also I have it combined with the RJM clutch pedal which I also highly recommend. Lets you dial in the engagement zone right where you like it!!

break in is over rated IMO, do some heat cycles and some light stop and go traffic and let it rip, just pulled my clutch out after 25k hard miles, the last 1k boosted and it looked good, I upgraded it to a better disk, one of the daily disks with a higher TQ capacity.

So JWT vs Southbend vs SZ, which kit is the best? I concern more on the drivability, performance and durability. I assume all the lw flywheels will have some noises. I am cool with that.

And what's the differences between the Southbend stage 2 daily and stage 3 daily. I know one rated 450 and the other rated 550. But how's the drivability between the 2 kits?

I've had both the JWT and Southbend stage 2 setup. They both pretty much felt the same, and drivability is pretty much just like stock. The only time I could really tell I had an aftermarket clutch was when I would power shift or dump the clutch, it grabbed a lot harder than the stock setup. I also had the Southbend lightened flywheel. It was 22lbs (stock is 31lbs).. it was a little noisy when sitting at idle, but while you're driving you won't be able to hear it. Plus it revs up so much faster than the stock crap.

Hello man, how is the FI project? Can you give us more review on the Southbend Stage 2? Thanks

i got the same set up no complaints here

So from the looks of it,there's about 3 options for aluminum flywheels. Of coarse the lighter the better performance wise. I'm assuming the heavier you go,the less "chatter" you get because of more material to absorb the vibrations. So anything lighter than stock is a win,and with the heavier of the aluminum flywheels would be more street friendly?

Great info as always.:tiphat: Do you know how heavy is the JWT flywheel? Is it aluminum or steel? Also are both JWT and Sounthbent stage 2 kit can hold similar amount of power?

I've had the JWT aluminum flywheel, it's about 16 lb.

Now I have the Southbend steel flywheel, iirc that one is about 21 lb.

^ which one do you like most? The JWT or the southbend?
Why the switch to a light weight to a 21lbs?

I'd be willing to bet its chatter. Going to something heavier has no performance benefit so I'm assuming its to quiet things down a little.

Do you feel the performance differences between the two?

Also for you guys have JWT or Southbend for years, do you have thrust bearing issue or did you guys bypass the clutch start switch as you will dry start the bearing?

To be honest bro... I have no idea what the hell you are saying.. lol

I had the JWT flywheel with a stock clutch for about 20k miles then swapped out for a Clutchmasters stage 1. After another 30k miles I broke a flywheel bolt and the head beat up the flywheel + clutch. It sounded HORRIBLE hearing that little bolt head bouncing around.

When I ordered the southbend flywheel +clutch I wasn't sure what broke yet so I just went with a different brand clutch and more durable steel flywheel.

Southbend flywheel is a bit quieter but to be honest the noise from the JWT never bothered me.

Slight difference I guess but I hardly drive it much lately (weekend fun car) and no matter what I do, it always feels like a rocket ship compared to my daily driver.

I hope this helps.

Usually with upgraded pressure plate, there will be increased load/wear on the thrust washers in the crankshaft during the initial crank/start up because there is little oil to lubricate the washers before pressure gets a chance to build up. When thrust washers get worn out, crank walk will result. A lot of people bypass the clutch start switch when running high tq capacity clutch setup so that there is no load on the thrust washers during cranking.

^ how to bypass the clutch start switch? Whats a crank walk?

You can bypass the clutch switch by modifying the wiring to the actual switch on the pedal. Crank walk is when the crank moves front to back, which is catastrophic to the engine.

I haven't heard of any crank walk issues on the 370z though. Im not saying that there havent been any, but I haven't heard of any cases.

Lol... wow, that sounds really scientific for a clutch install. I've never heard anything like that before.

Sorry I didn't explain this well... Lol. So basically most aftermarket clutches have high spring load that will add extra force on the main thrust bearings when you depress the clutch and cause premature main thrust bearing wear. If the thrust bearings wear out it will cause the "Crank Walk" and eventually engine failure. This won't happen immediately but after 30k-40k driving. My friend's 350 had this issue. He had to rebuild the engine. My mechanic friend who worked on vqs for 12 years told me bypass the clutch start switch is a must for those clutches(that includes the JWT). However, while I am doing researches I found Z1 pointed this out and claimed their clutch has the low spring load while still keeping the high clamping force which looks pretty promising to me. That's why I want to ask you guys that have JWT or Southbend clutches on your car for a while has encountered anything like that.

Here is the quote from Z1:

The pressure plate in this kit exceeds OEM specifications and features high clamping force while maintaining a low spring load. A low spring load eases lateral force on the main thrust bearings in your engine which is especially important during "dry" start-up. (High pressure plate spring loads result in high lateral forces being exerted on the crank when the pedal is depressed and the clutch is disengaged which can cause premature thrust bearing failure resulting in "crank walk" and ultimately engine failure).

Z1 370Z / G37 Clutch and Flywheel Combo

I got a JWT Clutch and flywheel.Love it performance wise but not the chatter sounds like im running on no oil.Plus my CMC is going out

Did you change out the CSC and CMC when you install the clutch?

I did a new CMC, the zspeed CSC, and stage two daily clutch and steel flywheel from south bend. I love it! Revs noticeably faster for me, but the chatter isn't terrible. I honestly think engagement is smoother than my stock clutch as well. I also have some peace of mind now that I've been autocrossing and tracking the car on a consistent basis. I switched it all out due to CSC failure around 35k miles.