FritzMan

My 350z is a year-round daily driver. Because of that, one of my goals when purchasing the car was to improve all aspects of the car's performance while retaining OEM appearance and driveability. Sort of like how Nissan would deliver a true Nismo version of the 350z.

I did a lot of research before purchasing and Unorthodox Racing flywheel appeared to have the performance improvements I was looking for while meeting my goals. I was guaranteed that there would be no change compared to OEM “under any RPM”. There was a large $270 premium in cost over JWT quote, but for OEM quietness I felt it was worth it.

I get the car back after a 4hr install. The car fired right up and was dead silent (with and without the clutch in). As an earlier review of a JWT stated, 50% decrease in rev time is approximately correct. It could easily pass for OEM at a Nissan dealership although I was personally hoping for a little more rev-ability.

I started with a mellow cruise through a residential area to warm up the car and then take a blast down the highway. Starting and stopping was the same - no stalling issues. Slow accelerations were also pretty much no different. I could hear a slight increase in volume when below 2K RPM, but no biggie.

On the highway, the acceleration was improved (in the lower gears), but frankly it wasn't impressing me that much for the investment. Still, it was quiet so I was at least happy with that.

I decided to head back home on a city street. I cruised in 4th gear between 20-30 MPH (ie: below 2K). That's where the noise reared its ugly head. Cruising in lower gears you pass through 2K RPM so quickly and typically under so little load it’s easy to miss/ignore. In the larger gears, you use more throttle and spend more time in that gear. Under these conditions, THE UR FLYWHEEL CAN DEFINITELY BE HEARD!

I was pissed. The performance was mediocre, increased noise was present for my typical daily style and I just coughed up $1K for this ‘privilege’.

The only saving grace was that right before getting back to work I disabled the VDC and redlined 1st and 2nd gear. Running on 215 Blizzaks you don’t expect much traction but I was a shocked at just how much wheel spin there was all through 2nd gear.

Still, how much time am I going to be redlining it compared to lugging the car in a large gear? Sure I can drive around it by constantly making sure I stay above 2K RPM, but now the car’s lost a huge amount of its benefit/flexability. If I wanted to drive to work reving a motor, I’d buy an S2000 thanks.

Note, following a couple recent postings of other reviews of this flywheel indicating there's more noise than OEM, I notified the vendor that I’d like to return the flywheel. He said it would cost me 25% to restock – an insult considering it wouldn’t be on his shelf that long and that I was mislead to get the sale in the first place. I hate having to call someone out (even though I've been a nice fellow and haven't actually mentioned the shop's name - a quick search will give you that), but it's my duty to inform other prospective buyers the truth.

teacher

iTrader: (1)

I`m not surprised that you`re not enamored with this mod, but the level of dislike is more than I had expected to hear

My UR mainly makes noise in 5th gear. I think it`s pretty silent chatter-wise in lower gears, even under the magic 2000-2400 rpm mark. I do hear a `whoosh` or gravelly noise at light accel. many times though. It isn`t as intrusive IMO.

I didn`t have to pop as much $ for my UR, especially on the install, so I can see you giving it lower marks compared to me.

The performance improvement is subjective too. I feel that it livened my car up noticeably.

I hope something good can come of it.

Jack

FritzMan

I was more pissed about the noise than anything else. I made such an effort to prevent it, but I still got deceived. I was also a little grumpy because my insurance yanked my coverage yesterday after learning I autocrossed my car which they consider "racing".

Finally getting new coverage today (promising not to Solo2 again), I managed to get a second drive. Pretty much the same as the first post except I had a much harder time duplicating that noise (happened only once). It's definitely random and only when below 2-2.5K RPM with moderate throttle for any duration.

When the VDC is off (it interferes much sooner than the SLIP light indicates) the flywheel is given much more authority over the powertrain. There's definitely a stronger kick in the lower gears.

Not considering cost, it's a decent mod. If you can find a deal (ebay seller apparently has a bunch of 350z UR flywheels for $500) and better yet, install it yourself, it's a solid bang for the buck.

Still, buyer beware - the flywheel will make noises under certain situations but it's easy to drive around. Thankfully, the noises are not present at idle.

Diesel350

iTrader: (6)

Man thanks for the post. I was going to get this flywheel but now your post has me on the fence. I think I'm just going to save my pennies for the APS Turbo.

joust75

iTrader: (1)

I understand his being upset. I was led to believe that the UR flywheel was as quiet as OEM.
So he gets it and its just as noisy as any aftermarket flywheel. That sucks.
He coughed up the extra bucks to get a flywheel that would be more quiet and was dissapointed.

Thanks for posting Fritzman. Lesson learned. Get the JWT over the UR and save a few bucks.

FritzMan

As much as I hate being the guinnea pig, I'm happy to accurately tell others the truth and prevent potienal future disappointment. One more thing about deception. The UR is advertised as 12 lbs, not so. I personally weighted it as 13.6lbs pretty much identical to what I've read about JWT. If they're advertising wieght without the bolt-on steel friction interface, they should say so.

While I haven't personally heard the JWT setup, I have read the drivetrain noises disappear above 2500 RPM. If it's quiet at idle like the UR setup, then it's definitely a better bang for the buck (get a quote from Performance Nissan).

Drove the car around yesterday some more and the noise was very apparent below 2500 RPM. For some reason, it was easy to produce today. If you want to know what that noise is like, try driving around slowly with your OEM flywheel in a large gear, below 2500 ROM. You will hear a very muted drivetrain noise. With the UR flywheel, it becomes *much* more amplified. So much so that a passenger unaware of the situation will definitely hear it. It doesn't sound broken or anything, more like a big truck accelerating from a stop.

JKDman

From my gathering of info:

JWT SETUP:
-Noise at IDLE (unless clutch is depressed)
-Noise below ~2500rpm (louder in higher gears)

UR FLYWHEEL:
-QUIET at IDLE (with and without clutch depressed)
-Noise below ~2500rpm (louder in higher gears)

Anyone else know of any other differences between these?
I'm not sure if the JWT can use the stock clutch.