JWT Flywheel Details
10-01-2003, 07:57 PM
#1
JWT Flywheel Details
Tired of the 3rd and 5th gear grind, I requested and received my new transmission. I'll discuss that on another thread tomorrow. Since my tranny was being dropped, this was the ideal time to add the JWT lightweight flywheel.
I ordered from Concept Z for a price that beat all other competition, including JWT direct. Thank you Coz. My dealership, Torrance Nissan, installed the flywheel without charge. For you So. Cal. folks, this dealership has some very cool people. I had a chance to speak with the service manager, Brian. Jeff at Performance may have some competition in the near future.
Okay, enough about the vendors and dealers, let's talk about the flywheel.
1st, the car will stall. On my very first start up, my Z stalled, something it never has done before. It wasn't a singular event. Revs will dip below 750 rpm and stall out. I expect that the ECU will adjust for this after a week or so. I'll report on this problem as time goes by.
2nd, there is a definite noise between 1,000 rpm and 2,000 rpm. When I first drove the car with the windows down, I heard nothing. Then, with the windows rolled up, I did hear a definite sound that is similar to the "sand in the gears" or more like something that's in a shaker. It is not a cement mixer sound I have seen said for the Jun flywheel. The sound is not noticable with music on. It is noticable when the windows are down and there is a car with a flat surface like a van next to you when you're driving 1k to 2k. The noise is not noticable on downshift. Is the noise annoying? Not for me.
Beyond 2k to 2.2k, there is very little difference in noise.
3rd, there is some very significant performance gains above 4,000 rpm. The needle when it reaches 4k will keep going to the right very freely through 5k and beyond. I have no doubt that in straight line acceleration, you will be shifting faster as the throttle response is definitely improved. In my lay opinion, and in a rough 1st day opinion, the flywheel shaves off .1 to .2 seconds off a 0-60 time.
4th, yes the revs drop quicker. It's very subtle. But, if you do a lot of stop and go freeway traffic, you will notice that downshifting will slow the car slightly more than the stock flywheel. This is good for the brakes and for the twisties.
5th, the flipside to 4th, and as Jeff over at Performance Nissan said, I believe that there will be a slight loss of fuel efficiency. By the way, I very much appreciate the comments from Jeff. I spoke with him for 20 minutes and he held off a page from his GM to respond to my questions. Jeff is definitely an A+ resource in my book.
You need to give the Z a little more gas than with the stock flywheel to keep it going due to the loss of mass in the rotation. The JWT flywheel is between 13 lbs to 14 lbs so it doesn't spin as long as a stock flywheel.
I'll make some more comments about the flywheel after it's set in. But, aside from the above objective comments, I definitely believe the JWT flywheel is a performance enhancing modification and worth the money. I will comment on the problem of car stall and low idle as well as the sound issues in a week or two.
I ordered from Concept Z for a price that beat all other competition, including JWT direct. Thank you Coz. My dealership, Torrance Nissan, installed the flywheel without charge. For you So. Cal. folks, this dealership has some very cool people. I had a chance to speak with the service manager, Brian. Jeff at Performance may have some competition in the near future.
Okay, enough about the vendors and dealers, let's talk about the flywheel.
1st, the car will stall. On my very first start up, my Z stalled, something it never has done before. It wasn't a singular event. Revs will dip below 750 rpm and stall out. I expect that the ECU will adjust for this after a week or so. I'll report on this problem as time goes by.
2nd, there is a definite noise between 1,000 rpm and 2,000 rpm. When I first drove the car with the windows down, I heard nothing. Then, with the windows rolled up, I did hear a definite sound that is similar to the "sand in the gears" or more like something that's in a shaker. It is not a cement mixer sound I have seen said for the Jun flywheel. The sound is not noticable with music on. It is noticable when the windows are down and there is a car with a flat surface like a van next to you when you're driving 1k to 2k. The noise is not noticable on downshift. Is the noise annoying? Not for me.
Beyond 2k to 2.2k, there is very little difference in noise.
3rd, there is some very significant performance gains above 4,000 rpm. The needle when it reaches 4k will keep going to the right very freely through 5k and beyond. I have no doubt that in straight line acceleration, you will be shifting faster as the throttle response is definitely improved. In my lay opinion, and in a rough 1st day opinion, the flywheel shaves off .1 to .2 seconds off a 0-60 time.
4th, yes the revs drop quicker. It's very subtle. But, if you do a lot of stop and go freeway traffic, you will notice that downshifting will slow the car slightly more than the stock flywheel. This is good for the brakes and for the twisties.
5th, the flipside to 4th, and as Jeff over at Performance Nissan said, I believe that there will be a slight loss of fuel efficiency. By the way, I very much appreciate the comments from Jeff. I spoke with him for 20 minutes and he held off a page from his GM to respond to my questions. Jeff is definitely an A+ resource in my book.
You need to give the Z a little more gas than with the stock flywheel to keep it going due to the loss of mass in the rotation. The JWT flywheel is between 13 lbs to 14 lbs so it doesn't spin as long as a stock flywheel.
I'll make some more comments about the flywheel after it's set in. But, aside from the above objective comments, I definitely believe the JWT flywheel is a performance enhancing modification and worth the money. I will comment on the problem of car stall and low idle as well as the sound issues in a week or two.
10-01-2003, 10:26 PM
#3
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Originally posted by webcarconnection
So you are the one who bougth my flywheel in Coz... J/K
I recieve mine today... thanks for the review, I post mine in the next couple of days!
So you are the one who bougth my flywheel in Coz... J/K
I recieve mine today... thanks for the review, I post mine in the next couple of days!
10-01-2003, 10:28 PM
#4
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With a lighter flywheel, you will have to get used to it, and you'll stop stalling it. I had problems in the beginning also with stalling the car, but after the first day of driving it, no problems. It's a great upgrade, and I recommend people to do it while you're in there. Thanx Again!!
10-02-2003, 04:08 AM
#6
Originally posted by Coz@CZP
With a lighter flywheel, you will have to get used to it, and you'll stop stalling it. I had problems in the beginning also with stalling the car, but after the first day of driving it, no problems. It's a great upgrade, and I recommend people to do it while you're in there. Thanx Again!!
With a lighter flywheel, you will have to get used to it, and you'll stop stalling it. I had problems in the beginning also with stalling the car, but after the first day of driving it, no problems. It's a great upgrade, and I recommend people to do it while you're in there. Thanx Again!!
My auto tech asked about this problem and I responded, yes I've heard about the issue. Bobowah noted the problem when he sat for a ride in Richard350z's car. I'm going to wait a week or two and will report if the problem persists or if it goes away.
One other thing. If you're replacing your tranny and are considering the JWT flywheel, you should also consider getting a new clutch. At 25k miles, I didn't think about it until I got to the dealership. By that time, it was too late to acquire a new clutch.
Originally posted by Mike Wazowski
please review CZP
https://my350z.com/forum/forumdi...p?forumid=93
please review CZP
https://my350z.com/forum/forumdi...p?forumid=93
10-02-2003, 04:39 AM
#7
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If your car still seems to want to stall, have the service dept use their consult unit to bump the idle up 100rpm and bump the timing 2 degrees at the same time. As long as you run 91 octane you wont have any detonation problems.
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10-02-2003, 04:43 AM
#8
Originally posted by Jeff@Performance
If your car still seems to want to stall, have the service dept use their consult unit to bump the idle up 100rpm and bump the timing 2 degrees at the same time. As long as you run 91 octane you wont have any detonation problems.
If your car still seems to want to stall, have the service dept use their consult unit to bump the idle up 100rpm and bump the timing 2 degrees at the same time. As long as you run 91 octane you wont have any detonation problems.
10-02-2003, 08:35 AM
#9
Originally posted by Jeff@Performance
If your car still seems to want to stall, have the service dept use their consult unit to bump the idle up 100rpm and bump the timing 2 degrees at the same time. As long as you run 91 octane you wont have any detonation problems.
If your car still seems to want to stall, have the service dept use their consult unit to bump the idle up 100rpm and bump the timing 2 degrees at the same time. As long as you run 91 octane you wont have any detonation problems.
I believe I will follow-up with both your suggestions on my next service date.
10-02-2003, 09:56 AM
#10
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Originally posted by Coz@CZP
lol, first credit card that worked got the flywheel
lol, first credit card that worked got the flywheel
Last edited by webcarconnection; 10-02-2003 at 10:01 AM.
10-02-2003, 01:22 PM
#12
Originally posted by raceboy
No stalling issues here.
No stalling issues here.
10-03-2003, 07:46 AM
#14
Originally posted by raceboy
No, Performance Nissan installed it and as far as I know, nothing was done to raise the idle speed. Chatter and that nice cement mixer sound is another matter!!
No, Performance Nissan installed it and as far as I know, nothing was done to raise the idle speed. Chatter and that nice cement mixer sound is another matter!!
Additionally, after hard driving when the revs are at 750 rpm, chatter is noticably present in neutral unless the clutch is depressed. Giving her some gas to about 850 rpm or 900 rpm gets lessens or relieves the chatter.
For this, I'm going to have the idle increased by 100 rpm to 150 rpm and I'll have the timing advanced 2 degrees. Hopefully, that will also prevent the rev dips and the start up stalls.
As for the pebble shaking in the transmission sound, it's there when you're at low rpms (1,000 rpm - 2,000 rpm). Yes it's annoying especially if you're driving by someone and you know they might think there is something wrong with your car. For this reason alone, I don't think the modification is suitable for pure daily drivers that don't need the extra performance gains.
On the other hand, freeing up the revs is simply terrific. And, the downshifts slow you down significantly better. If you're interested in maximizing performance, the flywheel is almost an essential modification.
10-03-2003, 08:12 AM
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What does advansing the timing 2 deg do? I havent noticed this but I will look more carefully at this on my drive home today.. That clatter was realy annoying my car was parked and i was about 100 ft or so away and I heard it.... So I will play with it next time to see at what RMP does it go away..
10-03-2003, 09:20 PM
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10-06-2003, 05:40 PM
#17
Originally posted by hfm
And, the downshifts slow you down significantly better.[/i].
And, the downshifts slow you down significantly better.[/i].
10-07-2003, 10:14 AM
#18
Re: Engine braking?
Originally posted by Richard 350z
Why use your engine and gearbox to brake at all? Downshifting without matching revs, which is what you do when you engine brake, is hard on engines and gearboxes, which are a lot more expensive than brakes. I just stand on my Brembos. That's what they are there for. (sorry for the digression, and no flaming by the professional race drivers, please).
Why use your engine and gearbox to brake at all? Downshifting without matching revs, which is what you do when you engine brake, is hard on engines and gearboxes, which are a lot more expensive than brakes. I just stand on my Brembos. That's what they are there for. (sorry for the digression, and no flaming by the professional race drivers, please).
As for the sound, I reluctantly agree that at 1,000 to 2,000 rpm, the sound is a cement grinder type. I don't really like the sound at all but, the pay off at the high end is good. On the other hand, I believe that I've lost some low end torque. I really wish I had a baseline dyno before the installation.
This is definitely a high performance part that has significant pros and cons.
10-07-2003, 12:18 PM
#20
Originally posted by Chebosto
engine braking is fun... if you can do it right..
i ALWAYS rev-match whenever possible..
HFM-- did u install a new clutch while u were at it? or stock clutch?
engine braking is fun... if you can do it right..
i ALWAYS rev-match whenever possible..
HFM-- did u install a new clutch while u were at it? or stock clutch?
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