Before I put it in Saturday, I have heard a lot of negative stuff about such a light flywheel. I am here to say that it is a great upgrade to do if you are going to go through the effort of changing out your clutch. Granted, the idle is ever so slightly lumpier. But it only bounces +/- 50 rpm. It also only stalled when I was breaking in the clutch. Later the same night it was good to go. The clutch is the ACT heavy duty set, not extreme set. If there is anybody out there on the fence trying to decide if they want to go with a 9.5# flywheel or not, I'll say go for it. For those that say it is unstreetable, they are on crack. I thought I would compromise streetability, but that was not the case at all.
This is kind of the same thing as when I gutted my cats. Many people wrote that the car would run lean and I would need at least a FCD. I ran my car on a Dyno (Carburetor Connection in Kirkland, WA) it read out that my car was way rich.
BTW, this was all done on an '89 T2. Your actual results may vary and some settling may occur during shipment.

jerk_racer@hotmail.com

 

sounds like you are extremely happy with this swap. everyone is telling me not to go with the 9.5 lb flywheel. I think i will. gald to hear someone who actually using one.

 

I too heard a lot of bad stuff from people that probably just know about it from hearsey. I am very pleased with it. I suggest if you are going to do this yourself, get the Mazda flywheel puller. Me and my buddy used a conventional puller with great difficulty. The built in counterweight gives the flywheel a beveled edge all around except for a few inches. Not too easy to get a grip on it. Mind you I just installed it Saturday, so I have yet to drive it too much. But so far so good, even in traffic that is crawling along. With this flywheel, then engine is very responsive and quick to rev up or down. If you are into drag racing, this is not the flywheel for you as it is more difficult to launch as well as with a heavy flywheel. But once you get going from a dead standstill, this is where it shines. Good luck with your decision.

jerk_racer@hotmail.com

 

Another has seen the light (and ignored the BS). Congrats!

One of the comments I used to hear is "You can't get a good launch." Well, I practiced and 5-5500 seems to ripsnort - doesn't bog and you can control spin with the gas.

 

I have a 9.5 lb. flywheel, and I also put one in my friend's car. He likes it alot. I drove his car with the flywheel and some exhaust and intake mods, and it feels pretty close to my brother's TII.

 

Ooops.

 

I guess I can't get a good launch because my tires are getting too worn out (Costco style tires anyway) so when I do rev that high, my tires can't get enough grip. Looks like it's finally time to get some new tires. I'm also getting a lot of hop, but that probably easily cured by polyurethane (sp?) bushing instead of the 13 y/o stock rubber ones. Apparently the previous owner put in a CFDF with the stock flywheel. It was toasted. I never liked the way it felt. Very soft and not much feel. All this time I thought it was a OEM clutch. I'm sold on the ACT.

jerk_racer@hotmail.

 

So it revs quicker, but does that help 0-60 or 1/4 mile times at all?

I think the only drawbacks were shorter lifespan and reduced lower end torque (ie higher revs needed for starts). For those who drive the TII in rush hour traffic - I could see streetability complaints being valid.

Of course I assume your like me and give "launch gaps" in stopped traffic instead of slipping/killing the clutch. So the weight of the flywheel is a mute point.

 

i'm thinking with my style of driving anyways, the 9.5 act setup will suit me fine. Is it good for auto-x?

 

Yes, if you know how to launch. Most of my battles are from a roll because I don't like to beat my ride and there is no doubt in my mind or my ***-o-meter that my car is faster in 1st and 2nd (less noticeable after that).

If I could give an analogy - imagine how your car feels when you have a 200lb. passenger. Now reverse that - imagine your car is 200+lbs. lighter. That's how it drives.

Anytime you reduce weight/rotating mass the car will accelerate faster. Why do you think people do this upgrade - looks?

 

people are telling me you won't get a good launch so it would hurt your 1/4 time. I was think ing though, you can compinsate. Plus auto- x, you are only starting from a stop once right, unless you spin out, etc.

 

I bought the "heavy" 11lb alum. flywheel w/ ACT clutch and I love it, though I wish I had bought the 9.5lb one. Before adjusting my idle w/ TID mod it was idling very smoothly at about 350 rpm and I though "damn I coulda got the 9.5 lb-er!" Though I imagine idle quality will vary alot if your compression isn't even accross the faces of the rotors. Drive-ability is excellent, no excessive slipping or gaps in traffic needed, I even drove it in a terrible traffic jam and around the hills of SF w/ the 350rpm idle!

 

I'm surprised that nobody mentioned one of the greatest benefits of a lightweight flywheel, quicker downshifts.

 

Stop and go traffic is just fine. Downshifting is way better. Matching engine speed it much easier and quicker. It really makes the engine come alive and feel like a real sports car (more so than before). When accelerating, it feels as though my car has dropped a lot of weight. I haven't had fun with my G-Tech (way cool gadget) yet after I did this but subjectively it feels better. To me, how it feels is where it counts. I don't really care about the hard numbers and specs for 0-60 or 1/4 too much, as long as it is fun to drive. I drive my car for fun, not points going towards a score. It has been my impression that lightweight flywheels are not the way to go if you are building a car for drag racing, but as usual I could be way off base with this idea. I'm not too crazy about drag racing. I haven't been to auto-x with this yet but I will when the Slush Series starts back up next January.
vaughnc: what are you talking about, shorter lifespan? The clutch should a last time because I'm not making much more power than stock (yet) and this clutch far exceeds stock capacities. If you are talking about a shorter lifespan for the flywheel, that shouldn't be an issue as well. It has a replacable friction surface. That beats getting a whole new unit.
FEDREX: too bad this upgrade wasn't for looks. When I first got this flywheel out of the box that it came in I thought it would be a damn shame to hide it in the bellhousing. Too bad such a good looking piece of gear has to be out of site.
If anybody needs any advise on the install for one, e-mail me. I'll be in Japan for the next couple of weeks. I suggest you do it yourself if you can, otherwise this could get very expensive with labor charges. It took me and my buddy (he is way cool and did most of the work) about 8 hours. This was without a lift or special Mazda tools. Amazing what one can accomplish with angle iron, cinderblocks, and a whole lot of persistance.

jerk_racer@hotmail.com

 

I took pics of mine sitting up against the door of the garage. The parts do look sweet - especially the red-trimmed flywheel.

Mykl and you brought up a good point about matching rpm for the downshifts. I never really paid much attention to that - but you guys are right. Approaching lights, I just blip and downshift a lot faster and smoothly.