I was just looking through the racing beat website and came across the 16lb. Steel flywheel for 13b's. My question is that is it worth the money ($377) and what kind of performance gains will i get? I want to get my car a little faster but since my engine has only 40k on it, theres not much point in swapping it for a TII just yet...

 

are you driving on the street or just track? The guys in my local club bitch about the lightweight flywheels as they screw up your idle... apparently a 2 rotor engine has a natural harmonic that makes it vibrate around 800-1000 RPM and the heavy flywheel helps to balance it out - the lighter ones require a higher RPM.

I emphisize I'm repeating what they have told me. If it's inaccurate I'm sure someone else here (hopefully one WITH a lightweight flywheel) will post evidence or first-hand anecdotes to the contrary.

 

Its street driven.. RB says that its for street driven cars, because they have the lightweight aluminum model also which is 4lbs lighter but is recommended only for track cars.

 

I'm using the RB aluminium flywheel on my 13B. It's a street car and it works really well..
I got it really cheap and that's why it's on the car.
The only thing is you need to rew some more at the start.. but the response in the engine is lovely!!

//magnus

 

Magnus,
Besides reving a bit quicker, has it improved your acceleration much? Any other downsides to it besides rev a bit more at the start?

 

I love my RB lightweight steel flywheel. I infact would like to go to aluminum one next and sell the steel one. MY OPINION: Its VERY worth it for the quicker response otherwise lost to inertia acceration of a "slow response" stock flywheel. Its like hidden horsepower(even though HP remains the same) that would otherwise be wasted on the 23lb+ stock one holding you back. Lightweight steel flywheel is a good comprimise for dragging, but is a good street, race course choice. But I am going Aluminum since I don't have a problem with questionable-streetablilty some people complain about.

Anyway, if you are concerned about peddlely 800-1000rpm when driving a rx-7, you need to re-evaluate how and were you drive a rotary and what people tell you about this RB flywheel, I can't tell any difference between stock and RB's, except the much better acceration in 1st, 2nd, 3rd, and to a lesser extent, 4th and 5th.

Now with a aluminum flywheel, mass is less then half of stock(in the right places at least->outside edge), so the inertia reduction is VERY significient, so engine pulses at low rpm/light throttling are not absorbed into the flywheel mass like a heavier flywheel would do. The reward is very quick reving, and quick engine braking.

With the bridgeport, I used a stock flywheel for a while and it had good acceration, but was considerablily better with the RB flywheel. Down side was a need to dump the clutch a little higher and not get on the gas really quick or it would bog worse below 4000rpm(damn weber carbs and bridgeports powerband ). Its either full throttle or no throttle!!

 

The only time im in the 1000-2000 rpm range is at idle.... lol

My other choice was to get Nitrous Oxide but i'd rather be quick all the time...

So basically, as long as im not near idle, shouldn't have many problems?

 

I've had the RB lightweight steel flywheel for over two years, with no problems or complaints whatsoever. It's wonderful. I don't know where these "idle problem" rumors come from (for this flywheel), but there's no basis in fact behind that rumor.

I've been running a Centerforce II clutch for over 2 years also, and after many MANY burn-outs and "putting down some rubber" the clutch disc is finally starting to wear and needs replacing (I'll probably go with a stock disc), but I've had no problems at all with the flywheel or with the clutch.

As for whether the flywheel is worth $370.. well yes and no. If RB chose to sell it for about $200, they'd still make a nice profit, so they are overcharging for what the product is worth in terms of producing it, you know? But in terms of the enhanced driving pleasure and satisfaction, with no concerns about inertia/idle pulses/etc, this flywheel is perfect for the GSL-SE, whether it be for frequent burn-outs, city driving (laid-back or spirited), and highway cruising at the usual 60 - 75 mph or whatever. Idle speed is fine, cruising speed is fine.

The performance gain is significant.. a few car lengths in the 1/4-mile, for sure.. maybe 0.5 sec or so? In city driving, acceleration in traffic and "being where you want to be" happens almost as an afterthought.

 

so........any of you guys have an electric fan hooked up with the RB flywheel? I have a GSL-SE........With air on its.....a different car...........I was told this one two punch will increase my performance.........

 

Man buy one from Australia, RB is a rip off. I could have gotten a nice clutch and flywheel for what I paid for the RB flywheel by itself..

www.horsepowerinabox.com

If you dont see what your looking for email Tim, he can get anything including 12A parts

 

Mike,
Thanks alot for the link! Any idea on how shipping would be from there?

 

You guys DID notice that I specified that the problem may occur at idle, right??

 

I love my RB Aluminum Flywheel. My idle is set @ 500 RPM.

I've often wondered about the harmonics of the engine just in general; specifically @ which RPMs the vibrations are the worst, possibly increasing engine wear.
I had noticed when I drove my first Rx-7 that vibrations seemed to come at certain RPMs if just reving in the driveway.
After I installed the aluminum flywheel, they were alot stronger.

I don't seem to have to slip the clutch like everyone has always said - which, BTW, is what is written in the RB catalogue. But I tend to drive pretty hard, and almost always squeek a bit of tire when I'm starting off.

I am concerned about the construction of the aluminum flywheel, as it has a steel ring for the clutch surface. They are 80 bucks to replace.

Does blip like a bike, though. (an old bike, but a bike! )

 

The way I figured with the chromoly billet flywheel and the clutch, it worked out to be $100 or so less , shipping included... Its way better then that RB flywheel they sell... You need to ask Tim for the specifcs but it will be cheaper and the parts ARE WAY BETTER

 

oh be sure to note

go to www.expedia.com for a currency converter I think its .56 US per AUS $.

 

yea with my new intake and light fly my ported 12a revs like a m.f. next mod sence i bolted all of the **** i had on is a dual pully...thats anoying to slip the blet when your passing the hondas

 

It has!
The car has a differnt feel to it.. I run my idle at around 800 rpm and has no problem with it.. so besides the higher startrew I can see no downsides with the Alu flywheel.. that is if you don't count the cost.. *s*

BTW, just updating my site.. come and have a look!

 

just checked out your site... Gotta say thats still one of the most Badass rx7's!

Im planning on getting my flywheel like Mikep28 said from Australia... Price doesn't seem TOO bad.... There not much left i can do anyways, besides tearing the engine apart etc.

 

I had a quote from a shop in Australia for a 3.85 Kg (8.5#) Flywheel and the Automatic Counterweight for 330$CAN and last time I checked that was just a shade under 200$US......don't think I'll be getting the RB one anytime soon.

 

Yeah for what I gave for my clutch and RB flywheel, I could have had a twin plate clutch and a billet LIGHT flywheel for $175 more

I could have had the equalevent of what I have now, for $100 less, with a lot better made flywheel

 

The one thing that I don't understand about the lightened flywheels that horsepowerinabox.com, is the size: 9.5", 8.5" clutch? I though our clutches were metric...(for a TII tranny) MIKE-P is this standard size?

 

That i dont know, I think mine was a 225mm? Just email Tim, he has a contact us link on his site. Very very nice guy..

 

I got an email from Tim saying that my clutch is the unusual 9"? So i have to purchase a new clutch for the flywheel? But with exchange rates its cheaper for me to buy the flywheel, clutch, counterweight, and shipping from australia then to get just the aluminum flywheel from RB because of the horribe exchance rate for canadian money... Not to mention what shipping would be like! It comes out ot about $690 CAN for everything including shipping.